Tereshenko Vlad, Dotzauer Dominik C, Maierhofer Udo, Festin Christopher, Luft Matthias, Laengle Gregor, Politikou Olga, Klein Holger J, Blumer Roland, Aszmann Oskar C, Bergmeister Konstantin D
Clinical Laboratory for Bionic Extremity Reconstruction, Department of Plastic, Reconstructive and Aesthetic Surgery, Medical University of Vienna, Vienna, Austria.
Center for Biomedical Research, Medical University of Vienna, Vienna, Austria.
Front Neuroanat. 2021 Mar 22;15:650761. doi: 10.3389/fnana.2021.650761. eCollection 2021.
The facial dermato-muscular system consists of highly specialized muscles tightly adhering to the overlaying skin and thus form a complex morphological conglomerate. This is the anatomical and functional basis for versatile facial expressions, which are essential for human social interaction. The neural innervation of the facial skin and muscles occurs via branches of the trigeminal and facial nerves. These are also the most commonly pathologically affected cranial nerves, often requiring surgical treatment. Hence, experimental models for researching these nerves and their pathologies are highly relevant to study pathophysiology and nerve regeneration. Experimental models for the distinctive investigation of the complex afferent and efferent interplay within facial structures are scarce. In this study, we established a robust surgical model for distinctive exploration of facial structures after complete elimination of afferent or efferent innervation in the rat. Animals were allocated into two groups according to the surgical procedure. In the first group, the facial nerve and in the second all distal cutaneous branches of the trigeminal nerve were transected unilaterally. All animals survived and no higher burden was caused by the procedures. Whisker pad movements were documented with video recordings 4 weeks after surgery and showed successful denervation. Whole-mount immunofluorescent staining of facial muscles was performed to visualize the innervation pattern of the neuromuscular junctions. Comprehensive quantitative analysis revealed large differences in afferent axon counts in the cutaneous branches of the trigeminal nerve. Axon number was the highest in the infraorbital nerve (28,625 ± 2,519), followed by the supraorbital nerve (2,131 ± 413), the mental nerve (3,062 ± 341), and the cutaneous branch of the mylohyoid nerve (343 ± 78). Overall, this surgical model is robust and reliable for distinctive surgical deafferentation or deefferentation of the face. It may be used for investigating cortical plasticity, the neurobiological mechanisms behind various clinically relevant conditions like facial paralysis or trigeminal neuralgia as well as local anesthesia in the face and oral cavity.
面部皮肤肌肉系统由高度特化的肌肉组成，这些肌肉紧密附着于覆盖其上的皮肤，从而形成一个复杂的形态学集合体。这是多样面部表情的解剖学和功能基础，而面部表情对于人类社交互动至关重要。面部皮肤和肌肉的神经支配通过三叉神经和面神经的分支进行。这些也是最常发生病理改变的颅神经，常常需要手术治疗。因此，用于研究这些神经及其病理的实验模型对于研究病理生理学和神经再生具有高度相关性。用于独特研究面部结构内复杂传入和传出相互作用的实验模型很少。在本研究中，我们建立了一个强大的手术模型，用于在大鼠完全消除传入或传出神经支配后对面部结构进行独特的探索。根据手术程序将动物分为两组。第一组切断面神经，第二组单侧切断三叉神经的所有远端皮支。所有动物均存活，且手术未造成更高的负担。术后4周用视频记录触须垫运动，显示去神经成功。对面部肌肉进行全层免疫荧光染色，以观察神经肌肉接头的神经支配模式。综合定量分析显示三叉神经皮支中传入轴突数量存在很大差异。轴突数量在眶下神经中最高（28,625±2,519），其次是眶上神经（2,131±413）、颏神经（3,062±341）和下颌舌骨肌神经皮支（343±78）。总体而言，该手术模型对于面部独特的手术去传入或去传出是强大且可靠的。它可用于研究皮质可塑性、面瘫或三叉神经痛等各种临床相关病症背后的神经生物学机制以及面部和口腔局部麻醉。
