The terminations of single, physiologically identified, somatosensory, corticospinal tract axons in the lumbar spinal cord of the cat

1991 ◽  
Vol 66 (5) ◽  
pp. 1738-1749 ◽  
Author(s):  
E. J. Casale ◽  
A. R. Light
Keyword(s):  
Spinal Cord ◽  
Gray Matter ◽  
Corticospinal Tract ◽  
Lumbar Spinal Cord ◽  
Spinal Cord Segment ◽  
Apparent Correlation ◽  
Dorsolateral Funiculus ◽  
The Mean ◽  
Lumbar Spinal ◽  
Area 3B

1. Two hundred and twelve corticospinal axons were identified by stimulation in the hindlimb representation in area 3b of the somatosensory cortex and were recorded in the left dorsolateral funiculus of the spinal cord of the cat. The mean conduction velocity was 38 m/s, range 9-113 m/s. 2. Electrical stimulation of the receptive field evoked discharge in corticospinal axons with a mean latency of 36 ms (range 9-100 ms). 3. One hundred nine of the 212 recorded axons were successfully intra-axonally labeled by iontophoretic injection of horseradish peroxidase, with the mean length of labeled axon being 4.8 mm. Seventy-three of the labeled axons issued no collaterals, and 36 issued at least one labeled collateral into the spinal gray matter along the labeled portion of the parent axon. 4. Most labeled axons issued only one labeled collateral per spinal cord segment. Fourteen collaterals from 10 units were labeled well enough to permit reconstruction of their terminal arborizations. 5. Most terminal collaterals were oriented rostrocaudally and terminated in laminae V, VI, and VII. Most collaterals terminated within large mediolateral extents of the gray matter with no apparent topographic organization. 6. No collaterals terminated in laminae I or II or within the motoneuron pools, and no apparent correlation was found between their anatomic and physiological characteristics.

scholarly journals Tail Nerve Electrical Stimulation and Electro-Acupuncture Can Protect Spinal Motor Neurons and Alleviate Muscle Atrophy after Spinal Cord Transection in Rats

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Yu-Ting Zhang ◽  
Hui Jin ◽  
Jun-Hua Wang ◽  
Lan-Yu Wen ◽  
Yang Yang ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Muscle Atrophy ◽  
Motor Neurons ◽  
Lumbar Spinal Cord ◽  
Hindlimb Muscle ◽  
Neurotrophin 3 ◽  
Spinal Cord Segment ◽  
Cord Injury ◽  
Lumbar Spinal

Spinal cord injury (SCI) often results in death of spinal neurons and atrophy of muscles which they govern. Thus, following SCI, reorganizing the lumbar spinal sensorimotor pathways is crucial to alleviate muscle atrophy. Tail nerve electrical stimulation (TANES) has been shown to activate the central pattern generator (CPG) and improve the locomotion recovery of spinal contused rats. Electroacupuncture (EA) is a traditional Chinese medical practice which has been proven to have a neural protective effect. Here, we examined the effects of TANES and EA on lumbar motor neurons and hindlimb muscle in spinal transected rats, respectively. From the third day postsurgery, rats in the TANES group were treated 5 times a week and those in the EA group were treated once every other day. Four weeks later, both TANES and EA showed a significant impact in promoting survival of lumbar motor neurons and expression of choline acetyltransferase (ChAT) and ameliorating atrophy of hindlimb muscle after SCI. Meanwhile, the expression of neurotrophin-3 (NT-3) in the same spinal cord segment was significantly increased. These findings suggest that TANES and EA can augment the expression of NT-3 in the lumbar spinal cord that appears to protect the motor neurons as well as alleviate muscle atrophy.

