【摘要】 目的观察5-HT对正常大鼠丘脑底核神经元放电频率的影响及其作用机制。方法用多管微电极在体细胞外电生理记录观察5-HT及5-HT1B、5-HT2C、5-HT4和5-HT1A受体激动剂对丘脑底核神经元的电生理效应,免疫组织化学法观察丘脑底核神经元4种受体亚型的表达情况。结果 5-HT既可使丘脑底核神经元的自发放电频率明显升高(P<0.001),也可使其明显降低(P<0.05)。作为5-HT受体激动剂,CP-93129、RO-600175和ML-10302可明显增加丘脑底核神经元的放电频率(CP-93129:P<0.001;RO-600175:P<0.01;ML-10302:P<0.001),8-OHDPAT则使其放电频率明显降低(P<0.01)。正常大鼠丘脑底核表达丰富的5-HT1B、5-HT2C、5-HT4和5-HT1A受体。结论 5-HT可以改变正常大鼠丘脑底核神经元的兴奋性,产生使放电频率升高和降低的双向效应。5-HT的这种兴奋效应主要是通过激活5-HT1B、5-HT2C和5-HT4受体实现的,而抑制效应则与5-HT1A受体的激活有关。更多还原

【Abstract】 Objective To study the effects and mechanism of 5-HT on the firing rate of subthalamic neurons in normal rats. Methods With in vivo extracellular single unit recordings,the electrophysiological effects of 5-HT and 5-HT1 B,5-HT2 C,5-HT4 and 5-HT1 A receptor agonist on subthalamic neurons were studied. Then to observe the expression of four kinds of 5-HT receptor subtypes on subthalamic nucleus neurons,the immunohistochemical staining was used in the present study. Results Results showed that exogenous 5-HT increased( P < 0. 001) or decreased( P < 0. 05) the discharge frequency of subthalamic nucleus neurons in normal rats As 5-HT receptor agonists,CP-93129,RO-600175 and ML-10302 significantly increased the firing rate of subthalamic neurons( CP-93129: P < 0. 001; RO-600175: P < 0. 01; ML-10302: P < 0. 001),while 8-OH-DPAT decreased the firing rate( P < 0. 01). Conclusions 5-HT changes the excitability of subthalamic nucleus neurons in normal rats,resulting in the dual role of raising and lowering the discharge frequency. The activation of 5-HT1 B,5-HT2 C and 5-HT4 receptor increases the firing rate of subthalamic nucleus neurons,while when 5-HT1 A receptor is activated,the firing rate is decreased.更多还原