Trigeminal Phythmical Activity Evoked in an Isolated Brainstem Preparation in vitro

本研究旨在分析与三叉神经活动相关的中枢模式产生机制。我们成功地利用化学方法增强了体外颌骨附着脑干块制备中颌骨的节律性运动。我们需要改进制备方法。GABAa拮抗剂、双核碱和NMDA受体激动剂NMA联合使用可引起大鼠有节奏的下颚运动和下颌开闭肌的节律性活动。通过对开颌肌和闭颌肌节律活动的分析，发现开颌肌和闭颌肌存在两种节律产生器。而双边关系也表明节奏发生器是双边存在的。关于节律发生器的位置，我们进行了连续的切片研究。最小脑干阻滞预备边界为；并分析了三叉运动核吻侧：吻侧至吻侧边界1000 ~ 1200ma、尾侧：mov尾侧边界、内侧：mov内侧至内侧边界200 ~ 400ma、背侧：mov背侧至背侧边界700 ~ 800 ma对节律发生器的抑制作用。尾侧脑干抑制双侧节律产生回路。脑脊液连续切片显示神经元分布于面核吻侧至面核尾侧。这些都是三叉神经研究的新发现。

This study was performed to analyzed about the central pattern generators related to trigeminal activities. We succeeded in enhancing rhythmical jaw movements in jaw attached brainstem block preparation in vitro with chemical application. We needed to improve the preparation method. The combination of GABAa antagonist, bicuculline and NMDA receptor agonist, NMA,elicited the rhythmical jaw movements and the rhythmical activities in jaw opener and closer muscles. Analysis of rhythmical activities in jaw opener and closer muscle, showed the existance of two type of rhythm generators, one is for jaw opener and another for jaw closer. And also bilateral relationship indicated that rhythm generator exists bilaterally. About the location of rhythm generator, we made serial a sectioning study. The boundary of minimum brainstem block preparation is ; Rostral : 1000-1200mum rostral to rostral boundary of trigeminal motor nucleus (Mo.V), Caudal : caudal boundary of Mo.V,Medial : 200-400mum medial to medial boundary of Mo.V,Dorsal : 700-800 dorsal to dorsal boundary of Mo.V.Inhibition to rhythm generator was also analyzed. Caudal brainstem inhibits bilateral rhythm generation circuits. Serial section from obex suggested that the neurons locates from the level of rostral of ambiguus to the level of caudal of facial nucleus. These are quite new findings in the trigeminal research.