Spinal Cord Module, Professor Frederick R Carrick.
The compulsory reading requirements for Prof Carrick's lecture on the
Spinal Cord are taken from Joynt and Griggs text CLINICAL NEUROLOGY
published by Lippincott-Raven
1 Chapter 43, Anatomy and Clinical Neurology of the Spinal Cord
2 Chapter 47, Trauma of the Spine and Spinal Cord
3 Chapter 48, Myelitis and Myelopathy
The reference list for this module is extensive due to the importance of
this information to those physicians that utilize spinal manipulation in
the treatment of neurological conditions. Prof Carrick's lecture
references are listed in this bibliography.
Bibliography
1. Abbott, F. V.; Hong, Y.; Franklin, K. B. The effect of lesions of the
dorsolateral funiculus on formalin pain and morphine
analgesia: a dose-response analysis. Pain. 1996 Apr; 65(1): 17-
23; ISSN: 0304-3959.
NETHERLANDS. There has been conflicting evidence concerning
the role of descending bulbospinal influences on pain and
opioid analgesia in the formalin test. We examined the effect
of lesions of the dorsolateral funiculus (DLF) on dose-effect
relations for formalin and morphine in the formalin test.
Experiment 1 showed that DLF lesions reduced the effect of 5
mg/kg morphine on pain in the tail-flick test, and eliminated
morphine's effect on pain produced by 2.5% formalin. When
lower concentrations of formalin were used, DLF lesions
produced hyperalgesia, indicated by a left shift 1.7-fold) of
the formalin concentration-response curve. In experiment 2,
DLF lesions increased the pain produced by 1.25% formalin and
shifted the dose-response relation for the effect of morphine
on the second phase of the pain response produced by 1.25%
formalin to 2.5-fold higher doses. The data show that DLF
lesions increase sensitivity to the pain-inducing effect of
formalin, and this accounts for a substantial component of the
effect of DLF lesions on morphine analgesia.. 0; 50-00-0; 57-
27-2.
2. Abbott, F. V.; Hong, Y.; Franklin, K. B. The effect of lesions of the
dorsolateral funiculus on formalin pain and morphine
analgesia: a dose-response analysis. Pain. 1996 Apr; 65(1): 17-
23; ISSN: 0304-3959.
NETHERLANDS. There has been conflicting evidence concerning
the role of descending bulbospinal influences on pain and
opioid analgesia in the formalin test. We examined the effect
of lesions of the dorsolateral funiculus (DLF) on dose-effect
relations for formalin and morphine in the formalin test.
Experiment 1 showed that DLF lesions reduced the effect of 5
mg/kg morphine on pain in the tail-flick test, and eliminated
morphine's effect on pain produced by 2.5% formalin. When
lower concentrations of formalin were used, DLF lesions
produced hyperalgesia, indicated by a left shift 1.7-fold) of
the formalin concentration-response curve. In experiment 2,
DLF lesions increased the pain produced by 1.25% formalin and
shifted the dose-response relation for the effect of morphine
on the second phase of the pain response produced by 1.25%
formalin to 2.5-fold higher doses. The data show that DLF
lesions increase sensitivity to the pain-inducing effect of
formalin, and this accounts for a substantial component of the
effect of DLF lesions on morphine analgesia.. 0; 50-00-0; 57-
27-2.
3. Agius, E.; Sagot, Y.; Duprat, A. M.; Cochard, P. Antibodies directed
against the beta 1-integrin subunit and peptides containing the
IKVAV sequence of laminin perturb neurite outgrowth of
peripheral neurons on immature spinal cord substrata.
Neuroscience. 1996 Apr; 71(3): 773-86; ISSN: 0306-4522.
UNITED-STATES. Neuron-substratum interactions regulating
axon growth in the developing central nervous system of the
rat have been studied by means of an in vitro bioassay: the
tissue section culture. We have previously shown that purified
chicken sensory or sympathetic neurons grown on natural
substrata consisting of cryostat sections of neonatal rat
spinal cord elaborate numerous long neurites [Sagot et al.
(1991) Brain Res. 543, 25-35]. Perturbation experiments, in
which neuron-substratum interactions are modified by
antibodies and peptides, have allowed us to analyse some of
the molecular determinants which control neurite outgrowth
in this system. Antibodies directed against the beta 1-integrin
subunit, one of the neuronal receptors for extracellular matrix
molecules, reduced the percentage of growing neurons by about
30% and the length of neurites by about 50%. In contrast,
antibodies directed against laminin-1 or fibronectin, two
extracellular matrix proteins transiently expressed in various
areas of the developing central nervous system, were unable to
block neurite outgrowth. Paradoxically, a peptide containing
the IKVAV sequence, which mimics an active sequence of the
laminin alpha 1 chain responsible for neurite extension, also
blocked neurite outgrowth on neonatal spinal cord substrata.
These results indicate that integrin receptors containing the
beta 1 subunit may play a role in regulating axon growth in the
developing nervous system. Among the putative extracellular
matrix ligands for these receptors, laminin and fibronectin do
not appear as prominent candidates in the neonatal spinal cord.
However, our data also suggest that the developing central
nervous system may contain neurite outgrowth-promoting
proteins carrying the IKVAV sequence, different from laminin-
1.. 0.
4. Agius, E.; Sagot, Y.; Duprat, A. M.; Cochard, P. Antibodies directed
against the beta 1-integrin subunit and peptides containing the
IKVAV sequence of laminin perturb neurite outgrowth of
peripheral neurons on immature spinal cord substrata.
Neuroscience. 1996 Apr; 71(3): 773-86; ISSN: 0306-4522.
UNITED-STATES. Neuron-substratum interactions regulating
axon growth in the developing central nervous system of the
rat have been studied by means of an in vitro bioassay: the
tissue section culture. We have previously shown that purified
chicken sensory or sympathetic neurons grown on natural
substrata consisting of cryostat sections of neonatal rat
spinal cord elaborate numerous long neurites [Sagot et al.
(1991) Brain Res. 543, 25-35]. Perturbation experiments, in
which neuron-substratum interactions are modified by
antibodies and peptides, have allowed us to analyse some of
the molecular determinants which control neurite outgrowth
in this system. Antibodies directed against the beta 1-integrin
subunit, one of the neuronal receptors for extracellular matrix
molecules, reduced the percentage of growing neurons by about
30% and the length of neurites by about 50%. In contrast,
antibodies directed against laminin-1 or fibronectin, two
extracellular matrix proteins transiently expressed in various
areas of the developing central nervous system, were unable to
block neurite outgrowth. Paradoxically, a peptide containing
the IKVAV sequence, which mimics an active sequence of the
laminin alpha 1 chain responsible for neurite extension, also
blocked neurite outgrowth on neonatal spinal cord substrata.
These results indicate that integrin receptors containing the
beta 1 subunit may play a role in regulating axon growth in the
developing nervous system. Among the putative extracellular
matrix ligands for these receptors, laminin and fibronectin do
not appear as prominent candidates in the neonatal spinal cord.
However, our data also suggest that the developing central
nervous system may contain neurite outgrowth-promoting
proteins carrying the IKVAV sequence, different from laminin-
1.. 0.
5. Anderson, B.; Rutledge, V. Age and hemisphere effects on
dendritic structure. Brain. 1996 Dec; 119( Pt 6): 1983-90;
ISSN: 0006-8950.
ENGLAND. The dendritic structures of 187 small supragranular
pyramidal neurons of the posterior superior temporal gyrus
were studied with rapid Golgi impregnations in postmortem
samples from 10 men aged 21-71 years. The number of primary
basilar dendritic branches, the total number of basilar
dendritic endings, the total basilar dendritic length, the total
number of visible basilar dendritic spines and the cell soma
sizes were all positively inter-correlated and all features
were correlated to age (r = -0.77, -0.88, -0.82, -0.72, -0.86,
respectively; all P < 0.05). These neuronal measures all
correlated with brain weight (r = 0.79*, 0.65*, 0.51, 0.45,
0.55, respectively; *denotes P < 0.05). A first principle
component derived from the inter-correlations of the neuronal
features plus brain weight correlated almost perfectly with
age (r = -0.93). The neuronal features differed between the
right and left hemispheres (Wilks' Lambda = 0.91, P < 0.01).
Post hoc tests showed that the dendritic trees of the right
hemisphere were longer (P = 0.002), more branched (P = 0.008)
and possessed more dendritic spines (P = 0.0009; Sheffe's
tests). In conclusion, there are hemispheric differences in the
dendritic structure of the small pyramidal neurons of
presumptive human speech cortex and its right hemisphere
analogue. Generalized neuronal atrophy is highly correlated
with both brain weight and age, and is a candidate process to
explain the decline in cognition with age.
6. Anderson, B.; Rutledge, V. Age and hemisphere effects on
dendritic structure. Brain. 1996 Dec; 119( Pt 6): 1983-90;
ISSN: 0006-8950.
ENGLAND. The dendritic structures of 187 small supragranular
pyramidal neurons of the posterior superior temporal gyrus
were studied with rapid Golgi impregnations in postmortem
samples from 10 men aged 21-71 years. The number of primary
basilar dendritic branches, the total number of basilar
dendritic endings, the total basilar dendritic length, the total
number of visible basilar dendritic spines and the cell soma
sizes were all positively inter-correlated and all features
were correlated to age (r = -0.77, -0.88, -0.82, -0.72, -0.86,
respectively; all P < 0.05). These neuronal measures all
correlated with brain weight (r = 0.79*, 0.65*, 0.51, 0.45,
0.55, respectively; *denotes P < 0.05). A first principle
component derived from the inter-correlations of the neuronal
features plus brain weight correlated almost perfectly with
age (r = -0.93). The neuronal features differed between the
right and left hemispheres (Wilks' Lambda = 0.91, P < 0.01).
Post hoc tests showed that the dendritic trees of the right
hemisphere were longer (P = 0.002), more branched (P = 0.008)
and possessed more dendritic spines (P = 0.0009; Sheffe's
tests). In conclusion, there are hemispheric differences in the
dendritic structure of the small pyramidal neurons of
presumptive human speech cortex and its right hemisphere
analogue. Generalized neuronal atrophy is highly correlated
with both brain weight and age, and is a candidate process to
explain the decline in cognition with age.
7. Andrew, E. R.; Inglis, B. A.; Kempka, M.; Mareci, T.; Szczesniak, E.
Magnetic field gradient system for nuclear magnetic resonance
microimaging. MAGMA. 1996 Jun; 4(2): 85-91; ISSN: 0968-
5243.
UNITED-STATES. In this study we present an orthogonal
magnetic field gradient system for nuclear magnetic
resonance (NMR) microimaging applications. The construction
details are given for a prototype assembly for proton
microscopy inside a 50-mm vertical bore magnet, which is
designed to fit into a commercial 300-MHz NMR probe. This
system has been used to acquire images of the human spinal
cord in vitro. Its performance has been evaluated and compared
to that predicted by computer simulation.
8. Andrew, E. R.; Inglis, B. A.; Kempka, M.; Mareci, T.; Szczesniak, E.
Magnetic field gradient system for nuclear magnetic resonance
microimaging. MAGMA. 1996 Jun; 4(2): 85-91; ISSN: 0968-
5243.
UNITED-STATES. In this study we present an orthogonal
magnetic field gradient system for nuclear magnetic
resonance (NMR) microimaging applications. The construction
details are given for a prototype assembly for proton
microscopy inside a 50-mm vertical bore magnet, which is
designed to fit into a commercial 300-MHz NMR probe. This
system has been used to acquire images of the human spinal
cord in vitro. Its performance has been evaluated and compared
to that predicted by computer simulation.
