The Experts below are selected from a list of 228 Experts worldwide ranked by ideXlab platform
Glenn J Giesler - One of the best experts on this subject based on the ideXlab platform.
-
spinohypothalamic tract neurons in the Cervical Enlargement of rats locations of antidromically identified ascending axons and their collateral branches in the contralateral brain
Journal of Neurophysiology, 1997Co-Authors: Ewa Kostarczyk, Xijing Zhang, Glenn J GieslerAbstract:Kostarczyk, Ewa, Xijing Zhang, and Glenn J. Giesler, Jr. Spinohypothalamic tract neurons in the Cervical Enlargement of rats: locations of antidromically identified ascending axons and their collateral branches in the contralateral brain. J. Neurophysiol. 77: 435–451, 1997. Antidromic activation was used to determine the locations of ascending spinohypothalamic tract (SHT) axons and their collateral projections within C1, medulla, pons, midbrain, and caudal thalamus. Sixty-four neurons in the Cervical Enlargement were antidromically activated initially by stimulation within the contralateral hypothalamus. All but one of the examined SHT neurons responded either preferentially or specifically to noxious mechanical stimuli. A total of 239 low-threshold points was classified as originating from 64 ascending (or parent) SHT axons. Within C1, 38 ascending SHT axons were antidromically activated. These were located primarily in the dorsal half of the lateral funiculus. Within the medulla, the 29 examined ascending SHT axons were located ventrolaterally, within or adjacent to the lateral reticular nucleus or nucleus ambiguus. Within the pons, the 25 examined ascending SHT axons were located primarily surrounding the facial nucleus and the superior olivary complex. Within the caudal midbrain, the 23 examined SHT ascending axons coursed dorsally in a position adjacent to the lateral lemniscus. Within the anterior midbrain, SHT axons traveled rostrally near the brachium of the inferior colliculus. Within the posterior thalamus, all 17 examined SHT axons coursed rostrally through the posterior nucleus of thalamus. A total of 114 low-threshold points was classified as collateral branch points. Sixteen collateral branches were seen in C1; these were located primarily in the deep dorsal horn. Forty-five collateral branches were located in the medulla. These were primarily in or near the medullary reticular nucleus, nucleus ambiguus, lateral reticular nucleus, parvocellular reticular nucleus, gigantocellular reticular nucleus, cuneate nucleus, and the nucleus of the solitary tract. Twenty-six collateral branches from SHT axons were located in the pons. These were in the pontine reticular nucleus caudalis, gigantocellular reticular nucleus, parvocellular reticular nucleus, and superior olivary complex. Twenty-three collateral branches were located in the midbrain. These were in or near the mesencephalic reticular nucleus, brachium of the inferior colliculus, cuneiform nucleus, superior colliculus, central gray, and substantia nigra. In the caudal thalamus, two branches were in the posterior thalamic nucleus and two were in the medial geniculate. These results indicate that SHT axons ascend toward the hypothalamus in a clearly circumscribed projection in the lateral brain stem and posterior thalamus. In addition, large numbers of collaterals from SHT axons appear to project to a variety of targets in C1, the medulla, pons, midbrain, and caudal thalamus. Through its widespread collateral projections, the SHT appears to be capable of providing nociceptive input to many areas that are involved in the production of multifaceted responses to noxious stimuli.
