Nefiracetam (DM‐9384) Preserves Hippocampal Neural Cell Adhesion Molecule‐Mediated Memory Consolidation Processes During Scopolamine Disruption of Passive Avoidance Training in the Rat

Abstract: Scopolamine (0.15 mg/kg), a muscarinic antagonist, when administered during training or at a discrete 6‐h posttraining time point, is demonstrated to inhibit the recall of a step‐down passive avoidance response when tested at 24 and 48 h after task acquisition. Nefiracetam (3 mg/ kg), a piracetam‐related nootropic, when given with scopolamine during training tended to improve task recall, and this effect was more pronounced when given at the 6‐h posttraining time. Co‐administration of nefiracetam with scopolamine was not necessary to achieve the antiamnesic action, as nefiracetam given during training significantly improved the memory deficits produced by scopolamine at the 6‐h posttraining time. The paradigm‐specific increase in hippocampal neural cell adhesion molecule sialylation, which is observed during consolidation of a passive avoidance response, was attenuated by the presence of scopolamine during training and at the 6‐h posttraining time, and this effect was reversed by co‐administration of nefiracetam, albeit in a paradigm‐independent manner. These results suggest nefiracetam exerts a neurotrophic action that protects memory consolidation from drug inter‐ ventive insults.