9. Araki, I.; De Groat, W. C. Unitary excitatory synaptic currents in
preganglionic neurons mediated by two distinct groups of
interneurons in neonatal rat sacral parasympathetic nucleus.
J-Neurophysiol. 1996 Jul; 76(1): 215-26; ISSN: 0022-3077.
UNITED-STATES. 1. Excitatory postsynaptic currents (EPSCs)
in parasympathetic preganglionic neurons (PGNs) were
examined by the use of the whole cell patch-clamp recording
technique in slice preparations of the neonatal rat lumbosacral
spinal cord. Synaptic responses were evoked in PGNs by
extracellular stimulation of a neighboring interneuron. 2.
Stimulation of interneurons medial to the sacral
parasympathetic nucleus (SPN) elicited EPSCs or inhibitory
postsynaptic currents in 58 and 11%, respectively, of PGNs.
Stimulation of interneurons dorsal to the SPN evoked EPSCs in
70% of PGNs. 3. EPSCs occurred at short latency (2.1 ms) and
were usually elicited in an all-or-none manner, indicating that
they were monosynaptic and mediated by a single interneuron
(i.e., unitary). 4. EPSCs were mediated by both non-N-methyl-
D-aspartate (non-NMDA) and NMDA receptors. 5. Unitary
excitatory postsynaptic potentials evoked by single stimuli
did not induce action potentials in PGNs, but repetitive
stimulation (> 20 Hz) of the single interneurons could evoke
firing of PGNs. 2-Amino-5-phosphonovalerate, an NMDA
receptor antagonist, reduced the synaptic depolarization
induced in PGNs by high-frequency interneuronal impulses. 6.
EPSCs mediated by dorsal interneurons were smaller in
amplitude (36.3 +/- 15.7 pA, mean +/- SD) than EPSCs
mediated by medial interneurons (88.4 +/- 45.7 pA). 7. Paired-
pulse facilitation of EPSCs was observed in PGNs (147.2 +/-
26.2%). The degree of facilitation was higher in dorsal (174.6
+/- 10.3%) than in medial interneuronal pathways (120.9 +/-
3.6%). Within each of interneuronal pathways the degree of
facilitation was independent of the magnitude of the unitary
EPSC. 8. The results show that PGNs receive monosynaptic
glutamatergic excitatory inputs from two distinct populations
of interneurons in the dorsal and medial regions of the SPN.
These two populations of interneurons are likely to have
different functions in the regulation of the preganglionic
outflow to the pelvic organs.. 0.
10. Araki, I.; De Groat, W. C. Unitary excitatory synaptic currents in
preganglionic neurons mediated by two distinct groups of
interneurons in neonatal rat sacral parasympathetic nucleus.
J-Neurophysiol. 1996 Jul; 76(1): 215-26; ISSN: 0022-3077.
UNITED-STATES. 1. Excitatory postsynaptic currents (EPSCs)
in parasympathetic preganglionic neurons (PGNs) were
examined by the use of the whole cell patch-clamp recording
technique in slice preparations of the neonatal rat lumbosacral
spinal cord. Synaptic responses were evoked in PGNs by
extracellular stimulation of a neighboring interneuron. 2.
Stimulation of interneurons medial to the sacral
parasympathetic nucleus (SPN) elicited EPSCs or inhibitory
postsynaptic currents in 58 and 11%, respectively, of PGNs.
Stimulation of interneurons dorsal to the SPN evoked EPSCs in
70% of PGNs. 3. EPSCs occurred at short latency (2.1 ms) and
were usually elicited in an all-or-none manner, indicating that
they were monosynaptic and mediated by a single interneuron
(i.e., unitary). 4. EPSCs were mediated by both non-N-methyl-
D-aspartate (non-NMDA) and NMDA receptors. 5. Unitary
excitatory postsynaptic potentials evoked by single stimuli
did not induce action potentials in PGNs, but repetitive
stimulation (> 20 Hz) of the single interneurons could evoke
firing of PGNs. 2-Amino-5-phosphonovalerate, an NMDA
receptor antagonist, reduced the synaptic depolarization
induced in PGNs by high-frequency interneuronal impulses. 6.
EPSCs mediated by dorsal interneurons were smaller in
amplitude (36.3 +/- 15.7 pA, mean +/- SD) than EPSCs
mediated by medial interneurons (88.4 +/- 45.7 pA). 7. Paired-
pulse facilitation of EPSCs was observed in PGNs (147.2 +/-
26.2%). The degree of facilitation was higher in dorsal (174.6
+/- 10.3%) than in medial interneuronal pathways (120.9 +/-
3.6%). Within each of interneuronal pathways the degree of
facilitation was independent of the magnitude of the unitary
EPSC. 8. The results show that PGNs receive monosynaptic
glutamatergic excitatory inputs from two distinct populations
of interneurons in the dorsal and medial regions of the SPN.
These two populations of interneurons are likely to have
different functions in the regulation of the preganglionic
outflow to the pelvic organs.. 0.
11. Aribal, M. E.; Gurcan, F.; Aslan, B. Chiari III malformation: MRI.
Neuroradiology. 1996 May; 38 Suppl 1: S184-6; ISSN: 0028-
3940.
GERMANY.
12. Aribal, M. E.; Gurcan, F.; Aslan, B. Chiari III malformation: MRI.
Neuroradiology. 1996 May; 38 Suppl 1: S184-6; ISSN: 0028-
3940.
GERMANY.
13. Armand, J.; Olivier, E.; Edgley, S. A.; Lemon, R. N. Postnatal
development of corticospinal projections from motor cortex to
the cervical enlargement in the macaque monkey. J-Neurosci.
1997 Jan 1; 17(1): 251-66; ISSN: 0270-6474.
UNITED-STATES. The postnatal development of corticospinal
projections was investigated in 11 macaques by means of the
anterograde transport of wheat germ agglutin-horseradish
peroxidase injected into the primary motor cortex hand area.
Although the fibers of the corticospinal tract reached all
levels of the spinal cord white matter at birth, their
penetration into the gray matter was far from complete. At
birth, as in the adult, corticospinal projections were
distributed to the same regions of the intermediate zone,
although they showed marked increases in density during the
first 5 months. The unique feature of the primate corticospinal
tract, namely direct cortico-motoneuronal projections to the
spinal motor nuclei innervating hand muscles, was not present
to a significant extent at birth. The density of these cortico-
motoneuronal projections increased rapidly during the first 5
months, followed by a protracted period extending into the
second year of life. The densest corticospinal terminations
occupied only 40% of the hand motor nuclei in the first
thoracic segment at 1 month, 73% at 5 months, and 75.5% at 3
years. A caudo-rostral gradient of termination density within
the hand motor nuclei was present throughout development and
persisted into the adult. As a consequence, the more caudal the
segment within the cervical enlargement, the earlier the adult
pattern of projection density was reached. No transitory
corticospinal projections were found. The continuous postnatal
expansion of cortico-motoneuronal projections to hand motor
nuclei in primates is in marked contrast to the retraction of
exuberant projections that characterizes the development of
other sensory and motor pathways in subprimates.. 0.
14. Armand, J.; Olivier, E.; Edgley, S. A.; Lemon, R. N. Postnatal
development of corticospinal projections from motor cortex to
the cervical enlargement in the macaque monkey. J-Neurosci.
1997 Jan 1; 17(1): 251-66; ISSN: 0270-6474.
UNITED-STATES. The postnatal development of corticospinal
projections was investigated in 11 macaques by means of the
anterograde transport of wheat germ agglutin-horseradish
peroxidase injected into the primary motor cortex hand area.
Although the fibers of the corticospinal tract reached all
levels of the spinal cord white matter at birth, their
penetration into the gray matter was far from complete. At
birth, as in the adult, corticospinal projections were
distributed to the same regions of the intermediate zone,
although they showed marked increases in density during the
first 5 months. The unique feature of the primate corticospinal
tract, namely direct cortico-motoneuronal projections to the
spinal motor nuclei innervating hand muscles, was not present
to a significant extent at birth. The density of these cortico-
motoneuronal projections increased rapidly during the first 5
months, followed by a protracted period extending into the
second year of life. The densest corticospinal terminations
occupied only 40% of the hand motor nuclei in the first
thoracic segment at 1 month, 73% at 5 months, and 75.5% at 3
years. A caudo-rostral gradient of termination density within
the hand motor nuclei was present throughout development and
persisted into the adult. As a consequence, the more caudal the
segment within the cervical enlargement, the earlier the adult
pattern of projection density was reached. No transitory
corticospinal projections were found. The continuous postnatal
expansion of cortico-motoneuronal projections to hand motor
nuclei in primates is in marked contrast to the retraction of
exuberant projections that characterizes the development of
other sensory and motor pathways in subprimates.. 0.
15. Asada, H.; Yamaguchi, Y.; Tsunoda, S.; Fukuda, Y. The role of spinal
cord activation before neurectomy in the development of
autotomy. Pain. 1996 Jan; 64(1): 161-7; ISSN: 0304-3959.
NETHERLANDS. A model of deafferentation pain is provided by
sectioning the sciatic and saphenous nerves in the rat and
mouse. This procedure leads to self-mutilation of the
denervated hindpaw (autotomy). A noxious stimulus to the
denervated area before neurectomy is known to enhance the
autotomy. To understand the mechanism underlying this
enhancement by prior noxious stimuli, we examined the
effects of intrathecal (i.t.) injection of substance P (SP) and
somatostatin (SOM) on autotomy behavior. These peptides are
known to be released from primary afferent terminals in the
dorsal horn by noxious stimuli. A single i.t. injection of SP or
SOM just before neurectomy dramatically enhanced autotomy
behavior in mice. Autotomy was enhanced in a dose-dependent
manner with i.t. injection of SP (0.1-20 nmol) 5 min before
neurectomy or SOM (0.1-1.0 nmol) 20 min before neurectomy.
Autotomy significantly decreased by extending the interval
between i.t. injection of SP or SOM and neurectomy. Intact
mice injected with the same doses of SP or SOM showed dose-
dependent acute nociceptive responses directed to the
hindpaw. The severity of autotomy in neurectomized mice and
the duration of acute nociceptive responses induced by the
same doses of SP or SOM in intact mice were related. These
results suggest that neuropeptides applied to the spinal dorsal
horn just before deafferentation induce a state of central
neural activation with long-lasting effects on the function of
CNS cells. Augmentation of autotomy is a result of this
activation which is kept as a 'memory'.. 33507-63-0; 51110-
01-1.
16. Asada, H.; Yamaguchi, Y.; Tsunoda, S.; Fukuda, Y. The role of spinal
cord activation before neurectomy in the development of
autotomy. Pain. 1996 Jan; 64(1): 161-7; ISSN: 0304-3959.
NETHERLANDS. A model of deafferentation pain is provided by
sectioning the sciatic and saphenous nerves in the rat and
mouse. This procedure leads to self-mutilation of the
denervated hindpaw (autotomy). A noxious stimulus to the
denervated area before neurectomy is known to enhance the
autotomy. To understand the mechanism underlying this
enhancement by prior noxious stimuli, we examined the
effects of intrathecal (i.t.) injection of substance P (SP) and
somatostatin (SOM) on autotomy behavior. These peptides are
known to be released from primary afferent terminals in the
dorsal horn by noxious stimuli. A single i.t. injection of SP or
SOM just before neurectomy dramatically enhanced autotomy
behavior in mice. Autotomy was enhanced in a dose-dependent
manner with i.t. injection of SP (0.1-20 nmol) 5 min before
neurectomy or SOM (0.1-1.0 nmol) 20 min before neurectomy.
