MK-801诱发精神分裂症对大鼠探索能力、疼痛反应及海马神经细胞增殖的影响

目的:观察大鼠精神分裂症后探索能力、痛觉及海马齿状回颗粒细胞层神经细胞增殖的改变。方法:MK-801腹腔注射制备精神分裂症动物模型,分别监测给药后第1、5、10、14 d大鼠的探洞次数和甩尾时间。Brdu标记后取材,应用免疫荧光染色和激光共聚焦显微技术观察海马齿状回神经细胞的增殖情况。结果:①洞板试验:实验组大鼠的探洞次数较对照组显著下降(P<0.01),且随着MK-801给药时间的增加而减少(P<0.01);②甩尾试验:实验组大鼠对疼痛刺激的反应时间较对照组缩短(P<0.01),且随着MK-801给药时间的延长痛觉敏感度不断增加(P<0.01);③神经细胞的增殖:停药后第1 d,实验组海马齿状回颗粒层神经细胞增殖数较对照组减少(P<0.05),第16 d两组间无显著差异(P>0.05)。结纶:MK-801诱发精神分裂症后可致大鼠的探索能力减退、痛觉敏感,同时可降低海马齿状回颗粒细胞层神经细胞的增殖。

Effect of MK-801 induced schizophrenia on the exploratory ability and pain reaction of rats and proliferation changes in hippocampal neurons

Objective: To observe changes of the exploratory ability and pain reaction and proliferation changes in hippocampal neurons in dentate gyrus of rats subject to schizophrenia.Methods:Schizophrenic model rats were made by intraperitoneally injected with MK-801.The times of poking into holes and reactive time in tail-flick were detected after treatment at 1,5,10,14 days respectively.To observe proliferation of hippocampal neurons,the newly generated neurocytes were labeled with bromodeoxyuridinge(Brdu).The number of Brdu positive cells in hippocampal dentate gyrus was detected by immunofluorescence histochemical staining.Results: ① Hole board test:The times of poking into holes of rats were significantly less in experimental group than those of the control group(P<0.01),and the times decreased with the increase of treatment time of MK-801(P<0.01).② Tail-flick test: The rats of experimental group showed significantly shorter reactive time than that of the control group in tail-flick test(P<0.01),and the pain reaction was detected to be relatively susceptible to schizophrenia model with the the increase of treatment time of MK-801(P<0.01).③ Proliferation of hippocampal neurons: The number of proliferation of hippocampal neurons significantly decreased in experimental rats than that of control group after drug withdrawal at day 1,(P<0.05).There were no significant difference after drug withdrawal at 16 day in two groups(P>0.05).Conclusion:The exploratory ability decreased and pain reaction was more sensitive in rats subjected to schizophrenia induced by MK-801,and the number of proliferation of hippocampal neurons in dentate gyrus was less in schizophrenic model rats.