The Road to Genetic Targeting of Distinct Classes of Sensory Afferent in Rodents, and an Application to Spinal Cord Injury

A Physiology Brownbag Seminar

Andrew Spence, PhD
Department of Bioengineering
Temple University

Abstract
How do animals use information from peripheral sense organs when they move? Long, distinguished scientific lineages have given insight into this question, both at the level of how these organs function, and how their input is integrated with more central nervous structures. Despite standing on the shoulders of these giants, interesting open questions remain; what is the relative contribution of different classes of sensory afferent to specific locomotor tasks? how is sensory feedback used as a function of phase? and to what extent can modulating sensory feedback be useful in treating neuromuscular disease or injury, and understanding mechanisms of recovery from injury? This talk will present ongoing work that seeks to use genetic tools to target and manipulate the activity of specific classes of sensory afferent in intact rodents. Early work using optogenetics in mice will be presented, followed by recent work using DREADDs to excite or inhibit large diameter afferents in rats. DREADDs are drug-activated, engineering receptors that allow remote activation or inhibition of neurons. Results of pilot work applying selective afferent modulation by DREADDs to both enhancement of the recovery from spinal cord injury, and to understanding the mechanisms underlying that recovery, in rats, suggest that this approach holds promise. Current limitations of genetic approaches will be discussed, and a risky foray into what may lie ahead will be presented.

About the Speaker
Andrew Spence is an applied physicist by training who leads a research group in animal locomotion. As a group, we are focused on how the nervous and mechanical systems work together to produce movement, taking an integrative approach that combines experimental work with mathematical modeling,  instrumentation, and some robotics. Andrew did his undergraduate work in physics at UC Berkeley, before doing a PhD in neuroscience and biomedical microdevices at Cornell University. He returned to Berkeley for a postdoc, and worked with Bob Full on the control of many-legged locomotion.

Before coming to Temple University, he was a faculty member in the Structure and Motion Laboratory at the Royal Veterinary College, London, working with Alan Wilson before becoming an independent researcher. Currently his group is focused on the role of constraints (stability, energetics) in shaping quadrupedal gait control, and in applying new neurogenetic techniques (chemogenetics in the form of DREADDs; optogenetics) to dissect the control of fast legged locomotion and to better treat spinal cord injuries.

Physiology Brownbag Seminars
The Physiology Group in the School of Biological Sciences hosts Brownbag Lunchtime Seminars twice a month on Wednesdays at noon in room 1253 of the Applied Physiology Building located at 555 14th Street NW, Atlanta, GA 30318. You are welcome to bring a lunch and join us as we ruminate with us on topics in Physiology! A full listing of seminars can be found at http://pwp.gatech.edu/bmmc/physiology-brownbag-seminars-fall-2018/.

Event Details

Date/Time:

  • Wednesday, September 19, 2018 - 12:00pm

Location:
Room 1253, 555 14th Street NW

For More Information Contact

Greg Sawicki, Ph. D.