Visual experience and deprivation bidirectionally modify the composition and function of NMDA receptors in visual cortex

The receptive fields of visual cortical neurons are bidirectionally modifie d by sensory deprivation and experience, but the synaptic basis for these c hanges is unknown. Here we demonstrate bidirectional, experience-dependent regulation of the composition and function of synaptic NMDA receptors (NMDA Rs) in visual cortex layer 2/3 pyramidal cells of young rats. Visual experi ence decreases the proportion of NR2B- only receptors, shortens the duratio n of NMDAR-mediated synaptic currents, and reduces summation of synaptic NM DAR currents during bursts of high-frequency stimulation. Visual deprivatio n exerts an opposite effect. Although the effects of experience and depriva tion are reversible, the rates of synaptic modification vary. Experience ca n induce a detectable change in synaptic transmission within hours, while d eprivation-induced changes take days. We suggest that experience-dependent changes in NMDAR composition and function regulate the development of recep tive field organization in visual cortex.