DEPARTMENT of PSYCHOLOGY
2018-2019 COLLOQUIUM SERIES
presents
Adema Ribic, PhD
Research Associate
Department of Neuroscience
Tufts University School of Medicine
“Synaptic Brakes on Neuroplasticity:
Mechanism of Critical Period Closure in Visual Cortex”
Neural connectivity is robustly restructured in response to environmental factors during defined developmental windows. Heightened neuroplasticity during these critical periods is essential for establishment of circuit function and tapering of developmental plasticity is thought to stabilize mature circuits. However, increased stability of mature circuits also limits their experience-driven plasticity. Mechanisms that control critical periods have been extensively studied using sensory systems, particularly visual system. Rising levels of cortical inhibitory tone during development open the critical period for vision and refine visual function, but it is unclear how visual critical period closes. The goal of my research is to define mechanisms that stabilize circuits during critical period closure and that limit remodeling in adult brain. My recent research indicated that cortical connectivity is stabilized by Synaptic Cell Adhesion Molecule 1 (SynCAM 1/CADM1), a synapse-organizing protein that mediates synapse development and remodeling across different brain regions. SynCAM 1 selectively controls the development of subcortical inputs from the visual thalamus onto cortical inhibitory Parvalbumin interneurons, and loss of SynCAM 1 from Parvalbumin interneurons retards the development of cortical inhibition. Mice deficient in SynCAM 1 expression have immature visual function and increased visual plasticity at all ages, indicating that synaptic adhesion limits circuit plasticity. Even a brief loss of SynCAM 1 in Parvalbumin interneurons elevates plasticity in adult mice, suggesting that plasticity in the mature brain is actively restricted through SynCAM 1. These results identify a synaptic mechanism for closure of developmental windows of plasticity, as well as a synaptic brake that limits plasticity in the mature brain.
Monday, February 11, 2019
3:30 p.m.
Gilmer 190
Coffee/cookies at 3:15pm.
Reception will be held after the talk.