Trigeminal nerve stimulation-induced c-Fos expression in trigeminal spinal nucleus

本研究的目的是观察电刺激一侧舌神经中央断端是否在乌拉坦麻醉的人工呼吸颈迷走神经切断大鼠双侧下唇产生三叉神经-副交感神经反射血管扩张和刺激三叉神经核复合体神经元。采用免疫组织化学方法检测c-Fos蛋白的表达，以评价长时间刺激舌神经的影响。结果发现，每隔10min刺激单侧舌神经200min，刺激后同侧下唇血流量明显增加，c-fos蛋白在同侧三叉神经脊束核内除三叉神经口亚核外均有较深的表达，在同侧三叉神经内插/尾侧移行区…区有大量c-fos阳性神经元。与三叉神经尾侧亚核/上颈脊髓移行区、尾侧亚核、内侧亚核、口侧亚核相比，c-Fos在对侧三叉神经脊束核各亚核的表达数量均无统计学意义的增加。这些结果表明，乌拉坦可用于三叉神经-副交感神经反射血管扩张和舌神经刺激后c-Fos表达的同步监测。本研究结合我们以往的研究结果，认为电刺激舌神经产生的冲动汇聚于同侧三叉神经脊束核内插/尾过渡区和副交感血管扩张神经元唾液核，经三叉神经核内三叉神经内插/尾过渡区投射至下唇。较少

The aim of the present study was to investigate whether electrical stimulation of the unilateral central cut ends of lingual nerve produces an trigeminal-parasympathetic reflex vasodilatation in both sides of the lower lips and stimulate neurons in the trigeminal nuclear complex in the artificially ventilated, cervically vagosympathectomized rats deeply anesthetized with urethane. Immunohistochemical detection of c-Fos expression was used to assess the impact of prolonged lingual nerve stimulation. It was found that the unilateral lingual nerve stimulation at 10 min intervals for 200 min (i)elicited consistent blood flow increases predominantly in the ipsilateral side of the lower lip when stimulated, (ii)evoked the more profound expression of c-Fos protein ipsilaterally in all subnuclei of trigeminal spinal nucleus except trigeminal subnucleus oralis, (iii)induced the greater number of c-Fos positive neurons in the ipsilateral trigeminal subnucleus interpolaris/caudalis transition zon … More e compared with the four other areas (trigeiminal subnucleus caudalis/upper cervical spinal cord transition zone, subnucleus caudalis, subnucleus interpolaris, subnucleus oralis) of trigeminal spinal nucleus, and (iv)did not induce a statistical significant increase in the number of c-Fos expression in all subnucleus of the trigeminal spinal nucleus of the contralateral side in comparison with the control rats. These results suggest that urethane can be useful for the investigation of the simultaneous measurements of the trigeminal-parasympathetic reflex vasodilatation and the c-Fos expression following the lingual nerve stimulation. The present studies together with our previous data, it is suggested that impulse elicited by electrical stimulation of the lingual nerve converge on the ipsilateral trigeminal subnucleus interpolaris/caudalis transition zone in the trigeminal spinal nucleus and the parasympathetic vasodilator neurons, salivatory nucleus, after receiving projection from the trigeminal subnucleus interpolaris/caudalis transition zone in the trigeminal spinal nucleus, project to the lower lip via the otic ganglion. Less