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Local and external circuit influences on neural computation in the striatum

When Nov 02 2016 12:00 EDT
Where Mellon Institute Conference Room
Who Sotiris Masmanidis, Ph.D.

About the presenter: Assistant Professor, Neurobiology University of California Los Angeles

Abstract: The ability to use learned associations between environmental cues and appetitive outcomes is a critical aspect of behavior. The striatum is a brain area that is implicated in learning and performing reward-conditioned behaviors. Information processing of striatal projection neurons is thought to be shaped by both local input from interneurons, and external input from other brain areas. I will describe results from electrophysiological and behavioral experiments to unveil the role of a prominent local circuit element—parvalbumin-expressing interneurons—and source of external input—the motor cortex. We find that parvalbumin interneurons, which are GABAergic, unexpectedly amplify, rather than reduce projection neuron activity. Additionally, we find a critical role for these interneurons in supporting behavior during the early stage of associative learning. Together, this work reveals that parvalbumin interneurons and cortical input enhance striatal information coding and are necessary for performing reward-conditioned behaviors.

I will also describe a technology resource, called opto-microprobes, which my group developed for causally determining the network-wide computational contribution of specific brain circuits. This entails coupling large-scale neural recording tools with optical fibers to test how optogenetically perturbing a circuit element alters network dynamics during behavior.