Figure 6
Opioid receptor agonist-induced locomotor activity in STEP+/+ and STEPC230X−/− mice. (a–c) Total locomotor activity of STEP+/+ and STEPC230X−/− mice in the open field. The μ-opioid selective agonist, DAMGO (15 ng per side, intrastriatal injection, (a); the δ-opioid agonist, DPDPE (2.5 μg per side, intrastriatal injection, b; and the κ-opioid receptor agonist, U69593 (3 mg kg−1, intraperitoneal; c) were used. Significant differences between indicated groups at *P<0.05 and **P<0.01, respectively (n=6–7 animals per group, one-way analysis of variance followed by Newman–Keuls multiple comparison test). (d) Expression of opioid receptor subtypes in the dorsal striatum was performed. RT-PCR analysis and western blot analysis results are presented. DOR-1, δ-opioid receptor-1; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; KOR, κ-opioid receptor; MOR, μ-opioid receptor (n=4).
