scholarly journals I. Preliminary note on bilateral degeneration in the spinal cord of monkeys ( Macacus sinicus ) following unilateral lesion of the cortex cerebri

1894 ◽  
Vol 55 (331-335) ◽  
pp. 207-210 ◽  

Having for some time been engaged in an investigation of the question as to how far the fibres of each pyramid descend both halves of the spinal cord, I am in a position to state that in the bonnet monkey ( Macacus sinicus ) the following arrangement prevails. Method of Investigation .—The animal being etherised, and the left hemisphere of the brain exposed by a single trephine hole (sometimes enlarged afterwards), a small portion of the excitable area of the motor cortex was selected as detailed below, the selection being confirmed in each case by electrical stimulation. A small piece of the cortex, about 0.4 cm. square, constituting the focus of the movement observed, was removed, care being taken to remove also a little of the underlying corona radiata to be sure that no cortex was left.

1895 ◽  
Vol 58 (347-352) ◽  
pp. 206-214 ◽  

The object of this investigation was to trace by the so-called anatomical method the degeneration resulting from minute lesions of the motor area of the cortex cerebri through the brain and spinal cord, to locate the path of the conducting fibres in the internal capsule and elsewhere, to follow them as far as possible to their destinations, and by such control observations to check off the results obtained by previous excitation experiments.


Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 143
Author(s):  
Ganchimeg Davaa ◽  
Jin Young Hong ◽  
Tae Uk Kim ◽  
Seong Jae Lee ◽  
Seo Young Kim ◽  
...  

Exercise training is a traditional method to maximize remaining function in patients with spinal cord injury (SCI), but the exact mechanism by which exercise promotes recovery after SCI has not been identified; whether exercise truly has a beneficial effect on SCI also remains unclear. Previously, we showed that epigenetic changes in the brain motor cortex occur after SCI and that a treatment leading to epigenetic modulation effectively promotes functional recovery after SCI. We aimed to determine how exercise induces functional improvement in rats subjected to SCI and whether epigenetic changes are engaged in the effects of exercise. A spinal cord contusion model was established in rats, which were then subjected to treadmill exercise for 12 weeks. We found that the size of the lesion cavity and the number of macrophages were decreased more in the exercise group than in the control group after 12 weeks of injury. Immunofluorescence and DNA dot blot analysis revealed that levels of 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) in the brain motor cortex were increased after exercise. Accordingly, the expression of ten-eleven translocation (Tet) family members (Tet1, Tet2, and Tet3) in the brain motor cortex also elevated. However, no macrophage polarization was induced by exercise. Locomotor function, including Basso, Beattie, and Bresnahan (BBB) and ladder scores, also improved in the exercise group compared to the control group. We concluded that treadmill exercise facilitates functional recovery in rats with SCI, and mechanistically epigenetic changes in the brain motor cortex may contribute to exercise-induced improvements.


2021 ◽  
Author(s):  
S.S. Ananiev ◽  
D.A. Pavlov ◽  
R.N. Yakupov ◽  
V.A. Golodnova ◽  
M.V. Balykin

The study was conducted on 22 healthy men aged 18-23 years. The primary motor cortex innervating the lower limb was stimulated with transcranial magnetic stimulation. Using transcutaneous electrical stimulation of the spinal cord, evoked motor responses of the muscles of the lower extremities were initiated when electrodes were applied cutaneous between the spinous processes in the Th11-Th12 projection. Research protocol: Determination of the thresholds of BMO of the muscles of the lower extremities during TESCS; determination of the BMO threshold of the TA muscle in TMS; determination of the thresholds of the BMO of the muscles of the lower extremities during TESCS against the background of 80% and 90% TMS. It was found that magnetic stimulation of the motor cortex of the brain leads to an increase in the excitability of the neural structures of the lumbar thickening of the spinal cord and an improvement in neuromuscular interactions. Key words: transcranial magnetic stimulation, transcutaneous electrical stimulation of the spinal cord, neural networks, excitability, neuromuscular interactions.


2020 ◽  
pp. 833-851
Author(s):  
Poulami Ghosh ◽  
Ankita Mazumder ◽  
Anwesha Banerjee ◽  
D.N. Tibarewala

Loss or impairment in the ability of muscle movement or sensation is called Paralysis which is caused by disruption of communication of nerve impulses along the pathway from the brain to the muscles. One of the principal reasons causing paralysis is Spinal Cord Injury (SCI) and Neurological rehabilitation by using neuro-prostheses, based on Functional Electrical Stimulation (FES) is extensively used for its treatment. Impaired muscles are activated by applying small amplitude electrical current. Electromyography (EMG), the recording of biosignals generated by muscle activity during the application of FES can be used as the control signal for FES based rehabilitative devices. This method is predominantly used for restoring upper extremity functioning (wrist, hand, elbow, etc.), standing, walking (speed, pattern) in stroke patients. FES, collaborated with conventional methods, has the potential to be utilized as a useful tool for rehabilitation and restoration of muscle strength, metabolic responses etc. in paralyzed patients.


Author(s):  
Vedran Deletis ◽  
Francesco Sala ◽  
Sedat Ulkatan

Transcranial electrical stimulation is a well-recognized method for corticospinal tract (CT) activation. This article explains the use of TES during surgery and highlights the physiology of the motor-evoked potentials (MEPs). It describes the techniques and methods for brain stimulation and recording of responses. There are two factors that determine the depth of the current penetrating the brain, they are: choice of electrode montage for stimulation over the scalp and the intensity of stimulation. D-wave collision technique is a newly developed technique that allows mapping intraoperatively and finding the anatomical position of the CT within the surgically exposed spinal cord. Different mechanisms may be involved in the pathophysiology of postoperative paresis in brain and spinal cord surgeries so that different MEP monitoring criteria can be used to avoid irreversible damage and accurately predict the prognosis.


Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1310 ◽  
Author(s):  
Jin Young Hong ◽  
Ganchimeg Davaa ◽  
Hyunjin Yoo ◽  
Kwonho Hong ◽  
Jung Keun Hyun

Axonal regeneration after spinal cord injury (SCI) is difficult to achieve, and no fundamental treatment can be applied in clinical settings. DNA methylation has been suggested to play a role in regeneration capacity and neuronal growth after SCI by controlling the expression of regeneration-associated genes (RAGs). The aim of this study was to examine changes in neuronal DNA methylation status after SCI and to determine whether modulation of DNA methylation with ascorbic acid can enhance neuronal regeneration or functional restoration after SCI. Changes in epigenetic marks (5-hydroxymethylcytosine (5hmC) and 5-methylcytosine (5mC)); the expression of Ten-eleven translocation (Tet) family genes; and the expression of genes related to inflammation, regeneration, and degeneration in the brain motor cortex were determined following SCI. The 5hmC level within the brain was increased after SCI, especially in the acute and subacute stages, and the mRNA levels of Tet gene family members (Tet1, Tet2, and Tet3) were also increased. Administration of ascorbic acid (100 mg/kg) to SCI rats enhanced 5hmC levels; increased the expression of the Tet1, Tet2, and Tet3 genes within the brain motor cortex; promoted axonal sprouting within the lesion cavity of the spinal cord; and enhanced recovery of locomotor function until 12 weeks. In conclusion, we found that epigenetic status in the brain motor cortex is changed after SCI and that epigenetic modulation using ascorbic acid may contribute to functional recovery after SCI.


In the following paper we propose to give the results of a research on which we have been engaged nearly three years, and by which we hoped to elucidate the arrangement of the motor fibres in the internal capsule. The fibres which connect the excitable areas in the cortex cerebri with the bulbospinal grey matter in the medulla oblongata and spinal cord are commonly spoken of as forming the pyramidal tract .


1970 ◽  
Vol 32 (5) ◽  
pp. 553-559 ◽  
Author(s):  
J. Thomas Mortimer ◽  
C. Norman Shealy ◽  
Connie Wheeler

Author(s):  
Poulami Ghosh ◽  
Ankita Mazumder ◽  
Anwesha Banerjee ◽  
D.N. Tibarewala

Loss or impairment in the ability of muscle movement or sensation is called Paralysis which is caused by disruption of communication of nerve impulses along the pathway from the brain to the muscles. One of the principal reasons causing paralysis is Spinal Cord Injury (SCI) and Neurological rehabilitation by using neuro-prostheses, based on Functional Electrical Stimulation (FES) is extensively used for its treatment. Impaired muscles are activated by applying small amplitude electrical current. Electromyography (EMG), the recording of biosignals generated by muscle activity during the application of FES can be used as the control signal for FES based rehabilitative devices. This method is predominantly used for restoring upper extremity functioning (wrist, hand, elbow, etc.), standing, walking (speed, pattern) in stroke patients. FES, collaborated with conventional methods, has the potential to be utilized as a useful tool for rehabilitation and restoration of muscle strength, metabolic responses etc. in paralyzed patients.


1995 ◽  
Vol 73 (3) ◽  
pp. 1223-1233 ◽  
Author(s):  
G. N. Sholomenko ◽  
M. J. O'Donovan

1. We used an isolated preparation of the embryonic chick brain stem and spinal cord to examine the origin, trajectory, and effects of descending supraspinal pathways on lumbosacral motor activity. The in vitro preparation remained viable for < or 24 h and was sufficiently stable for electrophysiological, pharmacological, and neuroanatomic examination. In this preparation, as in the isolated spinal cord, spontaneous episodes of both forelimb and hindlimb motor activity occur in the absence of phasic afferent input. Motor activity can also be evoked by brain stem electrical stimulation or modulated by the introduction of neurochemicals to the independently perfused brain stem. 2. At embryonic day (E)6, lumbosacral motor activity could be evoked by brain stem electrical stimulation. At E5, neither brain stem nor spinal cord stimulation evoked activity in the lumbosacral spinal cord, although motoneurons did express spontaneous activity. 3. Lesion and electrophysiological studies indicated that axons traveling in the ventral cord mediated the activation of lumbosacral networks by brain stem stimulation. 4. Partition of the preparation into three separately perfused baths, using a zero-Ca2+ middle bath that encompassed the cervical spinal cord, demonstrated that the brain stem activation of spinal networks could be mediated by long-axoned pathways connecting the brain stem and lumbosacral spinal cord. 5. Using retrograde tracing from the spinal cord combined with brain stem stimulation, we found that the brain stem regions from which spinal activity could be evoked lie in the embryonic reticular formation close to neurons that send long descending axons to the lumbosacral spinal cord. The cells giving rise to these descending pathways are found in the ventral pontine and medullary reticular formation, a region that is the source of reticulospinal neurons important for motor activity in adult vertebrates. 6. Electrical recordings from this region revealed that the activity of some brain stem neurons was synchronized with the electrical activity of lumbosacral motoneurons during evoked or spontaneous episodes of rhythmic motor activity. 7. Both brain stem and spinal cord activity could be modulated by selective application of the glutamate agonist N-methyl-D-aspartate to the brain stem, supporting the existence of functionally active descending projections from the brain stem to the spinal cord. It is not yet clear what role the brain stem activity carried by these pathways has in the genesis and development of spinal cord motor activity.


Sign in / Sign up

Export Citation Format

Share Document