6-羟基多巴胺损伤黑质致密部对大鼠脚桥核神经元的影响

Effect of 6-hydroxydopamine lesion in substantia nigra pars compacta on neurons in rat pedunculopontine nucleus

目的观察6-羟基多巴胺损伤黑质致密部对大鼠脚桥核神经元的影响。方法选择健康雄性Wistar大鼠22只,13只大鼠内侧前脑束位点注射6-羟基多巴胺损伤黑质致密部多巴胺能神经元建立帕金森病大鼠模型作为模型组,另9只大鼠作为正常组。分别记录分析正常组9只和模型组7只脚桥核神经元信号电生理特性的变化,同时利用尼氏染色法观察6只帕金森病大鼠脚桥核神经元形态学变化。结果模型组脚桥核神经元类型Ⅰ和神经元类型Ⅱ放电频率较正常组显著增加[(12.09±1.62)Hz vs(7.35±0.98)Hz,P<0.05;(4.09±0.34)Hz vs(2.87±0.26)Hz,P<0.01],放电变得不规则;脚桥核神经元数量减少,形态发生显著变化,损伤侧脚桥核大型神经元、中型神经元、小型神经元较正常侧分别减少了20.3%,19.4%和20.9%(P<0.05)。结论 6-羟基多巴胺损伤黑质致密部多巴胺能神经元导致了脚桥核内神经元电生理特征和形态学特征的广泛变性及损伤。

Objective To study the effect of 6-hydroxydopamine lesion in substantia nigra pars compacta on neurons in rat pedunculopontine nucleus.Methods Twenty-two healthy male Wistar rats were divided into normal group（n=9）and model group（n=13）.A rat model of Parkinson＇s disease was established by injecting 6-hydroxydopamine into the medial forebrain bundle of rats.The electrophysiology of neuron signals from pedunculopontine nucleus was analyzed.The morphology of neurons in pedunculopontine nuclei was observed with cresyl violet staining.ResultsThe discharge frequency was significanty higher in model group than in normal group（12.09±1.62 Hz vs 7.35±0.98 Hz,P〈0.05;4.09±0.34 Hz vs2.87±0.26 Hz,P〈0.01）.The number of neurons in pedunculopontine nucleus decreased and the morphology of neurons in pedunculopontine nucleus changed dramatically.The large,medium and small neurons in pedunculopontine nuclei decreased 20.3%,19.4% and 20.9% respectively in lesioned side as compared with those in normal side（P〈0.05）.Conclusion 6-hydroxydopamine lesion in substantia nigra pars compacta can dramatically change the state of morphology and electrophysiology of neurons in pedunculopontine nucleus.