大鼠特殊内脏运动核团多巴胺D1和D2受体的表达及对BDNF水平的影响

Expression of dopamine D1 and D2 receptor in the special visceral motor nuclei of rat and its effect on the level of BDNF

目的检测多巴胺D1受体(DRD1)和D2受体(DRD2)在大鼠三叉神经运动核、面神经核、疑核和副神经核内的表达及功能。方法免疫荧光双标法检测DRD1和DRD2在4种核团的表达与分布特征;大鼠随机分成对照组(C)组,DRD1和DRD2激动剂罗替戈汀组(Roti)和罗替戈汀+DRD2抑制剂氟哌啶醇组(Roti+halo)组(n=6),Western blot检测三叉神经运动核和面神经核内BDNF和TrkB蛋白的表达变化。结果4种核团内DRD1和DRD2阳性细胞数量较多,与胆碱能神经元大量共存。与C组相比,Roti组三叉神经运动核和面神经核内BDNF表达升高(P<0.05);与Roti组相比,Roti+halo组面神经核内BDNF表达下降(P<0.05)。TrkB的表达在3组之间差异无统计学意义(P>0.05)。结论DRD1和DRD2在大鼠4种核团内胆碱能神经元大量表达,罗替戈汀可能通过激活DRD1和DRD2二聚体诱导胆碱能神经元表达BDNF。

Objective To investigate the expression and function of dopamine D1 receptor(DRD1 and D2 receptor(DRD2)in the trigeminal motor nucleus,the facial nucleus,ambiguous nucleus,accessory nucleus of rat.Methods The expression and distribution characteristics of DRD1 and DRD2 in the above 4 nuclei were detected by double staining immunofluorescence.SD rats were randomly divided into three groups:a control group(C),a DRD1 and DRD2 agonist rotigotine group(Roti)and a rotigotine plus DRD2 inhibitor haloperidol group(Roti+halo),each group had 6 rats.The protein expression changes of BDNF and TrkB in trigeminal motor nucleus and the facial nerve were detected by Western blot.Results There were large numbers of DRD1 and DRD2 positive cells in the cholinergic neurons of trigeminal motor nucleus,facial nucleus,ambiguous nucleus and accessory nucleus.Compared with the C group,the expression of BDNF in the trigeminal motor nucleus and facial nucleus increased in Roti group(P<0.05).The expression of BDNF in the facial nucleus decreased in the Roti+halo group when compared with the Roti group(P<0.05).There was no statistical difference in the expression of TrkB among three groups(P>0.05).Conclusions DRD1 and DRD2 are abundantly expressed in the cholinergic neurons of the above 4 nuclei.Rotigotine may induce BDNF expression in the cholinergic neurons through activating DRD1 and DRD2 dimers.