Yichao Zhao
BME PhD Proposal Presentation

Date: 2025-05-19
Time: 1:00 PM-2:30 PM
Location / Meeting Link: UAW 2110

Committee Members:
Ming-fai Fong, PhD (Advisor); Timothy Cope, PhD; Garrett Stanley, PhD; Bilal Haider, PhD; Hey-Kyoung Lee, PhD


Title: In vivo assessment of thalamocortical plasticity in the mature mouse visual system using optogenetic stimulation

Abstract:
Thalamocortical (TC) plasticity plays a critical role in the early development of sensory systems by enabling the formation of precise topographic connections between the thalamus and layer 4 (L4) of the neocortex. While this form of synaptic plasticity declines with age and is traditionally thought to be restricted to an early postnatal "critical period", recent in vivo studies suggest that thalamocortical plasticity can be reactivated in the mature visual cortex under certain conditions. To investigate the conditions that enable thalamocortical plasticity beyond the canonical critical period in mice, we developed a system for evaluating the strength of TC-L4 synapses in vivo via optical stimulation of the dorsal lateral geniculate nucleus (dLGN) and field recording in L4 of the primary visual cortex (V1). The main goals of this thesis include: 1) characterizing the capabilities and limitations of optogenetic stimulation of dLGN in driving thalamocortical activity and plasticity in V1; 2) determining how visual experience and deprivation alter the capacity for TC plasticity in V1 of mature mice; and 3) evaluating how inhibitory and neuromodulatory circuits contribute to TC plasticity in V1 of mature mice.