Possible involvement of CA1 5-HT1B/1D and 5-HT2A/2B/2C receptors in harmaline-induced amnesia.
In the present study, effects of the serotonergic system of the dorsal hippocampus (CA1) on harmaline-induced amnesia were examined. A single-trial step-down passive avoidance task was used for the assessment of memory retention in adult male NMRI mice. Pre-training intra-peritoneal (i.p.) administration of harmaline (1mg/kg) induced impairment of memory retention. Moreover, intra-CA1 administration of 5-HT1B/1D receptor agonist, CP94253 (5 ng/mouse), 5-HT1B/1D receptor antagonist, GR127935 (0.05 and 0.5 ng/mouse), 5-HT2A/2B/2C receptor agonist, α-methyl 5-HT (0.5 ng/mouse) and 5-HT2 receptor antagonist, cinancerine (0.5 ng/mouse) impaired memory acquisition, but did not affect locomotor activity and tail flick. Furthermore, pre-training intra-CA1 injection of subthreshold dose of CP94253 (0.05 ng/mouse) or GR127935 (0.005 ng/mouse) reversed impairment of memory acquisition induced by harmaline (1 mg/kg, i.p.). However, pre-training intra-CA1 infusion of subthreshold dose of α-methyl 5-HT (0.005 ng/mouse) or cinancerine (0.005 ng/mouse) with the administration of harmaline (0.5 and 1 mg/kg, i.p.) heighten impairment of memory acquisition. These findings implicate the involvement of CA1 serotonergic mechanism in harmaline-induced impairment of memory acquisition.
['Nasehi|Mohammad|M|', 'Jamshidi-Mehr|Mehdi|M|', 'Khakpai|Fatemeh|F|', 'Zarrindast|Mohammad-Reza|MR|']
D000647:Amnesia D000818:Animals D056547:CA1 Region, Hippocampal D000697:Central Nervous System Stimulants D002928:Cinanserin D006246:Harmaline D008297:Male D008568:Memory D008815:Mice, Inbred Strains D010069:Oxadiazoles D010879:Piperazines D011725:Pyridines D044302:Receptor, Serotonin, 5-HT1B D044346:Receptor, Serotonin, 5-HT1D D044402:Receptor, Serotonin, 5-HT2A D044403:Receptor, Serotonin, 5-HT2B D044405:Receptor, Serotonin, 5-HT2C D012701:Serotonin D058825:Serotonin 5-HT1 Receptor Agonists D058829:Serotonin 5-HT1 Receptor Antagonists
Serotonergic system Passive avoidance Memory Mice Harmaline