大鼠三叉神经中脑核神经元中枢突在脑干内投射的光、电镜观察(中脑核-丘脑投射通路研究之一)

THE PROJECTION PATHWAY FROM THE TRIGEMINAL MESENCEPHALIC NUCLEUS(Vme)TO THE THALAMUS IN THE RAT.Ⅰ.THE BRAIN STEM DISTINATION OF THE"CENTRAL"PROCESSES OF Vme—A LIGHT AND ELECTRON MICROSCOPE STUDY

为了进一步搞清三叉神经中脑核(Vine)向丘脑的投射通路,本文首先用HRP跨节追踪技术在大鼠研究了接受咬肌本体觉传入的Vme神经元中枢突在脑干内的终止情况。结果证明它除终止于三叉运动核及三叉上核外,主要终止于面神经核水平的三叉神经脊束核吻侧亚核背内侧部(Vodm)及邻接的外侧网状结构(LRF)。在电镜观察到Vme神经元中枢突终末在Vodm区主要和该区内的树突形成突触。并观察到这些终末接受另外来源的神经终末的突触前控制。

The projection pathway of the proprioceptive information from the orofacial region to the thalamus is yet unknown.The purpose of this study is to reveal the organization of the projection pathway from the trigeminal mesencephalic nucleus(Vme)to thalamus.The present experiment which is the first part of the serial study was designed to trace the brainstem destination of the Vme neurons conveying proprioceptive input from the masseter muscle.In the experiment 28 rats were used,of which 22 were studied with HRP transganglionic tracing technique to identify the termination of the"central"processes of Vme neurons The result showed that,beside trigemihal motor nucleus and supratrigeminal nucleus,the terminating area of Vme neurons were the dorso-medial portion of the subnueleus oralis of the trigeminal spinal nucleus(Vodm)and the adjacent lateral reticular formation(LRF)at the level of the facial nucleus.The Vodm of 6 rats were examined under electron microscope after transganglionic labeling with HRP.The terminals of the Vme neurons containing HRP reaction products were found to synapse mainly with the dendrites in this area,and these labeled terminals were observed to receive presynaptic control from the terminals of unknown origins.