PARTICIPATION OF DIFFERENT 5-HT RECEPTORS IN THE MEMORY PROCESS IN RATS AND ITS MODULATION BY THE SEROTONIN DEPLETOR P-CHLOROPHENYLALANINE

The memory effects of agonists and antagonists of some serotonin (5-HT ) receptor subtypes were examined in experiments on rats using an acti ve avoidance method (shuttle-box). The S-HT receptor antagonists NAN 1 90 (1 mg/kg i.p.) and pindolol (6 mg/kg i.p.) improved some indices fo r memory; the 5-HT2 and 5-HT3 receptor antagonists ritanserin (1 mg/kg i.p.) and ondansetron (0.1 mg/kg i.p.) exerted a favourable effect on the mastering of active avoidance performance. The tryptophan hydroxy lase inhibitor para-chlorophenylalanine (300 mg/kg i.p.) alone produce d no significant changes in the indices for retention of learned behav iour but in combination with the 5-HT-receptor agonists and antagonist s influenced some of their effects. The results obtained show differen t participation of 5-HT1A, 5-HT2 and 5-HT3 receptors in the mechanisms of the memory process; the nature of this involvement is modulated by the brain level of serotonin.