title: GABA(A) receptors in the central amygdala are involved in memory retention deficits induced by cannabinoids in rats.
abstract: The central nucleus of the amygdala (CeA) as the main output of amygdala plays an important role in memory processes. In this study we first evaluated the effects of intra-CeA administrations of different doses of a cannabinoid CB1 agonist, WIN55, 212-2, GABA(A) receptor agonist and antagonist, muscimol and bicuculline, alone on memory retention using passive avoidance learning (PAL) test in rats. Then we examined the effects of GABA(A) receptor agents on the responses induced by intra-CeA microinjection of different doses of WIN55, 212-2. We found that administration of WIN55, 212-2 (0.05, 0.1, 0.2 and 0.4μg/rat) immediately after training impaired memory retrieval in a dose-dependent fashion. Although pre-test intra-CeA administration of muscimol (125, 250 and 500ng/rat) alone had no effect on the step-through latency, its co-administration (125ng/rat) with different doses of WIN55, 212-2 potentiated the amnesic effects of any doses of WIN55, 212-2. The results also showed that pre-test intra-CeA administration of bicuculline (200, 400 and 800ng/rat) alone had no significant effect, but at dose of 200ng/rat disrupted post-training WIN55, 212-2-induced amnesia in the retention test. Furthermore, the additional effect of muscimol (125ng/rat) on memory impairment induced by WIN55, 212-2 (0.1μg/rat) was prevented by intra-CeA co-injection of bicuculline (200ng/rat). We indicated that stimulating or blocking GAGA(A) receptors in the CeA by muscimol and bicuculline interfere with WIN55, 212-2-induced deficits in memory retention in a PAL task and therefore suggests an interaction between cannabinergic and GABAergic systems of the CeA in memory process.
authors.affiliation: Department of Biology, School of Basic Sciences, Bu-Ali Sina University, Hamedan, Iran. Electronic address: p.hasanein@basu.ac.ir.
authors.forename: Parisa
authors.initials: P
authors.lastname: Hasanein
authors.affiliation: Department of Biology, School of Basic Sciences, Bu-Ali Sina University, Hamedan, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Sharifi
mesh_terms: D000647:Amnesia / Q000139:chemically induced / Q000523:psychology; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D048588:Benzoxazines / Q000494:pharmacology; D001640:Bicuculline / Q000037:antagonists & inhibitors / Q000494:pharmacology; D002186:Cannabinoids; D066274:Central Amygdaloid Nucleus / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D018755:GABA Agonists / Q000494:pharmacology; D018756:GABA Antagonists / Q000494:pharmacology; D008297:Male; D008569:Memory Disorders / Q000139:chemically induced* / Q000523:psychology; D008845:Microinjections; D009025:Morpholines / Q000494:pharmacology; D009118:Muscimol / Q000037:antagonists & inhibitors / Q000494:pharmacology; D009281:Naphthalenes / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011963:Receptors, GABA-A / Q000187:drug effects*
chemical_list: D048588:Benzoxazines; D002186:Cannabinoids; D018755:GABA Agonists; D018756:GABA Antagonists; D009025:Morpholines; D009281:Naphthalenes; D011963:Receptors, GABA-A; D009118:Muscimol; C070417:(3R)-((2,3-dihydro-5-methyl-3-((4-morpholinyl)methyl)pyrrolo-(1,2,3-de)-1,4-benzoxazin-6-yl)(1-naphthalenyl))methanone; D001640:Bicuculline
keywords: Amygdala; Bicuculline; Cannabinoids; Memory; Muscimol; Rats; WIN55, 212-2