Piracetam is a cyclic derivative of g-aminobutyric acid (GABA) reported to improves learning and memory consolidation, facilitates inter-hemispheric transfer and increases the cerebral resistance to cognitive impairments induced by hypoxia and other noxious stimuli including ageing. Therefore, the present study was designed to investigate the effect of piracetam on scopolamine (3 mg Kg-1, i.p.), cyclohexamide (28 mg Kg-1, i.p.), diazepam (1 mg Kg-1, i.p.), sodium nitrite (75 mg Kg-1, i.p.) and BN52021 (15 mg Kg-1, i.p.) were administred to mice before acquisition or retrieval trial using water maze test. Scopolamine, cyclohexamide and diazepam have produced only anterograde amnesia. Sodium nitrite has produced both anterograde and retrograde amnesia. BN52021 (PAF receptor antagonist) has produced only retrograde amnesia. The present results exhibit that the anterograde amnesia produced by scopolamine, cyclohexamide and sodium nitrite has been prevented by piracetam (200 mg Kg-1, i.p.). On the other hand diazepam induced anterograde amnesia has not been affected by piracetam. However, retrograde amnesia produced by sodium nitrite and BN52021 has been attenuated by piracetam (200 mg Kg-1, i.p.). It is speculated that ameliorative effect of piracetam in experimental amnesia may be due to increase in intracellular calcium, restoration of synthesis of cerebral proteins, improvement in cholinergic mechanism and consequent restoration of brain cell fluidity.
