大鼠三叉神经脊束核尾侧亚核内代谢型谷氨酸受体的分布及谷氨酸样阳性终末的来源

DISTRIBUTION OF METABOTROPIC GLUTAMATE RECEPTORS AND ORIGIN OF GLUTAMATE-LIKE IMMUNOREACTIVE TERMINALS IN SPINAL TRIGEMINAL SUBNUCLEUS CAUDALIS IN THE RAT

本文用抗磷酸激活的谷氨酰胺酶的单克隆抗体和抗代谢型谷氨酸受体五种亚型（1，1α，2／3，5）的4种抗体，研究了三叉神经脊束核尾侧亚核和三叉神经半月节内磷酸激活的谷氨酰胺酶样免疫反应阳性神经元和终末以及五种代谢型谷氨酸受体的分布，同时结合HRP逆标技术对三叉神经脊束核尾侧亚核内磷酸激活的谷氨酰胺酶样阳性终末的来源进行了观察．发现磷酸激活的谷氨酰胺酶样阳性胞体和终末主要集中在三叉尾侧亚核的Ⅰ、Ⅱ层；半月节内仅有它的阳性胞体。半月节内HRP逆标神经元中呈磷酸激活的谷氨酰胺酶样阳性者占71．4％，这些双重反应阳性神经元占半月节内磷酸激活的谷氨酰胺酶样阳性神经元的33．2％．五种代谢型谷氨酸受体亚型中，只有5型密集地分布于三叉尾侧亚核的Ⅰ、Ⅱ层。以上结果说明：（1）三叉尾侧亚核内的磷酸激活的谷氨酰胺酶样阳性终末主要位于其浅层，它们主要来源于三叉神经的初级传入；（2）三叉尾侧亚核的代谢型谷氨酸受体五种亚型中，只有5型可能参与西口部伤害性刺激信息的传递；（3）三叉尾侧亚核内磷酸激活的谷氨酰胺酶样阳性终末的分布与代谢型谷氨酸受体5型的分布互相匹配。

Distributions of phosphate-activated glutaminase (PAG)- and 5 subtypes (1, 1a ,2/3, 5 ) of metabotropic gluta-mate receptor (mGluR)-like immunoreactivities in the spinal trigeminal subnucleus caudalis (Vc) and trigeminal ganglion(TG) of the rat were examined by using a monoclonal antibody against PAG and 4 kinds of antibody against those 5 subtypesof mGluR in the present study. Moreover, HRP retrograde tracing combined with immunohistochemical staining for PAGwas applied to investigate the origin of PAG-like immunoreactive (PAG-LI) terrninals in the Vc. PAG-LI neuronal cell bodies and terminals were mainly located in the superficial laminae (laminae Ⅰ and Ⅱ ) of the Vc, only PAG-LI cell bodies werefound in the TG. Among 5 kinds of mGluR subtypes, mG1uR5-LI neuronal cell bodies, fibers and terminals were denselyobserved in the Iaminae Ⅰ and Ⅱ of the Vc. In the TG, 71. 4% of the HRP retrogradely labeled cells that sent their axonsto the Vc contained PAG-like immunoreactivities and 33. 4% of PAG-LI cells in the TG were labeled by HRP. Altogether,these results indicated that: (1)PAG-LI terminals mainly distributed in the superficial laminae of the Vc and they originated mainly from the primary afferents of the trigeminal nerve; (2)In the Vc, only mGluR5 might be closely related to the transmission of orofacial noxious stimulation information; (3)Distributions of PAG-LI terminals and mGluR5 matched to eachotller in the Ve.