¦ February 16, 2011
SUPPORTING RESEARCH
SSPF Grant for Study of Interneurons Necessary for Walking Movements

  The Sam Schmidt Paralysis Foundation recently provided a grant to Martyn Goulding, Ph.D. of the Salk Institute for Biological Studies in La Jolla, CA.  Dr. Goulding’s research project, titled “Axon Guidance, Synapse Formation and Neurotransmission”,  focuses on modulation and activation of excitatory spinal interneurons that are necessary for walking movements.

Interneurons in the spinal cord play a key role in generating the complex patterns of muscle activity that enable us to walk. These interneurons, together with motor neurons, form a neural network known as the central pattern generator (GPG). The CPG is able to function independently of the brain to generate the coordinated and rhythmic firing of motor neurons needed for walking.

Goulding's lab has studied the function of many of the cell types in the CPG, including a class of excitatory neurons that connect with motor neurons. These cells, the V3 interneurons, are important for maintaining the overall excitability of the locomotor network.

Goulding found that removing V3 cells from motor circuits in the spinal cord causes a loss of organized "walking" activity. This has led to the working hypothesis that enhanced V3 neuronal activity is important to maintain ambulation.

Goulding, therefore, proposes to see whether certain drugs known to modify locomotor activity in the spinal cord can directly activate V3 cells. He further plans to test whether V3 interneurons are direct targets of descending pathways that are already known to activate the CPG.

Said Goulding, "These studies will help us devise new therapies and approaches that are aimed at activating V3 interneurons and the locomotor network in the injured spinal cord," and therefore improved walking ability.