"The more things change the more they remain the same: constructing linear synaptic integration from non-linear conductances in the mammalian sound localization circuitry"
Mon, November 19, 2012 • 12:00 PM - 1:00 PM • SEA 4.242 (Note room change from SEA 4.244 to SEA 4.242)
Location of talk has been changed to SEA 4.242 (the room next to 4.244)
Nace Golding, Ph.D.
Section of Neurobiology and Center for Learning and Memory
The University of Texas at Austin
Bag Lunch Talk
Find information about current and upcoming talks at CPS on our website: http://www.utexas.edu/cola/centers/cps/events/calendar.php
Abstract: Feedforward inhibition sharpens the precision of neurons throughout ascending auditory pathways, including the binaural neurons of the medial superior olive (MSO). However, the biophysical influence of inhibition is poorly understood, particularly at higher frequencies where the relative phase of inhibition and excitation becomes ambiguous. I will discuss new data in MSO principal cells in vitro that trisynaptic feedforward inhibition unexpectedly precedes disynaptic excitation, providing both a concurrent hyperpolarization and conductance shunt during EPSP summation. Using dual patch recordings and dynamic clamp we have shown that both the linearity and temporal fidelity of synaptic integration is improved by reducing Kv1 potassium channel conductance during inhibition, which counters membrane shunting even at high frequencies. The reduction of peak excitation by inhibition lowers spike probability, narrowing but not shifting the window for detecting binaural coincidence. Our findings prompt a reexamination of current models of binaural processing that rely on inhibition altering the timing of binaural excitation.