手术应激与心理应激对老年小鼠学习记忆功能影响的研究

发布时间：2018-07-28 11:36

【摘要】：术后认知功能障碍(POCD, Postoperative cognitive dysfunction)是在临床工作中常见的并发症之一,尤其好发于老年患者麻醉手术之后。在围手术期,患者不仅接受了外科手术所带来的躯体创伤,而且承受着一定程度的心理负担。实验室研究表明,单纯外科手术可导致动物的认知功能损伤。然而,老年患者围术期心理应激是否会对其术后的学习记忆功能产生影响尚未见报道。本研究拟评估手术应激及心理应激对老年C57小鼠学习及记忆功能的影响,并进一步探讨影响产生的可能机制。第一部分手术应激与心理应激对老年小鼠学习记忆功能的影响目的：探讨手术应激、心理应激以及心理应激联合手术应激对老年C57小鼠学习及记忆功能的影响。方法：老年雌性C57BL/6小鼠(14月龄,96只),按体重依次排序,随机分为三个大组：手术应激组(n=32)、心理应激组(n=32)、联合应激组(n=32)；每个大组下设两个亚组分别为：干预组(n=16)和对照组(n=16)。手术应激干预组小鼠接受局麻开腹探查术,其对照组仅接受局麻,不开腹。心理应激干预组小鼠旁观其他小鼠被电击15天,每天2次,其对照组小鼠观察的小鼠未被电击。联合应激干预组在旁观其他小鼠电击15天后接受局麻开腹手术,其对照组联合上述两种对照方式。在造模结束后1-7天,进行旷场实验、新物体识别实验和Morris水迷宫实验评价老年小鼠的学习及记忆功能。结果：1.手术应激组和联合应激组中的干预组相比其各自对照组的水迷宫逃避潜伏期明显延长,新物体辨别能力下降；2.心理应激组内干预组与对照组的水迷宫逃避潜伏期及新物体辨别能力无明显差异；3.手术应激组中干预组与联合应激组中干预组的水迷宫逃避潜伏期及新物体辨别能力无明显差别。结论：本研究未发现旁观电击实验所致的心理应激会对老年小鼠的学习记忆能力产生影响,心理应激联合手术应激所致的认知功能损伤程度与单纯手术应激所致的认知功能损伤程度无明显差别。第二部分手术应激与心理应激影响老年小鼠学习记忆功能的相关机制目的：探讨手术应激、心理应激及心理应激联合手术应激对老年C57小鼠学习及记忆功能产生影响的可能机制。方法：老年雌性C57BL/6小鼠(14月龄,108只),按体重依次排序,随机分为三个大组：手术应激组(n=36)、心理应激组(n=36)、联合应激组(n=36)；每个大组下设两个亚组分别为：干预组(n=18)和对照组(n=18)。手术应激干预组小鼠接受局麻开腹探查术,其对照组仅接受局麻,不开腹。心理应激干预组小鼠旁观其他小鼠被电击15天,每天2次,其对照组小鼠观察的小鼠未被电击。联合应激干预组在旁观其他小鼠电击15天后接受局麻开腹手术,其对照组联合上述两种对照方式。在造模结束后的第1、3、7天,取血、取脑检测各组C57小鼠血清、皮层及海马内TNF-α、p-AKT、p-mTOR及p-PKCα蛋白含量及海马CAl区尼氏小体数量。结果：1.尼氏染色发现在造模后第7天手术应激干预组和联合应激干预组小鼠海马CA1区尼氏体数目显著低于其余各实验亚组；2. ELISA结果显示造模后第1天手术应激组干预组和联合应激组干预组相比其各自对照组小鼠,血清内TNF-α水平显著升高；3.造模后第1-3天手术应激组干预组和联合应激组干预组相比其各自对照组小鼠,海马内p-AKT表达被显著抑制,皮层p-AKT无明显改变；4.造模后第3天,手术应激组干预组和联合应激组干预组相比其各自对照组小鼠,海马和皮层内p-mTOR表达量降低。5.所有干预组小鼠的皮层与海马内p-PKC a蛋白含量在术后第1天升高,第3天后恢复正常。结论：海马CAl区尼氏小体数量减少和脑内AKT/mTOR信号通路的异常调节与老年C57小鼠造模后学习与记忆能力的改变有关。
[Abstract]:Postoperative cognitive dysfunction (POCD, Postoperative cognitive dysfunction) is one of the common complications in clinical work, especially after anesthesia in elderly patients. In the perioperative period, patients not only receive physical trauma from surgery, but also bear a certain degree of psychological burden. Laboratory studies have shown that However, the influence of psychological stress on the learning and memory function of the elderly patients has not been reported. This study is to evaluate the effect of surgical stress and psychological stress on the learning and memory function of C57 mice and to further explore the possibility of the effect. The effect of surgical stress and psychological stress on the learning and memory function of aged mice in the first part: To explore the effects of surgical stress, psychological stress and psychological stress on the learning and memory function of the aged C57 mice. Methods: the elderly female C57BL/6 mice (14 month old, 96) were sorted in order by weight and were randomly divided into Three large groups: operation stress group (n=32), psychological stress group (n=32), combined stress group (n=32), two subgroups in each group were divided into intervention group (n=16) and control group (n=16). The mice in the operation stress intervention group received local anesthesia open abdominal exploration, the control group only accepted local anesthesia and not open the abdomen. The mice in the psychological stress intervention group looked on the other mice. After 15 days of electric shock, 2 times a day, the mice in the control group were not subjected to electric shock. The combined stress intervention group received local anesthesia for 15 days after the other mice, and the control group combined the two control methods. After the end of the model, the open field experiment, the new object recognition experiment and the Morris water maze test were used to evaluate the elderly. Results: 1. the escape latency of water maze in the control group and the control group were significantly longer than those in the control group, and the discrimination ability of the new objects