Modulated Effect of Dorsal Hippocampus (CA1) Antagonist of 5HT4 upon ACPA Induced Amnesia in Mice

The aim of present study is investigates the effects of bilateral injection of dorsal hippocampal (CA1) serotonergic system (Antagonist of 5-HT4) in fear memory formation process induced by ACPA (Arachidonylcyclopropylamide). Male NMRI mice were used in our experiments. Fear conditioning task was used for conditioning of fear. 24 hours after train we estimated the fear memory formation. The data show that intra peritoneal administration of ACPA (0. 005، 0. 05 and 0. 5 mg/kg) causes impairment of fear memory and amnesia. Moreover، intra-CA1 injection of 5-HT4 receptor antagonist، (RS23597-190) (0. 01، 0. 1 and 0. 2 µg/mice) had no effect on fear memory in saline-treated mice but restored the impairment of fear memory in ACPA-treated mice. The data strongly showed that serotonergic system (Antagonist) in the CA1 of hippocampus induced by ACPA interferes in impairment of fear memory.