PV中间神经元在氯胺酮抗抑郁及致精神分裂样表现中的作用

发布时间：2018-05-21 01:37

本文选题：氯胺酮 + 抑郁　；参考：《南京大学》2013年硕士论文

【摘要】：目的：新近临床研究及动物实验均证实全身麻醉药氯胺酮具有快速有效的抗抑郁作用,然而,氯胺酮的抗抑郁作用机制仍不清楚。同时,研究表明氯胺酮可致精神分裂样表现,其作用机制可能为氯胺酮导致微清蛋白(Parvalbumin, PV)中间神经元表达PV和谷氨酸脱羧酶67(Glutamate decarboxylase67, GAD67)下降,使其对谷氨酸信号传导去抑制,增强了锥体细胞兴奋性,从而使大脑皮层兴奋,产生精神分裂样表现。鉴于氯胺酮抗抑郁时谷氨酸信号亦增强,我们推测氯胺酮使PV中间神经元抑制功能下调是其抗抑郁的重要机制。本研究探讨PV中间神经元在氯胺酮抗抑郁及致精神分裂样表现中的作用,同时观察PV中间神经元、谷氨酸(Glutamic acid, Glu)及γ-氨基丁酸(Gamma-aminobutyric acid, GAB A)在氯胺酮抗抑郁作用及致精神分裂样表现中的不同变化。方法：采用强迫游泳实验(Forced swimming test, FST)建立大鼠急性抑郁模型；氯胺酮30mg/kg连续5天腹腔注射建立精神分裂样表现模型。结合工具药氯胺酮、夹竹桃麻素(Apocynin, Nox2抑制剂,能够逆转氯胺酮导致的PV和GAD67表达减少)及GABA进行干预。观察FST不动时间、敞箱实验(Open field test,OFT)自主活动评分、刻板行为评分等大鼠行为学改变。行为学测试结束后,取大鼠前额皮层,采用免疫荧光双标法检测前额皮层PV和GAD67蛋白的表达,生化方法及ELISA法检测大鼠前额皮层Glu和GABA含量。结果：与生理盐水相比,氯胺酮10mg/kg给药后0.5h,大鼠FST不动时间减少,前额皮层PV及GAD67蛋白表达的下降,Glu含量增加,GABA含量下降(P0.05)；给药后2h,不动时间仍减少(P0.05),但生化改变均恢复(P0.05)。夹竹桃麻素及GABA预处理阻断了氯胺酮的抗抑郁作用(P0.05),这两种药物单独应用并未影响不动时间。精神分裂样表现模型中最后一次氯胺酮30mg/kg给药后0.5h,大鼠自主活动增强,刻板行为评分增高,PV及GAD67蛋白表达下降,大鼠前额皮层Glu含量增加,GABA含量下降(P0.05)；给药后2h,行为学差异无统计学意义(P0.05),而生化指标改变仍未恢复(P0.05)。最后一次氯胺酮30mg/kg给药后0.5h,大鼠前额皮层Glu含量高于10mg/kg单次给药(P0.05),而GABA含量、PV及GAD67蛋白表达无统计学意义(P0.05)；给药后2h, Glu含量高于、GABA含量低于、PV及GAD67蛋白表达低于10mg/kg单次给药(P0.05)。结论：PV中间神经元功能下调在氯胺酮抗抑郁及致精神分裂中均发挥重要作用,这可能与其介导的Glu信号系统去抑制有关。在氯胺酮抗抑郁及致精神分裂样表现中,PV中间神经元功能下调与Glu信号系统去抑制的程度及持续时间不同。
[Abstract]:Objective: recent clinical studies and animal experiments have confirmed that ketamine has a rapid and effective antidepressant effect. However, the antidepressant mechanism of ketamine is still unclear. At the same time, it has been shown that ketamine can induce schizophrenia, and its mechanism may be that ketamine induces the decrease of PV expression and glutamate decarboxylase 67(Glutamate decarboxylase67 (GAD67) in the interneuron of microalbumin Parvalbumin (PVV), which can inhibit the transduction of glutamate signal. It enhances the excitability of pyramidal cells, which excites the cerebral cortex and produces schizophrenic manifestations. In view of the increase of glutamate signal during ketamine antidepressant, we speculate that ketamine down-regulates the inhibitory function of PV intermediate neurons, which is an important antidepressant mechanism of ketamine. The purpose of this study was to investigate the role of PV intermediate neurons in ketamine antidepressant and schizophrenic manifestations, and to observe the role of PV intermediate neurons in antidepressant and schizophrenic manifestations. Different changes of Glutamic acid (Gluid) and Gamma-aminobutyric acid, GAB A) in antidepressant and schizophrenic manifestations of ketamine. Methods: a rat model of acute depression was established by forced swimming test, FST) and ketamine 30mg/kg was injected intraperitoneally for 5 days to establish a schizophreniform model. Combined with Ketamine, Apocyninine, Nox2 inhibitor, can reverse the decreased expression of PV and GAD67 induced by ketamine) and GABA intervention. FST immobility time, open field test score, stereotypical behavior score and other behavioral changes in rats were observed. The expression of PV and GAD67 protein in prefrontal cortex was detected by immunofluorescence double labeling method, and the contents of Glu and GABA in prefrontal cortex were detected by biochemical method and ELISA method. Results: compared with normal saline, the immobility time of FST decreased and the expression of PV and GAD67 protein decreased in prefrontal cortex of rats at 0.5 h after administration of ketamine 10mg/kg. The antidepressant effect of ketamine was blocked by the pretreatment of diosgenin and GABA. The two drugs alone did not affect the immobility time. At 0.5 h after administration of ketamine 30mg/kg in the schizophreniform model, the autonomic activity increased and the stereotypical behavior score increased and the expression of PV and GAD67 decreased. The content of Glu in prefrontal cortex of rats was increased and the content of Glu was decreased (P0.05A), but there was no significant difference in behavior at 2 h after administration, but the change of biochemical indexes was still not recovered (P0.05). At 0.5 h after administration of ketamine 30mg/kg, the content of Glu in prefrontal cortex of rats was higher than that in single dose of 10mg/kg (P0.05), while the expression of GABA in PV and GAD67 was not statistically significant, and at 2 h after administration, the content of Glu was higher than that of GABA-GABA and the expression of GAD67 protein was lower than that of single dose of 10mg/kg. Conclusion the down-regulation of the function of the intermediate neurons in the PV may play an important role in the antidepressant and schizophrenia induced by ketamine, which may be related to the inhibition of the Glu signaling system mediated by Ketamine. In ketamine antidepressant and schizophrenic manifestations, the down-regulation of the function of PV intermediate neurons is different from the degree and duration of deinhibition of Glu signal system.
【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R749

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