title: The effect of CA1 dopaminergic system in harmaline-induced amnesia.
abstract: In the present study, the effects of bilateral injections of dopaminergic drugs into the hippocampal CA1 regions (intra-CA1) on harmaline-induced amnesia were examined in male mice. A one-trial step-down passive avoidance task was used for the assessment of memory retention in adult male mice. Pre-training intra-peritoneal (i.p.) administration of harmaline (1 mg/kg) induced impairment of memory retention. Moreover, intra-CA1 administration of dopamine D1 receptor antagonist, SCH23390 (0.02 μg/mouse), dopamine D1 receptor agonist, SKF38393 (0.5 μg/mouse), dopamine D2 receptor antagonist, sulpiride (1 μg/mouse) and dopamine D2 receptor agonist, quinpirole (0.25 and 0.5 μg/mouse) suppressed the learning of a single-trial passive avoidance task. Also, pre-training intra-CA1 injection of subthreshold doses of SCH23390 (0.001 μg/mouse) or sulpiride (0.25 μg/mouse) with the administration of harmaline (1 mg/kg, i.p.) reversed impairment of memory formation. However, pre-training intra-CA1 injection of SKF38393 (0.1 μg/mouse) or quinpirole (0.1 μg/mouse) increased pre-training harmaline (0.25 and 0.5 mg/kg, i.p.)-induced retrieval impairment. Moreover, SKF Ca blocker (SKF) (0.01 μg/mouse) decrease the amnesia induced by harmaline (1 mg/kg), while co-administration of SKF (0.01 μg/mouse)/sulpiride (0.25 μg/mouse) or SCH23390 (0.001 μg/mouse)/sulpiride (0.25 μg/mouse) potentiate amnesia caused by harmaline. These findings implicate the involvement of CA1 dopaminergic mechanism in harmaline-induced impairment of memory acquisition.
authors.affiliation: School of Advanced Sciences in Medicine, Islamic Azad University, Tehran Medical Sciences Branch, Tehran, Iran; Institute for Cognitive Science Studies (ICSS), Tehran, Iran. Electronic address: Nasehi@iricss.org.
authors.forename: M
authors.initials: M
authors.lastname: Nasehi
authors.affiliation: Department of Biology, Faculty of Basic Sciences, Northern Branch, Islamic Azad University, Tehran, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Ketabchi
authors.affiliation: Institute for Cognitive Science Studies (ICSS), Tehran, Iran.
authors.forename: F
authors.initials: F
authors.lastname: Khakpai
authors.affiliation: School of Advanced Sciences in Medicine, Islamic Azad University, Tehran Medical Sciences Branch, Tehran, Iran; Institute for Cognitive Science Studies (ICSS), Tehran, Iran; Department of Pharmacology School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Iranian National Center for Addiction Studies, Tehran University of Medical Sciences, Tehran, Iran; School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran. Electronic address: zarinmr@ams.ac.ir.
authors.forename: M-R
authors.initials: MR
authors.lastname: Zarrindast
mesh_terms: D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000494:pharmacology; D000647:Amnesia / Q000139:chemically induced* / Q000188:drug therapy / Q000378:metabolism; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects / Q000502:physiology; D001552:Benzazepines / Q000494:pharmacology; D056547:CA1 Region, Hippocampal / Q000187:drug effects* / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D018491:Dopamine Agonists / Q000494:pharmacology*; D018492:Dopamine Antagonists / Q000494:pharmacology*; D006246:Harmaline / Q000633:toxicity*; D008297:Male; D008568:Memory / Q000187:drug effects / Q000502:physiology; D051379:Mice; D008996:Monoamine Oxidase Inhibitors / Q000633:toxicity*; D017447:Receptors, Dopamine D1 / Q000378:metabolism; D017448:Receptors, Dopamine D2 / Q000378:metabolism; D013469:Sulpiride / Q000494:pharmacology
chemical_list: D001552:Benzazepines; D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D008996:Monoamine Oxidase Inhibitors; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; C534628:SCH 23390; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D013469:Sulpiride; D006246:Harmaline; D004298:Dopamine
keywords: CA1; dopamine; harmaline; passive avoidance memory; step-down