EFFECTS OF TACRINE ON DEFICITS IN ACTIVE-AVOIDANCE PERFORMANCE INDUCED BY AF64A IN RATS

Effects of tacrine (1,2,3,4-tetrahydro-9-aminoacridine) on memory defi cits in rats treated with ethylcholine aziridinium ion (AF64A) were st udied using active avoidance test in the two-way shuttle box. Neurotox in AF64A injected at a dose of 6 nmol (icy, bilaterally) causes nonspe cific tissue damage in hippocampal fields CA2 and CA3. Two weeks after treatment with 6 nmol, AF64A active avoidance performance of toxin-tr eated rats was significantly deteriorated compared to vehicle-treated animals estimated in learning test (68 +/- 3.5 and 83 +/- 3.2% of corr ect responses, respectively; p < 0.01) and in retention test (53 +/- 5 and 76 +/- 3.6%, respectively; p < 0.01). Under these conditions, chr onic treatment with tacrine at a daily dose of 1 mg/kg for 12-14 d rev erses the effect of AF64A on the active avoidance performance both in learning (78 +/- 3.2%) and retention (72 +/- 4%) tests. It is supposed that behavioral effects of tacrine considerably depend on a severity of neurodegeneration in the hippocampus.