Autotomy significantly decreased by extending the interval
between i.t. injection of SP or SOM and neurectomy. Intact
mice injected with the same doses of SP or SOM showed dose-
dependent acute nociceptive responses directed to the
hindpaw. The severity of autotomy in neurectomized mice and
the duration of acute nociceptive responses induced by the
same doses of SP or SOM in intact mice were related. These
results suggest that neuropeptides applied to the spinal dorsal
horn just before deafferentation induce a state of central
neural activation with long-lasting effects on the function of
CNS cells. Augmentation of autotomy is a result of this
activation which is kept as a 'memory'.. 33507-63-0; 51110-
01-1.
17. Ataka, H.; Murakami, M.; Goto, S.; Moriya, H.; Hayashi, F.; Fukuda, Y.
Effects of hypoxia on the ventral root motor-evoked potential
in the in vitro spinal cord preparation. Spine. 1996 Sep 15;
21(18): 2095-100; ISSN: 0362-2436.
UNITED-STATES. STUDY DESIGN: This study investigated the
effects of hypoxia and glucose on motor functions of spinal
cord, monitoring ventral root motor-evoked potential in the in
vitro cervical cord preparations. OBJECTIVE: To study
ischemia-induced changes in ventral root motor-evoked
potential of spinal cord. SUMMARY OF BACKGROUND DATA:
Previous studies demonstrated ischemic changes caused by
local circulatory impairment might be a major
pathophysiologic basis of neuron damage in cord compression.
METHODS: Ventral root motor-evoked potential elicited by
stimulation of ventrolateral funiculus was recorded from the
ventral root in the isolated spinal cord preparations obtained
from a newborn rat. The preparations were exposed to
artificial cerebrospinal fluid equilibrated with severe or mild
hypoxia for 90 minutes. Inhibitory and excitatory
neurotransmitter antagonists were added to artificial
cerebrospinal fluid to investigate synaptic transmission. The
artificial cerebrospinal fluids containing various
concentrations of glucose were used to study the glucose's
effects. RESULTS: Ventral root motor-evoked potential
consisted of the early and late components, which were
excitatory transsynaptic potentials. The amplitudes were
increased in the early phase of severe hypoxia and declined in
the prolonged exposure. In mild hypoxia, there was a sustained
increase of the amplitudes. The application of inhibitory
neurotransmitter antagonists abolished the augmentation of
the amplitudes in the early phase of severe hypoxia. Hypoxia
without glucose accelerated hypoxic change. CONCLUSION:
Inhibitory synaptic transmission was depressed preferentially
in the early phase of severe hypoxia or in mild hypoxia.
Excitatory and inhibitory transmissions were suppressed in
prolonged severe hypoxia. Glucose deficiency aggravated
hypoxic inhibition of synaptic transmissions.. 124-87-8; 50-
99-7; 57-24-9.
18. Ataka, H.; Murakami, M.; Goto, S.; Moriya, H.; Hayashi, F.; Fukuda, Y.
Effects of hypoxia on the ventral root motor-evoked potential
in the in vitro spinal cord preparation. Spine. 1996 Sep 15;
21(18): 2095-100; ISSN: 0362-2436.
UNITED-STATES. STUDY DESIGN: This study investigated the
effects of hypoxia and glucose on motor functions of spinal
cord, monitoring ventral root motor-evoked potential in the in
vitro cervical cord preparations. OBJECTIVE: To study
ischemia-induced changes in ventral root motor-evoked
potential of spinal cord. SUMMARY OF BACKGROUND DATA:
Previous studies demonstrated ischemic changes caused by
local circulatory impairment might be a major
pathophysiologic basis of neuron damage in cord compression.
METHODS: Ventral root motor-evoked potential elicited by
stimulation of ventrolateral funiculus was recorded from the
ventral root in the isolated spinal cord preparations obtained
from a newborn rat. The preparations were exposed to
artificial cerebrospinal fluid equilibrated with severe or mild
hypoxia for 90 minutes. Inhibitory and excitatory
neurotransmitter antagonists were added to artificial
cerebrospinal fluid to investigate synaptic transmission. The
artificial cerebrospinal fluids containing various
concentrations of glucose were used to study the glucose's
effects. RESULTS: Ventral root motor-evoked potential
consisted of the early and late components, which were
excitatory transsynaptic potentials. The amplitudes were
increased in the early phase of severe hypoxia and declined in
the prolonged exposure. In mild hypoxia, there was a sustained
increase of the amplitudes. The application of inhibitory
neurotransmitter antagonists abolished the augmentation of
the amplitudes in the early phase of severe hypoxia. Hypoxia
without glucose accelerated hypoxic change. CONCLUSION:
Inhibitory synaptic transmission was depressed preferentially
in the early phase of severe hypoxia or in mild hypoxia.
Excitatory and inhibitory transmissions were suppressed in
prolonged severe hypoxia. Glucose deficiency aggravated
hypoxic inhibition of synaptic transmissions.. 124-87-8; 50-
99-7; 57-24-9.
19. Barnes, P. D. Atypical idiopathic scoliosis in childhood. Semin-
Pediatr-Neurol. 1996 Sep; 3(3): 207-11; ISSN: 1071-9091.
UNITED-STATES. Scoliosis, common in preadolescent females
is a finding which warrants investigation in any other age
group or if the clinical or neuroimaging features are atypical
even in the preadolescent female. The cause of scoliosis are
numerous but include several important conditions some of
which are treatable and some of which are genetic. A rational
approach to sequencing the neuroimaging studies to be used is
based on what the clinical suspicions are and the results of
the initial studies.
20. Barnes, P. D. Atypical idiopathic scoliosis in childhood. Semin-
Pediatr-Neurol. 1996 Sep; 3(3): 207-11; ISSN: 1071-9091.
UNITED-STATES. Scoliosis, common in preadolescent females
is a finding which warrants investigation in any other age
group or if the clinical or neuroimaging features are atypical
even in the preadolescent female. The cause of scoliosis are
numerous but include several important conditions some of
which are treatable and some of which are genetic. A rational
approach to sequencing the neuroimaging studies to be used is
based on what the clinical suspicions are and the results of
the initial studies.
21. Beardsley, T. Steps to recovery. Researchers finding ways of
coaxing spinal nerves to grow [news]. Sci-Am. 1997 Jan;
276(1): 26, 28; ISSN: 0036-8733.
UNITED-STATES.
22. Beardsley, T. Steps to recovery. Researchers finding ways of
coaxing spinal nerves to grow [news]. Sci-Am. 1997 Jan;
276(1): 26, 28; ISSN: 0036-8733.
UNITED-STATES.
23. Bjartmar, C. Oligodendroglial sheath lengths in developing rat
ventral funiculus and corpus callosum. Neurosci-Lett. 1996
Sep 27; 216(2): 85-8; ISSN: 0304-3940.
IRELAND. The lengths of uncompacted and partly compacted
oligodendroglial sheaths in the developing rat spinal cord (SC)
ventral funiculus (ages F19 and F21) and corpus callosum (CC;
ages P12 and P17) were studied by serial section electron
microscopy. The average newly formed uncompacted sheath is
21 and 33 microns long in the SC (F19) and CC (P12),
respectively, many being less than 10 microns. In these early
series, approximately 2/3 of the analysed axon length is
unensheathed. The average partly compacted sheath is 102 and
69 microns long in the SC (F21) and CC (P17), respectively.
Here, about 1/3 of the examined axon length is unensheathed.
These results suggest that oligodendroglial sheaths initially
are very short, and that they elongate actively before and
during compaction. The limited unensheathed space along these
axons indicate that some early sheaths must be eliminated.
24. Bjartmar, C. Oligodendroglial sheath lengths in developing rat
ventral funiculus and corpus callosum. Neurosci-Lett. 1996
Sep 27; 216(2): 85-8; ISSN: 0304-3940.
IRELAND. The lengths of uncompacted and partly compacted
oligodendroglial sheaths in the developing rat spinal cord (SC)
ventral funiculus (ages F19 and F21) and corpus callosum (CC;
ages P12 and P17) were studied by serial section electron
microscopy. The average newly formed uncompacted sheath is
21 and 33 microns long in the SC (F19) and CC (P12),
respectively, many being less than 10 microns. In these early
series, approximately 2/3 of the analysed axon length is
unensheathed. The average partly compacted sheath is 102 and
69 microns long in the SC (F21) and CC (P17), respectively.
Here, about 1/3 of the examined axon length is unensheathed.
These results suggest that oligodendroglial sheaths initially
are very short, and that they elongate actively before and
during compaction. The limited unensheathed space along these
axons indicate that some early sheaths must be eliminated.
25. Blomqvist, A.; Ericson, A. C.; Craig, A. D.; Broman, J. Evidence for
glutamate as a neurotransmitter in spinothalamic tract
terminals in the posterior region of owl monkeys. Exp-Brain-
Res. 1996 Feb; 108(1): 33-44; ISSN: 0014-4819.
GERMANY. Previous studies have suggested that glutamate is a
neurotransmitter in ascending somatosensory pathways to the
thalamus. The present study examined with quantitative
immunohistochemical methods the presence of glutamate in
spinothalamic tract terminals of owl monkeys (Aotus
trivirgatus). Such terminals in the posterior region, in which a
nucleus was recently identified as a specific pain and
temperature relay in macaques and humans, were labeled by
anterograde transport of wheat germ agglutinin conjugated to
horseradish peroxidase, injected into the spinal dorsal horn.
Glutamate-like immunoreactivity was demonstrated with a
postembedding immunogold procedure using a well-
characterized glutamate antiserum. Quantitative analysis of
the immunogold labeling demonstrated that the spinothalamic
tract terminals contained more than twice the tissue average
of glutamate-like immunoreactivity. Enrichment of glutamate-
like immunoreactivity was also found in terminals of
presumed cortical origin. Presynaptic dendrites, cell bodies
and non-vesicle-containing dendrites displayed low levels of
glutamate-like immunoreactivity. A strong positive
correlation (r = 0.69; P < 0.0001) was found between the
density of synaptic vesicles and the density of gold particles
in spinothalamic tract terminals, in contrast to a weak
negative relationship (r = -0.28; P = 0.089) present in
GABAergic presynaptic dendrites. These data provide strong
evidence that the gold labeling in the spinothalamic tract
terminals represents transmitter labeling, implying that
glutamate is a neurotransmitter for ascending nociceptive and
thermoreceptive information in primates.. 0; 56-86-0.
26. Blomqvist, A.; Ericson, A. C.; Craig, A. D.; Broman, J. Evidence for
glutamate as a neurotransmitter in spinothalamic tract
terminals in the posterior region of owl monkeys. Exp-Brain-
Res. 1996 Feb; 108(1): 33-44; ISSN: 0014-4819.
GERMANY. Previous studies have suggested that glutamate is a
neurotransmitter in ascending somatosensory pathways to the
thalamus. The present study examined with quantitative
immunohistochemical methods the presence of glutamate in
spinothalamic tract terminals of owl monkeys (Aotus
trivirgatus). Such terminals in the posterior region, in which a
nucleus was recently identified as a specific pain and
temperature relay in macaques and humans, were labeled by
anterograde transport of wheat germ agglutinin conjugated to
horseradish peroxidase, injected into the spinal dorsal horn.