-
Spinohypothalamic Tract Neurons in the Cervical Enlargement of Rats: Locations of Antidromically Identified Ascending Axons and Their Collateral Branches in the Contralateral Brain
Journal of Neurophysiology, 1997Co-Authors: Ewa Kostarczyk, Xijing Zhang, Glenn J GieslerAbstract:Antidromic activation was used to determine the locations of ascending spinohypothalamic tract (SHT) axons and their collateral projections within C1, medulla, pons, midbrain, and caudal thalamus. Sixty-four neurons in the Cervical Enlargement were antidromically activated initially by stimulation within the contralateral hypothalamus. All but one of the examined SHT neurons responded either preferentially or specifically to noxious mechanical stimuli. A total of 239 low-threshold points was classified as originating from 64 ascending (or parent) SHT axons. Within C1, 38 ascending SHT axons were antidromically activated. These were located primarily in the dorsal half of the lateral funiculus. Within the medulla, the 29 examined ascending SHT axons were located ventrolaterally, within or adjacent to the lateral reticular nucleus or nucleus ambiguus. Within the pons, the 25 examined ascending SHT axons were located primarily surrounding the facial nucleus and the superior olivary complex. Within the caudal midbrain, the 23 examined SHT ascending axons coursed dorsally in a position adjacent to the lateral lemniscus. Within the anterior midbrain, SHT axons traveled rostrally near the brachium of the inferior colliculus. Within the posterior thalamus, all 17 examined SHT axons coursed rostrally through the posterior nucleus of thalamus. A total of 114 low-threshold points was classified as collateral branch points. Sixteen collateral branches were seen in C1; these were located primarily int he deep dorsal horn. Forty-five collateral branches were located in the medulla. These were primarily in or near the medullary reticular nucleus, nucleus ambiguus, lateral reticular nucleus, parvocellular reticular nucleus, gigantocellular reticular nucleus, cuneate nucleus, and the nucleus of the solitary tract. Twentysix collateral branches from SHT axons were located in the pons. These were in the pontine reticular nucleus caudalis, gigantocellular reticular nucleus, parvocellular reticular nucleus, and superior olivary complex. Twenty-three collateral branches were located in the midbrain. These were in or near the mesencephalic reticular nucleus, brachium of the inferior colliculus, cuneiform nucleus, superior colliculus, central gray, and substantia nigra. Int he caudal thalamus, two branches were in the posterior thalamic nucleus and two were in the medial geniculate. These results indicate that SHT axons ascend toward the hypothalamus in a clearly circumscribed projection in the lateral brain stem and posterior thalamus. In addition, large numbers of collaterals from SHT axons appears to project to a variety of targets in C1, the medulla, pons, midbrain, and caudal thalamus. Through its widespread collateral projections, the SHT appears to be capable of providing nociceptive input to many areas that are involved in the production of multifaceted responses to noxious stimuli.
-
spinohypothalamic tract neurons in the Cervical Enlargement of rats descending axons in the ipsilateral brain
The Journal of Neuroscience, 1995Co-Authors: Xijing Zhang, Ewa Kostarczyk, Glenn J GieslerAbstract:Spinohypothalamic tract (SHT) cells are spinal cord neurons with axons that project directly to or through the contralateral hypothalamus. Frequently, SHT axons decussate in the posterior optic chiasm, turn posteriorly and descend to unknown locations in the ipsilateral brain. We attempted to determine the course and the termination of these descending axons. Sixty neurons in the Cervical Enlargement of rats were antidromically activated initially from the contralateral hypothalamus and then from multiple anterior-posterior levels in the ipsilateral brain. Fifty-three (88%) were backfired with low currents at increased latencies from the ipsilateral brain. The axons of 35 neurons were surrounded with electrode penetrations from which high currents could not activate the neuron antidromically, suggesting the examined axons terminated in the surrounded areas. Seven SHT axons that were surrounded (20%) appeared to terminate in the contralateral hypothalamus, 5 (14%) in the ipsilateral hypothalamus, and 9 (26%) in the ipsilateral thalamus. Fourteen SHT axons (40%) ended in the ipsilateral midbrain mainly in the superior colliculus, cuneiform nucleus or nucleus brachium inferior colliculus. An additional 11 axons were followed even further posteriorly into the ventral pons or rostral medulla. Each of the 26 neurons that could be physiologically classified responded either preferentially or specifically to noxious mechanical stimuli. These results indicate that SHT axons course through a surprisingly long and complex path. After decussating in the hypothalamus, the axons of many SHT neurons descend into the ipsilateral posterior thalamus, midbrain, pons, or even rostral medulla. These axons may provide nociceptive information to a variety of nuclei throughout the diencephalon and brainstem bilaterally.
