|
|
|
 |
|
Dan Butts
Department of Biology, University of Maryland, USA
Friday 26 March 2010
12.00
Seminar Room B10 (Basement)
Alexandra House, 17 Queen Square, London, WC1N 3AR
Beyond the receptive field: the role of inhibition in formatting sensory information
Despite being well characterized anatomically and physiologically, our understanding of how the visual pathway processes information is relatively impoverished, due in part to our inability to constrain appropriately complex descriptions of visual processing with experimental data. I will describe a general nonlinear (GN) modeling framework that can identify separate [putative] excitatory and inhibitory inputs into sensory neurons, and be determined using standard extracellular recordings. This modeling approach reveals that neurons in the retina and LGN -- thought to be relatively linear -- generate responses through the interplay of nonlinear excitatory and inhibitory receptive fields. This interplay is responsible for the precise timing in LGN spike trains, and also is likely responsible for many aspects of adaptation to stimulus contrast. This modeling framework can be applied more generally, and I will also talk about application to neurons in primary auditory cortex, where separate excitatory and inhibitory elements can also be identified and potentially play a role in the diversity of neuronal responses there. Thus, in both the visual and auditory system, inhibition likely plays an important role in sensory processing, through which more complex aspects of neuronal computation might be understood.