Microglia and synapses: partners in experience-dependent plasticity

Speaker: Ania Majewska, Ph.D.
Affiliation: Associate Professor, Department of Neuroscience, University of Rochester

Date: April 18, 2018

Talk title: Microglia and synapses: partners in experience-dependent plasticity

Abstract: The ability to tune synapses, and thus alter neural networks, is critical to both the normal development of brain circuitry and brain function throughout life, underlying processes such as learning and memory. Microglia are immune cells that infiltrate the brain early in development before the formation of the blood brain barrier. They have critical roles during brain injury, infection or disease. However, new data has thrust these non-neural cells into the spotlight as regulators of synapses. In the absence of pathology, microglia display dynamic interactions with synapses, and contribute to experience-dependent plasticity in the visual cortex in vivo. Manipulations of visual experience elicit a remarkably rapid behavioral response in microglia which is distinct from their inflammatory response, and includes an increase in phagocytosis that corresponds to the early phase of plasticity when synapses are lost in this model and when microglia increase their synaptic interactions. Our recent work has focused on identifying the molecular mechanisms through which microglia respond to changes in neuronal activity and communicate with synapses. I will also discuss our work exploring the contribution of these cells to plasticity deficits observed in a mouse model of third trimester alcohol exposure. Together, our findings suggest that microglia play an important role in synaptic plasticity, and use a subset of their pathological molecular repertoire to implement plastic changes in the non-pathological brain.