“Synaptic Inhibition Controls Operating Regimes of the Cerebral Cortex in vivo”

Bilal Haer, Ph.D.*
Post-Doctoral Fellow
University College London
Institute of Ophthalmology
Department of Visual Neuroscience

Seminar will be made available via videoconference in the Health Sciences Research Building, room E 182 and Technology Enterprise Park, room 104.

The cerebral cortex in vivo displays many regimes of spontaneous and sensory evoked activity.  What are the cellular and circuit mechanisms that determine these regimes? What consequences do they have for sensory processing?  And how do these mechanisms vary across behavioral states? 

 To address these questions, I will present three electrophysiological studies of spiking and sub-threshold (synaptic) activity recorded from specific cortical neuron types in vivo.  First, I will show that cortical excitation and inhibition closely balance each other during ongoing spontaneous activity.  I will next show how inhibitory circuits are engaged to produce reliable and precise cortical activity during naturalistic visual stimulation.  Finally, I will show that in the awake cortex, the specific recruitment of inhibitory circuits dramatically sharpens the spatial and temporal resolution of visual processing.  Taken together, these studies suggest a dominant role for cortical inhibitory circuits in the rapid modulation of sensory processing according to the demands of the environment and behavior.

Faculty Host: Chris Rozell, Ph.D.