The neural basis of touch and proprioreception in the primate orofacial sensorimotor cortex

灵长类口面部感觉运动皮层触觉和本体感受的神经基础

• 批准号: 10543656
• 负责人: Fritzie Arce-McShane
• 金额: $ 54.38万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-12-23 至 2023-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10543656
• 关键词: neural; basis; touch; proprioreception; primate

PROJECT SUMMARY There is a fundamental gap in understanding the cortical representations and integration of tactile and proprio- ceptive sensations accompanying bodily movements in general and oromotor behavior in particular. This repre- sents an important problem because until it is understood, the mechanisms underlying orofacial pain, sensorimo- tor impairments, and sensorimotor integration will remain largely incomprehensible. The goal of the proposed research is to dissociate the cortical representations of touch and proprioception during natural feeding behavior by using an innovative sequence of nerve blocks together with multi-electrode array recordings and 3D tracking of tongue and jaw movements in non-human primates. The tongue is a unique structure for investigating this because it is in constant motion and assumes various postures when touching other oral structures (e.g., teeth, palate, and gingiva) during feeding. More importantly, the tactile and proprioceptive afferent fibers innervating the tongue enter the central nervous system separately in trigeminal (lingual nerve branch) and hypoglossal cranial nerves, respectively. Such unique anatomy enables experimental dissociation of touch and propriocep- tion. The central hypothesis is that tongue posture and contact with other oral structures are reflected in the proprioception- and tactile-related responses of neurons in the primary somatosensory (SIo) and primary motor (MIo) areas of the orofacial sensorimotor cortex (OSMcx). This hypothesis will be tested by pursuing three spe- cific aims: (1) determine how information about tongue posture and contact with other oral structures is encoded in MIo and SIo during natural feeding by eliminating tactile stimuli to the tongue and surrounding oral structures through sequential nerve blocks to the maxillary and mandibular sensory branches of the trigeminal nerve, (2) dissociate the neurons’ motor response from a proprioceptive response by using intracortical microstimulation (ICMS) to evoke muscle twitches while tactile inputs to the tongue and other oral structures are blocked, and (3) characterize the functional connectivity between tactile- and proprioceptive-related regions in OSMcx by spectral coherence analysis and by the effects of low-intensity ICMS of a tactile region on a proprioceptive one and vice versa. The proposed research uses an innovative approach that leverages the unique sensory innervation of the oral region by different cranial nerves and integrates the simultaneous neural recording and tracking of the tongue and jaw movements in 3D. The proposed research is significant because it will bridge the results of decades of research on cortical representation of oral somatosensation and on the biomechanics of tongue/jaw movements during oromotor behavior, thus filling an important gap in the field. The knowledge gained from this work will lay the groundwork for future studies on oral somatosensation, pain mechanisms, and sensorimotor integration. Ultimately such knowledge has the potential to inform the development of strategies for treatment of sensory impairments associated with dental implants, trigeminal neuralgia, temporomandibular disorders, orofa- cial pain, and for the restoration of sensory feedback for use in brain-machine interface.

项目摘要 在理解触觉和本体的皮质表征和整合方面存在根本性的差距， 伴随着身体运动的感觉，特别是身体行为。这个代表- 发送一个重要的问题，因为直到它被理解，口面疼痛的机制，感觉， tor损伤和感觉运动整合将在很大程度上仍然无法理解。建议的目标 研究旨在分离自然进食行为期间触摸和本体感觉的皮质表征 通过使用创新的神经阻滞序列以及多电极阵列记录和3D跟踪， 非人类灵长类动物的舌头和下巴运动。舌头是研究这个的独特结构 因为它处于恒定运动中并且在接触其它口腔结构时呈现各种姿势（例如，牙齿， 上颚和牙龈）。更重要的是，触觉和本体感觉传入纤维支配 舌分别从三叉神经（舌神经分支）和舌下神经进入中枢神经系统 颅神经。这种独特的解剖结构使触觉和本体感觉的实验分离成为可能， 是的。中心假设是，舌头的姿势和与其他口腔结构的接触反映在 初级躯体感觉（SIo）和初级运动神经元的本体感觉和运动相关反应 (MIo)口面感觉运动皮质（OSMcx）区域。这一假设将通过追求三个特殊的测试- 具体目的：（1）确定舌位和舌与其他口腔结构接触的信息是如何编码的 通过消除对舌头和周围口腔结构的触觉刺激， 通过对三叉神经的上颌和下颌感觉支的顺序神经阻滞，（2） 通过使用皮质内微刺激将神经元的运动反应与本体感受反应分离 （ICMS），以引起肌肉抽搐，同时对舌头和其他口腔结构的触觉输入被阻断，以及（3） 通过光谱表征OSMcx中触觉和本体感受相关区域之间的功能连接 相干性分析和低强度ICMS的触觉区域的影响，对本体感受的一个和副 亦然拟议的研究使用了一种创新的方法，利用大脑中独特的感觉神经支配， 口腔区域由不同的脑神经进行记录，并集成了对口腔区域的同时神经记录和跟踪 舌头和下巴的三维运动拟议的研究是重要的，因为它将桥梁的结果， 几十年来对口腔躯体感觉的皮质表征和舌/颌的生物力学的研究 运动在orthopathic行为，从而填补了该领域的一个重要空白。从中获得的知识 这项工作将为未来口腔躯体感觉、疼痛机制和感觉运动的研究奠定基础 一体化最终，这些知识有可能为制定治疗糖尿病的战略提供信息。 与牙科植入物相关的感觉障碍、三叉神经痛、颞下颌关节紊乱病、口腔- 社会性疼痛，并用于恢复感觉反馈，用于脑机接口。