Transient increased density of NMDA binding sites in the developing rat hippocampus.

Using quantitative autoradiography and membrane preparations, the density of specific glutamate and N-methyl-D-aspartic acid (NMDA) binding sites have been determined in the developing rat hippocampus. We found an abrupt reduction in the density of NMDA binding sites after P8 (postnatal day) without change in affinity. The transient expression of NMDA receptors during maturation suggests that they may play a particularly important role in synaptogenesis.