Dr. Jeffrey Weiler – University of Western Ontario
Jeffrey Weiler, Paul L Gribble, J Andrew Pruszynski. (2019) Spinal stretch reflexes support efficient hand control. Nature Neuroscience. 22: 529-533. doi: 10.1038/s41593-019-0336-0
Dr. Jeffrey Weiler lives in London, Ontario.
The spinal cord can process and control complex functions, like the positioning of the hand in external space.
Trying to keep your hand still while your arm gets bumped may seem like an easy task, but it requires coordination of many muscles and joints in the elbow and wrist. Multiple motor signals and external environmental forces must be considered to return the hand to its initial position. This control is widely thought to be done through neural processing that exclusively occurs within the brain, in a region called the cerebral cortex, in a top-down fashion.
Research published by Dr. Jeffrey Weiler, at the University of Western Ontario, in the laboratory of Dr. Andrew Pruszynski, challenges this notion of top-down control. In a new study, Dr. Weiler shows that rather than relying on processing done in the brain, correction of hand position following disturbance depends on much faster reflexes, which occur at the level of the spinal cord. This is the first demonstration of a “spinal circuit,” that can first sense information from the wrist and elbow, then understand how this affects hand position and finally produce reflexes that help stabilize the hand’s position in space.
This work was the first to show spinal circuits can in fact generate efficient corrective responses to help control the position of the hand – a finding that forces the field of sensorimotor neuroscience to re-evaluate how the nervous system derives the control laws that support motor behaviour. These results not only show that efficient and flexible motor control is not exclusively dependent on processing that occurs within the brain, but also provides an exciting avenue to start testing how novel therapeutic interventions that focus on spinal circuits, which may aid those suffering from movement deficits caused by injury, aging or disease.
Dr. Jeffrey Weiler
Dr. Jeffrey Weiler performed this research as a post-doctoral in the laboratory of Dr. Andrew Pruszynski at the University of Western Ontario. He conceived of the idea and designed all the experiments associated with this project in collaboration with his postdoctoral mentor. Dr. Weiler wrote the computer code to run all the experiments, collected most of the data for this project and analyzed this data. He wrote the manuscript and made all the figures that appear in the manuscript, in collaboration with his co-authors.
Natural Sciences and Engineering Research Council of Canada, BrainsCAN Canada First Research Excellence Fund