Glutamate-like immunoreactivity was demonstrated with a
postembedding immunogold procedure using a well-
characterized glutamate antiserum. Quantitative analysis of
the immunogold labeling demonstrated that the spinothalamic
tract terminals contained more than twice the tissue average
of glutamate-like immunoreactivity. Enrichment of glutamate-
like immunoreactivity was also found in terminals of
presumed cortical origin. Presynaptic dendrites, cell bodies
and non-vesicle-containing dendrites displayed low levels of
glutamate-like immunoreactivity. A strong positive
correlation (r = 0.69; P < 0.0001) was found between the
density of synaptic vesicles and the density of gold particles
in spinothalamic tract terminals, in contrast to a weak
negative relationship (r = -0.28; P = 0.089) present in
GABAergic presynaptic dendrites. These data provide strong
evidence that the gold labeling in the spinothalamic tract
terminals represents transmitter labeling, implying that
glutamate is a neurotransmitter for ascending nociceptive and
thermoreceptive information in primates.. 0; 56-86-0.
27. Blottner, D.; Wolf, N.; Lachmund, A.; Flanders, K. C.; Unsicker, K.
TGF-beta rescues target-deprived preganglionic sympathetic
neurons in the spinal cord. Eur-J-Neurosci. 1996 Jan; 8(1):
202-10; ISSN: 0953-816X.
ENGLAND. Transforming growth factors beta (TGF-beta), a
family of pleiotropic cytokines, are widely distributed in the
developing and adult nervous system. In order to further
determine the neural functions of TGF-beta, we have localized
the TGF-beta isoforms 1, 2 and 3 in the adult rat adrenal
medulla and studied the neuroprotective capacity of one
representative family member, TGF-beta 2, for those spinal
cord neurons which innervate adrenal chromaffin cells and
which die after destruction of the adrenal medulla. Unilateral
electrothermal destruction of the adrenal medulla led to the
disappearance of 25% of sympathetic preganglionic neurons,
which are located in the intermediolateral (IML) column of
thoracic spinal cord segments 7-10 and can be selectively
marked by NADPH-diaphorase. The neurons which disappeared
following adrenomedullectomy constitute the full set of
neurons that innervate the adrenal medulla. Implantation of
gelfoam soaked with 0.5 micrograms TGF-beta 2 into the
adrenal wound cavity rescued all spinal cord neurons in the IML
ipsilaterally to the lesioned side. Cytochrome c was not
effective. Injections of [125I]TGF-beta 2 into the adrenal
medulla did not result in retrograde transport and subsequent
labelling of spinal cord neurons, suggesting that TGF-beta may
exert its neuroprotective actions by indirect mechanisms.
TGF-beta applied to cultured adrenocortical cells did not
overtly increase the amount of mRNA for fibroblast growth
factor-2, an established trophic molecule for sympathetic
preganglionic spinal cord neurons. The mechanisms by which
TGF-beta exerts its neurotrophic effect are therefore unclear.
Even so, our data provide the first evidence that TGF-beta may
play an important role in vivo in the control of maintenance of
a population of spinal cord neurons.. EC 1.6.99.1; 0; 0; 0; 0;
9007-43-6.
28. Blottner, D.; Wolf, N.; Lachmund, A.; Flanders, K. C.; Unsicker, K.
TGF-beta rescues target-deprived preganglionic sympathetic
neurons in the spinal cord. Eur-J-Neurosci. 1996 Jan; 8(1):
202-10; ISSN: 0953-816X.
ENGLAND. Transforming growth factors beta (TGF-beta), a
family of pleiotropic cytokines, are widely distributed in the
developing and adult nervous system. In order to further
determine the neural functions of TGF-beta, we have localized
the TGF-beta isoforms 1, 2 and 3 in the adult rat adrenal
medulla and studied the neuroprotective capacity of one
representative family member, TGF-beta 2, for those spinal
cord neurons which innervate adrenal chromaffin cells and
which die after destruction of the adrenal medulla. Unilateral
electrothermal destruction of the adrenal medulla led to the
disappearance of 25% of sympathetic preganglionic neurons,
which are located in the intermediolateral (IML) column of
thoracic spinal cord segments 7-10 and can be selectively
marked by NADPH-diaphorase. The neurons which disappeared
following adrenomedullectomy constitute the full set of
neurons that innervate the adrenal medulla. Implantation of
gelfoam soaked with 0.5 micrograms TGF-beta 2 into the
adrenal wound cavity rescued all spinal cord neurons in the IML
ipsilaterally to the lesioned side. Cytochrome c was not
effective. Injections of [125I]TGF-beta 2 into the adrenal
medulla did not result in retrograde transport and subsequent
labelling of spinal cord neurons, suggesting that TGF-beta may
exert its neuroprotective actions by indirect mechanisms.
TGF-beta applied to cultured adrenocortical cells did not
overtly increase the amount of mRNA for fibroblast growth
factor-2, an established trophic molecule for sympathetic
preganglionic spinal cord neurons. The mechanisms by which
TGF-beta exerts its neurotrophic effect are therefore unclear.
Even so, our data provide the first evidence that TGF-beta may
play an important role in vivo in the control of maintenance of
a population of spinal cord neurons.. EC 1.6.99.1; 0; 0; 0; 0;
9007-43-6.
29. Bonfanti, L.; Merighi, A.; Theodosis, D. T. Dorsal rhizotomy induces
transient expression of the highly sialylated isoform of the
neural cell adhesion molecule in neurons and astrocytes of the
adult rat spinal cord. Neuroscience. 1996 Oct; 74(3): 619-23;
ISSN: 0306-4522.
UNITED-STATES. Expression of the weakly adhesive, highly
sialylated isoform of the neural cell adhesion molecule is a
feature common to cell capable of migration and conformation
changes. 11,18,19 Polysialylated neural cell adhesion molecule
also intervenes in axonal outgrowth and synaptogenesis during
development and after lesion. 11,13 High levels of
polysialylated neural cell adhesion molecule immunoreactivity
are normally visible in laminae I,II and X of the adult rat
spinal cord. 2,15 We how here that unilateral cervical dorsal
rhizotomy induced no detectable changes in immunoreactivity
in these areas. However, 24 h after lesion, polysialylated
neural cell adhesion molecule immunoreactivity appeared in
neurons scattered in laminae III-IX, ipsi-and contralateral to
lesion. This reaction increased particularly on the
contralateral side, became maximal at four days and
disappeared eight days later. At this time, there was
immunolabelling of astrocytes with an activated morphology.
The astrocytic labelling, predominant on the side ipsilateral to
the lesion, was strongest 12 days after rhizotomy, then
diminished progressively. Deafferentation thus causes a
transient expression of polysialylated neural cell adhesion
molecule within areas of the spinal cord distinct from those
which permanently express this adhesion molecule. Such
expression occurs both in neurons and glial cells, with a
temporal pattern specific to each type of cell.. 0; 0.
30. Bonfanti, L.; Merighi, A.; Theodosis, D. T. Dorsal rhizotomy induces
transient expression of the highly sialylated isoform of the
neural cell adhesion molecule in neurons and astrocytes of the
adult rat spinal cord. Neuroscience. 1996 Oct; 74(3): 619-23;
ISSN: 0306-4522.
UNITED-STATES. Expression of the weakly adhesive, highly
sialylated isoform of the neural cell adhesion molecule is a
feature common to cell capable of migration and conformation
changes. 11,18,19 Polysialylated neural cell adhesion molecule
also intervenes in axonal outgrowth and synaptogenesis during
development and after lesion. 11,13 High levels of
polysialylated neural cell adhesion molecule immunoreactivity
are normally visible in laminae I,II and X of the adult rat
spinal cord. 2,15 We how here that unilateral cervical dorsal
rhizotomy induced no detectable changes in immunoreactivity
in these areas. However, 24 h after lesion, polysialylated
neural cell adhesion molecule immunoreactivity appeared in
neurons scattered in laminae III-IX, ipsi-and contralateral to
lesion. This reaction increased particularly on the
contralateral side, became maximal at four days and
disappeared eight days later. At this time, there was
immunolabelling of astrocytes with an activated morphology.
The astrocytic labelling, predominant on the side ipsilateral to
the lesion, was strongest 12 days after rhizotomy, then
diminished progressively. Deafferentation thus causes a
transient expression of polysialylated neural cell adhesion
molecule within areas of the spinal cord distinct from those
which permanently express this adhesion molecule. Such
expression occurs both in neurons and glial cells, with a
temporal pattern specific to each type of cell.. 0; 0.
31. Borja, A. Z. M.; Murphy, C.; Zeller, R. AltFGF-2, a novel ER-
associated FGF-2 protein isoform: its embryonic distribution
and functional analysis during neural tube development. Dev-
Biol. 1996 Dec 15; 180(2): 680-92; ISSN: 0012-1606.
UNITED-STATES. A novel fibroblast growth factor-2 (FGF-2)
protein isoform, called altFGF-2, is expressed abundantly
during chicken embryogenesis. The amino-terminal domain of
the 21.5-kDa altFGF-2 protein diverges completely from the
other three FGF-2 proteins due to alternative splicing of their
first coding exons. Furthermore, the altFGF-2 protein, in
contrast to FGF-2 proteins, is targeted predominantly to the
endoplasmic reticulum. In chicken embryos, altFGF-2 and FGF-
2 proteins are differentially distributed in several
mesodermal structures including developing limbs and kidneys.
All four FGF-2 protein isoforms are also expressed in the
developing neural tube from early neural plate stages onward.
In contrast to FGF-2 proteins, the altFGF-2 isoform is
distributed in a dynamic, spatially restricted pattern in
notochord and ventral neural tube (floor plate and motor
neurons) during specification of neuronal populations. To study
the possible shared or differential signaling functions of
chicken altFGF-2 and FGF-2 gene products, they were
ectopically expressed in the dorsal neural tube aspect of
transgenic mouse embryos. Dorsal expression of altFGF-2, but
not FGF-2 gene products, induced alteration of neural tube
morphology in a significant fraction of mouse embryos (25%).
However, no alterations of dorsoventral (d/v) neural tube
polarity were detected, indicating that altFGF-2 and FGF-2
gene products either function as permissive cofactors or
regulate neural tube growth without affecting establishment
of its primary d/v polarity.. 0.
32. Borja, A. Z. M.; Murphy, C.; Zeller, R. AltFGF-2, a novel ER-
associated FGF-2 protein isoform: its embryonic distribution
and functional analysis during neural tube development. Dev-
Biol. 1996 Dec 15; 180(2): 680-92; ISSN: 0012-1606.
UNITED-STATES. A novel fibroblast growth factor-2 (FGF-2)
protein isoform, called altFGF-2, is expressed abundantly
during chicken embryogenesis. The amino-terminal domain of
the 21.5-kDa altFGF-2 protein diverges completely from the
other three FGF-2 proteins due to alternative splicing of their
first coding exons. Furthermore, the altFGF-2 protein, in
contrast to FGF-2 proteins, is targeted predominantly to the
endoplasmic reticulum. In chicken embryos, altFGF-2 and FGF-
2 proteins are differentially distributed in several
mesodermal structures including developing limbs and kidneys.
All four FGF-2 protein isoforms are also expressed in the
developing neural tube from early neural plate stages onward.
In contrast to FGF-2 proteins, the altFGF-2 isoform is
distributed in a dynamic, spatially restricted pattern in
notochord and ventral neural tube (floor plate and motor
neurons) during specification of neuronal populations. To study
the possible shared or differential signaling functions of
chicken altFGF-2 and FGF-2 gene products, they were
ectopically expressed in the dorsal neural tube aspect of
transgenic mouse embryos. Dorsal expression of altFGF-2, but
not FGF-2 gene products, induced alteration of neural tube
morphology in a significant fraction of mouse embryos (25%).
However, no alterations of dorsoventral (d/v) neural tube
polarity were detected, indicating that altFGF-2 and FGF-2
gene products either function as permissive cofactors or
regulate neural tube growth without affecting establishment
of its primary d/v polarity.. 0.
