Shi Suming, Xu Lei, Li Jianfeng, Han Yuechen, Wang Haibo
Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, PR China; Shandong Provincial Key Laboratory of Otology, Jinan 250022, PR China.
Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, PR China.
Neurosci Lett. 2016 Aug 26;629:180-185. doi: 10.1016/j.neulet.2016.07.018. Epub 2016 Jul 14.
Facial nucleus motoneurons innervating the facial expressive muscles are involved in a wide range of motor activities, however, the types of movement related neurons and their electrophysiological transformation after peripheral facial nerve injury haven't been revealed. This study was designed to elucidate the types of facial nucleus motoneurons and their alterations of discharge parameters following peripheral facial nerve injury in vivo. Here we set up a rat model by implanting electrode arrays into the brainstem and recorded the electrophysiological signals of facial nucleus neurons in the intact rats for 5 days, then transected the trunk of facial nerve (TF), and continued the record for 4 weeks. At the 4th week post-surgery, the morphological changes of TFs were analyzed. In this paper, we described two types of putative facial nucleus motoneurons based on their electrophysiological properties and their firing frequency adaptation. Type I motoneurons (n=57.6%) were characterized by a sustained spike adaptation, Type II motoneurons (n=26.2%) were identified by a phasic fast spike firing. Facial palsy and synkinesia, caused by neurotmesis of TF, were accompanied by firing rates reduction and firing pattern alteration of motoneurons. Our findings suggest the presence of two types of facial nucleus motorneurons, and their response patterns after neurotmesis support the notion that the discharge pattern of motorneurons may play an important role in the facial nerve function.
支配面部表情肌的面神经核运动神经元参与多种运动活动，然而，与运动相关的神经元类型及其在周围面神经损伤后的电生理变化尚未明确。本研究旨在阐明体内周围面神经损伤后面神经核运动神经元的类型及其放电参数的变化。在此，我们通过将电极阵列植入脑干建立大鼠模型，在完整大鼠中记录面神经核神经元的电生理信号5天，然后切断面神经主干（TF），并继续记录4周。在术后第4周，分析TF的形态变化。在本文中，我们根据其电生理特性和放电频率适应性描述了两种假定的面神经核运动神经元。I型运动神经元（n = 57.6%）的特征是持续的峰适应，II型运动神经元（n = 26.2%）通过相位快速峰放电来识别。TF神经切断术引起的面瘫和联带运动伴随着运动神经元的放电率降低和放电模式改变。我们的研究结果表明存在两种类型的面神经核运动神经元，并且它们在神经切断术后的反应模式支持运动神经元的放电模式可能在面神经功能中起重要作用这一观点。
