The Study on the Role of NMDA Receptors in Rat Visual Cortex

ABSTRACT

The amino acid L-glutamate is a major excitatory neurotransmitter in central nervous system of vertebrates. NMDA( n-methyl-d-aspartate) is one of the L-glutamate receptor subtypes. During a critical period of early postnatal development, the visual cortex is susceptible to experience-dependent modification of neuronal response. Recently, the activation of NMDA receptors has been supposed as an prerequisite for the induction of such modification We therefore investigated developmental changes of NMDA receptors in rat visual cortex and questioned whether they could be related to the visual development. We assessed the density of [3H] NMDA receptor in visual cortex of normally reared rats (Group I) and visually deprivated rats (Group II) using quantitative autoradiography. The density of [3H] NMDA receptor was increased rapidly by postnatal 1 week and decreased after postnatal 5 weeks, and was significantly lower in Group II than Group I during early postnatal period. These results suggest that NMDA receptors may have a role in neuronal development in visual cortex.