Progressive plastic changes in the hand representation of the primary motor cortex parallel incomplete recovery from a unilateral section of the corticospinal tract at cervical level in monkeys

Details

Serval ID
serval:BIB_6DE5400817BF
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Progressive plastic changes in the hand representation of the primary motor cortex parallel incomplete recovery from a unilateral section of the corticospinal tract at cervical level in monkeys
Journal
Brain Research
Author(s)
Schmidlin  E., Wannier  T., Bloch  J., Rouiller  E. M.
ISSN
0006-8993
Publication state
Published
Issued date
08/2004
Peer-reviewed
Oui
Volume
1017
Number
1-2
Pages
172-83
Notes
Comparative Study
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Aug 13
Abstract
After a sub-total hemisection of the cervical cord at level C7/C8 in monkeys, a paralysis of the homolateral hand is rapidly followed by an incomplete recovery of manual dexterity, reaching a plateau after about 40-50 days, whose extent appears related to the size of the lesion. During a few days after the lesion, the hand representation in the contralateral motor cortex disappeared, replaced by representations of either face or more proximal body parts. Later, however, following a time course (about 40 days) consistent with the functional recovery, progressive plastic changes in the contralateral motor cortex took place, as demonstrated by a progressive reappearance of digit movements elicited by intracortical microstimulation. These progressive plastic changes, which parallel the functional recovery, correspond to a reinstallation of a hand representation, though substantially diminished in size as compared to pre-lesion. Regarding the functional recovery, the motor cortex (including the reestablished hand area) contralateral to the unilateral cervical cord lesion played a crucial role in reestablishing control on finger movements, as assessed by reversible inactivation experiments. In contrast, the motor cortex ipsilateral to the cervical cord lesion, with largely intact projections to the spinal cord, did not contribute significantly to the recovered movements by the affected hand. These observations indicate that the CS fibers spared by the lesion are not sufficient, at least in their pre-lesion condition, to control the motoneurones innervating the digit muscles and that the pathways conveying signals from the contralateral M1 underwent reorganization.
Keywords
Animals Brain Diseases/physiopathology Brain Mapping Functional Laterality/*physiology Hand/innervation/*physiopathology Macaca mulatta Male Motor Cortex/*physiopathology Neuronal Plasticity/*physiology Psychomotor Performance/physiology Pyramidal Tracts/physiology/*surgery Recovery of Function/*physiology Time Factors
Pubmed
Web of science
Create date
06/02/2008 11:03
Last modification date
20/08/2019 15:27
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