decreased, and there was no significant difference in the escape latency of water maze and the ability to distinguish the new objects in the 2. psychological stress group and the control group; 3. hands. There was no significant difference in the escape latency of water maze and the ability to distinguish new objects between the intervention group and the intervention group in the intervention group and the intervention group. Conclusion: the study did not find that the psychological stress caused by the observation of the electric shock could affect the learning and memory ability of the aged mice, and the cognitive impairment caused by the psychological stress combined with the operation stress. There is no significant difference in the degree of cognitive impairment caused by degree and simple operation stress. Second the mechanism of the related mechanisms of psychological stress and psychological stress on the learning and memory function of the aged mice: the possible mechanism of the effects of surgical stress, psychological stress and psychological stress combined with surgical stress on the learning and memory function of the aged C57 rats Methods: the elderly female C57BL/6 mice (14 month old, 108) were sorted in order by weight and were randomly divided into three groups: operation stress group (n=36), psychological stress group (n=36), combined stress group (n=36); two subgroups of each group were divided into intervention group (n= 18) and control group (n=18). Operation stress intervention group received local anesthesia open exploration. In the control group, the other mice in the psychological stress intervention group were subjected to electric shock for 15 days, 2 times a day, and the mice in the control group were not subjected to electric shock. The combined stress intervention group received local anesthesia for 15 days after the other mice, and the control group combined the above two control methods. The serum of C57 mice, TNF- alpha, p-AKT, p-mTOR and p-PKC alpha protein content in cortex and hippocampus and the number of Nissl corpuscles in hippocampal CAl region were measured by taking blood after 1,3,7 days after the bundle. Results: 1. Nissl staining found that the number of Nissl bodies in hippocampal CA1 area of the operation stress intervention group and the combined stress intervention group was significantly lower than the rest seventh days after the model building. The results of 2. ELISA showed that the level of TNF- alpha in the serum of the intervention group and the control group was significantly higher than that of the control group of the intervention group and the intervention group of the combined stress group first days after the model building, and the expression of p-AKT in the hippocampus in the hippocampus of the operation stress group and the combined stress group on the 1-3 day after the model building was compared with the control group, and the expression of p-AKT in the hippocampus was observed. There was no significant change in the cortex p-AKT. 4. after third days of the model, the expression of p-mTOR in the hippocampus and the cortex of the intervention group of the operation stress group and the combined stress group decreased in the hippocampus and the cortex of the control group. The content of p-PKC a protein in the cortex and hippocampus of all the mice in the.5. intervention group increased at first days after the operation, and recovered to normal after third days. The decrease of Nissl bodies and abnormal regulation of AKT/mTOR signaling pathway in hippocampal CAl region are related to changes in learning and memory ability in aged C57 mice after modeling.
【学位授予单位】：中国人民解放军医学院
【学位级别】：博士
【学位授予年份】：2016
【分类号】：R614

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