Embryonic and postnatal development of [formula omitted] binding sites in rat forebrain homogenates and slices

Abstract

The development of N-(1-[2- thienyl]-cyclohexyl)[ 3 H]piperidine ([ 3H]TCP) binding to phencyclidine (PCP) receptors in both brain homogenates and slices has been investigated in the rat. The specific binding sites for [ 3H]TCP in the homogenate were already detected at prenatal stages and steadily increased after birth. A similar developmental pattern was seen in the autoradiography of the [ 3H]TCP binding to the brain slice in which the distribution of the binding in the young is more homogeneous than that in adult. There was an increase in the B max without changes in the K d of the [ 3H]TCP binding and there was no change in inhibition of the binding by TCP, PCP and d-(−)-2-amino-5-phosphonovalerate during postnatal maturation. These findings suggest an increase in the density with no change in the affinity of PCP receptors and the absence of a change in the interaction between the PCP and N- methyl- d-aspartate receptors in the developing rat forebrain.