Long-term motor cortical map changes following unilateral lesion of the hand representation in the motor cortex in macaque monkeys showing functional recovery of hand functions

SummaryCortical maps often undergo plastic changes during learning or in response to injury. In sensory areas, these changes are thought to be triggered by alterations in the pattern of converging inputs and a functional reassignment of the deprived cortical region. In the motor cortex, training on a task that engages distal effectors was shown to increase their cortical representation (as measured by response to intracortical microstimulation). However, this expansion could be a specific outcome of using a demanding dexterous task. We addressed this question by measuring the long-term changes in cortical maps of monkeys that were sequentially trained on two different tasks involving either proximal or distal joints. We found that motor cortical remodeling in adult monkeys was symmetric such that both distal and proximal movements can comparably alter motor maps in a fully reversible manner according to task demands. Further, we found that the change in mapping often included a switch between remote joints (e.g., a finger site switched to a shoulder site) and reflected a usage-consistent reorganization of the map rather than the local expansion of one representation into nearby sites. Finally, although cortical maps were considerably affected by the performed task, motor cortical neurons throughout the motor cortex were equally likely to fire in a task-related manner independent of the task and/or the recording site. These results may imply that in the motor system, enhanced motor efficiency is achieved through a dynamical allocation of larger cortical areas and not by specific recruitment of task-relevant cells.

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Asymmetric and Distant Effects of a Unilateral Lesion of the Primary Motor Cortex on the Bilateral Supplementary Motor Areas in Adult Macaque Monkeys

Journal of Neuroscience ◽

10.1523/jneurosci.0904-18.2018 ◽

2018 ◽

Vol 38 (50) ◽

pp. 10644-10656 ◽

Cited By ~ 3

Author(s):

A. Contestabile ◽

R. Colangiulo ◽

M. Lucchini ◽

A.-D. Gindrat ◽

A. Hamadjida ◽

...

Keyword(s):

Motor Cortex ◽

Primary Motor Cortex ◽

Unilateral Lesion ◽

Macaque Monkeys ◽

Motor Areas

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A Temporally Asymmetric Hebbian Rule Governing Plasticity in the Human Motor Cortex

Journal of Neurophysiology ◽

10.1152/jn.00900.2002 ◽

2003 ◽

Vol 89 (5) ◽

pp. 2339-2345 ◽

Cited By ~ 365

Author(s):

Alexander Wolters ◽

Friedhelm Sandbrink ◽

Antje Schlottmann ◽

Erwin Kunesch ◽

Katja Stefan ◽

...

Keyword(s):

Motor Cortex ◽

Median Nerve ◽

Cortical Excitability ◽

Long Term Potentiation ◽

Long Term Depression ◽

Human Motor Cortex ◽

Motor Cortical Excitability ◽

Human Motor ◽

Motor Cortical

Synaptic plasticity is conspicuously dependent on the temporal order of the pre- and postsynaptic activity. Human motor cortical excitability can be increased by a paired associative stimulation (PAS) protocol. Here we show that it can also be decreased by minimally changing the interval between the two associative stimuli. Corticomotor excitability of the abductor pollicis brevis (APB) representation was tested before and after repetitively pairing of single right median nerve simulation with single pulse transcranial magnetic stimulation (TMS) delivered over the optimal site for activation of the contralateral APB. Following PAS, depression of TMS-evoked motor-evoked potentials (MEPs) was induced only when the median nerve stimulation preceded the TMS pulse by 10 ms, while enhancement of cortical excitability was induced using an interstimulus interval of 25 ms, suggesting an important role of the sequence of cortical events triggered by the two stimulation modalities. Experiments using F-wave studies and electrical brain stem stimulation indicated that the site of the plastic changes underlying the decrease of MEP amplitudes following PAS (10 ms) was within the motor cortex. MEP amplitudes remained depressed for approximately 90 min. The decrease of MEP amplitudes was blocked when PAS(10 ms) was performed under the influence of dextromethorphan, an N-methyl-d-aspartate-receptor antagonist, or nimodipine, an L-type voltage-gated calcium-channel antagonist. The physiological profile of the depression of human motor cortical excitability following PAS(10 ms) suggests long-term depression of synaptic efficacy to be involved. Together with earlier findings, this study suggests that strict temporal Hebbian rules govern the induction of long-term potentiation/long-term depression-like phenomena in vivo in the human primary motor cortex.

