大鼠三叉神经中脑核神经元细胞内HRP标记的研究

NEURONS OF THE TRIGEMINAL MESENCEPHALIC NUCLEUS IN THE RAT——AN INTRACELLULAR HRP LABELING STUDY

本文用电生理方法对大鼠三叉神经中脑核进行定位后将微电极插入该核的神经元,进行细胞内HRP注射。对53个标记神经元的形态、突起的行径、投射范围及其终末分支的特点和终止模式进行了研究。结果表明:(1)三叉神经中脑核神经元有单极、假单极、双极和多极神经元等四种类型,这些神经元有大有小,形状也多样;(2)单极和假单极神经元的突起行程长,投射广泛,侧支极其丰富。它们投射到中间神经元核团(三叉上核、三叉间核,桥延网状结构小细胞网状核等),运动核团(三叉运动核、外展神经副核、面神经副核等)和感觉核团(感觉主核背肉侧部、三叉脊束核吻侧亚核背内侧部等)。此外,还有个别突起投射到动眼神经核、滑车神经核和孤束中。(3)本文首次注意到,这些神经元在性质不同的核群其终末特点和终止模式不同,而在同类核群的各核中其终末特点和终止模式相似。(4)本文还观察到中脑核神经元的周围轴突发出侧支分布到三叉运动核。(5)本文首次提供了三叉神经中脑核神经元向感觉主核背内侧部、外展神经副核和面神经副核投射的资料。此外,本文还就三叉神经本体觉脑内传递通路进行了讨论。

With the aid of electrophysiological technique,intracellular HRP injection was performed by inserting the microelectrode into the cells of the trigeminal mesencephalic nucleus of the rat.The morphology of 53 labeled neurons was observed,including their form,the course of their processes,the projecting area,and the pattern of their terminal arborization.The results are:(1)Labeled neurons of the trigeminal mesencephalic nucleus could be divided into 4 types,unipolar,pseudounipolar,bipolar,and multipolar.Di ference in size and form of the cell bodies was noticed.(2)Unipolar and pseudounipolar neurons showed long processes,with abundant collaterals and widespread projections.Their projection areas inclu ded the nuclei of interneurons(supratrigeminal nucleus,intertrigeminal nucleus,and the parvocellular nucleus of pontomedullary reticular formation,etc.),the motor nuclei(trigeminal motor nucleus,accessory facial nucleus,and ac cessory abducens nucleus),and the sensory nuclei(dorsal medial part of the principal sensory nucleus of trigeminal,dorsomedial part of the subnucleus oralis of trigeminal spinal nucleus,etc.).Besides,a few processes projected to oculcmotor,trochlear nucleiand solitary tract.(3)The present paper noticed,for the first time,that the features of terminals and the patterns of their termination were different in different functional groups of nuclei,while in nuclei of the same functional group they were similar in character.(4)It was observed that the peripheral axons of the mesencephalic neurons gave collaterals to the trigeminal motor nucleus.(5)The present paper provided materials about the projection of the trigeminal mesencephalic neurons onto the dorsomedial part of the principal sensory nucleus of trigeminal nerve,accessory facial nucleus,and accessory abducens nucleus.These findings seem new,at least to us.In addition,discussion about the trigeminal proprioceptive pathway in the brain was presented.