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发生器。我们成功地增强了有节奏的下颌运动的下颌附着脑干阻滞准备在体外与化学应用。我们需要改进制备方法。GABA_a拮抗剂荷包牡丹碱和NMDA受体激动剂NMA联合应用可引起大鼠下颌运动和开、闭口肌的节律性活动。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发生器，即开颌肌节律发生器和闭颌肌节律发生器。双侧关系也表明节律发生器是双侧存在的。对心律发生器的位置进行了连续的断层研究。最小脑干阻滞准备边界为：头侧：三叉神经运动核（Mo.V）的头侧至头侧边界1000- 1200 μ m，尾侧：Mo.V的尾侧边界，内侧：Mo.V的内侧至内侧边界200- 400 μ m，背侧：Mo.V的背侧至背侧边界700-800 μ m。尾侧脑干抑制双侧节律产生回路。Obex连续切片显示，神经元分布于疑核吻侧水平至面神经核尾侧水平。这些都是三叉神经研究中的新发现。

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.