丘脑底核电刺激对癫痫大鼠模型基底节神经元放电的影响

Effect of electrical stimulation of subthalamic nucleus on the neuronal activities of the basic ganglion in epileptic rats

目的应用不同频率的电刺激海人酸模型癫痫大鼠STN核,观察STN核以及SNr(黑质网状部)神经元细胞在刺激后放电频率的变化,研究电刺激STN对STN内神经元和SNr神经元放电的影响,探讨STN-DBS治疗癫痫的作用机制。方法10只癫痫大鼠为实验组,另10只正常大鼠作为对照组。参照大鼠立体定向图谱,将记录的玻璃微电极和刺激电极分别插入STN、SNr核团内,刺激频率分为三组,分别为30 Hz、130 Hz、260 Hz。通过单神经元放电细胞外记录方法分别于高频刺激前后记录脑内核团神经元放电情况,分析神经元在STN-HFS刺激前和刺激时放电改变情况。结果正常大鼠的STN及SNr神经元放电与癫痫模型大鼠相比,两者放电频率不存在显著性差异,对放电模式的分析发现两者也无明显差异(P>0.05)。癫痫大鼠的STN及SNr神经元在30 Hz的刺激过程中放电频率多数没有明显变化。随着放电频率的增加两种神经元在电刺激后多数神经元放电明显受到抑制。在130 Hz和260 Hz组,受抑制的神经元较30 Hz组明显增加,具有显著性差异(P<0.05)。结论本研究证实高频电刺激STN明显抑制了STN和SNr神经元的兴奋性,其效果与频率是相关的。推测STN-HFS的作用机制可能通过对STN神经元兴奋性的抑制,调节相关联系核团的输出。

Objective The purpose of this study is to evaluate the change of firing rates of STN and SNr neurons during and after the different frequency electrical stimulation of STN,study the its effect on the neuronal activities of the basic ganglion and the mechanism of deep brain stimulation of STN.Methods The stimulation electrodes and glass electrodes,were stereotaxically implanted in the unilateral subthalamic nucleus and substantia nigra pars reticulata,stimulated in high frequency 30Hz,130Hz and 260Hz in each group.Exetracellular recording approach was used to investigate the spikes and analysis of firing activity of subthalamic nucleus and substantia nigra pars reticulata with or without electrical stimulation.Results There is no significant difference on the firing rate of STN and SNr neurons between normal and epileptic rats（P0.05）.Their firing patterns are also similar.During 30Hz electrical stimulation,the firing rate of most neurons of STN and SNr is not changed.With the stimulation frequency increasing,the firing rate of most neurons in STN and SNr are inhibited by the electrical stimulation（P0.05）.The amount of the inhibited neurons in 130 Hz and 260Hz stimulation is significantly increased.There is significant difference compared with 30 Hz stimulation（P0.05）.Conclusion This study shows the high frequency electrical stimulation of STN obviously inhibits the excitability of STN and SNr neurons,and its inhibitory effect is related to the electrical frequency.It can be assumed that the mechanism of STN-HFS is to modulate the output of neurons involved with STN.There is no significant difference on the firing rate of STN and SNr neurons between normal and epileptic rats.Their firing patterns are also similar.