Postnatal behavioral alterations resulting from prenatal administration of dl-alphamethylparatyrosine.

We have previously reported that injection of dl-alphamethylparatyrosine methylester (AMPT) into the yolk sac of fertilized chicken eggs prior to incubation results in dose-related increases in the specific activity of tyrosine hydroxylase (TH) at 29 days postnatally. We now report that injection of 10.0 and 33.3 mg/kg of AMPT prior to incubation results in dose-related increases in acquisition rates of 2 operant responses. Between 1 and 3 weeks of postnatal age, we observed a dose-related decrease in latency to perform a detour response and, at 55-60 days of postnatal age, an increased rate of acquisition of a key peck response in an autoshaping paradigm. We could not discern any significant alteration in several measures of unconditioned behaviors in an open field situation at 3 weeks of postnatal age. Our data support the contention that early catecholamine (CA) depletion can produce long-term alterations in postnatal behavior.