Abstract
Unilateral intrastriatal microinjections of α-methyl-p-tyrosine followed by systemic amphetamine treatment produced turning ipsilateral to the side of the injection in rats from 12 days of age to maturity, but not in rats younger than 12 days. These results are consistent with other findings that indicate rapid development of the striatal dopaminergic system and dopaminergic component of the amphetamine stereotypy in the second postanatal week.