Ipidacrine is an inhibitor of acetylcholinesterase (AChE; IC50 = 270 nM). It induces long-term potentiation (LTP) in rat hippocampal slices, an effect that can be blocked by the muscarinic antagonists atropine or pirenzepine , when used at a concentration of 10 µM.2 Ipidacrine (0.03-1 mg/kg) prevents memory deficits induced by the anticholinergic agent scopolamine in the passive avoidance test in rats.