【摘要】 目的了解银杏叶提取物(EGb)对帕金森病(PD)大鼠多巴胺(DA)能神经元的作用。方法以6-OHDA部分损毁内侧前脑束的方法建立类似于人类PD早期的大鼠模型,通过电生理学及免疫组织化学方法观察PD大鼠黑质DA能神经元电活动和形态学的改变,以及EGb对其的影响。结果 PD组SNc、VTA区TH阳性细胞数明显减少,染色变浅,形状不规则,DA残存神经元百分比明显降低;给予EGb后,随剂量增加损伤侧SNc、VTA区TH阳性细胞数增加,染色变深,形状规则,DA神经元残存数量明显升高,以高剂量组升高最为明显。PD组大鼠神经元放电频率显著高于对照组,低剂量治疗组和高剂量治疗组放电频率虽低于PD组,但均无统计学差异。4组大鼠的DA神经元放电形式均表现为规则放电、爆发式放电和不规则放电3种,其中PD大鼠爆发式放电比率高于正常组,治疗组大鼠爆发式放电比率低于PD组,与正常组接近。结论 PD状态下,SNc的DA神经元电活动增强;EGb能够减少PD大鼠SNc DA神经元的丢失,部分抑制PD大鼠的电活动,对PD大鼠DA神经元具有一定保护作用。更多还原

【Abstract】 Objective To explore the role of Ginkgo biloba extract(EGb) on dopaminergic(DA) neurons of rat model Parkinson′s disease(PD).Methods The model as seen in patients with preclinical Parkinson′s disease(PD) was produced by 6-hydroxydopamine partially lesion of the medial forebrain-bundle in rats.Changes of the neuronal morphology and firing activity of dopaminergic neurons in PD rats were studied by using immunocytochemistry and extracellular recording.The effect of EGb treatment was also examined.Results In PD rats,the amount of TH immunoreactive(TH-ir) neurons decreased and the percentage of surviving DA neurons was significant lower than that of the normal rats.Systemic administration of EGb dose-dependently increased the amount of TH immunoreactive(TH-ir) neurons in the SNc and VTA of the lesioned side,and the number of surviving TH immunoreactive(TH-ir) neuron increased significantly at high doses.The firing rate of PD rats was significantly increased when compared to that of the normal rats.No significant difference was found in low doses and high doses,though the firing rates of the two groups were lower than PD rats.The four groups all showed regular firing,burst firing and irregular firing pattern.In PD rats,the percentage of the burst firing increased and the firing pattern of the neurons in EGb-treated rats changed significantly towards a less burst-firing pattern,nearly the same with the normal rats.Conclusion The surviving dopaminergic neurons in the SNc were hyperactive in an experimental model of moderate Parkinson′s disease.EGb reduced the loss of the dopaminergic neurons in SNc and partial suppressed the abnormal firing activity,which indicated that EGb had the neuroprotective effect on dopaminergic neurons of the PD rats.更多还原