Investigating the Use of Subthreshold Optogenetic Stimulation of Trunk Motor Cortex
Monday, March 13, 2017
12:00 PM-2:00 PM
BIOMED PhD Research Proposal
Title:
Investigating the Use of Subthreshold Optogenetic Stimulation of Trunk Motor Cortex Paired with Pelvic Based Locomotor Rehabilitation in Both Stepping and Non-Stepping Adult Complete Spinal Cord Injured Rats
Speaker:
Kendall A. Schmidt, PhD Candidate, School of Biomedical Engineering, Science and Health Systems
Advisor:
Simon F. Giszter, PhD, Professor of Neurobiology and Anatomy, College of Medicine, Drexel University
Abstract:
Due to altered sensory afferents and motor efferents, a complete T9/T10 spinal cord transection in rats results in a motorically silenced region of cortex below bregma. Thus, in addition to paralytic effects associated with regions of the body below the lesion site, the brain is altered. Neonatally transected rats (NTX) reared into adulthood, retain active lumbar central pattern generators (CPGs), and hence autonomous hindlimb alternation.
Improved functional recovery of NTX rats trained to weight support on a treadmill with robotic assistance is accompanied by unique plastic changes in cortex, namely, a caudal shift of trunk representation center of gravity (COG) toward the silenced cortical region, and increased cortical representation of trunk muscle segments below the lesion, evident from intracortical microstimulation (ISMS) motor mapping. Rats transected as adults (ATX) experience no autonomous hindlimb alternation, and when trained in the same paradigm as improved NTX rats above, do not experience the same cortical changes.
Biasing the trunk motor cortex with subthreshold optogenetic stimulation (SOS) in ATX animals to mimic the advantageous cortical changes seen in improved NTX animals is hypothesized to benefit ATX animals during rehabilitation by increasing trunk control based on preliminary data. Pairing cortical biasing with exogenous CPG activation using virally delivered brain derived neurotrophic factor (BDNF) is hypothesized to further benefit the rehabilitation of ATX rats by integrating increased trunk control with hindlimb alternation.
Contact Information
Ken Barbee
215-895-1335
barbee@drexel.edu