-
spinothalamic and spinohypothalamic tract neurons in the Cervical Enlargement of rats i locations of antidromically identified axons in the thalamus and hypothalamus
Journal of Neurophysiology, 1994Co-Authors: Robert J Dado, James T Katter, Glenn J GieslerAbstract:1. Seventy-seven neurons in the Cervical Enlargement of rats anesthetized with urethan were initially antidromically activated using currents < or = 30 microA from the contralateral posterior thala...
-
spinothalamic and spinohypothalamic tract neurons in the Cervical Enlargement of rats iii locations of antidromically identified axons in the Cervical cord white matter
Journal of Neurophysiology, 1994Co-Authors: Robert J Dado, James T Katter, Glenn J GieslerAbstract:1. Fifty-five neurons in the Cervical Enlargement (C6-C8) of urethan-anesthetized rats were antidromically activated from the contralateral posterior diencephalon. In all cases, antidromic thresholds were < or = 30 microA. The locations of the axons of these neurons within the white matter of segments C2-C6 were determined by tracking systematically using a second antidromic stimulating electrode. 2. The recording locations of 51 neurons were marked and recovered. Twenty neurons were recorded in the superficial dorsal horn (SDH) and 31 were in the deep dorsal horn (DDH). Eighty-three lowest threshold points for antidromic activation within the white matter of segments C2-C6 were determined for these 51 neurons. The mean antidromic threshold at these points was 9.5 +/- 0.5 (SE) microA. For 26 neurons, the lowest threshold point for antidromic activation was determined at one segmental level. We also attempted to determine whether individual axons maintained their position as they ascended through the Cervical cord white matter. In 25 cases, lowest threshold points were determined at two or more segmental levels. 3. In segments C5-C6, 88% (7/8) of the lowest threshold points of the examined axons were located in the contralateral ventral funiculus, indicating that the majority of examined axons crossed the midline within one or two segments. 4. In segments C3-C4, 32% (14/44) of all examined axons were found in the dorsal lateral funiculus (DLF) and 66% (29/44) were within the ventral quadrant [ventral lateral funiculus (VLF) and ventral funiculus (VF)]. Sixty-nine percent (11/16) of the axons of neurons recorded in the SDH were located in the contralateral DLF and 31% (5/16) were located in the ventral quadrant (VQ). In contrast, only 11% (3/28) of the axons of neurons recorded in the DDH were located in the contralateral DLF and 86% (24/28) were located in the VQ. Therefore, in segments C3-C4, the locations of axons differed significantly. Those from neurons recorded in the SDH were located primarily in the DLF and those from neurons recorded in the DDH were located principally in the VQ. 5. In segment C2, 74% (23/31) of all examined axons were found in the DLF, 23% (7/31) were in the VQ, and 3% (1/31) were in the dorsal horn. Thus, the percentage of all examined axons in the DLF in C2 was approximately 2.5 times greater than it was in C3-C4.(ABSTRACT TRUNCATED AT 400 WORDS)
Vania A Apkarian - One of the best experts on this subject based on the ideXlab platform.
