RATE OF RECOVERY OF D1 AND D2 DOPAMINERGIC RECEPTORS IN YOUNG VS ADULT-RAT STRIATAL TISSUE FOLLOWING ALKYLATION WITH ETHOXYCARBONYL-ETHOXY-DIHYDROQUINOLINE (EEDQ)

The rate of recovery of D1 and D2 receptor binding sites in rat striatal tissue labeled with [H-3]SCH-23390 or [H-3]YM-09151-2 was followed daily after irreversible blockade of these receptors with the alkylating agent ethoxycarbonyl-ethoxy-dihydroquinoline (EEDQ). These rates were significantly higher in young post-weaning rats than in young adults (14% vs. 7% per day). The findings suggest that rates of synthesis of new D1 and D2 receptor proteins may be increased during a phase of neurodevelopment in the first postnatal month when the accumulation of both receptor types, especially of D1 receptors, is about maximal.