33. Bosio, A.; Binczek, E.; Stoffel, W. Functional breakdown of the
lipid bilayer of the myelin membrane in central and peripheral
nervous system by disrupted galactocerebroside synthesis.
Proc-Natl-Acad-Sci-U-S-A. 1996 Nov 12; 93(23): 13280-5;
ISSN: 0027-8424.
UNITED-STATES. The lipid bilayer of the myelin membrane of
the central nervous system (CNS) and the peripheral nervous
system (PNS) contains the oligodendrocyte- and Schwann cell-
specific glycosphingolipids galactocerebrosides (GalC) and
GalC-derived sulfatides (sGalC). We have generated a UDP-
galactose ceramide galactosyltransferase (CGT) null mutant
mouse (cgt-/-) with CNS and PNS myelin completely depleted
of GalC and derived sGalC. Oligodendrocytes and Schwann cells
are unable to restore the structure and function of these
galactosphingolipids to maintain the insulator function of the
membrane bilayer. The velocity of nerve conduction of
homozygous cgt-/- mice is reduced to that of unmyelinated
axons. This indicates a severely altered ion permeability of
the lipid bilayer. GalC and sGalC are essential for the
unperturbed lipid bilayer of the myelin membrane of CNS and
PNS. The severe dysmyelinosis leads to death of the cgt-/-
mouse at the end of the myelination period.. EC 2.4.1.-; EC
2.4.1.62; 0; 0; 0.
34. Bosio, A.; Binczek, E.; Stoffel, W. Functional breakdown of the
lipid bilayer of the myelin membrane in central and peripheral
nervous system by disrupted galactocerebroside synthesis.
Proc-Natl-Acad-Sci-U-S-A. 1996 Nov 12; 93(23): 13280-5;
ISSN: 0027-8424.
UNITED-STATES. The lipid bilayer of the myelin membrane of
the central nervous system (CNS) and the peripheral nervous
system (PNS) contains the oligodendrocyte- and Schwann cell-
specific glycosphingolipids galactocerebrosides (GalC) and
GalC-derived sulfatides (sGalC). We have generated a UDP-
galactose ceramide galactosyltransferase (CGT) null mutant
mouse (cgt-/-) with CNS and PNS myelin completely depleted
of GalC and derived sGalC. Oligodendrocytes and Schwann cells
are unable to restore the structure and function of these
galactosphingolipids to maintain the insulator function of the
membrane bilayer. The velocity of nerve conduction of
homozygous cgt-/- mice is reduced to that of unmyelinated
axons. This indicates a severely altered ion permeability of
the lipid bilayer. GalC and sGalC are essential for the
unperturbed lipid bilayer of the myelin membrane of CNS and
PNS. The severe dysmyelinosis leads to death of the cgt-/-
mouse at the end of the myelination period.. EC 2.4.1.-; EC
2.4.1.62; 0; 0; 0.
35. Bowen, B. C.; DePrima, S.; Pattany, P. M.; Marcillo, A.; Madsen, P.;
Quencer, R. M. MR angiography of normal intradural vessels of
the thoracolumbar spine. AJNR-Am-J-Neuroradiol. 1996 Mar;
17(3): 483-94; ISSN: 0195-6108.
UNITED-STATES. PURPOSE: To identify and describe the normal
intradural vessels detected on MR angiograms of the
thoracolumbar spine. METHODS: Six adult subjects who had
clinical evidence of myelopathy, yet normal findings at spinal
digital subtraction angiography (DSA), were also studied
without and with contrast-enhanced MR imaging and three-
dimensional time-of-flight, single-slab MR angiography.
Sagittal and coronal subvolume (targeted) maximum intensity
projection images were compared with arterial and venous
phase DSA images. Angiographic images were then compared
with postmortem, formalin-fixed cord specimens. RESULTS:
Recognizable intradural vessels were detected only on
contrast-enhanced MR angiograms. These vessels corresponded
to the posterior and/or anterior median (midline) veins and the
great medullary veins. The median veins had variable but mild
tortuosity. The medullary veins, which extended from the
median veins and coronal venous plexus on the cord surface to
the epidural venous plexus, were relatively straight and
usually located at T-12 or L-1. The anterior spinal artery
could partially contribute to the anterior midline vascular
signal. CONCLUSION: The intradural vessels identified on
contrast-enhanced MR angiograms are primarily veins, and
these are usually the largest vessels on or near the cord
surface. The limited number and minimal tortuosity of these
veins may serve as a baseline for the examination of patients
with clinically suspected arteriovenous malformation or
fistula.
36. Bowen, B. C.; DePrima, S.; Pattany, P. M.; Marcillo, A.; Madsen, P.;
Quencer, R. M. MR angiography of normal intradural vessels of
the thoracolumbar spine. AJNR-Am-J-Neuroradiol. 1996 Mar;
17(3): 483-94; ISSN: 0195-6108.
UNITED-STATES. PURPOSE: To identify and describe the normal
intradural vessels detected on MR angiograms of the
thoracolumbar spine. METHODS: Six adult subjects who had
clinical evidence of myelopathy, yet normal findings at spinal
digital subtraction angiography (DSA), were also studied
without and with contrast-enhanced MR imaging and three-
dimensional time-of-flight, single-slab MR angiography.
Sagittal and coronal subvolume (targeted) maximum intensity
projection images were compared with arterial and venous
phase DSA images. Angiographic images were then compared
with postmortem, formalin-fixed cord specimens. RESULTS:
Recognizable intradural vessels were detected only on
contrast-enhanced MR angiograms. These vessels corresponded
to the posterior and/or anterior median (midline) veins and the
great medullary veins. The median veins had variable but mild
tortuosity. The medullary veins, which extended from the
median veins and coronal venous plexus on the cord surface to
the epidural venous plexus, were relatively straight and
usually located at T-12 or L-1. The anterior spinal artery
could partially contribute to the anterior midline vascular
signal. CONCLUSION: The intradural vessels identified on
contrast-enhanced MR angiograms are primarily veins, and
these are usually the largest vessels on or near the cord
surface. The limited number and minimal tortuosity of these
veins may serve as a baseline for the examination of patients
with clinically suspected arteriovenous malformation or
fistula.
37. Boxall, S. J.; Thompson, S. W.; Dray, A.; Dickenson, A. H.; Urban, L.
Metabotropic glutamate receptor activation contributes to
nociceptive reflex activity in the rat spinal cord in vitro.
Neuroscience. 1996 Sep; 74(1): 13-20; ISSN: 0306-4522.
UNITED-STATES. The contribution of metabotropic glutamate
receptor activation to the spinal segmental reflex response
evoked at high-intensity electrical stimulation suggesting a
role in nociception, has been examined in an in vitro
preparation of neonatal rat spinal cord. Segmental reflex
responses were recorded as a ventral root depolarization
evoked following drug perfusion to the spinal cord or by
electrical activation of high-threshold nociceptive afferent
fibres. Superfusion of the selective metabotropic glutamate
receptor agonist, (1S, 3R)-1-aminocyclopentane-1,3-
dicarboxylic acid [(1S,3R)-ACPD], to the spinal cord produced a
dose-dependent, reversible ventral root depolarization (EC50 =
58 +/- 7 microM; n = 4), which was antagonized by the
selective metabotropic glutamate receptor antagonist, (+)-
alpha-methyl-4-carboxyphenylglycine (MCPG; IC50 = 243 +/-
61 microM; n = 4). MCPG, over the same concentration range
(10 microM-5.0 mM) did not affect N-methyl-D-aspartate-
induced ventral root depolarizations. In contrast, the specific
N-methyl-D-aspartate receptor antagonist D(-)-2-amino-5-
phosphonopentanoic acid (D-AP5) reduced N-methyl-D-
aspartate-evoked ventral root depolarization but did not
affect the depolarization evoked by (1S,3R)-ACPD, thus
indicating the specificity of the antagonists for these
aggregate responses. MCPG significantly reduced the prolonged
phase of the single shock C-fibre-evoked ventral root
depolarization (IC50 = 2.9 +/- 0.2 mM; n = 3-5). Low frequency
high intensity stimulation of the dorsal root evoked a wind-up
response, the amplitude of which was attenuated by both D-
AP5 and MCPG in a dose-dependent manner. The ventral root
depolarization evoked by capsaicin application (1.0 microM, 30
s) was blocked by both MCPG (IC50 = 809 +/- 35 microM; n = 4)
and D-AP5 (IC50 = 143 +/- 43 microM; n = 4). These data
suggest that both D-AP5 and MCPG reduced C-fibre-induced
ventral root responses. In addition to N-methyl-D-aspartate
receptor, metabotropic glutamate receptor activation appears
to be involved in the generation of the segmental spinal reflex
evoked by high-intensity stimulation in the neonatal rat spinal
cord in vitro.. 0; 6384-92-5; 77521-29-0.
38. Boxall, S. J.; Thompson, S. W.; Dray, A.; Dickenson, A. H.; Urban, L.
Metabotropic glutamate receptor activation contributes to
nociceptive reflex activity in the rat spinal cord in vitro.
Neuroscience. 1996 Sep; 74(1): 13-20; ISSN: 0306-4522.
UNITED-STATES. The contribution of metabotropic glutamate
receptor activation to the spinal segmental reflex response
evoked at high-intensity electrical stimulation suggesting a
role in nociception, has been examined in an in vitro
preparation of neonatal rat spinal cord. Segmental reflex
responses were recorded as a ventral root depolarization
evoked following drug perfusion to the spinal cord or by
electrical activation of high-threshold nociceptive afferent
fibres. Superfusion of the selective metabotropic glutamate
receptor agonist, (1S, 3R)-1-aminocyclopentane-1,3-
dicarboxylic acid [(1S,3R)-ACPD], to the spinal cord produced a
dose-dependent, reversible ventral root depolarization (EC50 =
58 +/- 7 microM; n = 4), which was antagonized by the
selective metabotropic glutamate receptor antagonist, (+)-
alpha-methyl-4-carboxyphenylglycine (MCPG; IC50 = 243 +/-
61 microM; n = 4). MCPG, over the same concentration range
(10 microM-5.0 mM) did not affect N-methyl-D-aspartate-
induced ventral root depolarizations. In contrast, the specific
N-methyl-D-aspartate receptor antagonist D(-)-2-amino-5-
phosphonopentanoic acid (D-AP5) reduced N-methyl-D-
aspartate-evoked ventral root depolarization but did not
affect the depolarization evoked by (1S,3R)-ACPD, thus
indicating the specificity of the antagonists for these
aggregate responses. MCPG significantly reduced the prolonged
phase of the single shock C-fibre-evoked ventral root
depolarization (IC50 = 2.9 +/- 0.2 mM; n = 3-5). Low frequency
high intensity stimulation of the dorsal root evoked a wind-up
response, the amplitude of which was attenuated by both D-
AP5 and MCPG in a dose-dependent manner. The ventral root
depolarization evoked by capsaicin application (1.0 microM, 30
s) was blocked by both MCPG (IC50 = 809 +/- 35 microM; n = 4)
and D-AP5 (IC50 = 143 +/- 43 microM; n = 4). These data
suggest that both D-AP5 and MCPG reduced C-fibre-induced
ventral root responses. In addition to N-methyl-D-aspartate
receptor, metabotropic glutamate receptor activation appears
to be involved in the generation of the segmental spinal reflex
evoked by high-intensity stimulation in the neonatal rat spinal
cord in vitro.. 0; 6384-92-5; 77521-29-0.
