Effects of 5-HT(1A) receptor agonists on the passive avoidance task in mice

Effects of 5-HT agonists on learning and memory were examined using a step-down passive avoidance task in mice. A nonselective 5-HT agonist. 5- methoxy-N,N-dimethyltryptamine (5-MeODMT) given immediately after training remarkably decreased the step-down latencies in the retention test. A 5-HT₁ antagonist, (±)-pindolol significantly attenuated 5-MeODMT-induced amnesia. 5-HT(1A) selective agonists. 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH- DPAT) and 1-[2-(4-aminophenyl)ethyl]-4-(3-trifluoromethylphenyl) piperazine (PAPP) given immediately after training caused impairment of memory. 8-OH- DPAT-induced memory impairment was inhibited by a nonselective 5-HT antagonist, methysergide and a 5-HT₁ antagonist, (±)-pindolol, whereas a selective 5-HT₂ antagonist, ritanserin was inactive. These results suggest that 5-HT(1A) receptors may be linked to memory process in mice.