Antiamnestic effect of tetrahydroaminoacridine in hypoxia-exposed rats

Cerebral hypoxia is an important causal factor of memory disturbances. The present study was designed to determine the efficacy of acetylcholinesterase inhibitor tetrahydroamino- acridine (THA) in preventing the memory decline in hypoxia-exposed animals. The study was carried out on Hannover Wistar rats weighing 250 g. Various doses of THA (0.1 ; 0.3 ; 1.0 mg/kg) were given i.p. Sixty minutes later passive avoidance task was performed according to the step-through procedure. Immediately after the training trial, animals were subjected to a period of oxygen deprivation hypoxia. The level of 3.5 V% of oxygen was reached in about twenty minutes and maintained up to the loss of righting reflex. The retention trial was carried out 24 hours later. It has been found that all tested doses of mentioned cholinergic agent led to a significant enhancement of the passive avoidance in hypoxia treated rats. Our results confirm the hypothesis that increase of central cholinergic activity can antagonize memory decline in hypoxia-exposed rats.