Anxiety-like behavior induced by histaminergic agents can be prevented by cannabinoidergic WIN55,212-2 injected into the dorsal hippocampus in mice.
In the present study, we investigate the effects of the histaminergic system and cannabinoid receptor agents on anxiety-related behaviors and their interactions using the hole-board test on mice. Bilateral intra-CA1 administration of the CB1/CB2 receptor agonist, WIN55, 212-2 (0.1-0.5microg/mouse) did not modify exploratory behaviors in mice. On the other hand, intra-CA1 administration of CB1 receptor antagonist, AM251 (25 and 50ng/mouse) or histamine, pyrilamine and ranitidine (5-10microg/mouse) decreased the amount of head-dipping and increased the first head-dip, suggesting an anxiogenic-like response. Furthermore, our present data indicated that the co-administration of WIN55, 212-2 (0.25microg/mouse) with histaminergic agents, decreased the anxiogenic-like response of an effective dose (5microg/mouse) of histamine and pyrilamine, but not that of ranitidine. In addition, the results demonstrated that co-administration of an ineffective dose of AM251 (15ng/mouse) with histaminergic drugs did not alter the response induced by an ineffective dose (3.75microg/mouse) of either histamine or pyrilamine and ranitidine. In all experiments and doses, locomotor activity and other exploratory behaviors were not significantly changed. In conclusion, our results showed that there is a chance of partial interaction between the cannabinoidergic and the histaminergic systems of the dorsal hippocampus on anxiogenic/anxiolytic-like behaviors in hole-board test.
Department of Pharmacology and Iranian National Center for Addiction Studies, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. zarinmr@ams.ac.ir
Mohammad Reza
MR
Zarrindast
Mohammad
M
Nasehi
Morteza
M
Piri
Payvand
P
Bina
D000818:Animals; D001007:Anxiety / Q000139:chemically induced*; D048588:Benzoxazines / Q000008:administration & dosage / Q000494:pharmacology*; D005106:Exploratory Behavior / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects*; D006632:Histamine / Q000494:pharmacology*; D006633:Histamine Antagonists / Q000494:pharmacology; D008297:Male; D051379:Mice; D009025:Morpholines / Q000008:administration & dosage / Q000494:pharmacology*; D009281:Naphthalenes / Q000008:administration & dosage / Q000494:pharmacology*; D010880:Piperidines / Q000494:pharmacology; D011720:Pyrazoles / Q000494:pharmacology; D011738:Pyrilamine / Q000494:pharmacology; D011899:Ranitidine / Q000494:pharmacology
D048588:Benzoxazines; D006633:Histamine Antagonists; D009025:Morpholines; D009281:Naphthalenes; D010880:Piperidines; D011720:Pyrazoles; C103505:AM 251; C070417:(3R)-((2,3-dihydro-5-methyl-3-((4-morpholinyl)methyl)pyrrolo-(1,2,3-de)-1,4-benzoxazin-6-yl)(1-naphthalenyl))methanone; D006632:Histamine; D011899:Ranitidine; D011738:Pyrilamine