Embryonic and postnatal development of N-(1-[2-thienyl]cyclohexyl)[3H]piperidine binding sites in rat forebrain homogenates and slices.

The development of N-(1-[2-thienyl]-cyclohexyl)[3H]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 Bmax without changes in the Kd 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.