Minaprine cancels scopolamine effects on the rat's acquisition of passive avoidance responses in two multitrial...

The antiamnesic activity of minaprine has been studied in male Wistar rats. Two multitrial paradigms were employed: the light-dark box test (aversive stimulus: 0.6-mA foot-shocks) and the tail-handling test (aversive stimulus: manual tail-handling). In both paradigms, intraperitoneal scopolamine administration 30 min before testing significantly impaired the acquisition of the passive avoidance conditioned response. There were no significant differences in either paradigm between control rats and those to whom scopolamine and minaprine were simultaneously administered. These results show that minaprine fully protects the acquisition process of conditioned responses against scopolamine impairment not only in one-trial tests but also in multitrial paradigms. The effects of minaprine in reversing memory deficits are discussed in relation to its stimulating activity on central cholinergic systems.