Allen G V, Barbrick B, Esser M J
Faculty of Medicine, Department of Anatomy and Neurobiology, Dalhousie University, Halifax, Nova Scotia, Canada.
Brain Res. 1996 Apr 9;715(1-2):125-35. doi: 10.1016/0006-8993(95)01580-9.
Noxious stimulation of dental nerves elicits marked changes in cardiovascular function. In order to investigate central pathways mediating reflex changes in cardiovascular activity, immunohistochemical localization of cells expressing the immediate-early gene, c-fos, was used to identify central nervous responding to noxious electrical stimulation of mandibular, incisor tooth dentin or chemical (capsaicin) stimulation of tooth pulp in the anesthetized rat. Injections of Fluoro-Gold were made in the lateral parabrachial region to identify efferent projections from the spinal trigeminal nucleus. Electrical and chemical stimulation produced similar patterns of Fos-positive neurons in the spinal trigeminal nucleus: subnuclei caudalis, interpolaris and oralis. Fos-positive neurons were most dense in laminae I and II of the dorsomedial subnucleus caudalis with fewer Fos-positive neurons located in the interpolaris and oralis subnuclei. Sham stimulation of tooth dentin and control vehicle injections into the tooth pulp resulted in either a few weakly stained or no Fos-positive neurons in the spinal trigeminal nucleus. Cell bodies double labeled with Fluro-Gold following injections into the parabrachial region and Fos-protein subsequent to electrical stimulation of incisor tooth were present in all three subnuclei of the spinal trigeminal nucleus. The largest number of Fos-positive neurons with efferent projections to the lateral parabrachial region were located in subnucleus caudalis (32.2 +/- 5.3 S.E.M.) and fewer were located in the interpolaris (0.4 +/- 0.4 S.E.M.) and oralis (19.8 +/- 3.5 S.E.M.) subnuclei. The results demonstrate that nociceptive dental input received by the three subnuclei of the spinal trigeminal nucleus, particularly the subnucleus caudalis, is relayed to the lateral parabrachial nucleus.
对牙神经的伤害性刺激会引起心血管功能的显著变化。为了研究介导心血管活动反射性变化的中枢通路，利用免疫组织化学方法对表达即刻早期基因c-fos的细胞进行定位，以识别在麻醉大鼠中对下颌切牙牙本质的伤害性电刺激或牙髓的化学（辣椒素）刺激产生反应的中枢神经。向外侧臂旁核注射荧光金，以识别来自三叉神经脊束核的传出投射。电刺激和化学刺激在三叉神经脊束核中产生了相似的Fos阳性神经元模式：尾侧亚核、极间亚核和口侧亚核。Fos阳性神经元在背内侧尾侧亚核的I层和II层最为密集，极间亚核和口侧亚核中的Fos阳性神经元较少。对牙本质的假刺激和向牙髓注射对照载体，在三叉神经脊束核中导致少量弱阳性染色或无Fos阳性神经元。向臂旁核注射后用荧光金双重标记的细胞体，以及切牙电刺激后出现的Fos蛋白，存在于三叉神经脊束核的所有三个亚核中。向外侧臂旁核有传出投射的Fos阳性神经元数量最多的位于尾侧亚核（32.2±5.3标准误），极间亚核（0.4±0.4标准误）和口侧亚核（19.8±3.5标准误）中的较少。结果表明，三叉神经脊束核的三个亚核，特别是尾侧亚核所接收的伤害性牙齿传入信息，会传递至外侧臂旁核。
