engleski

Reversal of hypoxia-induced amnesia by arecoline in the rat

Many cognitive processes, especially memory functions are altered in cerebral hypoxic condition. Numerous evidences suggest that cholinergic neurotransmission activity of central nervous system is strongly involved in memory processes and particularly vulnerable to hypoxia. Therefore, the present study was designed to examine if hypoxia induced amnesia could be reversed by cholinergic agonist arecoline. The study was carried out on Hannover-Wistar rats weighing 250 g. Arecoline (0.1 ; 0.3 ; 1.0 mg/kg) was given i.p. The control group received saline i.p. Ten minutes later passive avoidance behavior was studied according to the step-through procedure. A two compartment apparatus with a grid floor which could be electrified was used. During the learning trial the rat was placed in the illuminated compartment. Ten seconds later the guillotine door was raised and the latency between the door opening and the entrance into the dark compartment was measured. After entering into the dark part of .the apparatus, the animals received an unavoidable foot shock. Immediately after the training, the rats were subjected to a period of oxygen deprivation hypoxia. The retention trial was carried out 24 hours later. Our results demonstrate that hypoxia produced significant impairment of passive avoidance behavior. Arecoline was effective in reversing the memory deficits in hypoxia exposed rats. Namely, all tested doses of mentioned drug produced significant improvement of the passive avoidance task in hypoxic animals. These results support the hypothesis that impairment of cholinergic neurotransmission activity is involved in memory deficit in hypoxic rats.

hypoxia; passive avoidance; arecoline; rat

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