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本研究通过观察兴奋性氨基酸受体拮抗剂对电休克(electroconvulsive therapy, ECT)后Wistar-Kyoto (WKY)抑郁大鼠模型学习记忆和Tau蛋白过度磷酸化的影响,探讨兴奋性氨基酸受体拮抗剂对Tau蛋白过度磷酸化的调节及两者对抑郁大鼠学习记忆的影响,以期为改善ECT后学习记忆障碍的神经心理学机制研究和临床干预性治疗提供实验依据。按随机单位组析因设计设置2个干预因素,即电休克干预(两水平:无处置、施行1疗程ECT)和兴奋性氨基酸受体拮抗剂干预(三水平:注射生理盐水、NMDAR拮抗剂MK-801、AMPAR拮抗剂DNQX)的所有组合(2×3析因设计)进行实验。将48只24周龄WKY大鼠随机分为6组(n=8):生理盐水组(经尾静脉注射2mL生理盐水)、MK-801组(经尾静脉注射2mL 5mg/kg MK-801)、DNQX组(经尾静脉注射2mL 5mg/kg DNQX)、生理盐水+ECT组(经尾静脉注射2 mL生理盐水+施行1疗程ECT)、MK-801+ECT组(经尾静脉注射2mL 5mg/kg MK-801+施行1疗程ECT)、DNQX+ECT组(经尾静脉注射2mL 5mg/kg DNQX+施行1疗程ECT)。全部ECT处置结束24h内开始Morris水迷宫检测,然后留取各组大鼠海马组织。高效液相色谱法检测海马组织中神经递质Glu含量;免疫组织化学SP法和Western blot检测Tau5 (总Tau蛋白)、p-PHF1Ser396/404、p-AT8Ser199/202、p-12E8Ser262在海马组织中的表达。结果显示,ECT和Glu离子型受体(NMDAR、AMPAR)均可造成大鼠学习记忆障碍,即延长逃避潜伏期,并缩短空间探索时间;ECT和Glu受体GluR拮抗剂合用之后,其造成的大鼠学习记忆障碍程度反而减轻。ECT可明显增加海马中Glu的浓度;GluR拮抗剂对海马中Glu的浓度没有明显影响。ECT和GluR拮抗剂对海马总Tau蛋白表达无明显影响。ECT可增加海马中磷酸化Tau蛋白的表达;GluR拮抗剂可减少海马中磷酸化Tau蛋白的表达;两者合用的影响呈相减效果,即GluR拮抗剂可使ECT造成的海马磷酸化Tau蛋白的表达增加的幅度降低。以上结果表明,ECT导致海马Glu浓度升高,Glu激动NMDAR和AMPAR,从而增加海马Tau蛋白的磷酸化程度,从而导致学习记忆功能障碍。
This study was designed to investigate the effects of excitatory amino acid receptor antagonists on learning and memory and Tau hyperphosphorylation in Wistar-Kyoto (WKY) -induced depression in rats after electroconvulsive therapy (ECT), and to investigate the effects of excitatory amino acid receptor antagonists The regulation of Tau hyperphosphorylation and the effects of both on learning and memory in depressive rats were investigated in order to provide experimental basis for the study of neuropsychological mechanism and clinical interventional therapy for learning and memory impairment after ECT. According to the randomized unit analysis, two interventional factors were set up, that is, the effects of electrical shock intervention (two levels: no treatment, one course of ECT) and excitatory amino acid receptor antagonist (three levels: saline injection, NMDAR antagonist MK -801, AMPAR antagonist DNQX) (2 x 3 factorial design). Forty-eight WKY rats, 24 weeks old, were randomly divided into 6 groups (n = 8): normal saline group (2mL normal saline injected through caudal vein), MK-801 group (2mL 5mg / kg MK- , DNQX group (2mL 5mg / kg DNQX via caudal vein injection), NS + ECT group (2mL saline injected through tail vein and ECT one course), MK-801 + ECT group kg MK-801 + for 1 course of ECT), DNQX + ECT group (2 ml of 5 mg / kg DNQX + for tail vein injection of ECT). Morris water maze test was started within 24 hours after the end of all ECT treatment, and then the hippocampal tissue of each group was taken. The content of neurotransmitter Glu in hippocampus was detected by high performance liquid chromatography (HPLC). Tau5 (total Tau protein), p-PHF1 Ser396 / 404, p-AT8Ser199 / 202 and p-12E8Ser262 were detected by immunohistochemical SP method and Western blot in hippocampus expression. The results showed that ECT and Glu ionotropic receptors (NMDAR, AMPAR) can cause learning and memory disorders in rats, that is, to extend the escape latency and shorten the space exploration time; ECT and Glu receptor GluR antagonist combined, resulting in large However, the extent of learning and memory impairment in rats decreased. ECT significantly increased the concentration of Glu in the hippocampus; GluR antagonist had no significant effect on Glu concentration in the hippocampus. ECT and GluR antagonist had no significant effect on total Tau protein expression in hippocampus. ECT can increase the expression of phosphorylated Tau protein in hippocampus; GluR antagonist can reduce the expression of phosphorylated Tau protein in hippocampus; the combined effect of them is a subtractive effect, that is, GluR antagonist can cause ECT induced phosphorylation of Tau protein The increase of expression decreased. These results suggest that ECT induces an increase in Glu concentration in the hippocampus and Glu agonizes NMDAR and AMPAR, thereby increasing phosphorylation of Tau in the hippocampus, leading to learning and memory dysfunction.