Tue Feb 15
Speaker: Adam Davidson (Univ of Rochester)
Title: Distributed Neural Control of Upper Limb Movements
Abstract: In many conditions, such as learning a new motor skill, the primary motor cortex can reorganize its outputs to upper limb muscles. Reorganization in motor output from the primary motor cortex likely involves changes in excitability levels within cortical circuits. Even so, changes in motor output also might occur at the level of throughput from single motor cortex neurons to muscle activity. We examined such throughput during a paradigm that provided incentive for enhancing functional connectivity from motor cortex neurons to muscles. Although primary motor cortex output dominates control of the distal upper limb during voluntary movements, our findings show the throughput from individual primary motor cortex neurons to upper limb muscles can change rapidly and dramatically. We speculate mechanisms underlying these rapid changes in motor outputs are likely subcortical, including changes in intrinsic motoneuron properties and competing outputs from other descending motor systems. In particular, the reticulospinal system, which may play a larger role in the control of upper limb movements than previously thought, can directly influence upper limb motoneurons during voluntary movements.
Host: Lee Miller