A study published in the January 2013 issue of the journal Neuron is giving new insight into how the neurons in our brains control our limbs. The research has potential implications in the design of more functional prosthetic limbs.
Neuroscience researcher Timothy Lillicrap, PhD, did the study as part of his doctoral thesis at Queen’s University, Kingston, Ontario, Canada, and worked with Stephen Scott, PhD, a professor in the Queen’s Department of Biomedical and Molecular Sciences. They used a novel network model, coupled with a computer biophysics model of a limb, to explain some of the prominent neural activity patterns seen in the brain during movements. The study findings refine previous notions of how neurons in the primary motor cortex fire and drive muscles. The primary motor cortex is the region of the brain that sends the largest number of connections to the spinal cord. Nerve impulses are sent along nerve fibers to control limb movements. Different movements require different nerve impulse patterns; the relationship between these neural patterns and the resulting movements is poorly understood.
The study demonstrates that the patterns of activity are related to specific details of limb physics-for example, neural activity patterns are tuned, or optimized, for muscle architecture and limb geometry.
Lillicrap, who is now a post-doctoral fellow at Oxford University, England, says better understanding of how the brain controls limbs will help develop prosthetic limbs in the future.
