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）躯体感觉皮层和丘脑在疼痛感觉方面的表征中的特定功能。虽然SI、SII和丘脑在疼痛的位置、强度和形式的表征中的重要作用早已被认识，但它们的具体功能以及潜在的解剖学和神经基础尚未建立。我们对伤害性系统的精细功能组织和伤害性神经元的电生理特性的有限知识已经成为完全理解疼痛现象的机制的主要障碍。为了解决这些问题，我们建议使用一个多模型的方法，包括亚毫米功能磁共振成像，单位电生理学和组织学在麻醉猴确定伤害性区域和定量表征其响应特性的有害和无害的热和机械刺激，检查伤害性神经元的电生理特性，并建立其功能和解剖连接。利用9.4T高信噪比的优势，我们建议使用功能连接性测量来探测伤害性感受区域之间的功能等级关系。有三个具体目标。目的1确定伤害性感受在SI和SII皮层的表达。目的2研究伤害性感受在丘脑的表达。目的3：确定丘脑上矢状核、下矢状核和丘脑伤害性感受区的功能和解剖学联系。本研究的完成，将使我们更好地了解SI、SII和丘脑伤害性感受系统的功能和解剖结构，以及伤害性感受加工的电生理基础。这一知识对于理解疼痛的神经机制至关重要，并最终将提供疼痛感知与其潜在神经机制和解剖框架之间的关键联系。 公共卫生相关性：这项研究的重点是了解疼痛感知的感觉方面，如疼痛的位置（在哪里），强度（有多强）和质量在大脑中编码。更全面地了解丘脑皮质回路中疼痛信息处理的流程图，将为慢性疼痛的治疗提供新的思路，从而为慢性疼痛的治疗提供更合理、更可靠的方法。

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. PUBLIC HEALTH RELEVANCE: This study centers on understanding where and how the sensory aspects of pain perception such as the location (where), intensity (how strong), and quality of pain are encoded in the brain. A more complete understanding of the flowchart of painful information processing in the thalamocortical circutry would promote new therapeutic ideas, which will lead to more rational and reliable treatments for chronic pain.