目的观察大脑运动皮质发出的下行投射终末或谷氨酸能终末与脑干面口部运动核内运动神经元的间接突触联系。方法顺行与逆行追踪相结合及免疫组织化学染色与逆行追踪相结合的双重标记技术。结果将ＰＨＡ－Ｌ电泳入大鼠额叶１区和／或２区和将ＨＲＰ分别注入三叉神经运动核（Ｖｍ）、面神经核（Ⅶ）或舌下神经核（ⅩⅡ），ＰＨＡ－Ｌ顺标终末和ＨＲＰ逆标神经元的重叠分布区主要见于臂旁核簇、三叉上核、Ｖｍ内侧的脑桥网状结构、延髓中缝核簇和延髓网状结构外侧部，而在脑干面口运动核内则很少见到ＰＨＡ－Ｌ顺标终末。上述区域内也有较密集的谷氨酸样阳性终末。在电镜下观察到除Ｖｍ、Ⅶ和ⅩⅡ以外的结构内ＰＨＡ－Ｌ顺标终末或谷氨酸样阳性终末与ＨＲＰ逆标神经元的胞体和树突形成以非对称性为主的轴－体和轴－树突触。结论本研究的结果为皮质脑干束的终止部位和运动皮质对脑干运动核的间接调控提供了直接的形态学依据。来自大脑运动皮质并呈谷氨酸样阳性锥体细胞的下行投射对脑干运动前神经元主要发挥兴奋性作用 Objective To observe the indirect synaptic connection between descending projection terminals of cerebrum motor cortex and glutamate terminal and motoneurons in the motoneurons of brainstem facial area. Methods The combination of antegrade and retrograde tracing combined with double labeling technique combining immunohistochemical staining and retrograde tracing. Results PHA-L was electrophoresed into the frontal lobe and / or zone 2 of rat and HRP was injected into the nucleus of the trigeminal nucleus (Vm), facial nucleus (Ⅶ) or sublingual nucleus (ⅩⅡ), PHA-L The overlapping distribution of terminal neurons and HRP neurons mainly found in the paraclavicular nucleus cluster, the trigeminal nucleus, the medial pontine reticular network of Vm, the medullary nucleus of the medulla oblongata and the lateral portion of the medulla oblongata. However, PHA-L cis-terminal is rare in the nucleus. There is also a dense glutamate-like positive terminal in these areas. Electron microscopy showed that within the structures except Vm, Ⅶ and ⅩII, PHA-L-labeled terminal or glutamate-like positive terminals and HRP-labeled neurons formed asymmetric axons - Body and Axis - Synapse. Conclusions The results of this study provide a direct morphological basis for the indirect regulation of brainstem motor nucleus by the termination of cortical brainstem and motor cortex. Downstream projections from cerebrum motor cortex and glutamate-like positive pyramidal cells exert mainly excitatory effects on pre-brainstem pre-motor neurons