Riley T. Zeller-Townson

BME Ph.D. Proposal Presentation

Date: Friday, April 28th 2017

Time: 10:00 AM

Location: McIntire Conference room- Whitaker 3115

Advisor: 

Dr. Rob Butera

Thesis Committee:

Dr. Garrett Stanley

Dr. Chris Rozell

Dr. Morten Raastad

Dr. Bilal Haider

Title: MECHANISMS OF HIGH-VARIANCE CONDUCTION IN THE AXON

Abstract:

The conduction of action potentials along the axon is taught to be reliable, consistent, and fast, with conduction failures dogmatically studied at the synapse.  However, measurements of action potential conduction both in vitro and in vivo suggest that conduction can transition into a state of high trial-to-trial variability and low reliability.  This unreliable conduction occurs along the axon, not at the synapse, and its mechanism is unknown.  Finding this mechanism would help determine the limits of axon conduction fidelity, and may shed light on the effects of clinical electrical stimulation on the nervous system.  

Preliminary results suggest that the high-variance state is inherently a multi-compartment phenomenon, requiring electrophysiology tools with the capacity for single-trial recording of axonal action potentials at multiple locations, over thousands of trials. CMOS-based high density micro-electrode arrays will be used to 1) locate the sources of this variance, 2) compare variability in naturalistic and stimulus evoked propagation, and 3) test possible underlying biophysical mechanisms.  This study will bridge gaps between the study of repeated electrical stimulation of neurons, activity-dependent conduction velocity, and homeostatic control of axon signaling.