损毁丘脑底核对大鼠苍白球神经元自发放电的影响

EFFECTS OF DESTRUCTION OF SUBTHALAMIC NUCLEUS ON SPOTANEOUS DISCHARGE OF GLOBUS PALLIDUS NEURONS IN RATS

目的探讨损毁丘脑底核(STN)对大鼠苍白球(GP)神经元自发放电的影响。方法大鼠单侧STN注射Ibotenic acid制备STN损毁模型,2周后采用细胞外电生理记录法,比较其与正常大鼠GP神经元自发放电情况的差异。电生理学实验结束后,处死大鼠,制备脑冷冻切片行NISSL染色,观察STN的损毁情况。结果与正常大鼠比较,STN损毁大鼠损毁侧GP神经元的放电频率差异无显著性(t=1.99,P>0.05);规则放电神经元百分比显著降低,不规则放电神经元百分比显著增加,差异有显著性(χ2=4.13,P<0.05),而簇状放电神经元的百分比差异无显著性(χ2=3.35,P>0.05)。组织学观察显示,STN损毁模型大鼠损毁对侧STN神经元密集分布,细胞结构呈梭形或多角形;损毁侧STN神经元消失,胶质细胞增生,周边结构正常。结论 STN损毁后大鼠GP神经元的放电模式明显改变,STN参与调节GP神经元放电模式。

Objective To investigate the effects of destruction of subthalamic nucleus （STN） on spontaneous discharge of globus pallidus （GP） neurons in rats. Methods A STN-destruction model in rats was created by microinjecting Ibotenic acid into unilateral STN. Extracellular electrophysiological recording was employed two weeks later to compare the difference of GP spontaneous discharge with that in normal rats. Upon completion of the experiment, frozen sections of the rats＇ brain were stained with NISS1, and STN was observed for its damage. Results Compared with normal rats, the difference of discharge frequency of STN-damage-side was not significant （t = 1.99,P〉0.05）; the percentage of regular-discharge neurons decreased, and that of irregular-discharge neurons increased, the difference was significant （x^ 2 = 4.13, P 〈 0.05）, the difference of percentage of burst- discharge neurons was not significant （x^2= 3.35, P〉0.05）. Histologically, the STN neurons on undamaged side in the damaged model were close-set, the cellular structures appeared as fusiform shape or polygon; on the damaged side, neurons disappeared, proliferation of Glial cells was seen, and surrounding structures were normal. Conclusion The pattern of discharge of GP neu- rons obviously changed followed by damage of STN in rats, suggesting that STN involves in regulation of the pattern of GP neurons discharge.