Liang Houcheng, Zhang Jingdong, Luo Pifu, Zhu Hongna, Qiao Ying, Su Anle, Zhang Ting
Xi'an BRIGHT Eye Hospital, Xi'an, Shaanxi 710000, China.
Shaanxi Provincial Eye Research Institute and Xi'an Eye Hospital Xi'an, Shaanxi 710002, China.
J Biomed Res. 2017 Jan 19;31(3):256-263. doi: 10.7555/JBR.31.20160127.
The objective of this study was to explore whether there was a functional link between trigeminal proprioception and the oculomotor system mediated through jaw muscle afferents. Electromyography (EMG) was undertaken of the levator palpebrae (LP) and superior rectus (SR), and Fos expression was detected in the brainstem following consecutive down-stretching of the lower jaw at 2-4 Hz in rats. Retrograde tracing was undertaken of the interstitial nucleus of Cajal and Darkschewitsch nucleus (INC/DN) pre-oculomotor neurons. EMG-like responses were recorded from the LP/SR during down-stretching of the lower jaw at 2-4 Hz in 3 out of 11 rats. Fos expression was induced by consecutive down-stretching of the lower jaw at 2-4 Hz for 20-30 seconds. Interestingly, Fos expression was distributed mainly in the bilateral INC/DN area. We also examined Fos-like immunoreactivity in central mesencephalic and paramedian pontine reticular formation that harbors premotor neurons controlling horizontal eye movement, but no Fos-like staining was observed therein. By injection of retrograde tracers into the oculomotor nucleus combined with Fos immunostaining, double labeled pre-oculomotor neurons were visualized to distribute in the INC/DN. In conclusions, there may exist a trigeminal proprioceptive - oculomotor system neural circuit through jaw muscle afferents in rats. Judging from Fos distribution pattern, this pathway might be related to vertical and torsional eye movements.
本研究的目的是探讨三叉神经本体感觉与动眼系统之间是否存在通过颌肌传入介导的功能联系。对大鼠提上睑肌(LP)和上直肌(SR)进行肌电图(EMG)检查,并在大鼠下颌以2 - 4 Hz连续向下伸展后,检测脑干中的Fos表达。对 Cajal间质核和动眼神经前核(INC/DN)的神经元进行逆行追踪。在11只大鼠中的3只,于下颌以2 - 4 Hz向下伸展时,从LP/SR记录到类似EMG的反应。通过下颌以2 - 4 Hz连续向下伸展20 - 30秒诱导Fos表达。有趣的是,Fos表达主要分布在双侧INC/DN区域。我们还检查了中脑中央和脑桥旁正中网状结构中的Fos样免疫反应性,该区域含有控制水平眼球运动的运动前神经元,但未观察到Fos样染色。通过将逆行示踪剂注入动眼神经核并结合Fos免疫染色,可见双标记的动眼神经前神经元分布在INC/DN中。总之,大鼠可能存在一条通过颌肌传入的三叉神经本体感觉 - 动眼系统神经回路。从Fos分布模式判断,该通路可能与垂直和扭转眼球运动有关。