Chronic stress in rats has been shown to impair learning and memory, and precipitate several affective disorders like depression and anxiety. The mechanisms involved in these stress-induced disorders and the possible reversal are poorly understood, thus limiting the number of drugs available for their treatment. Our earlier studies suggest cholinergic dysfunction as the underlying cause in the behavioral deficits following stress. Muscarinic cholinergic agonist, oxotremorine is demonstrated to have a beneficial effect in reversing brain injury-induced behavioral dysfunction. In this study, we have evaluated the effect of oxotremorine treatment on chronic restraint stress-induced cognitive deficits. Rats were subjected to restraint stress (6 h/day) for 21 days followed by oxotremorine treatment for 10 days. Spatial learning and memory was assessed in a partially baited eight-arm radial maze task. Stressed rats exhibited impairment in performance, with decreased percentage of correct choices and an increase in the number of reference memory errors (RMEs). Oxotremorine treatment (0.1 or 0.2 mg/kg, i.p.) to stressed rats resulted in a significant increase in the percent correct choices and a decrease in the number of RMEs compared with stress as well as the stress+vehicle-treated groups. In the retention test, oxotremorine treated rats committed less RMEs compared with the stress group. Chronic restraint stress decreased acetylcholinesterase (AChE) activity in the hippocampus, frontal cortex and septum, which was reversed by both the doses of oxotremorine. Further, oxotremorine treatment also restored the norepinephrine levels in the hippocampus and frontal cortex. Thus, this study demonstrates the potential of cholinergic muscarinic agonists and the involvement of both cholinergic and noradrenergic systems in the reversal of stress-induced learning and memory deficits.

译文

大鼠慢性应激已被证明会损害学习和记忆,并引发多种情绪障碍,如抑郁和焦虑。这些压力引起的疾病和可能的逆转涉及的机制了解甚少,因此限制了可用于治疗的药物数量。我们较早的研究表明,胆碱能功能障碍是压力后行为缺陷的根本原因。毒蕈碱胆碱能激动剂,oxotremorine被证明在逆转脑损伤引起的行为功能障碍方面具有有益作用。在这项研究中,我们评估了氧代雷莫林治疗对慢性束缚应激诱导的认知缺陷的影响。对大鼠进行束缚应激(6小时/天),持续21天,然后进行氧代莫瑞林治疗10天。在部分诱饵的八臂径向迷宫任务中评估了空间学习和记忆。应激大鼠表现出功能受损,正确选择的百分比降低,参考记忆错误(RME)数量增加。与应激组和应激载体治疗组相比,对应激大鼠进行氧代雷莫林治疗(0.1或0.2 mg / kg,腹膜内)导致正确选择的百分比显着增加,RME数量减少。在保留测试中,与应激组相比,用氧代苯甲酸治疗的大鼠的RME较少。慢性束缚应激会降低海马,额叶皮层和隔垫中的乙酰胆碱酯酶(AChE)活性,这两种剂量的奥索莫瑞宁均可逆转。此外,oxotremorine治疗还可以恢复海马和额叶皮层的去甲肾上腺素水平。因此,这项研究证明了胆碱能毒蕈碱激动剂的潜力以及胆碱能和去甲肾上腺素能系统在逆转应激诱导的学习和记忆缺陷中的作用。

+1
+2
100研值 100研值 ¥99课程
检索文献一次
下载文献一次

去下载>

成功解锁2个技能,为你点赞

《SCI写作十大必备语法》
解决你的SCI语法难题!

技能熟练度+1

视频课《玩转文献检索》
让你成为检索达人!

恭喜完成新手挑战

手机微信扫一扫,添加好友领取

免费领《Endnote文献管理工具+教程》

微信扫码, 免费领取

手机登录

获取验证码
登录