Reversal of cortical plasticity in human primary motor cortex following thumb reconstruction

2008 ◽  
Vol 1 (3) ◽  
pp. 286
Author(s):  
Z. Ni ◽  
D.J. Anastakis ◽  
C. Gunraj ◽  
R. Chen
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Cortical Plasticity ◽  
Thumb Reconstruction

Reversal of Cortical Reorganization in Human Primary Motor Cortex Following Thumb Reconstruction

2010 ◽  
Vol 103 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Zhen Ni ◽  
Dimitri J. Anastakis ◽  
Carolyn Gunraj ◽  
Robert Chen
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Short Interval ◽  
Body Part ◽  
Cortical Reorganization ◽  
Traumatic Amputation ◽  
Motor Threshold ◽  
Thumb Reconstruction ◽  
Intact Side ◽  
Injured Side

Deafferentation such as the amputation of a body part causes cortical reorganization in the primary motor cortex (M1). We investigated whether this reorganization is reversible after reconstruction of the lost body part. We tested two patients who had long-standing thumb amputations followed by thumb reconstruction with toe-to-thumb transfer 9 to 10 mo later and one patient who underwent thumb replantation immediately following traumatic amputation. Using transcranial magnetic stimulation, we measured the motor evoked potential (MEP) threshold, latency, short-interval intracortical inhibition (SICI), and intracortical facilitation (ICF) at different time points in the course of recovery in abductor pollicis brevis muscle. For the two patients who underwent late toe-to-thumb transfer, the rest motor threshold was lower on the injured side than that on the intact side before surgery and it increased with time after reconstruction, whereas the active motor threshold remained unchanged. The rest and active MEP latencies were similar on the injured side before and ≤15 wk after surgery and followed by restoration of expected latency differences. SICI was reduced before surgery and progressively normalized with the time after surgery. ICF did not change with time. These physiological measures correlated with the recovery of motor and sensory functions. All the measurements on the intact side of the toe-to-thumb transfer patients and in the patient with thumb replantation immediately following traumatic amputation remained stable over time. We conclude that chronic reorganization occurring in the M1 after amputation can be reversed by reconstruction of the lost body part.

scholarly journals Can genetic polymorphisms predict response variability to anodal transcranial direct current stimulation of the primary motor cortex?

2020 ◽  
Author(s):  
Michael Pellegrini ◽  
Maryam Zoghi ◽  
Shapour Jaberzadeh
Keyword(s):  
Motor Cortex ◽  
Genetic Polymorphisms ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Primary Motor Cortex ◽  
Cortical Plasticity ◽  
Individual Variability ◽  
Response Variability ◽  
Gaba A ◽  
Direct Current Stimulation

AbstractGenetic mediation of cortical plasticity and the role genetic variants play in previously observed response variability to transcranial direct current stimulation (tDCS) have become important issues in the tDCS literature in recent years. This study investigated whether inter-individual variability to tDCS was in-part genetically mediated. In sixty-one healthy males, anodal-tDCS (a-tDCS) and sham-tDCS were administered to the primary motor cortex at 1mA for 10-minutes via 6×4cm active and 7×5cm return electrodes. Twenty-five single-pulse transcranial magnetic stimulation (TMS) motor evoked potentials (MEP) were recorded to represent corticospinal excitability (CSE).Twenty-five paired-pulse MEPs were recorded with 3ms inter-stimulus interval (ISI) to assess intracortical inhibition (ICI) via short-interval intracranial inhibition (SICI) and 10ms ISI for intracortical facilitation (ICF). Saliva samples tested for specific genetic polymorphisms in genes encoding for excitatory and inhibitory neuroreceptors. Individuals were sub-grouped based on a pre-determined threshold and via statistical cluster analysis. Two distinct subgroups were identified, increases in CSE following a-tDCS (i.e. Responders) and no increase or even reductions in CSE (i.e. Non-responders). No changes in ICI or ICF were reported. No relationships were reported between genetic polymorphisms in excitatory receptor genes and a-tDCS responders. An association was reported between a-tDCS responders and GABRA3 gene polymorphisms encoding for GABA-A receptors suggesting potential relationships between GABA-A receptor variations and capacity to undergo tDCS-induced cortical plasticity. In the largest tDCS study of its kind, this study presents an important step forward in determining the contribution genetic factors play in previously observed inter-individual variability to tDCS.

Increased occlusal vertical dimension induces cortical plasticity in the rat face primary motor cortex

2013 ◽  
Vol 72 (4) ◽  
pp. 1-1
Author(s):  
Chiho Kato ◽  
Koichi Fujita ◽  
Satoshi Kokai ◽  
Takayoshi Ishida ◽  
Mai Shibata ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Cortical Plasticity ◽  
Vertical Dimension ◽  
Occlusal Vertical Dimension

scholarly journals MRI-based visualization of rTMS-induced cortical plasticity in the primary motor cortex

PLoS ONE ◽  
2019 ◽  
Vol 14 (10) ◽  
pp. e0224175 ◽  
Author(s):  
Kaori Tamura ◽  
Takahiro Osada ◽  
Akitoshi Ogawa ◽  
Masaki Tanaka ◽  
Akimitsu Suda ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Cortical Plasticity

scholarly journals Electroacupuncture-Induced Plasticity between Different Representations in Human Motor Cortex

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Weiqin Peng ◽  
Tiange Yang ◽  
Jiawei Yuan ◽  
Jianpeng Huang ◽  
Jianhua Liu
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Cortical Plasticity ◽  
Body Part ◽  
Cortical Function ◽  
Somatosensory Stimulation ◽  
Human Motor Cortex ◽  
Face Representation ◽  
Before And After ◽  
The Face

Somatosensory stimulation can effectively induce plasticity in the motor cortex representation of the stimulated body part. Specific interactions have been reported between different representations within the primary motor cortex. However, studies evaluating somatosensory stimulation-induced plasticity between different representations within the primary motor cortex are sparse. The purpose of this study was to investigate the effect of somatosensory stimulation on the modulation of plasticity between different representations within the primary motor cortex. Twelve healthy volunteers received both electroacupuncture (EA) and sham EA at the TE5 acupoint (located on the forearm). Plasticity changes in different representations, including the map volume, map area, and centre of gravity (COG) were evaluated by transcranial magnetic stimulation (TMS) before and after the intervention. EA significantly increased the map volume of the forearm and hand representations compared to those of sham EA and significantly reduced the map volume of the face representation compared to that before EA. No significant change was found in the map volume of the upper arm and leg representations after EA, and likewise, no significant changes in map area and COG were observed. These results suggest that EA functions as a form of somatosensory stimulation to effectively induce plasticity between different representations within the primary motor cortex, which may be related to the extensive horizontal intrinsic connectivity between different representations. The cortical plasticity induced by somatosensory stimulation might be purposefully used to modulate human cortical function.

Increased occlusal vertical dimension induces cortical plasticity in the rat face primary motor cortex

2012 ◽  
Vol 228 (2) ◽  
pp. 254-260 ◽  
Author(s):  
C. Kato ◽  
K. Fujita ◽  
S. Kokai ◽  
T. Ishida ◽  
M. Shibata ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Cortical Plasticity ◽  
Vertical Dimension ◽  
Occlusal Vertical Dimension
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