scholarly journals Do neurons from the primary motor cortex grow in response to signals from the developing spinal cord in vitro?

2015 ◽  
Author(s):  
F Alhumaid ◽  
S Almutairi ◽  
P Roach ◽  
HR Fuller ◽  
MA Gates
Keyword(s):  
Spinal Cord ◽  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Developing Spinal Cord

The effect of transcranial magnetic stimulation on the excitability of the motor neuron pools of the muscles of the lower extremities

2021 ◽  
Author(s):  
S.S. Ananiev ◽  
D.A. Pavlov ◽  
R.N. Yakupov ◽  
V.A. Golodnova ◽  
M.V. Balykin
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Transcranial Magnetic Stimulation ◽  
Motor Cortex ◽  
Magnetic Stimulation ◽  
Primary Motor Cortex ◽  
Lower Extremities ◽  
Transcutaneous Electrical Stimulation ◽  
Stimulation Of

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.

The effect of continuous theta burst stimulation over premotor cortex on circuits in primary motor cortex and spinal cord

2009 ◽  
Vol 120 (4) ◽  
pp. 796-801 ◽  
Author(s):  
Ying-Zu Huang ◽  
John C. Rothwell ◽  
Chin-Song Lu ◽  
JiunJie Wang ◽  
Yi-Hsin Weng ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Theta Burst Stimulation ◽  
Burst Stimulation ◽  
Theta Burst ◽  
Continuous Theta Burst Stimulation

scholarly journals Trains of Epidural DC Stimulation of the Cerebellum Tune Corticomotor Excitability

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Nordeyn Oulad Ben Taib ◽  
Mario Manto
Keyword(s):  
Spinal Cord ◽  
Motor Cortex ◽  
Spatial Representation ◽  
Primary Motor Cortex ◽  
Anterior Horn ◽  
Adult Rats ◽  
Afferent Inhibition ◽  
Antagonist Muscles ◽  
Conditioned Motor ◽  
Stimulation Of

We assessed the effects of anodal/cathodal direct current stimulation (DCS) applied epidurally over the cerebellum. We studied the excitability of both the motor cortex and the anterior horn of the spinal cord in adult rats under continuous anesthesia. We also investigated the effects on the spatial representation of a couple of agonist/antagonist muscles on primary motor cortex. Moreover, we evaluated the effects on the afferent inhibition in a paradigm of conditioned corticomotor responses. Anodal DCS of the cerebellum (1) decreased the excitability of the motor cortex, (2) reduced the excitability ofFwaves, as shown by the decrease of both meanF/meanMratios and persistence ofFwaves, (3) exerted a “smoothing effect” on corticomotor maps, reshaping the representation of muscles on the motor cortex, and (4) enhanced the afferent inhibition of conditioned motor evoked responses. Cathodal DCS of the cerebellum exerted partially reverse effects. DCS of the cerebellum modulates the excitability of both motor cortex and spinal cord at the level of the anterior horn. This is the first demonstration that cerebellar DCS tunes the shape of corticomotor maps. Our findings provide a novel mechanism by which DCS of the cerebellum exerts a remote neuromodulatory effect upon motor cortex.

scholarly journals Different contributions of primary motor cortex, reticular formation, and spinal cord to fractionated muscle activation

2018 ◽  
Vol 119 (1) ◽  
pp. 235-250 ◽  
Author(s):  
Boubker Zaaimi ◽  
Lauren R. Dean ◽  
Stuart N. Baker
Keyword(s):  
Spinal Cord ◽  
Motor Cortex ◽  
Reticular Formation ◽  
Upper Limb ◽  
Muscle Activation ◽  
Primary Motor Cortex ◽  
Cervical Spinal Cord ◽  
Motor Output ◽  
Natural Activity ◽  
Limb Muscles

