Representation of Nociception in SII and Thalamus of Primates

描述（由申请人提供）：本提案的总体目标是了解初级（SI）和次级（SII）体感皮层和丘脑在疼痛感觉方面的具体功能。虽然SI、SII和丘脑在表征疼痛的位置、强度和形态方面的重要作用早已被认识到，但它们的具体功能及其潜在的解剖学和神经基础尚未建立。我们对痛觉系统的精细功能组织和痛觉神经元的电生理特性的有限知识已经成为全面理解疼痛现象背后机制的主要障碍。为了解决这些问题，我们建议使用多模型方法，包括亚毫米fMRI，单位电生理学和麻醉猴子的组织学，以确定伤害感觉区域，定量表征它们对有害和无害的热和机械刺激的反应特性，检查伤害感觉神经元的电生理特性，并建立它们的功能和解剖联系。利用9.4 T的高信噪比，我们提出使用功能连接度量来探测伤害感觉区域之间的功能层次关系。有三个具体目标。目的1旨在确定损伤感觉在骶髂和骶髂皮质中的皮层表征。目的2旨在研究伤害感觉在丘脑中的表征。目的3旨在确定SI、SII和丘脑中伤害感觉区域的功能和解剖连通性。在本研究完成后，我们将更好地了解SI、SII和丘脑中伤害感觉系统的功能和解剖组织，以及伤害感觉加工的电生理基础。这些知识对于理解疼痛的神经机制是至关重要的，并最终将提供疼痛感知与其潜在的神经机制和解剖学框架之间的关键联系。

DESCRIPTION (provided by applicant): The overall aim of this proposal is to understand the specific functions of the primary (SI) and secondary (SII) somatosensory cortices and the thalamus in the representation of sensory aspects of pain. Although the important roles of SI, SII, and thalamus in the representation of the location, intensity, and modality of pain have long been recognized, their specific functions and the underlying anatomical and neural basis have not yet been established. Our limited knowledge of the fine-scale functional organization of the nociceptive system and of the electrophysiological properties of nociceptive neurons has become a major obstacle to a complete understanding of the mechanisms underlying the phenomenon of pain. To address these issues, we propose to use a multi-model approach including submillimeter fMRI, unit electrophysiology, and histology in anesthetized monkeys to identify nociceptive regions and quantitatively characterize their response properties to noxious and innocuous thermal and mechanical stimuli, to examine the electrophysiological properties of nociceptive neurons, and to establish their functional and anatomical connections. By taking advantages of the high signal to noise ratio at 9.4 T, we propose to use the functional connectivity measure to probe the functional hierarchical relationship among nociceptive regions. There are three specific aims. Aim 1 proposes to determine the cortical representation of nociception in SI and SII cortices. Aim 2 proposes to examine the representation of nociception in thalamus.. Aim 3 proposes to determine the functional and anatomical connectivity of nociceptive regions in SI, SII and thalamus. At the completion of this study, we will have a better understanding about the functional and anatomical organization of the nociceptive system in SI, SII, and thalamus and the electrophysiological basis for nociceptive processing. This knowledge is crucial for understanding the neural mechanisms of pain and ultimately will provide a crucial link between the perception of pain and its underlying neural mechanisms and anatomical framework.