Antenatal effect of imipramine on the ontogeny of the imipramine receptors in the cerebral cortex of rats

Ontogenetic study of imipramine binding sites in the rat brain cortex employing autoradiographic and radioreceptor methods revealed that they can be detected at the 19th day of gestation and that by the 14 day of postnatal development their amount reaches the adult levels. The affinity constants of imipramine binding sites did not change significantly throughout the ontogenetic development. Exposure to the therapeutic doses of imipramine on days 17-19 of gestation resulted in a significant increase in the amount of binding sites (24% of the control level) on day 3 of postnatal development, which returned to normal by the end of the second week of postnatal development. The distribution of imipramine binding sites in the cortical layers did not change either in normal rats or in those antenatally treated with imipramine.