39. Brackett, N. L.; Padron, O. F.; Lynne, C. M. Semen quality of spinal
cord injured men is better when obtained by vibratory
stimulation versus electroejaculation. J-Urol. 1997 Jan;
157(1): 151-7; ISSN: 0022-5347.
UNITED-STATES. PURPOSE: Most spinal cord injured men
require assisted ejaculation procedures to obtain semen, and
the majority can achieve this result by vibratory stimulation
or electroejaculation. We determined if semen obtained by
vibratory stimulation differed in quality from that obtained by
electroejaculation. MATERIALS AND METHODS: Between
subjects and within subjects designs were used. Of 77 spinal
cord injured men 23 underwent vibratory stimulation only, 44
electroejaculation only and 10 both procedures. Antegrade,
retrograde and total ejaculates were analyzed in each subject
for total sperm count, percent motile sperm and percent sperm
with rapid linear motion. RESULTS: With vibratory stimulation
compared to electroejaculation the percent motile sperm and
percent sperm with rapid linear motion were significantly
greater, whereas total sperm count was similar, in the
antegrade specimens and total ejaculates. This finding was
true for different groups of subjects as well as within a group
of the same subjects. CONCLUSIONS: Semen obtained by
vibratory stimulation is of better quality than that obtained by
electroejaculation. In medical practices that include assisted
ejaculation of spinal cord injured men, we recommend
obtaining a specimen by vibratory stimulation. If that method
fails electroejaculation should be performed.
40. Brackett, N. L.; Padron, O. F.; Lynne, C. M. Semen quality of spinal
cord injured men is better when obtained by vibratory
stimulation versus electroejaculation. J-Urol. 1997 Jan;
157(1): 151-7; ISSN: 0022-5347.
UNITED-STATES. PURPOSE: Most spinal cord injured men
require assisted ejaculation procedures to obtain semen, and
the majority can achieve this result by vibratory stimulation
or electroejaculation. We determined if semen obtained by
vibratory stimulation differed in quality from that obtained by
electroejaculation. MATERIALS AND METHODS: Between
subjects and within subjects designs were used. Of 77 spinal
cord injured men 23 underwent vibratory stimulation only, 44
electroejaculation only and 10 both procedures. Antegrade,
retrograde and total ejaculates were analyzed in each subject
for total sperm count, percent motile sperm and percent sperm
with rapid linear motion. RESULTS: With vibratory stimulation
compared to electroejaculation the percent motile sperm and
percent sperm with rapid linear motion were significantly
greater, whereas total sperm count was similar, in the
antegrade specimens and total ejaculates. This finding was
true for different groups of subjects as well as within a group
of the same subjects. CONCLUSIONS: Semen obtained by
vibratory stimulation is of better quality than that obtained by
electroejaculation. In medical practices that include assisted
ejaculation of spinal cord injured men, we recommend
obtaining a specimen by vibratory stimulation. If that method
fails electroejaculation should be performed.
41. Brennan, T. J.; Olson, E. N.; Klein, W. H.; Winslow, J. W. Extensive
motor neuron survival in the absence of secondary skeletal
muscle fiber formation. J-Neurosci-Res. 1996 Jul 1; 45(1): 57-
68; ISSN: 0360-4012.
UNITED-STATES. Mice with a null mutation in the myogenic
basic helixloop-helix regulatory gene myogenin have severe
developmental muscle defects resulting in loss of secondary
muscle fibers and perinatal death. In this study, we used the
myogenin mutant mouse as a model to study the effects of the
loss of secondary muscle fibers and the contribution of
primary muscle fibers on the survival of motor neurons during
programmed cell death. We demonstrate that in the absence of
secondary skeletal muscle fibers there is complete survival of
facial motor nucleus motor neurons and approximately 60%
survival of spinal lumbar motor neurons in the myogenin
mutant mouse. The surviving spinal motor neurons maintain
axonal projections into the hindlimb and display aspects of
synaptic contact into the remaining rudimentary fibers. These
findings suggest that primary muscle fibers, representing
approximately 10% of normal muscle mass, contribute
significantly to the control of motor neuron cell survival in
mammals.. 0.
42. Brennan, T. J.; Olson, E. N.; Klein, W. H.; Winslow, J. W. Extensive
motor neuron survival in the absence of secondary skeletal
muscle fiber formation. J-Neurosci-Res. 1996 Jul 1; 45(1): 57-
68; ISSN: 0360-4012.
UNITED-STATES. Mice with a null mutation in the myogenic
basic helixloop-helix regulatory gene myogenin have severe
developmental muscle defects resulting in loss of secondary
muscle fibers and perinatal death. In this study, we used the
myogenin mutant mouse as a model to study the effects of the
loss of secondary muscle fibers and the contribution of
primary muscle fibers on the survival of motor neurons during
programmed cell death. We demonstrate that in the absence of
secondary skeletal muscle fibers there is complete survival of
facial motor nucleus motor neurons and approximately 60%
survival of spinal lumbar motor neurons in the myogenin
mutant mouse. The surviving spinal motor neurons maintain
axonal projections into the hindlimb and display aspects of
synaptic contact into the remaining rudimentary fibers. These
findings suggest that primary muscle fibers, representing
approximately 10% of normal muscle mass, contribute
significantly to the control of motor neuron cell survival in
mammals.. 0.
43. Britton, N. F.; Chaplain, M. A.; Skevington, S. M. The role of N-
methyl-D-aspartate (NMDA) receptors in wind-up: a
mathematical model. IMA-J-Math-Appl-Med-Biol. 1996 Sep;
13(3): 193-205; ISSN: 0265-0746.
ENGLAND. We present a mathematical model for the
phenomenon of wind-up (Mendell, 1966, Exper. Neur. 16,316-
22) which occurs in many neurons. We concentrate on its
occurrence in the substantia gelatinosa of the dorsal horns of
the spinal cord, where it is connected with certain
pathological and nonpathological pain states. The model is a
development of the model by Britton & Skevington (1989, J.
Theor. Biol. 137, 91-105) for Melzack & Wall's gate control
theory of pain (1965, Science, New York, 150, 971-9; 1982,
The Challenge of Pain, Penguin: Harmondsworth), modified to
take account of more recent information. Its variables are the
electric potentials of various cells in the midbrain and the
spinal cord. Britton & Skevington's original model simulated
many of the phenomena observed in acute pain in humans, but
not the wind-up mechanism. This is not surprising, since this
model did not include the N-methyl-D-aspartate (NMDA)
receptors that are now recognized as being crucial to the
phenomenon. Here we rectify this omission, and obtain good
agreement between the model and experimental data on wind-
up. The positive feedback that NMDA receptors exhibit is
shown to be the essential feature in producing wind-up. As an
independent test of the model we simulate a completely
different experimental set-up, and obtain good qualitative
agreement with data there. Finally, we present a prediction of
the model that has yet to be tested experimentally.. 0.
44. Britton, N. F.; Chaplain, M. A.; Skevington, S. M. The role of N-
methyl-D-aspartate (NMDA) receptors in wind-up: a
mathematical model. IMA-J-Math-Appl-Med-Biol. 1996 Sep;
13(3): 193-205; ISSN: 0265-0746.
ENGLAND. We present a mathematical model for the
phenomenon of wind-up (Mendell, 1966, Exper. Neur. 16,316-
22) which occurs in many neurons. We concentrate on its
occurrence in the substantia gelatinosa of the dorsal horns of
the spinal cord, where it is connected with certain
pathological and nonpathological pain states. The model is a
development of the model by Britton & Skevington (1989, J.
Theor. Biol. 137, 91-105) for Melzack & Wall's gate control
theory of pain (1965, Science, New York, 150, 971-9; 1982,
The Challenge of Pain, Penguin: Harmondsworth), modified to
take account of more recent information. Its variables are the
electric potentials of various cells in the midbrain and the
spinal cord. Britton & Skevington's original model simulated
many of the phenomena observed in acute pain in humans, but
not the wind-up mechanism. This is not surprising, since this
model did not include the N-methyl-D-aspartate (NMDA)
receptors that are now recognized as being crucial to the
phenomenon. Here we rectify this omission, and obtain good
agreement between the model and experimental data on wind-
up. The positive feedback that NMDA receptors exhibit is
shown to be the essential feature in producing wind-up. As an
independent test of the model we simulate a completely
different experimental set-up, and obtain good qualitative
agreement with data there. Finally, we present a prediction of
the model that has yet to be tested experimentally.. 0.
45. Budai, D.; Larson, A. A. Role of substance P in the modulation of C-
fiber-evoked responses of spinal dorsal horn neurons. Brain-
Res. 1996 Feb 26; 710(1-2): 197-203; ISSN: 0006-8993.
NETHERLANDS. Substance P (SP) as well as excitatory amino
acids (EAAs) appear to be released in response to stimulation
of primary afferent C-fibers. Activity at N-methyl-D-
aspartate (NMDA) receptors is essential for wind-up (the
progressive potentiation of C-fiber-evoked responses of single
neurons in response to an electrical stimulation), however, the
role of SP in wind-up is unclear. To address this, the effects
of iontophoretically applied CP-99,994 (a NK-1 receptor
antagonist), SP and SP(1-7) (an N-terminal breakdown product
of SP), were compared on responses of spinal dorsal horn wide
dynamic range (WDR) neurons of the rat. Post-stimulus time
histograms (PSTH) were summed over 12 responses to low
frequency (0.5 Hz) electrical stimulation of the cutaneous
receptive field. Changes in responses of dorsal horn neurons
were evaluated by monitoring C-fiber input, wind-up, and the
total number of spikes evoked by C-fiber activity in response
to the 12 stimuli. The NK-1 receptor antagonist CP-99,994
significantly inhibited the total number of C-spikes and
caused a significant reduction in wind-up without changing the
C-fiber input, indicating the involvement of NK-1 receptors in
wind-up. Application of SP led to an overall increase in the
total number of C-fiber evoked responses of dorsal horn
neurons and C-fiber input, however, wind-up, as defined, was
significantly decreased following SP. In contrast, substance
P(1-7) evoked a long-lasting increase in the total number of
C-fiber-related spikes which was initially sustained by a
transient increase in the input followed by a longer lasting
increase in wind-up, an effect opposite that of CP-99,994. As
NMDA activity has been previously shown to be inhibited and
then potentiated by SP N-terminal activity over a similar time
interval, the present data are consistent with the mediation of
wind-up by NMDA and its modulation by SP N-terminal activity.
Release of SP in response to noxious stimulation may,
therefore, increase primary afferent C-fiber activity (input)
whereas an accumulation of SP N-terminal metabolites
appears to potentiate wind-up, perhaps via positive
modulation of EAA activity.. 0; 0; 0; 136982-36-0; 33507-63-
0; 72226-88-1.
46. Budai, D.; Larson, A. A. Role of substance P in the modulation of C-
fiber-evoked responses of spinal dorsal horn neurons. Brain-
Res. 1996 Feb 26; 710(1-2): 197-203; ISSN: 0006-8993.
