CD1 mice received 4 mg/kg of DADLE (i.p.) before each i.p. injection of 10 mg/kg of METH which was given four times in a day at 2-hr intervals. Animals were killed 2 wk later and striata removed for analysis of TH activity after the previously described methods (Reinhard et al., 1986; Vrana et al., 1992). Numbers in parentheses indicate numbers of animals examined.

↵2-a P < .05 compared to the saline + saline group.