帕金森病模型大鼠丘脑底核及初级运动皮质放电模式的变化

背景:以丘脑底核作为刺激靶点的脑深部刺激在治疗帕金森病上取得了良好的效果,但其治疗机制尚不明确。目的:观察帕金森病病理状态下丘脑底核和初级运动皮质的局部场电位变化。方法:实验组在Wistar大鼠脑黑质致密部和中脑腹侧被盖区两点注射6-羟基多巴胺建立帕金森病大鼠模型,以在脑黑质致密部和中脑腹侧被盖区两点注射生理盐水的大鼠为对照。通过植入金属电极采集两组大鼠不同状态下丘脑底核和初级运动皮质的局部场电位。结果与结论:实验组丘脑底核放电频率整体上明显高于对照组,且放电能量高于对照组(P<0.05)。与静止状态相比,对照组大鼠抓食运动状态下的初级运动皮质局部场电位在7～12Hz及12～30Hz内变化显著(P<0.05),在30～100Hz内变化极显著(P<0.01),抓食过程中信号频率整体变小;实验组大鼠在两种状态下初级运动皮质局部场电位在不同频率范围内的分布变化不大,仅在30～100Hz内差异有非常显著性意义(P<0.01)。说明帕金森病大鼠表现为丘脑底核电活动过强,而初级运动皮质电活动受到明显抑制。

Discharge pattern changes of the subthalamic nucleus and primary motor cortex in Parkinson's disease rats

BACKGROUND:Deep brain stimulation of the subthalamic nucleus represents an effective technique for the treatment of Parkinson’s disease.However,the underlying therapeutic mechanisms remain undefined.OBJECTIVE:To observe the changes of the local field potentials of subthalamic nucleus and primary motor cortex in Parkinson’s disease.METHODS:Parkinson’s disease model of experimental group was constructed by injecting 6-hydroxydopamine into substantia nigra pars compacta and ventral tegmental area of Wistar rats.Normal saline was injected into substantia nigra pars compacta and ventral tegmental area of control rats.The metal electrode was used to record local field potentials of subthalamic nucleus and primary motor cortex of control and Parkinson’s disease rats in different states.RESULTS AND CONCLUSION:The frequency and energy of local field potentials in the subthalamic nucleus of experimental group was higher than that of the control group as a whole(P < 0.05).Compared with stationary state,the local field potentials in the primary motor cortex of control rats during the execution of reach movement changed significantly at 7 to 12 Hz and 12 to 30 Hz(P < 0.05),and the changes at 30 to 100 Hz were extremely significant(P < 0.01).The frequency became smaller as a whole during the execution of reach movement.Spectral decomposition of the local field potentials in the primary motor cortex of Parkinson’s disease rats changed little in different states.The only extremely significant change was observed at 30 to 100 Hz(P < 0.01).These results suggest that the electrical activity of subthalamic nucleus is overactive and the electrical activity of primary motor cortex is inhibited in Parkinson’s disease rats.