Thalamic and Cortical Mechanisms of Itch

 描述(申请人提供)：瘙痒是一种常见的临床问题，通常很难治疗。目前对中枢神经系统产生瘙痒的机制知之甚少，这可能是导致无法治疗瘙痒的原因之一。近年来，与瘙痒有关的信息在外周和脊髓中由神经元携带，这些神经元也被伤害性刺激激活，这一点变得越来越明显。这表明，在大脑中产生瘙痒所需的信息必须从多感觉神经元的反应中提取出来，这个过程被称为解码。这项拟议中的研究将首次使用单一单位电生理学技术来确定丘脑和皮质中处理瘙痒信息的区域。将确定丘脑中单个神经元对各种瘙痒和疼痛刺激的反应。丘脑瘙痒感觉神经元投射到的皮质区域将使用逆行激活方法确定。此外，还将确定单个皮质神经元对瘙痒原和产生疼痛的刺激的反应。这项拟议的研究将确定丘脑核团和皮质区域，在那里处理与瘙痒和疼痛有关的信息。此外，使用机器学习方法，我们将确定反应中动作电位的强度和模式的贡献 涉及对瘙痒和疼痛相关反应的不同编码。拟议的研究将极大地扩大我们对产生瘙痒和疼痛的中枢神经系统机制的理解。 相关性：对丘脑和大脑皮层产生瘙痒感觉的神经系统知之甚少。这种缺乏理解很可能是导致 对于大多数类型的慢性瘙痒缺乏有效的治疗方法。建议进行的研究 将确定丘脑和皮质中单个神经元处理和传递有关瘙痒和疼痛信息的区域。

 DESCRIPTION (provided by applicant): Itch is a common clinical problem that is often difficult to treat. There is currently little understanding of the mechanism used in the CNS to produce itch and this likely contributes to the inability to treat itch. In recent years it have become cler that information related to itch is carried in the periphery and spinal cord by neurons that are also activated by noxious stimuli. This suggests that information necessary for the production of itch in the brain must be extracted from the responses of polysensory neurons in a process called decoding. The proposed studies, will for the first time, use single unit electrophysiologica techniques to determine the areas in the thalamus and cortex where processing of pruriceptive information occurs. The responses of single neurons in the thalamus to various itch-and pain-producing stimuli will be determined. The cortical areas to which pruriceptive thalamic neurons project will be determined using antidromic activation methods. In addition, responses of individual cortical neurons to pruritogens and pain-producing stimuli will be determined. The proposed studies will determine the thalamic nuclei and cortical areas in which processing of information related to itch and pain occur. In addition, using a Machine Learning approach, we will determine the contributions of the intensity and pattern of action potentials within responses to differential coding of itch and pain related responses. The proposed studies will considerably expand our understanding of the CNS mechanisms that produce itch and pain. RELEVANCE: Very little is known about the neural systems in the thalamus and cerebral cortex that underlie production of the sensation of itch. This lack of understanding likely contributes to the paucity of effective treatments for the majority of types of chronic itch. The proposed studies will determine the areas in the thalamus and cortex in which single neurons process and transmit information about itch and pain.