Rapid, experience-dependent expression of synaptic NMDA receptors in visual cortex in vivo

Sensory experience is crucial in the refinement of synaptic connections in the brain during development. It has been suggested that some forms of expe rience-dependent synaptic plasticity in vivo are associated with changes in the complement of postsynaptic glutamate receptors, although direct eviden ce has been lacking. Here we show that visual experience triggers the rapid synaptic insertion of new NMDA receptors in visual cortex. The new recepto rs have a higher proportion of NR2A subunits and, as a consequence, differe nt functional properties. This effect of experience requires NMDA receptor activation and protein synthesis. Thus, rapid regulation of postsynaptic gl utamate receptors is one mechanism for developmental plasticity in the brai n. Changes in NMDA receptor expression provide a mechanism by which brief s ensory experience can regulate the properties of NMDA receptor-dependent pl asticity in visual cortex.