-
direct spinal projections to limbic and striatal areas anterograde transport studies from the upper Cervical spinal cord and the Cervical Enlargement in squirrel monkey and rat
The Journal of Comparative Neurology, 1996Co-Authors: Heike M Newman, Richard T Stevens, Vania A ApkarianAbstract:With the anterograde tracers Phaseolus vulgaris-leucoagglutinin (PHA-L) and biotinylated dextranamine (BD), direct spinal connections from the upper Cervical spinal cord (UC; C1 and C2) and the Cervical Enlargement (CE; C5-T1) were demonstrated in various striatal and limbic nuclei in both squirrel monkey and rat. Within each species and from each spinal level, the total number of terminals seen in the limbic and striatal areas was approximately 50–80% of the number seen within the thalamus. Labeled terminal structures were seen in the hypothalamic nuclei, ventral striatum, globus pallidus, amygdala, preoptic area, and septal nuclei. In both species, the number of labeled terminals in limbic and striatal regions was larger from UC than from CE, although the distributions to each nucleus varied with the specific lamina injected. In both species and from both UC and CE, approximately one-half of the projections to striatal and limbic areas terminated in the hypothalamus. The only region that demonstrated a topographical organization was the globus pallidus, where terminals from the CE were located dorsomedially to those from the UC. In the rat, UC and CE injections into the lateral dorsal horn and pericentral laminae resulted in the largest number of limbic and striatal terminations. The proportion of ipsilateral terminations was greatest when the medial laminae in the UC or the lateral dorsal horn in the CE received injections. Analysis of the morphology of these spinohypothalamic and spinotelencephalic terminals showed that, in the squirrel monkey, terminals from CE injections were larger than terminals from UC injections; no such size difference was evident in the rat. However, limbic and striatal terminals in the rat were generally larger than those in the squirrel monkey following injections into the UC or CE. The exact function of these direct spinal projections to various striatal and limbic areas in primates and in rodents remains to be determined. These findings, however, support recent imaging studies that suggest that the limbic system plays an important role in the mediation of chronic pain, perhaps directly through these spinolimbic and spinostriatal pathways. © 1996 Wiley-Liss, Inc.
John H Martin - One of the best experts on this subject based on the ideXlab platform.
-
differential joint specific corticospinal tract projections within the Cervical Enlargement
PLOS ONE, 2013Co-Authors: Curtis Oware Asante, John H MartinAbstract:The motor cortex represents muscle and joint control and projects to spinal cord interneurons and–in many primates, including humans–motoneurons, via the corticospinal tract (CST). To examine these spinal CST anatomical mechanisms, we determined if motor cortex sites controlling individual forelimb joints project differentially to distinct Cervical spinal cord territories, defined regionally and by the locations of putative last-order interneurons that were transneuronally labeled by intramuscular injection of pseudorabies virus. Motor cortex joint-specific sites were identified using intracortical-microstimulation. CST segmental termination fields from joint-specific sites, determined using anterograde tracers, comprised a high density core of terminations that was consistent between animals and a surrounding lower density projection that was more variable. Core terminations from shoulder, elbow, and wrist control sites overlapped in the medial dorsal horn and intermediate zone at C5/C6 but were separated at C7/C8. Shoulder sites preferentially terminated dorsally, in the dorsal horn; wrist/digit sites, more ventrally in the intermediate zone; and elbow sites, medially in the dorsal horn and intermediate zone. Pseudorabies virus injected in shoulder, elbow, or wrist muscles labeled overlapping populations of predominantly muscle-specific putative premotor interneurons, at a survival time for disynaptic transfer from muscle. At C5/C6, CST core projections from all joint zones were located medial to regions of densely labeled last-order interneurons, irrespective of injected muscle. At C7/C8 wrist CST core projections overlapped the densest interneuron territory, which was located in the lateral intermediate zone. In contrast, elbow CST core projections were located medial to the densest interneuron territories, and shoulder CST core projections were located dorsally and only partially overlapped the densest interneuron territory. Our findings show a surprising fractionation of CST terminations in the caudal Cervical Enlargement that may be organized to engage different spinal premotor circuits for distal and proximal joint control.
