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.

项目概要 在理解皮质表征以及触觉和本体的整合方面存在着根本性的差距。 一般伴随身体运动的感受，特别是口腔运动行为。这个代表 提出了一个重要的问题，因为在我们理解之前，口面部疼痛的机制、感觉 神经元损伤和感觉运动整合在很大程度上仍是难以理解的。拟议的目标 研究目的是分离自然进食行为期间触摸和本体感觉的皮层表征 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。舌头是研究这一问题的独特结构 因为它在接触其他口腔结构（例如牙齿、 上颚和牙龈）在喂食期间。更重要的是，触觉和本体感觉传入纤维支配 舌头分别进入中枢神经系统：三叉神经（舌神经支）和舌下神经 分别是脑神经。这种独特的解剖结构使得触觉和本体头的实验分离成为可能。 。中心假设是舌头的姿势和与其他口腔结构的接触反映在 初级体感 (SIo) 和初级运动神经元的本体感觉和触觉相关反应 (MIo) 口面部感觉运动皮层 (OSMcx) 区域。这个假设将通过追求三个特定的 具体目标：（1）确定如何编码有关舌头姿势和与其他口腔结构接触的信息 通过消除对舌头和周围口腔结构的触觉刺激，在自然喂养期间减少 MIo 和 SIo 通过对三叉神经的上颌和下颌感觉支进行连续神经阻滞，(2) 通过使用皮质内微刺激将神经元的运动反应与本体感觉反应分离 （ICMS）引起肌肉抽搐，同时舌头和其他口腔结构的触觉输入被阻止，以及（3） 通过光谱表征 OSMcx 中触觉和本体感觉相关区域之间的功能连接 一致性分析以及触觉区域低强度 ICMS 对本体感觉区域和副感觉区域的影响 反之亦然。拟议的研究采用了一种创新方法，利用了独特的感觉神经支配 口腔区域由不同的脑神经组成，并整合了口腔区域的同步神经记录和跟踪 舌头和下巴的 3D 运动。拟议的研究意义重大，因为它将弥合以下结果： 对口腔体感的皮质表征和舌头/下颌的生物力学进行了数十年的研究 口腔运动行为期间的运动，从而填补了该领域的重要空白。由此获得的知识 这项工作将为未来口腔体感、疼痛机制和感觉运动的研究奠定基础 一体化。最终，这些知识有可能为治疗策略的制定提供信息 与牙种植相关的感觉障碍、三叉神经痛、颞下颌关节紊乱病、口腔颌面部疾病 社会疼痛，以及恢复用于脑机接口的感觉反馈。