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Motor cortex and corticospinal excitability in humans with a history of illicit stimulant use

Journal of Applied Physiology ◽

10.1152/japplphysiol.00718.2012 ◽

2012 ◽

Vol 113 (9) ◽

pp. 1486-1494 ◽

Cited By ~ 14

Author(s):

Stanley C. Flavel ◽

Jason M. White ◽

Gabrielle Todd

Keyword(s):

Motor Cortex ◽

Muscle Activity ◽

Corticospinal Excitability ◽

Urine Drug Screen ◽

Paired Pulse ◽

Stimulant Use ◽

Resting Motor Threshold ◽

History Of ◽

Motor Cortical

Illicit use of stimulant drugs such as methamphetamine, ecstasy, and cocaine is a current and growing problem throughout the world. The aim of the current study was to investigate the long-term effect of illicit stimulant use on human motor cortical and corticospinal circuitry. We hypothesized that individuals with a history of primarily methamphetamine and ecstasy use would exhibit altered corticospinal excitability and intracortical inhibition within motor cortex. The study involved 52 healthy adults (aged 26 ± 7 yr) comprising 26 abstinent stimulant users, 9 cannabis users, and 17 nondrug users. The experiment involved a routine urine drug screen, drug history questionnaire, neuropsychological assessment, and single- and paired-pulse transcranial magnetic stimulation (TMS) over motor cortex. EMG responses to stimulation [motor evoked potentials (MEPs)] were recorded from the contralateral first dorsal interosseus. At a given stimulus intensity, MEP area was significantly larger in abstinent stimulant users than in nondrug users during both relaxation ( P = 0.045) and muscle contraction ( P < 0.001). MEP latency was also significantly longer in abstinent stimulant users ( P < 0.009), and they exhibited significantly greater muscle activity during performance of a given task ( P = 0.004). However, resting motor threshold and the response to paired-pulse TMS were unaffected. The results suggest that abstinent stimulant users exhibit long-term changes in the excitability of motor cortical and corticospinal circuitry and muscle activity during movement. These changes may partly underlie anecdotal and objective reports of movement dysfunction in chronic stimulant users.

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Reprogramming the motor cortex for functional recovery after neonatal or adult unilateral lesion of the corticospinal system in the macaque monkey

Reprogramming the Cerebral Cortex ◽

10.1093/acprof:oso/9780198528999.003.0017 ◽

2006 ◽

pp. 309-324 ◽

Cited By ~ 1

Author(s):

E. M. Rouiller ◽

T. Wannier ◽

E. Schmidlin ◽

Y. Liu

Keyword(s):

Motor Cortex ◽

Functional Recovery ◽

Macaque Monkey ◽

Unilateral Lesion ◽

Corticospinal System

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Patterns of muscular and motor cortical activity during a simple arm movement in the monkey

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y81-111 ◽

1981 ◽

Vol 59 (7) ◽

pp. 748-756 ◽

Cited By ~ 24

Author(s):

Y. Lamarre ◽

G. Spidalieri ◽

J. P. Lund

Keyword(s):

Motor Cortex ◽

Macaca Mulatta ◽

Arm Movement ◽

Cortical Activity ◽

Macaque Monkeys ◽

Direction Of Movement ◽

Motor Cortical ◽

Movement Parameters ◽

Fusimotor System ◽

Flexion And Extension

This article describes the behavior of motor cortex neurons recorded in macaque monkeys (Macaca mulatta) which had been trained to make extension and flexion movements about the elbow in response to auditory, visual, or somesthetic cues. The pattern of activity of 65% of those movement-related neurons which were recorded during both flexion and extension was reciprocally related to the direction of movement. However, the movements of extension and flexion were made by co-contraction of the biceps and triceps in a pattern that did not match that of the motor cortex neurons. The majority of motor cortex neurons had firing frequencies that were related to movement parameters but by their nature could not be directly involved in the control of α motoneurons in both directions of movement. We suggest that they could, instead, control the fusimotor system. It is more likely that α motoneurons are controlled by the 35% of motor cortex neurons that, like the muscles, do not show reciprocal patterns of activity for movements in opposite directions.

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