-
Differential spinal projections of subregions in the forelimb area of the motor cortex in the cat
Neuroscience Letters, 1993Co-Authors: John H MartinAbstract:Abstract Anterograde transport of wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP) was used to examine the topography of projections from the forelimb area of motor cortex to the Cervical spinal cord in the cat. Tracer was injected in sites in the rostrolateral (RL-MCx) and caudolateral (CL-MCx) subregions concerned with the distal forelimb. Whereas both subregions projected throughout the Cervical cord, with the greatest density of label present in the Cervical Enlargement, the dorso-ventral distributions were different for the two injection sites. Injections in RL-MCx produced labeling in the lateral portions of laminae VI, VII, and VIII in the upper Cervical segments. This corresponds to the locations of propriospinal neurons that project to forelimb motor nuclei used in reaching [Exp. Brain Res., 42 (1981) 299–318]. In the Cervical Enlargement, labeling was present in laminae V, VI, VII, and part of VIII. At all levels examined, the density of labeling was greatest in the intermediate zone. After CL-MCx injection, labeling was concentrated in the dorsal horn both in the upper Cervical segments and in the Cervical Enlargement. These findings suggest that the two motor cortical subregions project to different propriospinal and interneuronal systems in the Cervical cord and support the idea that the two subregions play different roles in controlling forelimb movements.
Robert J Dado - One of the best experts on this subject based on the ideXlab platform.
-
spinothalamic and spinohypothalamic tract neurons in the Cervical Enlargement of rats i locations of antidromically identified axons in the thalamus and hypothalamus
Journal of Neurophysiology, 1994Co-Authors: Robert J Dado, James T Katter, Glenn J GieslerAbstract:1. Seventy-seven neurons in the Cervical Enlargement of rats anesthetized with urethan were initially antidromically activated using currents < or = 30 microA from the contralateral posterior thala...
-
spinothalamic and spinohypothalamic tract neurons in the Cervical Enlargement of rats iii locations of antidromically identified axons in the Cervical cord white matter
Journal of Neurophysiology, 1994Co-Authors: Robert J Dado, James T Katter, Glenn J GieslerAbstract:1. Fifty-five neurons in the Cervical Enlargement (C6-C8) of urethan-anesthetized rats were antidromically activated from the contralateral posterior diencephalon. In all cases, antidromic thresholds were < or = 30 microA. The locations of the axons of these neurons within the white matter of segments C2-C6 were determined by tracking systematically using a second antidromic stimulating electrode. 2. The recording locations of 51 neurons were marked and recovered. Twenty neurons were recorded in the superficial dorsal horn (SDH) and 31 were in the deep dorsal horn (DDH). Eighty-three lowest threshold points for antidromic activation within the white matter of segments C2-C6 were determined for these 51 neurons. The mean antidromic threshold at these points was 9.5 +/- 0.5 (SE) microA. For 26 neurons, the lowest threshold point for antidromic activation was determined at one segmental level. We also attempted to determine whether individual axons maintained their position as they ascended through the Cervical cord white matter. In 25 cases, lowest threshold points were determined at two or more segmental levels. 3. In segments C5-C6, 88% (7/8) of the lowest threshold points of the examined axons were located in the contralateral ventral funiculus, indicating that the majority of examined axons crossed the midline within one or two segments. 4. In segments C3-C4, 32% (14/44) of all examined axons were found in the dorsal lateral funiculus (DLF) and 66% (29/44) were within the ventral quadrant [ventral lateral funiculus (VLF) and ventral funiculus (VF)]. Sixty-nine percent (11/16) of the axons of neurons recorded in the SDH were located in the contralateral DLF and 31% (5/16) were located in the ventral quadrant (VQ). In contrast, only 11% (3/28) of the axons of neurons recorded in the DDH were located in the contralateral DLF and 86% (24/28) were located in the VQ. Therefore, in segments C3-C4, the locations of axons differed significantly. Those from neurons recorded in the SDH were located primarily in the DLF and those from neurons recorded in the DDH were located principally in the VQ. 5. In segment C2, 74% (23/31) of all examined axons were found in the DLF, 23% (7/31) were in the VQ, and 3% (1/31) were in the dorsal horn. Thus, the percentage of all examined axons in the DLF in C2 was approximately 2.5 times greater than it was in C3-C4.(ABSTRACT TRUNCATED AT 400 WORDS)
-
Evidence that Fluoro-Gold can be transported avidly through fibers of passage.
