Objective: To determine the opening and closing action of the external muscle, the projection pathway of the axon terminal of trigeminal motor nucleus (Vmo) neuron to the lateral pterygoid muscle was revealed. Methods: In this study, 10 SD rats of 8 weeks old were included. The left lateral pterygoid muscle of SD rats was surgically exposed, and the wound was closed after intramuscular injection of hydroxystilbamidine/fluorogold (FG) 3-5 μl. Seven days after the operation, the experimental animals were perfused, samples collected and sectioned for immunofluorescence staining. After FG injection into the lateral pterygoid muscle, the FG reversed in the Vmo neurons. Results: In the Vmo neurons on the FG injection side (left side), a large number of FG reversed neurons were found in the corpus luteum and dendrites. These neurons were not only distributed in the dorsolateral part of the trigeminal motor nucleus that innervated the closed muscle, but also in the ventral medial portion of the trigeminal nucleus of the open muscle. Conclusions: The neuronal conduction pathway between the Vmo and the lateral pterygoid muscle innervates the lateral pterygoid muscle. The neurons are distributed both in the dorsolateral and in the nucleus of the ventral ventricle. It is concluded that the lateral pterygoid muscle involve in the jaw closing and opening movement.
目的: 通过对SD大鼠三叉神经运动核(trigeminal motor nucleus,Vmo)-翼外肌神经元投射通路的定性研究分析,揭示Vmo神经元轴突终末向翼外肌的投射通路,以确定翼外肌的开闭口作用。 方法: 纳入8周龄SD大鼠10只,手术暴露SD大鼠左侧翼外肌,肌内注射荧光金3~5 μl后,关闭并缝合伤口。术后7 d,实验动物灌注、取材、切片后免疫荧光染色,荧光显微镜下观察荧光金注入翼外肌后,在三叉神经运动核内荧光金的逆行标记情况。 结果: 在荧光金注射侧的Vmo神经元内可见大量的荧光金逆标神经元的胞体和树突,这些神经元不仅分布于支配闭口肌的三叉神经运动核的背外侧部,也分布于支配开口肌的三叉神经运动核的腹内侧部。 结论: Vmo与翼外肌之间的神经元传导通路支配翼外肌,神经元既分布在背外侧部也分布在腹内侧部的核团内,推断翼外肌既在开口运动中发挥作用,又在闭口运动中发挥作用。.