Pharmacological protection against hypoxia-induced effects on medium-term memory in a two-way avoidance paradigm

Male guinea-pigs were trained in a two-way avoidance task. They were exposed for 1 min to 100% nitrogen after each of the two daily sessions on 5 consecutive days. Eight groups of 10 animals were pretreated with a single dose of either flunarizine (0.16 or 0.63 mg/kg), nimodipine (0.16 or 0.63 mg/kg), nifedipine (0.16 or 0.63 mg/kg) or verapamil (0.63 or 2.5 mg/kg) 1 h before the first daily session. Only flunarizine protected against the hypoxia-induced amnesia. The results are discussed with reference to protective effects in other paradigms and the utility of the paradigm for pharmacological research purposes.