Effects of neonatal lead exposure on apomorphine-induced aggression and stereotypy in the rat.

Rats were exposed to lead via the maternal milk. At 90 days of age, lead-exposed pairs and control pairs were tested for aggression induced by 5.0 mg/kg apomorphine. The large increase in aggression in response to apomorphine seen in controls was markedly attenuated in lead-treated subjects. In contrast, apomorphine-induced stereotypy was not affected. These results provide a further demonstration of persistent behavioral abnormalities resulting from early exposure to lead at levels which do not affect weight gain or mortality.