Effects of Glycine Administration on Canine Experimental Spinal Spasticity and the Levels of Glycine, Glutamate, and Aspartate in the Lumbar Spinal Cord

Neurosurgery ◽  
1979 ◽  
Vol 4 (2) ◽  
pp. 152-156 ◽  
Author(s):  
J. E. Smith ◽  
P. V. Hall ◽  
M. R. Galvin ◽  
A. R. Jones ◽  
R. L. Campbell
Keyword(s):  
Spinal Cord ◽  
White Matter ◽  
Gray Matter ◽  
Clinical Signs ◽  
Spinal Cord Transection ◽  
Lumbar Spinal Cord ◽  
Central Gray Matter ◽  
Central Gray ◽  
Lumbar Spinal

Abstract Twelve female mongrel dogs were made paraplegic by midthoracic spinal cord transection. Beginning at 9 weeks posttransection, either glycine (50 mg/kg) or saline was injected intramuscularly each day and the signs of spinal spasticity were assessed clinically. After treating the dogs for 3 weeks, we removed the lumbar enlargement of each dog and microdissected it into gray and white areas which we assayed for glycine, glutamate, and aspartate content. Some of the clinical signs of spasticity improved in the animals injected with glycine compared to the saline-injected controls. The content of glycine was significantly elevated in the central gray matter and ventral medial white matter of the glycinetreated dogs. The levels of glutamate were also significantly elevated in the central, lateral ventral, and medial ventral gray matter and in the dorsal lateral and ventral medial white matter of the glycine-treated dogs. The possible role of these segmental putative neurotransmitters in spinal spasticity is discussed.

Antinociception of Heterotopic Electro-Acupuncture Mediated by the Dorsolateral Funiculus

2007 ◽  
Vol 35 (02) ◽  
pp. 251-264 ◽  
Author(s):  
Seung Jae Lee ◽  
Yeoung Su Lyu ◽  
Hyung Won Kang ◽  
In Churl Sohn ◽  
Sungtae Koo ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Endogenous Opioids ◽  
Lumbar Spinal Cord ◽  
Formalin Injection ◽  
Thoracic Spinal Cord ◽  
Inhibitory Pathways ◽  
Thoracic Spinal ◽  
Antinociceptive Effects ◽  
Dorsolateral Funiculus ◽  
Lumbar Spinal

We investigated the inhibitory pathways that mediate the antinociceptive effects of heterotopic electro-acupuncture (EA) on formalin injection-induced pain in rats. EA (2 ms, 10 Hz, 3 mA) was delivered to heterotopic acupoints HT7 and PC7 for 30 min; this was followed immediately by subcutaneous injection of formalin into the left hind paw of rats. Naltrexone (10 mg/kg, i.p.), an opioid receptor antagonist, was administered to evaluate the involvement of endogenous opioids. The dorsolateral funiculus (DLF), which is a descending pathway that inhibits pain, was transected at the ipsilateral T10–11 level of the thoracic spinal cord. EA inhibited behavioral responses to formalin injection-induced pain and prevented the pain-induced increase in cFos expression in the lumbar spinal cord. Pretreatment with naltrexone did not inhibit the antinociceptive effects of EA on formalin injection-induced pain. Transection of the DLF ipsilateral to the acupuncture site eliminated the antinociceptive effects of EA. These results suggest that the antinociceptive effects of heterotopic EA are mediated by the DLF and not by endogenous opioids.

scholarly journals Functional and Structural Changes in the Corticospinal Tract of Streptozotocin-Induced Diabetic Rats

2021 ◽  
Vol 22 (18) ◽  
pp. 10123
Author(s):  
Ken Muramatsu ◽  
Satoshi Shimo ◽  
Toru Tamaki ◽  
Masako Ikutomo ◽  
Masatoshi Niwa
Keyword(s):  
Spinal Cord ◽  
Conduction Velocity ◽  
Corticospinal Tract ◽  
Morphological Changes ◽  
Cervical Spinal Cord ◽  
Diabetic Animal ◽  
Lumbar Spinal Cord ◽  
Dorsal Funiculus ◽  
Lumbar Spinal ◽  
G Ratio

