title: The amnesic effect of intra-central amygdala administration of a cannabinoid CB1 receptor agonist, WIN55,212-2, is mediated by a β-1 noradrenergic system in rat.
abstract: In this study, we investigated effects of intra-central amygdala (intra-CeA) administrations of a cannabinoid agonist, WIN55,212-2 by itself and its interaction with β1-adrenoceptor agents on memory consolidation. We used a step-through inhibitory avoidance (IA) task to assess memory in male Wistar rats. The results showed that post-training intra-CeA administrations of different doses of WIN55,212-2 at doses of 0.1 and 0.25 μg/rat impaired memory consolidation (or induced amnesia) as revealed by a decrease in step-through latency on the test day. Post-training intra-CeA injections of a β1-adrenoceptor agonist, isoprenaline (0.01, 0.025, 0.05 μg/rat) by itself had no significant effect on memory consolidation, while at all doses prevented the amnesia induced by post-training injections of WIN55,212-2 (0.25 μg/rat). Although, post-training intra-CeA administrations of β1-adrenoceptor antagonist, atenolol alone at different doses (0.01, 0.025, 0.05 and 0.1 μg/rat) had no significant effect, but its co-administrations at doses of 0.05 and 0.1 μg/rat along with an ineffective dose of WIN55,212-2 (0.05 μg/rat) induced amnesia, and at dose of 0.1 μg/rat along with an effective dose of WIN55,212-2 (0.25 μg/rat) increased amnesia that induced by the later drug. Moreover, the improving effect of isoprenaline (0.025 μg/rat) on amnesia induced by WIN55,212-2 (0.25 μg/rat) was prevented by intra-CeA co-injections of atenolol at doses of 0.01 and 0.025 μg/rat. The present results suggest that a β1-adrenoeceptor mechanism in the central amygdala (CeA) is involved in amnesia induced by post-training intra-CeA injections of WIN55,212-2.
authors.affiliation: Department of Neuroscience, School of Advanced Medical Technologies, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: M R
authors.initials: MR
authors.lastname: Zarrindast
authors.forename: M
authors.initials: M
authors.lastname: Ghiasvand
authors.forename: A
authors.initials: A
authors.lastname: Rezayof
authors.forename: S
authors.initials: S
authors.lastname: Ahmadi
mesh_terms: D000647:Amnesia / Q000139:chemically induced* / Q000378:metabolism / Q000503:physiopathology; D000679:Amygdala / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D048588:Benzoxazines / Q000494:pharmacology*; D063385:Cannabinoid Receptor Modulators / Q000494:pharmacology*; D008297:Male; D008568:Memory / Q000187:drug effects / Q000502:physiology*; D009025:Morpholines / Q000494:pharmacology*; D009281:Naphthalenes / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D043884:Receptor, Cannabinoid, CB1 / Q000819:agonists*; D018342:Receptors, Adrenergic, beta-1 / Q000502:physiology*
chemical_list: D048588:Benzoxazines; D063385:Cannabinoid Receptor Modulators; D009025:Morpholines; D009281:Naphthalenes; D043884:Receptor, Cannabinoid, CB1; D018342:Receptors, Adrenergic, beta-1; C070417:(3R)-((2,3-dihydro-5-methyl-3-((4-morpholinyl)methyl)pyrrolo-(1,2,3-de)-1,4-benzoxazin-6-yl)(1-naphthalenyl))methanone