AI Article Synopsis
- The cerebellum was traditionally thought to control movements on the same side of the body (ipsilateral), but this study suggests it also has a role in movements on the opposite side (contralateral).
- Microelectrode experiments in monkeys showed that stimulating the deep cerebellar nuclei activated muscles on both sides, indicating bilateral facilitation.
- The findings imply that the cerebellum has a significant influence on coordinating movements for both limbs, which is important for tasks that require bilateral coordination.
Article Abstract
The cerebellum is normally assumed to represent ipsilateral movements. We tested this by making microelectrode penetrations into the deep cerebellar nuclei (mainly nucleus interpositus) of monkeys trained to perform a reach and grasp task with either hand. Following weak single electrical stimuli, many sites produced clear bilateral facilitation of multiple forelimb muscles. The short onset latencies, which were similar for each side, suggested that at least some of the muscle responses were mediated by descending tracts originating in the brainstem, rather than via the cerebral cortex. Additionally, cerebellar neurones modulated their discharge with both ipsilateral and contralateral movements. This was so, even when we carefully excluded contralateral trials with evidence of electromyogram modulation on the ipsilateral side. We conclude that the deep cerebellar nuclei have a bilateral movement representation, and relatively direct, powerful access to limb muscles on both sides of the body. This places the cerebellum in an ideal position to coordinate bilateral movements.
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| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2268981 | PMC |
| http://dx.doi.org/10.1113/jphysiol.2007.144220 | DOI Listing |
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