Involvement of α-1-adrenergic receptors in central region of amygdala and the effects of cannabinoid agonist on inhibitory avoidance memory in male rats

Introduction: there are many similarities between memory impairment in patients suffering from alzheimer and animals treated by cannabinoids. the agonists of cannabinoid receptors affect on a variety of memories and leanings. the present study aims to investigate the role of α-1-adrenergic receptors in central region of amygdala in state-dependent learning induced by win55,212-2 (cannabinoid agonist) in rats. methods: cannulae placement was performed bilaterally in the central amygdala region of male rats. the rats were trained in the avoidance learning apparatus (step-down model). 24 hours after training, the memory was tested by measuring the lag time for stepping down the platform. results: injection of win55, 212-2 intra central amygdala (dose-dependent, 0.25, 0.5 μg/rat) post-training reduced lag time/latency for stepping down. injection induced amnesia was reversed by pre-test administration of the same dose of win55, 212-2. it is called state-dependent learning. pre-test intra-central injection of α-1-adrenoceptor agonist, phenylephrine (0.5, 0.25 μg/rat) improved post-training win55, 212-2 (0.5 μg/rat) intra central injection induced retrieval impairment. but intra injection of prazosin (0.5 μg/rat) 2 minutes before injection of win55, 212-2 (0.5 μg/rat) on the testing day inhibited win55, 212-2 state-dependent learning. conclusion: the results suggest that α-1-adrenergic receptors in central region of amygdala are involved in learning which dependent on the state induced by win55, 212-2.