Involvement of dorsal hippocampal α1-adrenergic receptors in the effect of WIN55,212-2 on memory retrieval in inhibitory avoidance task.
In the present study, the possible role of α1-adrenergic receptors of the dorsal hippocampus on WIN55,212-2-induced amnesia in male Wistar rats has been evaluated. As a model of learning, a step-down passive avoidance task was used. Results indicated that post-training or pre-test intra-CA1 administration of WIN55,212-2 (0.25 and 0.5 μg/rat) reduced the step-down latency, showing an amnestic response. Amnesia produced by post-training WIN55,212-2 (0.5 μg/rat) was reversed by pre-test administration of the same drug dose. Interestingly, pre-test intra-CA1 administration of α1-noradrenergic agonists, phenylephrine alone or with an ineffective dose of WIN55,212-2 (0.25 μg/rat) reversed post-training WIN55,212-2 (0.5 μg/rat)-induced retrieval impairment. On the other hand, pre-test intra-CA1 microinjection of an α1-adrenergic antagonist, prazosin (0.5 μg/rat), 2 min before administration of WIN55,212-2 (0.5 μg/rat) inhibited the pre-test WIN55,212-2 response. It may be concluded that α1-adrenergic receptors of the dorsal hippocampal CA1 regions play an important role in WIN55,212-2-induced amnesia and restoration of memory by pre-test WIN55,212-2 administration.
Moshfegh
Azam
A
Department of Biology, Sciences and Research Branch, Islamic Azad University, Tehran, Iran.
Babaei
Parvin
P
Oryan
Shahrbano
S
Soltani
Bahram
B
Zarrindast
Mohammad-Reza
MR
D058646:Adrenergic alpha-1 Receptor Agonists / Q000494:pharmacology; D058668:Adrenergic alpha-1 Receptor Antagonists / Q000494:pharmacology; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D048588:Benzoxazines / Q000494:pharmacology*; D056547:CA1 Region, Hippocampal / Q000378:metabolism*; D002186:Cannabinoids / Q000494:pharmacology*; D008297:Male; D008568:Memory / Q000187:drug effects*; D009025:Morpholines / Q000494:pharmacology*; D009281:Naphthalenes / Q000494:pharmacology*; D009433:Neural Inhibition; D010656:Phenylephrine / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D018340:Receptors, Adrenergic, alpha-1 / Q000502:physiology*
D058646:Adrenergic alpha-1 Receptor Agonists; D058668:Adrenergic alpha-1 Receptor Antagonists; D048588:Benzoxazines; D002186:Cannabinoids; D009025:Morpholines; D009281:Naphthalenes; D018340:Receptors, Adrenergic, alpha-1; D010656:Phenylephrine; C070417:(3R)-((2,3-dihydro-5-methyl-3-((4-morpholinyl)methyl)pyrrolo-(1,2,3-de)-1,4-benzoxazin-6-yl)(1-naphthalenyl))methanone; D011224:Prazosin