Fig. 9.

Role of κ-opioid and neurokinin 1 receptors in GRe-mediated dopaminergic neuroprotection. Effects of neurokinin 1 receptor antagonist L-733,060 on κ-opioid receptor antagonist Nor-B-mediated pharmacological activity in response to effects of GRe against changes in tyrosine hydroxylase-immunoreactivity (TH-IR; a), TH expression (b), dopamine level (c), and dopamine turnover rate (d) induced by MA in the striatum of DYN KO mice. Sal = saline, MA = methamphetamine 35 mg/kg, i.p., GRe = ginsenoside Re 20 mg/kg, i.p., Nor-B = Nor-binaltorphimine 3 or 6 mg/kg, i.p., L733 = L-733,060 5 or 10 mg/kg, i.p., WT = wild type, DYN KO = prodynorphin knockout. Each value is the mean ± SEM of six animals (one-way ANOVA followed by Fisher’s LSD pairwise comparisons)