Brain Research, 1990Co-Authors: Robert J Dado, Rami Burstein, Kenneth D. Cliffer, Glenn J GieslerAbstract:Small iontophoretic injections of the retrograde tracer Fluoro-Gold were restricted to the dorsal columns in the Cervical Enlargement of 6 rats. Large numbers of neurons were labeled in the lumbosacral dorsal horn in each rat. In the most effective case, more than 1800 neurons were labeled in alternate sections through nine examined segments. Many neurons were also labeled in lumbosacral dorsal root ganglia of all cases. This study, in contrast to previous reports, indicates that Fluoro-Gold can be transported avidly by axons passing through, but not terminating in, injection sites.
G Titov - One of the best experts on this subject based on the ideXlab platform.
-
New concept of pathogenesis of impaired circulation in traumatic Cervical spinal cord injury and its impact on disease severity: case series of four patients
European Spine Journal, 2016Co-Authors: M Salkov, V Tsymbaliuk, L Dzyak, A Rodinsky, Y Cherednichenko, G TitovAbstract:Purpose The purpose of this study is to justify a new concept of the pathogenesis of secondary changes in the Cervical spinal cord, and its correlation with the depth of development of neurological disorders in spinal injury. Methods Standard magnetic resonance imaging examination and angiography of the Cervical and vertebral arteries of four patients were performed to diagnose the prevalence rate of ischemia and edema, and examine the spinal cord vasculature. Correlation of the data obtained with the neurological status was performed. Results Collateral circulation is most apparent in the upper-Cervical region, above the C4 vertebra. Following occlusion of the vertebral artery, the circulation above the C4 vertebra is performed by collaterals of the ascending Cervical artery. With extensive damage to the spinal cord, the intensity of edema and ischemia can be regarded as the effect of damage to radicular medullary arteries, which are injured in the intervertebral foramen. Secondary changes of the spinal cord are most apparent by impaired circulation in the artery of Cervical Enlargement. Conclusions Collateral circulation is a significant factor that limits the damage to the Cervical spinal cord. Impaired circulation in the artery of Cervical Enlargement is significant in extension of perifocal ischemia. The appearance of early arteriovenous shunting in the region of a primary spinal cord injury (contusion focus) by angiography is pathognomonic. The data obtained open a perspective for the endovascular treatment of spinal cord injury.
-
New concept of pathogenesis of impaired circulation in traumatic Cervical spinal cord injury and its impact on disease severity: case series of four patients.
European spine journal : official publication of the European Spine Society the European Spinal Deformity Society and the European Section of the Cerv, 2015Co-Authors: M Salkov, V Tsymbaliuk, L Dzyak, A Rodinsky, Y Cherednichenko, G TitovAbstract:The purpose of this study is to justify a new concept of the pathogenesis of secondary changes in the Cervical spinal cord, and its correlation with the depth of development of neurological disorders in spinal injury. Standard magnetic resonance imaging examination and angiography of the Cervical and vertebral arteries of four patients were performed to diagnose the prevalence rate of ischemia and edema, and examine the spinal cord vasculature. Correlation of the data obtained with the neurological status was performed. Collateral circulation is most apparent in the upper-Cervical region, above the C4 vertebra. Following occlusion of the vertebral artery, the circulation above the C4 vertebra is performed by collaterals of the ascending Cervical artery. With extensive damage to the spinal cord, the intensity of edema and ischemia can be regarded as the effect of damage to radicular medullary arteries, which are injured in the intervertebral foramen. Secondary changes of the spinal cord are most apparent by impaired circulation in the artery of Cervical Enlargement. Collateral circulation is a significant factor that limits the damage to the Cervical spinal cord. Impaired circulation in the artery of Cervical Enlargement is significant in extension of perifocal ischemia. The appearance of early arteriovenous shunting in the region of a primary spinal cord injury (contusion focus) by angiography is pathognomonic. The data obtained open a perspective for the endovascular treatment of spinal cord injury.