大鼠三叉-小脑投射神经元表达磷酸激活的谷氨酰胺酶——双标法研究(英文)

Trigeminocerebellar projection neurons express phosphate activated glutaminase-like immunoreactivity: a double labeling study in the rat

磷酸激活的谷氨酰胺酶 (phosphateactivatedglutaminase,PAG)可作为谷氨酸能神经元的标志物。采用逆行束路追踪技术和PAG免疫荧光组织化学法 ,研究脑干三叉核团复合体中向小脑袢状小叶Crus1区投射神经元是否呈PAG样免疫反应阳性。结果表明 :将荧光金 (Fluoro Gold ,FG)注入小脑袢状小叶Crus1区后 ,在三叉神经感觉主核 (Pr5 )、三叉神经脊束核极间亚核 (Sp5I)和吻侧亚核背内侧部 (Sp5DM)、三叉间核 (I5 )以及三叉神经运动核与上橄榄核之间的一个小区域 (nucleusJ)中均可见到FG逆行标记细胞。标记细胞出现在上述核团的双侧 ,但以同侧为主。PAG免疫荧光组织化学反应结果显示 :许多FG标记神经元呈强PAG样免疫阳性 ,其中FG/PAG双标神经元占FG逆行标记神经元总数的 73%～ 94 %。结果提示 :脑干三叉神经核团中的谷氨酸能神经元可能参与触觉信息从面口部向小脑的传递。

China ) Phosphate activated glutaminase (PAG) has usually been considered as a marker for glutamatergic neurons. In the present study, combining immunofluorescence histochemistry for PAG with the retrograde tract tracing technique, we examined if the neurons in the trigeminal brainstem complex which project to the crus 1 of the ansiform lobule (Cr 1) of the cerebellum expressed PAG like immunoreactivity (PAG LI). The results showed that after injection of Fluoro Gold (FG) into the Cr 1 of the cerebellum, many neurons in the trigeminal nuclei were retrogradely labeled with FG. Although observed bilaterally, the FG labeled neurons were mainly distributed ipsilaterally in the principal sensory trigeminal nucleus (Pr5), the dorsomedial part of the subnucleus oralis (Sp5DM) and the subnucleus interpolaris (Sp5I) of the spinal trigeminal nucleus, the intertrigeminal nucleus (I5) and a small region located between the motor trigeminal nucleus and the superior olivary nuclei (nucleus J). After the processing of immunofluorescence for PAG, many FG labeled neurons showed intense PAG LI; and the percentages of the neurons double labeled with FG and PAG to the total number of the FG labeled neurons ranged from 73%～94%. The present results indicated that the glutamatergic neurons in the trigeminal brainstem complex might be involved in the transmission of tactile information from the orofacial region to the cerebellum.