大鼠面部和胃肠道伤害性传入信息在延髓内的汇聚──c-fos表达研究

CONVERGENCE OF NOXIOUS AFFERENT INFORMATION FROM FACIAL AREA AND GASTROINTESTINAL TRACT ON THE NUCLEI OF MEDULLA OBLONGATA IN THE RAT: A STUDY OF c-fos EXPRESSION

本研究应用神经元Fos样蛋白的表达作为对伤害性传人信息反应的标志，将少量Formalin分别注入大鼠一侧面部软组织或导入胃肠道作为伤害性刺激，然后用免疫细胞化学双重标记法，显示其延髓神经元对面部和胃肠道化学伤害性信息传人的反应及其与几条酚胺递质的关系。结果表明：（1）胃肠道伤害性刺激诱导延髓内大量神经元的c-fos表达，其Fos样免疫反应（Fos-LI）神经元主要位于孤束核（NIS）、延髓腹外侧区（VLM）和最后区（AP），少数分布于NIS与VLM之间的网状结构（RF）、三叉神经旁核（PaV）；（2）面部伤害性信息传人诱导的Fos－LI神经元除大量分布在三叉神经脊束核尾侧亚核（nSpVc）浅层和PaV外．也分布于NTS、VLM和RF；(3)两种不同区域伤害性刺激所诱导的Fos表达神经元在延髓NIS和VLM的分布明显重叠，其中许多Fos—LI神经元同时呈酪氨酸羟化酶（TH）－LI．Fos/TH双重阳性神经元约占TH—LI神经元总数的50％。本结果提示延髓NTS和VLM是面部和胃肠道伤害性传入信息所汇聚的主要区域，其儿茶酚胺能神经元是所汇聚的重要成分，并讨论了它们参与面部穴位针刺对胃肠道功能调节的中枢弥漫性伤害抑制性控制（DiffuseNoxiousInhibitoryControls，DNIC）过程的可能性。

In the present study by using c - Fos expression method we examined the response of medullaneurons to the noxious stimulation on the viscera and facial areas and its relationship with tyrosine hyaroxylase-likeimmunoreactivity (TH-LI). The results showed that (l) Fos- like immunoreactive (Fos- LI) neurons inducedwith visceral noxious stimulation mainly distributed in nucleus tractus solitarius(NTS), ventrolateral medulla(VLM),AREA postrema (AP), and a few of them were seen in the paratrigeminal nucleus (Pav) and reticular for-mation(RE) between NTS and VLM; (2) Fos - LI neurons induced with facial noxious stimulation were alsonuumerously seen in NTS and VLM, in addition to the caudal segment of spinal nucleus of trigeminal nucleus(nSpVc); (3) it was are that Fos- LI neurons induced by visceral and facial noxious simulation repectivelyoverlappe in their distribution within NTS and VLM, and about 50% of TH- LI neurons were simultaneouslyvisualized Fos- LI. This study indicated that noxious stimulative afferent information from visceral and facial areasmainly converged in the NTS and VLM, and on the catecholaminergic neurons. The convergence may be involvedin the diffuse noxious inhibitary controls or modulation of visceraglia.