POSTNATAL-DEVELOPMENT OF NMDA, AMPA AND KAINATE RECEPTORS IN INDIVIDUAL LAYERS OF RAT VISUAL-CORTEX AND THE EFFECT OF MONOCULAR DEPRIVATION

The postnatal development of the ligand binding to N-methyl-D-aspartat e (NMDA), lpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMP A), and kainate receptor sites was studied in individual layers of rat visual cortex with [H-3]MK-801, [H-3]CNQX and [H-3]kainate, respectiv ely. The studies were performed by quantitative receptor autoradiograp hy in the different visual cortical layers from normally raised rats a nd from monocularly deprived animals. In normally raised rats, in all visual cortical layers, [H-3]MK-801 and [H-3]CNQX binding increased si gnificantly from birth to around postnatal day 20, at which age alread y the adult values are reached. In contrast, the increase in [H-3]kain ate binding from day 1 to day 15 is followed by a significant decrease in binding sites up to day 25; at this age the adult binding level is nearly attained. Monocular deprivation, by unilateral eyelid suture a t the age of 11 days onwards, leads to a transient decrease in [H-3]CN QX binding in all visual cortical layers, whereas [H-3]kainate binding results to a permanent decrease in AMPA receptor sites in cortical la yers II to VI in both sides of the cortex. In contrast, only long-term monocular deprivation until the age of 90 days resulted in decreased [H-3]MK-801 binding levels as compared to age-matched controls. The da ta suggest that the laminar development of glutamate receptor subtypes is differentially affected by visual experience during early brain ma turation.