A Competition-based Mechanism for Coordinated Spine Pruning and Maturation

Abstract: Dendritic spines are the postsynaptic sites of most excitatory synapses in the central nervous system. In early postnatal life， spines are rapidly formed during the process of spinogenesis. However during the transition through adolescence， a significant amount of spines are actively pruned， a process believed to be critical for neural circuit refinement. Although the phenomenon of spine pruning has been extensively described， and its defects have been implicated in developmental neurological disorders including autism spectrum disorders and schizophrenia， its underlying mechanism remains largely unknown. Our recent study found that in the mouse sensory cortical region receiving tactile inputs from the whiskers， the pruning and maturation of spines were coordinated and bidirectionally regulated by neural activity. We further found the inter-spine competition for cadherin/catenin complexes induced by neural activity mediated the fate differentiation of neighboring spines with the cadherin/catenin-enriched spine becoming more mature at the expense of its neighbor. This cadherin/catenindependent and competition-based model provides specificity for concurrent spine pruning and maturation， and is critical for our understanding of the molecular control of neural circuit refinement.

CSTR: 32200.14.cjcb.2015.12.0001