Convergence of visceral and cutaneous input onto spinothalamic tract cells in the thoracic spinal cord of the cat

The spinothalamic tract (STT) is the primary pathway carrying nociceptive information from the spinal cord to the brain in humans. The aim of this study was to understand better the organization of STT axons within the spinal cord white matter of monkeys. The location of STT axons was determined using method of antidromic activation. Twenty-six lumbar STT cells were isolated. Nineteen were classified as wide dynamic range neurons and seven as high-threshold cells. Fifteen STT neurons were recorded in the deep dorsal horn (DDH) and 11 in superficial dorsal horn (SDH). The axons of 26 STT neurons were located at 73 low-threshold points (<30 μA) within the lateral funiculus from T9 to C6. STT neurons in the SDH were activated from 33 low-threshold points, neurons in the DDH from 40 low-threshold points. In lower thoracic segments, SDH neurons were antidromically activated from low-threshold points at the dorsal-ventral level of the denticulate ligament. Neurons in the DDH were activated from points located slightly ventral, within the ventral lateral funiculus. At higher segmental levels, axons from SDH neurons continued in a position dorsal to those of neurons in the DDH. However, axons from neurons in both areas of the gray matter were activated from points located in more ventral positions within the lateral funiculus. Unlike the suggestions in several previous reports, the present findings indicate that STT axons originating in the lumbar cord shift into increasingly ventral positions as they ascend the length of the spinal cord.

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Evidence that C1 and C2 propriospinal neurons mediate the inhibitory effects of viscerosomatic spinal afferent input on primate spinothalamic tract neurons

Journal of Neurophysiology ◽

10.1152/jn.1992.67.4.852 ◽

1992 ◽

Vol 67 (4) ◽

pp. 852-860 ◽

Cited By ~ 37

Author(s):

S. F. Hobbs ◽

U. T. Oh ◽

M. J. Chandler ◽

Q. G. Fu ◽

D. C. Bolser ◽

...

Keyword(s):

Spinal Cord ◽

Cell Activity ◽

Inhibitory Effect ◽

Afferent Input ◽

Spinothalamic Tract ◽

Spinal Transection ◽

Thoracic Spinal Cord ◽

Thoracic Spinal ◽

Before And After ◽

Propriospinal Neurons

1. Lumbosacral spinothalamic tract (STT) neurons can be inhibited by noxious pinch of the contralateral hindlimb or either forelimb and by electrical stimulation of cardiopulmonary sympathetic, splanchnic, and hypogastric afferents. A previous study found that spinal transections between C2 and C4 sometimes abolished the inhibitory effect of spinal afferent input and sometimes left it intact. This suggested that propriospinal neurons in the C1 and C2 segments might mediate this effect. To test whether neurons in the C1 and C2 segments were involved in producing this inhibitory effect, the magnitude of the reduction in neural activity was measured in the same STT neuron before and after spinal transection at C1 or between C3 and C7. 2. All neurons were antidromically activated from the contralateral thalamus and thoracic spinal cord. For us to accept a neuron for analysis, the characteristics of the somatic input and the latency and shape of the antidromatic spike produced by spinal cord stimulation had to be the same before and after the spinal transection. Also, spinal transection often causes a marked increase in spontaneous cell activity, which may affect the magnitude of an inhibitory response. To avoid this confounding problem, a cell was accepted for analysis only if it showed marked inhibition of high cell activity evoked by somatic pinch before spinal transection. For analysis 13 STT neurons met these criteria: 6 neurons were in monkeys with C1 transections, and 7 neurons were in animals with transections between C3 and C7.(ABSTRACT TRUNCATED AT 250 WORDS)

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Responses of spinothalamic tract cells in the thoracic spinal cord of the monkey to cutaneous and visceral inputs

Pain ◽

10.1016/0304-3959(81)90002-6 ◽

1981 ◽

Vol 11 (2) ◽

pp. 149-162 ◽

Cited By ~ 60

Author(s):

R. D. Foreman ◽

M. B. Hancock ◽

W. D. Willis

Keyword(s):

Spinal Cord ◽

Spinothalamic Tract ◽

Thoracic Spinal Cord ◽

Thoracic Spinal

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Spontaneous Herniation of the Thoracic Spinal Cord: A Case Report

Journal of the Korean Radiological Society ◽

10.3348/jkrs.2001.45.4.353 ◽

2001 ◽

Vol 45 (4) ◽

pp. 353 ◽

Cited By ~ 1

Author(s):

Sung Chan Jin ◽

Seoung Ro Lee ◽

Dong Woo Park ◽

Kyung Bin Joo

Keyword(s):

