ω-Conotoxin GVIA inhibits the methylphenidate-induced but not methamphetamine-induced behavior

We investigated the effects of antagonists for ω-conotoxin GVIA (ω-CTX)-sensitive N-type voltage-sensitive calcium channels (N-channels) on methylphenidate- and methamphetamine-induced behavior. I.c.v. injection of ω-CTX or neomycin, both N-channel antagonists, caused a dose-dependent inhibition of methylphenidate-induced hypermotility in mice but failed to inhibit methamphetamine-induced hyperactivity. Further, ω-CTX inhibited the circling behavior induced by methylphenidate in rats that had kainic acid-induced unilateral striatal lesions. These results suggest that calcium influx through ω-CTX-sensitive N-channels plays an important role in methylphenidate-induced behavior.