Coordinated movement requires patterned activation of muscles. In this study, we examined differences in selective activation of primate upper limb muscles by cortical and subcortical regions. Five macaque monkeys were trained to perform a reach and grasp task, and electromyogram (EMG) was recorded from 10 to 24 muscles while weak single-pulse stimuli were delivered through microelectrodes inserted in the motor cortex (M1), reticular formation (RF), or cervical spinal cord (SC). Stimulus intensity was adjusted to a level just above threshold. Stimulus-evoked effects were assessed from averages of rectified EMG. M1, RF, and SC activated 1.5 ± 0.9, 1.9 ± 0.8, and 2.5 ± 1.6 muscles per site (means ± SD); only M1 and SC differed significantly. In between recording sessions, natural muscle activity in the home cage was recorded using a miniature data logger. A novel analysis assessed how well natural activity could be reconstructed by stimulus-evoked responses. This provided two measures: normalized vector length L, reflecting how closely aligned natural and stimulus-evoked activity were, and normalized residual R, measuring the fraction of natural activity not reachable using stimulus-evoked patterns. Average values for M1, RF, and SC were L = 119.1 ± 9.6, 105.9 ± 6.2, and 109.3 ± 8.4% and R = 50.3 ± 4.9, 56.4 ± 3.5, and 51.5 ± 4.8%, respectively. RF was significantly different from M1 and SC on both measurements. RF is thus able to generate an approximation to the motor output with less activation than required by M1 and SC, but M1 and SC are more precise in reaching the exact activation pattern required. Cortical, brainstem, and spinal centers likely play distinct roles, as they cooperate to generate voluntary movements. NEW & NOTEWORTHY Brainstem reticular formation, primary motor cortex, and cervical spinal cord intermediate zone can all activate primate upper limb muscles. However, brainstem output is more efficient but less precise in producing natural patterns of motor output than motor cortex or spinal cord. We suggest that gross muscle synergies from the reticular formation are sculpted and refined by motor cortex and spinal circuits to reach the finely fractionated output characteristic of dexterous primate upper limb movements.

Abstract MP58: Motor Cortex and Spinal Cord Transcriptome After Post-Stroke Optogenetic Neuronal Stimulation

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Michelle Y Cheng ◽  
Haruto Uchino ◽  
Terrance Chiang ◽  
Anika Kim ◽  
Zhijuan Cao ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Motor Cortex ◽  
Rna Sequencing ◽  
Primary Motor Cortex ◽  
Cholesterol Metabolism ◽  
Sequencing Analysis ◽  
Beam Test ◽  
Rotating Beam ◽  
Molecular Changes ◽  
Post Stroke

Background: Post-stroke brain stimulation is a promising neurorestorative technique to promote recovery. However, the underlying molecular mechanisms driving recovery are still unclear. Here we investigate the molecular changes in both the primary motor cortex and the cervical spinal cord after large cortical stroke in mice receiving repeated optogenetic stimulations in the ipsilateral primary motor cortex (iM1). Methods: C57Bl6 male mice (8 weeks) underwent stereotaxic surgery to express Channelrhodopsin2 in excitatory neurons in iM1, with optical fiber implanted in the same location. After five weeks the mice underwent a transient middle cerebral artery occlusion to induce stroke. Optogenetic stimulations were given daily from post-stroke days (PD) 5-14. Non-stimulated mice were used as controls. Rotating beam test was used to evaluate functional recovery after stroke. At PD 7 and 15, ipsi- and contralesional primary motor cortex (iM1 and cM1) and cervical spinal cords (iSp and cSp) were dissected and processed for RNA sequencing. Results: Repeated iM1 stimulations resulted in a robust recovery on the rotating beam test at PD14, with significant improvement in distance traveled (p<0.05). RNA sequencing analysis (stimulated vs non-stimulated mice) revealed differential transcriptome in both motor cortex and spinal cord. Higher number of differentially expressed genes (DEGs) were observed in the ipsilesional regions (iM1 and iSp). At PD 7, stimulated mice exhibited upregulation of activity-dependent and neuroplasticity-related genes in iM1. Interestingly, at PD15, cholesterol metabolism and neuroinflammatory related genes in iM1 were downregulated. The expressions of the genes were negatively correlated with behavioral recovery. Higher number of DEGs were altered in the spinal cord than motor cortex, suggesting more dynamic molecular changes occur in this area during the post-stroke reinnervation processes. Expressions of synaptogenesis related genes were altered in both iSp and cSp at both timepoints. Conclusions: These transcriptome data reveal important insights into the molecular signaling involved in post-stroke stimulation-induced recovery and provide potential drug targets for enhancing recovery in stroke patients.

The role of the ipsilateral primary motor cortex in movement control after spinal cord injury: A TMS study

2013 ◽  
Vol 552 ◽  
pp. 21-24 ◽  
Author(s):  
Raffaele Nardone ◽  
Yvonne Höller ◽  
Peter Höller ◽  
Natasha Thon ◽  
Aljoscha Thomschewski ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Movement Control ◽  
Cord Injury
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