Nitric oxide in the dorsal hippocampal area is involved on muscimol state-dependent memory in the step-down passive avoidance test

作者：Jafari Sabet Majid^*; Khodadadnejad Mohammad Amin; Ghoraba Saeed; Ataee Ramin

来源：Pharmacology Biochemistry and Behavior, 2014, 117: 137-143.

DOI：10.1016/j.pbb.2013.12.010

• Muscimol
• L-arginine
• L-NAME
• State-dependent memory
• Dorsal hippocampus
• Mice

In the present study, the effects of intra-dorsal hippocampal (intra-CA1) injections of nitric oxide (NO) agents on muscimol state-dependent memory were examined in mice. A single-trial step-down passive avoidance task was used for the assessment of memory retrieval in adult male NMRI mice.
Post-training intra-CA1 administration of a GABA(A) receptor agonist, muscimol (0.05 and 0.1 mu g/mouse) dose dependently induced impairment of memory retention. Pre-test injection of muscimol (0.05 and 0.1 mu g/mouse) induced state-dependent retrieval of the memory acquired under post-training muscimol (0.1 mu g/mouse, intraCA1) influence.
Pre-test injection of a NO precursor, L-arginine (1 and 2 mu g/mouse, intra-CAI) improved memory retention, although the low dose of the drug (0.5 mu g/mouse) did not affect memory retention.
Pre-test injection of an inhibitor of NO-synthase, L-NAME (0.5 and 1 mu g/mouse, intra-CAI) impaired memory retention, although the low dose of the drug (0.25 mu g/mouse) did not affect memory retention.
In other series of experiments, pre-test intra-CAI injection of L-arginine (0.25 and 0.5 mu g/mouse) 5 min before the administration of muscimol (0.1 mu g/mouse, intra-CAI) dose dependently inhibited muscimol statedependent memory. Pre-test intra-CAI administration of L-arginine (0.125, 0.25 and 0.5 mu g/mouse) by itself cannot affect memory retention.
Pre-test intra-CA1 injection of L-NAME (0.25 mu g/mouse, intra-CA1) reversed the memory impairment induced by post-training administration of muscimol (0.1 mu g/mouse, intra-CA1). Moreover, pre-test administration ofi.NAME (0.125 and 0.25 mu g/mouse, intra-CAI) with an ineffective dose of muscimol (0.025 mu g/mouse, intra-CA1) significantly restored the retrieval and induced muscimol state-dependent memory. Pre-test intra-CAI administration of L-NAME (0.0625, 0.125 and 0.25 mu g/mouse) by itself cannot affect memory retention.
It may be suggested that the nitric oxide in the dorsal hippocampal area play an important role in muscimol statedependent memory.

• 出版日期2014-2