This study aimed to reveal functional and morphological changes in the corticospinal tract, a pathway shown to be susceptible to diabetes. Type 1 diabetes was induced in 13-week-old male Wistar rats administered streptozotocin. Twenty-three weeks after streptozotocin injection, diabetic animals and age-matched control animals were used to demonstrate the conduction velocity of the corticospinal tract. Other animals were used for morphometric analyses of the base of the dorsal funiculus of the corticospinal tract in the spinal cord using both optical and electron microscopy. The conduction velocity of the corticospinal tract decreased in the lumbar spinal cord in the diabetic animal, although it did not decrease in the cervical spinal cord. Furthermore, atrophy of the fibers of the base of the dorsal funiculus was observed along their entire length, with an increase in the g-ratio in the lumbar spinal cord in the diabetic animal. This study indicates that the corticospinal tract fibers projecting to the lumbar spinal cord experience a decrease in conduction velocity at the lumbar spinal cord of these axons in diabetic animals, likely caused by a combination of axonal atrophy and an increased g-ratio due to thinning of the myelin sheath.

scholarly journals Мікроскопічна будова та морфометричні показники грудної і поперекової частин спинного мозку свійського собаки

2017 ◽  
Vol 19 (78) ◽  
pp. 167-171
Author(s):  
L.P. Horalskyi ◽  
I.M. Sokulskyi ◽  
N.L. Kolesnik ◽  
N.V. Demus
Keyword(s):  
Spinal Cord ◽  
Gray Matter ◽  
Transverse Section ◽  
Nerve Cells ◽  
Domestic Dog ◽  
Lumbar Spinal Cord ◽  
Thoracic Region ◽  
Cross Sectional ◽  
Thoracic Part ◽  
Lumbar Spinal

The article describes the features of the macroscopic and microscopic structure of the spinal cord of the chest and lumbar parts of a mature dog for the use of morphological, neurohistological, morphometric and statistical methods of research. According to the results of histomorphology, the area and shape of the transverse section of the spinal cord is determined, the latter in the thoracic region has a round shape, in the lumbar – oval. Gray substance of the spinal cord in the form of a butterfly on a transverse section is formed by ventral, dorsal and lateral horns, in which are centers of the sympathetic nervous system. According to our research, in the gray matter of the spinal cord of a domestic dog, the core of the dorsal horn, the Clark core, the lateral and medial intermediate nuclei, the lateral and medial ventral nuclei are clearly differentiated.According to histometry of the spinal cord of the mature dog, conducted by us, the largest cross-sectional area is characteristic of the lumbar spinal cord (23.32 ± 0.44 mm²), is slightly lower in the breast (21.31 ± 0.34 mm2). In this case, the ratio of gray cerebrospinal fluid to white in the lumbar part is 1: 3.32, which is 2 times less in comparison with the such indicator of the thoratic part.The cytopupulation of the nerve cells is represented by large, medium and small neurocytes, which, in its turn, depend on their placement in certain areas of the gray matter of the spinal cord: the most small neurons are found in the lumbar part of the cord (22.58%), the least are in the thoracic (19.88%), medium neurons are the highest in the thoracic part (44.11%), the least are in the lumbar (24.37%), the largest cells are in the lumbar part (44.11%), the least are in the thoracic (36.01%).Our cytomorphometric studies indicate that the nerve cells of the gray matter of the spinal cord of mature dogs have a different volume of pericarions and their nuclei and, accordingly, a different nuclear-cytoplasmic ratio (NCR), which is an indicator of the functional activity of nerve cells. The largest average volume of pericarios of nerve cells is found in the lumbar part (17723.26 ± 816.72 mcm³), the smallest are in the chest (12913.53 ± 915.41 mcm³). The largest nuclear-cytoplasmic ratio was found in the thoracic part of the cord (0.120 ± 0.005), less are in the lumbar (0.110 ± 0.004). 

Lipomeningocele associated with diplomyelia in a dog

2018 ◽  
Vol 46 (05) ◽  
pp. 323-329 ◽  
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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