Spinal Cord ◽

Case Report ◽

Thoracic Spinal Cord ◽

Thoracic Spinal ◽

Spontaneous Herniation

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Lipomeningocele associated with diplomyelia in a dog

Tierärztliche Praxis Ausgabe K Kleintiere / Heimtiere ◽

10.15654/tpk-170751 ◽

2018 ◽

Vol 46 (05) ◽

pp. 323-329 ◽

Cited By ~ 2

Author(s):

Nele Ondreka ◽

Sara Malberg ◽

Emma Laws ◽

Martin Schmidt ◽

Sabine Schulze

Keyword(s):

Spinal Cord ◽

Neurological Status ◽

Split Cord Malformation ◽

Lumbar Spinal Cord ◽

Histopathological Diagnosis ◽

Type I ◽

Thoracic Spinal Cord ◽

Thoracic Spinal ◽

Subcutaneous Mass ◽

Lumbar Spinal

SummaryA 2-year-old male neutered mixed breed dog with a body weight of 30 kg was presented for evaluation of a soft subcutaneous mass on the dorsal midline at the level of the caudal thoracic spine. A further clinical sign was intermittent pain on palpation of the area of the subcutaneous mass. The owner also described a prolonged phase of urination with repeated interruption and re-initiation of voiding. The findings of the neurological examination were consistent with a lesion localization between the 3rd thoracic and 3rd lumbar spinal cord segments. Magnetic resonance imaging revealed a spina bifida with a lipomeningocele and diplomyelia (split cord malformation type I) at the level of thoracic vertebra 11 and 12 and secondary syringomyelia above the aforementioned defects in the caudal thoracic spinal cord. Surgical resection of the lipomeningocele via a hemilaminectomy was performed. After initial deterioration of the neurological status postsurgery with paraplegia and absent deep pain sensation the dog improved within 2 weeks to non-ambulatory paraparesis with voluntary urination. Six weeks postoperatively the dog was ambulatory, according to the owner. Two years after surgery the owner recorded that the dog showed a normal gait, a normal urination and no pain. Histopathological diagnosis of the biopsied material revealed a lipomeningocele which confirmed the radiological diagnosis.

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Effect of thoracic spinal cord injury on forelimb somatosensory evoked potential

Brain Research Bulletin ◽

10.1016/j.brainresbull.2021.05.005 ◽

2021 ◽

Author(s):

Angelo H. All ◽

Shiyu Luo ◽

Xiaogang Liu ◽

Hasan Al-Nashash

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Evoked Potential ◽

Somatosensory Evoked Potential ◽

Thoracic Spinal Cord ◽

Thoracic Spinal ◽

Cord Injury

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The Histopathology of Severe Graded Compression in Lower Thoracic Spinal Cord Segment of Rat, Evaluated at Late Post-injury Phase

Cellular and Molecular Neurobiology ◽

10.1007/s10571-021-01139-7 ◽

2021 ◽

Author(s):

Fedorova Jana ◽

Kellerova Erika ◽

Bimbova Katarina ◽

Pavel Jaroslav

Keyword(s):

Spinal Cord ◽

Spontaneous Recovery ◽

Traumatic Injury ◽

Blue Dye ◽

Post Injury ◽

Thoracic Spinal Cord ◽

Thoracic Spinal ◽

Severe Traumatic Injury ◽

Spinal Cord Segment ◽

Cord Injury

AbstractSpontaneous recovery of lost motor functions is relative fast in rodent models after inducing a very mild/moderate spinal cord injury (SCI), and this may complicate a reliable evaluation of the effectiveness of potential therapy. Therefore, a severe graded (30 g, 40 g and 50 g) weight-compression SCI at the Th9 spinal segment, involving an acute mechanical impact followed by 15 min of persistent compression, was studied in adult female Wistar rats. Functional parameters, such as spontaneous recovery of motor hind limb and bladder emptying function, and the presence of hematuria were evaluated within 28 days of the post-traumatic period. The disruption of the blood-spinal cord barrier, measured by extravasated Evans Blue dye, was examined 24 h after the SCI, when maximum permeability occurs. At the end of the survival period, the degradation of gray and white matter associated with the formation of cystic cavities, and quantitative changes of glial structural proteins, such as GFAP, and integral components of axonal architecture, such as neurofilaments and myelin basic protein, were evaluated in the lesioned area of the spinal cord. Based on these functional and histological parameters, and taking the animal’s welfare into account, the 40 g weight can be considered as an upper limit for severe traumatic injury in this compression model.

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