Department of Biomedical Sciences, Ohio University Heritage College of Osteopathic Medicine, Warrensville Heights, Ohio.
Department of Biological Sciences, Ohio University, Athens, Ohio.
J Appl Physiol (1985). 2020 Apr 1;128(4):941-951. doi: 10.1152/japplphysiol.00398.2019. Epub 2020 Mar 19.
During chewing, movements and deformations of the tongue are coordinated with jaw movements to manage and manipulate the bolus and avoid injury. Individuals with injuries to the lingual nerve report both tongue injuries due to biting and difficulties in chewing, primarily because of impaired bolus management, suggesting that jaw-tongue coordination relies on intact lingual afferents. Here, we investigate how unilateral lingual nerve (LN) transection affects jaw-tongue coordination in an animal model (pig, ). Temporal coordination between jaw pitch (opening-closing) and ) anteroposterior tongue position (i.e., protraction-retraction), ) anteroposterior tongue length, and ) mediolateral tongue width was compared between pre- and post-LN transection using cross-correlation analyses. Overall, following LN transection, the lag between jaw pitch and the majority of tongue kinematics decreased significantly, demonstrating that sensory loss from the tongue alters jaw-tongue coordination. In addition, decrease in jaw-tongue lag suggests that, following LN transection, tongue movements and deformations occur earlier in the gape cycle than when the lingual sensory afferents are intact. If the velocity of tongue movements and deformations remains constant, earlier occurrence can reflect less pronounced movements, possibly to avoid injuries. The results of this study demonstrate that lingual afferents participate in chewing by assisting with coordinating the timing of jaw and tongue movements. The observed changes may affect bolus management performance and/or may represent protective strategies because of altered somatosensory awareness of the tongue. Chewing requires coordination between tongue and jaw movements. We compared the coordination of tongue movements and deformation relative to jaw opening-closing movements pre- and post-lingual nerve transection during chewing in pigs. These experiments reveal that the timing of jaw-tongue coordination is altered following unilateral disruption of sensory information from the tongue. Therefore, maintenance of jaw-tongue coordination requires bilateral sensory information from the tongue.
咀嚼时，舌头的运动和变形与下颌运动相协调，以管理和操纵食团并避免受伤。报告有舌神经损伤的个体既会因咬伤舌头，也会因咀嚼困难，主要是因为食团管理受损，这表明下颌-舌协调依赖于完整的舌传入。在这里，我们研究了单侧舌神经（LN）切断术如何影响动物模型（猪）中的下颌-舌协调。使用互相关分析比较 LN 切断术前和术后下颌俯仰（开闭）和）前后舌位置（即伸舌-缩舌）、）前后舌长度和）中外舌宽度之间的时间协调性。总的来说，LN 切断术后，下颌俯仰和大多数舌运动学之间的滞后显著降低，表明来自舌头的感觉丧失改变了下颌-舌协调。此外，下颌-舌滞后的减少表明，LN 切断术后，舌运动和变形发生在张口周期较早的阶段，而不是在舌感觉传入完整时。如果舌运动和变形的速度保持不变，较早的发生可能反映出运动幅度较小，可能是为了避免受伤。这项研究的结果表明，舌传入参与咀嚼，有助于协调下颌和舌运动的时间。观察到的变化可能会影响食团管理性能，或者可能代表由于舌头的感觉改变而采取的保护策略。咀嚼需要协调舌头和下颌的运动。我们比较了咀嚼过程中 LN 切断术前和术后相对于下颌开闭运动的舌运动和变形的协调情况。这些实验表明，单侧切断舌的感觉信息会改变下颌-舌协调的时间。因此，维持下颌-舌协调需要来自舌头的双侧感觉信息。
