部門公開セミナー

Microglia continuously remodel their morphology by extending and retracting highly motile processes, which specifically interact with subsets of synaptic structures in the healthy brain. In my presentation, I will discuss recent in vivo and in situ imaging observations demonstrating that quiescent microglia play crucial roles at mature synapses under non-pathological conditions, beyond their essential contribution to the immune and inflammatory responses of the brain. In particular, I will show that microglial morphology and dynamic behavior, including their interactions with synaptic elements (axon terminals, dendritic spines, perisynaptic astrocytic processes), are regulated by various manipulations of sensory and behavioral experience during adolescence, adulthood and normal aging. Furthermore, I will show that quiescent microglia also contribute to the elimination of synaptic structures, by using specialized mechanisms that include the phagocytosis of axon terminals and dendritic spines and the proteolytic degradation of the extracellular matrix. In light of these discoveries, microglia are now emerging as important effectors of the neuronal circuit reorganization required for learning and memory throughout the lifespan.