تاثير مهاركننده نيتريك اكسايد سنتاز در ناحيه CA1 هيپوكامپ پشتي بر يادگيري وابسته به وضعيت كانابينوئيدها در مدل يادگيري اجتنابي مهاري

Influence of intracerebral administration of L-NAME in dorsal hippocampus (CA1) on WIN55, 212-2 induced state-dependent memory in the step-down passive avoidance test

Background and purpose: This study presents the effects of nitricoxide synthase inhibitor (L-NAME) on WIN55, 212-2 induced state-dependent memory of passive avoidance task, which were examined in mice. Materials and methods: Miee were anesthetized with intra-peritoneal injection of ketamine hydrochloride, plus xylazine and then placed in a stereotaxic apparatus. Also, two stainless-steel annuals were placed 1 min above CA1. One-trial step-down paradigm was used for the assessment of memory retention in adult male NMRI mice. Results: Post-training intra-CAl administration of WIN55, 212-2 (0.5 and 1 ng/mouse), dose- dependent decreased the memory retrieval. The memory impairment induced by post-training administration of WIN55, 212-2 (lug/mouse), was restored by pre-test administration with the same dose of drug (lug/mouse, intra-CAl). Single intra-CAl administration of L-NAME (0.3, 1 and 3 ng/mouse), 5 minute pre-test could not alter memory retrieval. Also, in animals in which retrieval was impaired due to post-training administration of W1N55, 212-2 (l^g/mouse), pre-test intra-CAl administration of L- NAME (0.3, 1 and 3 ^g/mouse) 24 hours after training, could not restore memory retrieval. Furthermore, in animals which received both post-training (l^g/mouse) and pre-test injection of WIN55, 212-2 (1 jig/mouse), the injection of L-NAME (3 ^g/mouse, intra-CAl), 2 minute before pre-test administration decreased retrieval. Conclusion: These findings may demonstrate the involvement ofNO in state-dependent memory induced by intra-CAl administration of WIN55, 212-2.