Abstract: Recognizing familiarity and novelty in the environment is critical for animal survival. Surprisingly, very little is known about how animals distinguish familiar from novel stimuli. We have recently discovered persistent stimulus-triggered theta oscillations in the visual cortex of mice, which are specific to the familiarity and spatial frequency features of the stimulus. These oscillations are dependent on the cholinergic muscarinic receptors for both induction and expression. Familiarity-evoked oscillations lead to the decrease in suprathreshold responses to the non-preferred directions of the drifting sinusoidal gratings and to the improved direction selectivity in V1 neurons. We then used optogenetics to directly measure the synaptic strength of the light-triggered EPSCs in V1 neurons in head-fixed mice. We discovered the weakening of the thalamocortical projections coinciding with the strengthening of the intracortical projections in V1 following visual experience and emergence of the familiarity-evoked theta oscillations. Finally, we have discovered theta oscillations in the higher visual areas (HVAs) which are synchronized with the theta oscillations in V1 following visual experience. This synchronization varies between different HVAs and depends on the properties of the visual stimuli.

Biography: Alex Chubykin is an Associate Professor at the Department of Biological Sciences, Purdue Institute for Integrative Neuroscience, Purdue Autism Research Center. Dr. Chubykin’s research aims to understand how experience shapes neural circuits and affects their function in health and disease. His laboratory uses state-of-the-art techniques, such as in vitro circuit mapping, in vivo electrophysiology, optogenetics, and behavior, to investigate the synaptic and network properties of the visual cortex and other brain regions. Dr. Chubykin has made significant contributions to the understanding of synaptic plasticity and its role in sensory processing, learning, memory, and neurological disorders. He has published over 28 peer-reviewed papers in prestigious journals, such as Nature Methods, Neuron, Cell Reports, and Journal of Neuroscience. He has received several awards and honors for his research, such as the Whitehall Foundation Research Award, and the Showalter Young Investigator Award.

~ BME Host: Fang Huang ~

Zoom link:  https://purdue-edu.zoom.us/j/98537319265

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