NETHERLANDS. Substance P (SP) as well as excitatory amino
acids (EAAs) appear to be released in response to stimulation
of primary afferent C-fibers. Activity at N-methyl-D-
aspartate (NMDA) receptors is essential for wind-up (the
progressive potentiation of C-fiber-evoked responses of single
neurons in response to an electrical stimulation), however, the
role of SP in wind-up is unclear. To address this, the effects
of iontophoretically applied CP-99,994 (a NK-1 receptor
antagonist), SP and SP(1-7) (an N-terminal breakdown product
of SP), were compared on responses of spinal dorsal horn wide
dynamic range (WDR) neurons of the rat. Post-stimulus time
histograms (PSTH) were summed over 12 responses to low
frequency (0.5 Hz) electrical stimulation of the cutaneous
receptive field. Changes in responses of dorsal horn neurons
were evaluated by monitoring C-fiber input, wind-up, and the
total number of spikes evoked by C-fiber activity in response
to the 12 stimuli. The NK-1 receptor antagonist CP-99,994
significantly inhibited the total number of C-spikes and
caused a significant reduction in wind-up without changing the
C-fiber input, indicating the involvement of NK-1 receptors in
wind-up. Application of SP led to an overall increase in the
total number of C-fiber evoked responses of dorsal horn
neurons and C-fiber input, however, wind-up, as defined, was
significantly decreased following SP. In contrast, substance
P(1-7) evoked a long-lasting increase in the total number of
C-fiber-related spikes which was initially sustained by a
transient increase in the input followed by a longer lasting
increase in wind-up, an effect opposite that of CP-99,994. As
NMDA activity has been previously shown to be inhibited and
then potentiated by SP N-terminal activity over a similar time
interval, the present data are consistent with the mediation of
wind-up by NMDA and its modulation by SP N-terminal activity.
Release of SP in response to noxious stimulation may,
therefore, increase primary afferent C-fiber activity (input)
whereas an accumulation of SP N-terminal metabolites
appears to potentiate wind-up, perhaps via positive
modulation of EAA activity.. 0; 0; 0; 136982-36-0; 33507-63-
0; 72226-88-1.
47. Burke, R. E.; Glenn, L. L. Horseradish peroxidase study of the
spatial and electrotonic distribution of group Ia synapses on
type-identified ankle extensor motoneurons in the cat. J-
Comp-Neurol. 1996 Aug 26; 372(3): 465-85; ISSN: 0021-9967.
UNITED-STATES. Eight functionally identified group Ia muscle
afferents from triceps surae or plantaris muscles were
labeled intraaxonally with horseradish peroxidase (HRP) in
seven adult cats. Subsequently, HRP was injected into two to
six homonymous or heteronymous alpha-motoneurons per
animal (total = 22), each identified by motor unit type and
located near the site of afferent injection. The complete
trajectories of labeled afferents were reconstructed, and
putative synaptic contacts on HRP-labeled motoneurons were
identified at high magnification. Dendritic paths from each
contact were also mapped and measured. A total of 24 contact
systems (the combination of a group Ia afferent and a
postsynaptic motoneuron) were reconstructed, of which 17
were homonymous, and seven were heteronymous. Overall,
homonymous contact systems had an average of 9.6 boutons,
whereas heteronymous contact systems had an average of 5.9
boutons. The average number of boutons found on type S
motoneurons in homonymous contact systems was smaller
(6.4, range 3-17) than in systems involving types FF or FR
motoneurons (FF: 10.4, range 4-18; FR: 11.3, range 4-32).
Neither of these differences were statistically significant. In
contrast to earlier reports, a majority (15/24) of contact
systems included more than one collateral from the same Ia
afferent. The complexity (number of branch points) in the
arborization pathway leading to each contact (overall mean 8.4
+/- 3.3) was virtually identical in all contact systems,
irrespective of the type of postsynaptic motoneuron. The
three-dimensional distribution of group Ia contacts was not
coextensive with the radially organized dendrites of
motoneurons: Dendrites oriented in the ventromedial to
dorsolateral axis had the fewest (8%) contacts, whereas
rostrocaudal dendrites had the most (63%) contacts.
Nevertheless, contacts were widely distributed on the
motoneuron surface, with few on and near the soma (< or = 200
microns radial distance from the soma) or on the most distal
parts of the tree (> or = 1,000 microns). The boutons in
individual contact systems also showed wide spatial and
estimated electrotonic distributions; only 3/24 systems had
all contact located within a restricted spatial/electrotonic
region. The relations between these anatomical results and
existing electrophysiological data on group Ia synaptic
potentials are discussed.. EC 1.11.1.-.
48. Burke, R. E.; Glenn, L. L. Horseradish peroxidase study of the
spatial and electrotonic distribution of group Ia synapses on
type-identified ankle extensor motoneurons in the cat. J-
Comp-Neurol. 1996 Aug 26; 372(3): 465-85; ISSN: 0021-9967.
UNITED-STATES. Eight functionally identified group Ia muscle
afferents from triceps surae or plantaris muscles were
labeled intraaxonally with horseradish peroxidase (HRP) in
seven adult cats. Subsequently, HRP was injected into two to
six homonymous or heteronymous alpha-motoneurons per
animal (total = 22), each identified by motor unit type and
located near the site of afferent injection. The complete
trajectories of labeled afferents were reconstructed, and
putative synaptic contacts on HRP-labeled motoneurons were
identified at high magnification. Dendritic paths from each
contact were also mapped and measured. A total of 24 contact
systems (the combination of a group Ia afferent and a
postsynaptic motoneuron) were reconstructed, of which 17
were homonymous, and seven were heteronymous. Overall,
homonymous contact systems had an average of 9.6 boutons,
whereas heteronymous contact systems had an average of 5.9
boutons. The average number of boutons found on type S
motoneurons in homonymous contact systems was smaller
(6.4, range 3-17) than in systems involving types FF or FR
motoneurons (FF: 10.4, range 4-18; FR: 11.3, range 4-32).
Neither of these differences were statistically significant. In
contrast to earlier reports, a majority (15/24) of contact
systems included more than one collateral from the same Ia
afferent. The complexity (number of branch points) in the
arborization pathway leading to each contact (overall mean 8.4
+/- 3.3) was virtually identical in all contact systems,
irrespective of the type of postsynaptic motoneuron. The
three-dimensional distribution of group Ia contacts was not
coextensive with the radially organized dendrites of
motoneurons: Dendrites oriented in the ventromedial to
dorsolateral axis had the fewest (8%) contacts, whereas
rostrocaudal dendrites had the most (63%) contacts.
Nevertheless, contacts were widely distributed on the
motoneuron surface, with few on and near the soma (< or = 200
microns radial distance from the soma) or on the most distal
parts of the tree (> or = 1,000 microns). The boutons in
individual contact systems also showed wide spatial and
estimated electrotonic distributions; only 3/24 systems had
all contact located within a restricted spatial/electrotonic
region. The relations between these anatomical results and
existing electrophysiological data on group Ia synaptic
potentials are discussed.. EC 1.11.1.-.
49. Burstein, R.; Falkowsky, O.; Borsook, D.; Strassman, A. Distinct
lateral and medial projections of the spinohypothalamic tract
of the rat. J-Comp-Neurol. 1996 Sep 30; 373(4): 549-74; ISSN:
0021-9967.
UNITED-STATES. We recently described a direct nociceptive
projection from the spinal cord to the hypothalamus in the rat.
Several electrophysiological studies of this projection
indicated that the axons of some spinohypothalamic tract
neurons (SHT) reach the hypothalamus either by a lateral or by
a medial route. The purpose of this study was to determine the
origin of all SHT neurons that reach the hypothalamus through
the lateral and the medial projections, and to investigate the
possibility of ablating the SHT without damaging other
important sensory and motor tracts by combining retrograde
tracing techniques with axonal ablation. As compared with
control cases, significant (P < .05) reductions in the number of
labeled SHT neurons were encountered, 26% in the ipsilateral
spinal cord following lesions of the medial projection, 67% in
the contralateral spinal cord following lesions of the lateral
projection, and 94% in both contra- and ipsilateral sides
following lesions of both the medial and lateral projections.
Bilateral lesions of the lateral projections had no effect on
the distribution of labeled neurons in the spinal cord and
dorsal column nuclei following injections of Fluoro-Gold (FG)
into the thalamus, and a small unilateral lesion of the lateral
projection reduced the ipsilateral labeling in the motor cortex
following injections of FG into the pyramidal decussation.
These findings suggest that most SHT neurons ascend through
the contralateral lateral projection and that less than half
continue in the medial projection to the ipsilateral side. They
also suggest a site that can be lesioned without affecting
other ascending sensory spinal pathways.
50. Burstein, R.; Falkowsky, O.; Borsook, D.; Strassman, A. Distinct
lateral and medial projections of the spinohypothalamic tract
of the rat. J-Comp-Neurol. 1996 Sep 30; 373(4): 549-74; ISSN:
0021-9967.
UNITED-STATES. We recently described a direct nociceptive
projection from the spinal cord to the hypothalamus in the rat.
Several electrophysiological studies of this projection
indicated that the axons of some spinohypothalamic tract
neurons (SHT) reach the hypothalamus either by a lateral or by
a medial route. The purpose of this study was to determine the
origin of all SHT neurons that reach the hypothalamus through
the lateral and the medial projections, and to investigate the
possibility of ablating the SHT without damaging other
important sensory and motor tracts by combining retrograde
tracing techniques with axonal ablation. As compared with
control cases, significant (P < .05) reductions in the number of
labeled SHT neurons were encountered, 26% in the ipsilateral
spinal cord following lesions of the medial projection, 67% in
the contralateral spinal cord following lesions of the lateral
projection, and 94% in both contra- and ipsilateral sides
following lesions of both the medial and lateral projections.
Bilateral lesions of the lateral projections had no effect on
the distribution of labeled neurons in the spinal cord and
dorsal column nuclei following injections of Fluoro-Gold (FG)
into the thalamus, and a small unilateral lesion of the lateral
projection reduced the ipsilateral labeling in the motor cortex
following injections of FG into the pyramidal decussation.
These findings suggest that most SHT neurons ascend through
the contralateral lateral projection and that less than half
continue in the medial projection to the ipsilateral side. They
also suggest a site that can be lesioned without affecting
other ascending sensory spinal pathways.
51. Carlton, S. M.; Hargett, G. L.; Coggeshall, R. E. Distribution of
glycine-immunoreactive profiles in the monkey spinal cord: a
light microscopic and ultrastructural study. J-Comp-Neurol.
1996 Aug 5; 371(4): 589-602; ISSN: 0021-9967.
UNITED-STATES. The present study analyzed the relationships
of glycine (GLY)-immunoreactive (-IR) and unlabeled profiles
in the primate spinal cord. Light microscopic analysis
demonstrated GLY-IR profiles in laminae III-VII, with fewer
labeled profiles in laminae I, II, VIII, IX and X. The dorsal part
of the lateral funiculus and the dorsal funiculus contained few
labeled axons, in contrast to all other areas of white matter,
which were heavily labeled. At the electron microscopic level,
GLY-IR terminals in monkeys contained mainly round, with
occasional pleomorphic, clear vesicles; however, F-type GLY-
IR terminals synapsing on motoneurons contained pleomorphic
vesicles. This seems to be an important species difference
because vesicles in GLY-IR terminals in rat and cat are
predominantly oval or elliptical. GLY-IR terminals synapsed on
unlabeled as well as GLY-IR cell bodies and dendrites. This is
morphological evidence that GLY may be both an inhibitor (GLY-
IR terminals synapse on and presumably inhibit non-GLY cell
bodies and dendrites) and a disinhibitor (GLY-IR terminals
synapse on and presumably inhibit other GLY elements) of
spinal activity. Also noteworthy was the conspicuous absence
of axoaxonic interactions involving GLY-IR terminals. A
related finding was that GLY profiles were always
postsynaptic, never presynaptic, to glomerular primary
afferent terminals. The functional implications would seem to
be that primary afferent input can activate the spinal GLY
system but that there is little GLY presynaptic control of
afferent input in monkeys. This is in contrast to rats and cats,
in which axoaxonic interactions involving GLY-IR terminals
have been observed and where it is common to find GLY-IR
terminals presynaptic to glomerular primary afferent
terminals.. 56-40-6.
