Neu-P11改善叠氮化钠诱导的大鼠记忆损伤

目的:本研究旨在评估一种新型褪黑素受体激动剂Neu-P11在后扣带皮层(PCC)代谢减退大鼠模型中的潜在保护作用。方法:跳台被动回避实验行为程序包括训练阶段和检测阶段,间隔24h。大鼠分为四组即溶媒对照组、Neu-P11组、NaN3组和NaN3+Neu-P11组。训练阶段1～1.5h后将大鼠麻醉,经PCC单次微量注射叠氮化钠(NaN3)或生理盐水(每侧0.5μL)。分别于微量注射2h和6h后注射1次Neu-P11(50mg/kg,腹腔注射)或PBS(与Neu-P11同体积)。检测阶段2h和4h后分别进行旷场行为实验和高架十字迷宫实验。结果:NaN3组的跳台潜伏期与溶媒对照组和Neu-P11组相比显著性降低;NaN3组在两阶段的跳台潜伏期相比无显著性差异;NaN3组与NaN3+Neu-P11组的跳台潜伏期相比无显著性差异;而NaN3+Neu-P11组在检测阶段的跳台潜伏期与训练阶段的相比显著性升高。大鼠在旷场行为实验中的水平活动距离和高架十字迷宫实验中的各项检测指标中无显著性组间差异。结论:Neu-P11在大鼠后扣带皮层代谢减退模型中发挥轻微的保护作用,改善大鼠的记忆损伤。

Effects of Neu-P11 on sodium azide induced memory deficit in rats

Objective: To assess the potential protective effects of the novel melatonin agonist Neu-P11 in the rat model of posterior cingulate cortex hypometabolism.Methods:The step-down inhibitory avoidance task was performed on rats,which involved a training session and a test session with a 24 h interval.Rats were under anesthesia about 1-1.5 h after training session and then received a microinjection of sodium azide(NaN3) into the posterior cingulate cortex or saline(0.5 μL/site).Rats received two injections of Neu-P11(50 mg/kg,i.p.) or PBS 2 h and 6 h after microinjection.The open field and elevated plus maze tests were run 2 and 4 h after test session of inhibitory avoidance task,respectively.Results:Microinjection of NaN3 produced a significant decrease of step-down latency.There was no significant difference in the latency in the only NaN3-treated rats during the test session compared with the training session.Although there was no significant difference in the latency between the NaN3 and Neu-P11-treated NaN3 rats during the test session,the Neu-P11-treated NaN3 rats presented a significant increase in latency during the test session compared with the training session.There was no significant difference in the open field and elevated plus maze activities between groups.Conclusions:Neu-P11 exerts a mild protective effect in the rat model of posterior cingulate cortex hypometabolism,and can improve sodium azide induced memory deficit in rats.