title: Possible involvement of the CA1 GABAergic system on harmaline induced memory consolidation deficit.
abstract: Activation of the GABABreceptors inhibit learning and memory processes. The current research was designed to examine the role of dorsal hippocampal (CA1) GABABreceptors on harmaline induced memory consolidation deficit in mice. For this purpose, the effects induced by the GABABantagonist phaclofen and the GABABagonist baclofen on memory consolidation were assessed by using the step-down inhibitory avoidance task. Furthermore, the possible involvement of harmaline on GABABreceptor's effects was also assessed through using the same behavioral procedure. In a first dose response experiments, post-training intra-CA1 injections of phaclofen did not change while baclofen (0.1μg/mouse) impaired animals' performance in this task, suggesting a modulation of storage of information. Moreover, Post-training intra-peritoneal (i.p.) infusion of harmaline (2 and 5mg/kg) also decreased memory consolidation. Interestingly, phaclofen at the sub-threshold dose (0.001μg/mouse, intra-CA1), successfully antagonized the deficits on memory consolidation induced by the highest doses of harmaline (2 and 4mg/kg, i.p.). On the other hand, non significant dose of baclofenc (0.001μg/mouse, intra-CA1) potentiated impairment of memory consolidation induced by harmaline (2mg/kg, i.p.). In addition in all experiments, locomotor activity did not alter significantly. These results indicate a) that the CA1 GABABreceptors are involved in memory consolidation b) that harmaline interact with the CA1 GABABreceptors in modulation of memory consolidation.
authors.affiliation: Cognitive and Neuroscience Research Center (CNRC), Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran. Electronic address: nasehi@iricss.org.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Nasehi
authors.affiliation: Department of Biology, Faculty of Basic Sciences, Northern Branch, Islamic Azad University, Tehran, Iran.
authors.forename: Naghmeh
authors.initials: N
authors.lastname: Saadati
authors.affiliation: Institute for Cognitive Science Studies (ICSS), Tehran, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Khakpai
authors.affiliation: Cognitive and Neuroscience Research Center (CNRC), Tehran Medical Sciences Branch, Islamic Azad University, 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; Medical Genomics Research Center, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran. Electronic address: Zarinmr@ams.ac.ir.
authors.forename: Mohammad-Reza
authors.initials: MR
authors.lastname: Zarrindast
mesh_terms: D000647:Amnesia / Q000139:chemically induced*; D000818:Animals; D001418:Baclofen / Q000008:administration & dosage / Q000031:analogs & derivatives; D056547:CA1 Region, Hippocampal / Q000187:drug effects / Q000502:physiology*; D058786:GABA-B Receptor Agonists; D058788:GABA-B Receptor Antagonists; D006246:Harmaline / Q000008:administration & dosage*; D008124:Locomotion / Q000187:drug effects; D008297:Male; D000069077:Memory Consolidation / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D018080:Receptors, GABA-B / Q000502:physiology*
chemical_list: D058786:GABA-B Receptor Agonists; D058788:GABA-B Receptor Antagonists; D018080:Receptors, GABA-B; C052329:phaclofen; D006246:Harmaline; D001418:Baclofen
keywords: GABA(B) receptor; Harmaline; Memory; Step-down; The CA1 region