52. Carlton, S. M.; Hargett, G. L.; Coggeshall, R. E. Distribution of
glycine-immunoreactive profiles in the monkey spinal cord: a
light microscopic and ultrastructural study. J-Comp-Neurol.
1996 Aug 5; 371(4): 589-602; ISSN: 0021-9967.
UNITED-STATES. The present study analyzed the relationships
of glycine (GLY)-immunoreactive (-IR) and unlabeled profiles
in the primate spinal cord. Light microscopic analysis
demonstrated GLY-IR profiles in laminae III-VII, with fewer
labeled profiles in laminae I, II, VIII, IX and X. The dorsal part
of the lateral funiculus and the dorsal funiculus contained few
labeled axons, in contrast to all other areas of white matter,
which were heavily labeled. At the electron microscopic level,
GLY-IR terminals in monkeys contained mainly round, with
occasional pleomorphic, clear vesicles; however, F-type GLY-
IR terminals synapsing on motoneurons contained pleomorphic
vesicles. This seems to be an important species difference
because vesicles in GLY-IR terminals in rat and cat are
predominantly oval or elliptical. GLY-IR terminals synapsed on
unlabeled as well as GLY-IR cell bodies and dendrites. This is
morphological evidence that GLY may be both an inhibitor (GLY-
IR terminals synapse on and presumably inhibit non-GLY cell
bodies and dendrites) and a disinhibitor (GLY-IR terminals
synapse on and presumably inhibit other GLY elements) of
spinal activity. Also noteworthy was the conspicuous absence
of axoaxonic interactions involving GLY-IR terminals. A
related finding was that GLY profiles were always
postsynaptic, never presynaptic, to glomerular primary
afferent terminals. The functional implications would seem to
be that primary afferent input can activate the spinal GLY
system but that there is little GLY presynaptic control of
afferent input in monkeys. This is in contrast to rats and cats,
in which axoaxonic interactions involving GLY-IR terminals
have been observed and where it is common to find GLY-IR
terminals presynaptic to glomerular primary afferent
terminals.. 56-40-6.
53. Celichowski, J.; Krutki, P.; Bichler, E. Axonal conduction velocity
of motor units of rat's medial gastrocnemius muscle. J-
Physiol-Paris. 1996; 90(2): 75-8; ISSN: 0928-4257.
FRANCE. Axonal conduction velocity and its relations to
different contractile properties of motor units of medial
gastrocnemius muscle were investigated in nine Wistar rats
anaesthetized with pentobarbitone. Functionally isolated
motor units were identified as slow (S), fast resistant (FR)
and fast fatigable (FF). Axons of S motor units conducted
significantly more slowly than of fast units, while there was
considerable overlap between conduction velocities measured
for FR and FF types. The mean values of conduction velocity
were 50.9 m/s for S, 68.9 m/s for FR and 71.3 m/s for FF type
motor units. Strong and significant negative correlation
between conduction velocity and contraction time as well as
half-relaxation time was demonstrated. However, only a weak
correlation between conduction velocity and twitch tension,
tetanic tension or fatigue index was found. The multiple
regression analysis revealed that the major factor to
determine conduction velocity was contraction time.
54. Celichowski, J.; Krutki, P.; Bichler, E. Axonal conduction velocity
of motor units of rat's medial gastrocnemius muscle. J-
Physiol-Paris. 1996; 90(2): 75-8; ISSN: 0928-4257.
FRANCE. Axonal conduction velocity and its relations to
different contractile properties of motor units of medial
gastrocnemius muscle were investigated in nine Wistar rats
anaesthetized with pentobarbitone. Functionally isolated
motor units were identified as slow (S), fast resistant (FR)
and fast fatigable (FF). Axons of S motor units conducted
significantly more slowly than of fast units, while there was
considerable overlap between conduction velocities measured
for FR and FF types. The mean values of conduction velocity
were 50.9 m/s for S, 68.9 m/s for FR and 71.3 m/s for FF type
motor units. Strong and significant negative correlation
between conduction velocity and contraction time as well as
half-relaxation time was demonstrated. However, only a weak
correlation between conduction velocity and twitch tension,
tetanic tension or fatigue index was found. The multiple
regression analysis revealed that the major factor to
determine conduction velocity was contraction time.
55. Chernoff, E. A. Spinal cord regeneration: a phenomenon unique to
urodeles? Int-J-Dev-Biol. 1996 Aug; 40(4): 823-31; ISSN:
0214-6282.
SPAIN. Studies of neuronal survival and axonal regeneration in
birds and mammals have made it clear that the
microenvironment of the CNS is critical to the failure of CNS
regeneration in these animals. This environment includes
growth and trophic factors, ECM components and matrix
turnover enzymes, cytokines and other immune system
contributions. Urodele amphibians (salamanders and newts)
can regenerate spinal cord even as adults, and environmental
contributions of glial populations are a major part of the
difference between urodele and higher vertebrate spinal cord
regeneration. In particular, the behavior of injury-reactive
ependymal cells (radial glia) is critical to the regenerative
capacity of urodele spinal cord. In this review we examine
what is known about cell-cell interactions between ependymal
cells and neurons and between ependymal cells and other glial
populations. The known contributions of ependymal cell
products such as matrix metalloproteinases and trophic
factors are discussed. There is evidence in the literature that
an ependymal response occurs during embryonic or fetal
development in birds and mammals following spinal cord
transection, and this review discusses the implications of
such a process for future studies of spinal cord injury.. 0; 0.
56. Chernoff, E. A. Spinal cord regeneration: a phenomenon unique to
urodeles? Int-J-Dev-Biol. 1996 Aug; 40(4): 823-31; ISSN:
0214-6282.
SPAIN. Studies of neuronal survival and axonal regeneration in
birds and mammals have made it clear that the
microenvironment of the CNS is critical to the failure of CNS
regeneration in these animals. This environment includes
growth and trophic factors, ECM components and matrix
turnover enzymes, cytokines and other immune system
contributions. Urodele amphibians (salamanders and newts)
can regenerate spinal cord even as adults, and environmental
contributions of glial populations are a major part of the
difference between urodele and higher vertebrate spinal cord
regeneration. In particular, the behavior of injury-reactive
ependymal cells (radial glia) is critical to the regenerative
capacity of urodele spinal cord. In this review we examine
what is known about cell-cell interactions between ependymal
cells and neurons and between ependymal cells and other glial
populations. The known contributions of ependymal cell
products such as matrix metalloproteinases and trophic
factors are discussed. There is evidence in the literature that
an ependymal response occurs during embryonic or fetal
development in birds and mammals following spinal cord
transection, and this review discusses the implications of
such a process for future studies of spinal cord injury.. 0; 0.
57. Chiba, T.; Tanaka, K.; Tatsuoka, H.; Dun, S. L.; Dun, N. J. The
synaptic structure of PACAP immunoreactive axons in the
intermediolateral nucleus of the rat. Neurosci-Lett. 1996 Aug
16; 214(1): 65-8; ISSN: 0304-3940.
IRELAND. Immuno-electronmicroscopic studies were
performed to detect the presence and features of synaptic
contacts between pituitary adenylate cyclase activating
polypeptide immunoreactive (PACAP-ir) axons and cholera
toxin B-horseradish peroxidase labeled preganglionic
sympathetic neurons (PSNs) in the intermediolateral nucleus
of the rat thoracic spinal cord. PACAP-ir axon varicosities,
which contained small clear and large core synaptic vesicles,
were found to form asymmetric type of synaptic contacts with
dendrites and infrequently with somata of labeled
preganglionic neurons. The present study provides
ultrastructural evidence of PACAP-ir synaptic contacts with
PSNs, raising the possibility that the peptide may function as
a transmitter/modulator to these neurons.. 0; 0.
58. Chiba, T.; Tanaka, K.; Tatsuoka, H.; Dun, S. L.; Dun, N. J. The
synaptic structure of PACAP immunoreactive axons in the
intermediolateral nucleus of the rat. Neurosci-Lett. 1996 Aug
16; 214(1): 65-8; ISSN: 0304-3940.
IRELAND. Immuno-electronmicroscopic studies were
performed to detect the presence and features of synaptic
contacts between pituitary adenylate cyclase activating
polypeptide immunoreactive (PACAP-ir) axons and cholera
toxin B-horseradish peroxidase labeled preganglionic
sympathetic neurons (PSNs) in the intermediolateral nucleus
of the rat thoracic spinal cord. PACAP-ir axon varicosities,
which contained small clear and large core synaptic vesicles,
were found to form asymmetric type of synaptic contacts with
dendrites and infrequently with somata of labeled
preganglionic neurons. The present study provides
ultrastructural evidence of PACAP-ir synaptic contacts with
PSNs, raising the possibility that the peptide may function as
a transmitter/modulator to these neurons.. 0; 0.
59. Chizh, B. A.; Headley, P. M. Thyrotropin-releasing hormone
facilitates spinal nociceptive responses by potentiating NMDA
receptor-mediated transmission. Eur-J-Pharmacol. 1996 Apr
11; 300(3): 183-9; ISSN: 0014-2999.
NETHERLANDS. The interaction of thyrotropin-releasing
hormone (TRH) with NMDA receptor-mediated responses has
been investigated in alpha-chloralose-anaesthetized
spinalized rats with respect to its relevance to spinal
nociceptive transmission. The effects of TRH and of the
uncompetitive NMDA antagonist ketamine were tested on
responses of dorsal horn wide dynamic range neurones to
noxious pinch, heat and electrical stimuli in parallel with
those to iontophoretically applied N-methyl-D-aspartate
(NMDA) and AMPA (alpha-amino-3-hydroxy-5-methylisoxazole-
4-propionic acid). Tests with NMDA blocking doses of ketamine
(4 mg/kg i.v.) demonstrated a variable NMDA receptor-
mediated component of all synaptic responses. TRH (0.5-1
mg/kg i.v.) enhanced the responses to NMDA (but not AMPA) in
parallel with an increase of responses to all noxious stimuli
and the 'wind-up' component of the responses to repeated
electrical stimulation. This potentiation was completely
reversed by a subsequent administration of ketamine (4 mg/kg
i.v.). The results indicate that TRH facilitates nociceptive
transmission in the spinal dorsal horn via a selective positive
modulation of NMDA receptor-mediated transmission.. 0; 0;
24305-27-9; 6384-92-5; 6740-88-1; 77521-29-0.
60. Chizh, B. A.; Headley, P. M. Thyrotropin-releasing hormone
facilitates spinal nociceptive responses by potentiating NMDA
receptor-mediated transmission. Eur-J-Pharmacol. 1996 Apr
11; 300(3): 183-9; ISSN: 0014-2999.
NETHERLANDS. The interaction of thyrotropin-releasing
hormone (TRH) with NMDA receptor-mediated responses has
been investigated in alpha-chloralose-anaesthetized
spinalized rats with respect to its relevance to spinal
nociceptive transmission. The effects of TRH and of the
uncompetitive NMDA antagonist ketamine were tested on
responses of dorsal horn wide dynamic range neurones to
noxious pinch, heat and electrical stimuli in parallel with
those to iontophoretically applied N-methyl-D-aspartate
(NMDA) and AMPA (alpha-amino-3-hydroxy-5-methylisoxazole-
4-propionic acid). Tests with NMDA blocking doses of ketamine
(4 mg/kg i.v.) demonstrated a variable NMDA receptor-
mediated component of all synaptic responses. TRH (0.5-1
mg/kg i.v.) enhanced the responses to NMDA (but not AMPA) in