Effects of 2-[2-(1-benzylpiperidin-4-yl)ethyl]-2,3-dihydro-9-methoxy-1H-pyrrolo[3,4-b]quinolin-1-one hemifumarate (T-82), a new quinoline derivative, on drug- and basal forebrain lesion-induced amnesia models were examined in rats. Scopolamine (0.5 mg/kg, i.p.) and cycloheximide (1.5 mg/kg, s.c.) shortened the step-through latency in the passive avoidance task. T-82 significantly ameliorated amnesia induced by scopolamine or cycloheximide at the dose of 0.03, 0.1 and 0.3 mg/kg, p.o., and 0.3 and 1.0 mg/kg, p.o., respectively. Basal forebrain lesions with ibotenic acid shortened the step-through latency in passive avoidance task. An acute (0.1 and 0.3 mg/kg, p.o.) or subacute (0.03-0.3 mg/kg, p.o., for 7 days) treatment of T-82 significantly reversed the shortened latency. These results suggest that T-82 may ameliorate the impairment of memory induced by acetylcholinergic dysfunction.