RT Journal Article SR Electronic T1 Possible involvement of the activation of voltage-sensitive calcium channels in the ameliorating effects of nefiracetam on scopolamine-induced impairment of performance in a passive avoidance task. JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 881 OP 892 VO 270 IS 3 A1 Yamada, K A1 Nakayama, S A1 Shiotani, T A1 Hasegawa, T A1 Nabeshima, T YR 1994 UL http://jpet.aspetjournals.org/content/270/3/881.abstract AB We investigated the effects of various types of calcium channel antagonists on the amelioration by nefiracetam [N-(2,6-dimethylphenyl)-2-(2-oxo-1-pyrrolidinyl) acetamide, DM-9384] of scopolamine-induced impairment of performance in a passive avoidance task in mice. The reversal of the scopolamine-induced impairment of performance by nefiracetam showed a bell-shaped plot. Both i.p. and i.c.v. injection of L-type calcium channel antagonists such as nifedipine and flunarizine attenuated the ameliorating effects of nefiracetam, although diltiazem had no effect. Neomycin, an N-type calcium channel antagonist, also attenuated these effects of nefiracetam in a dose-dependent manner. Further, LaCl3 but not NiCl2 showed inhibitory effects on the amelioration by nefiracetam. These results suggest that the activation of high-voltage-activated, but not low-voltage-activated, calcium channels is involved in the ameliorating effects of nefiracetam on scopolamine-induced impairment of performance in a passive avoidance task.