Spatial Properties of Cutaneous Temperature Sensitivity

动物模型中温度感受的生理学、神经生物学和分子生物学进展 已经超过了人类温度感受的研究。目前正在进行的项目试图将这一点纳入 心理物理学研究的新知识，测试关于人类基本机制的假设 温度敏感性以前对该项目的研究发现了大量重叠的证据， 在经典定义的温暖和寒冷的感觉和疼痛的感觉之间的敏感性， 触摸和温度之间的相互作用，改变了 温度感知拟议的研究建立在这些和其他最近的发现， 如何通过皮肤感觉系统之间的多感官相互作用感知非疼痛温度。 具体来说，目标1将调查的参数，触觉刺激的基础能力，简单的接触 抑制热敏感性，特别是在无害温度下感受到的伤害性感觉。的 有趣的是，这种抑制是否来自触摸对疼痛的一般抑制作用， 减弱对接触热刺激的敏感性的专门机制。目标2将测试假设 关于最近发现的瞬时受体电位（TRP）通道参与非疼痛性 使用局部应用化学试剂来感知冷和热， 这些渠道。目标3将测试低阈值热传入纤维如何会聚和相互作用的模型 脊髓丘脑束中的热和伤害感受神经元。该模型的测试部分基于 心理物理学证据表明，在温纤维和冷纤维范围内具有敏感性的传入纤维可以 对疼痛通路的中继刺激将提供有关非疼痛性热机制的基本信息。 perception.目标4将确定局部温度敏感性与全身温度的关系 perception.重点将放在局部敏感性是否是全身敏感性的预测， 热刺激的感知强度和愉悦度之间的关系。这两条线 研究将提供关于皮肤热敏感性如何有助于重要的体内平衡的缺失数据 行为体温调节功能。此外，通过测试关于 温度对疼痛的敏感性，拟议的研究有可能提供重要的新见解， 温和的温度如何在临床疾病中引发神经性疼痛，如纤维肌痛，多发性硬化症， 和中风

Advances in the physiology, neurobiology, and molecular biology of thermoreception in animal models have outpaced research on human thermoreception. The present continuing project seeks to incorporate this new knowledge into psychophysical studies that test hypotheses about basic mechanisms of human temperature sensitivity. Previous research on the project uncovered evidence of an extensive overlap in sensitivity between the classically defined senses of warmth and cold and the sense of pain, and of interactions between touch and temperature that modify the qualitative and quantitative dimensions of temperature perception. The proposed research builds on these and other more recent findings to investigate how nonpainful temperatures are sensed via multisensory interactions among the cutaneous sensory systems. Specifically, Aim 1 will investigate the parameters of tactile stimulation that underlie the ability of simple contact to suppress thermal sensitivity, particularly nociceptive sensations perceived at innocuous temperatures. Of interest is whether this suppression arises from a general inhibitory action of touch on pain or from a specialized mechanism that attenuates sensitivity to contact thermal stimulation. Aim 2 will test hypotheses about the involvement of recently discovered transient receptor potential (TRP) channels in nonpainful perception of cold and heat using topical application of chemical agents that have been shown to modulate these channels. Aim 3 will test a model of how low-threshold thermal afferent fibers may converge and interact with thermal and nociceptive neurons in the spinothalamic tract. Tests of the model, which is based in part on psychophysical evidence that afferent fibers with sensitivities in the range of warm fibers and cold fibers can relay stimulation to the pain pathway, will provide basic information about the mechanisms of nonpainful heat perception. Aim 4 will determine the relationship of local temperature sensitivity to whole-body temperature perception. Emphasis will be placed on whether local sensitivity is predictive of whole-body sensitivity and on the relationship between the perceived intensity and pleasantness of thermal stimulation. Both of these lines of research will provide missing data on how cutaneous thermal sensitivity contributes to the vital homeostatic function of behavioral thermoregulation. In addition, by testing new hypotheses about the relationship of temperature sensitivity to pain, the proposed research has the potential to provide important new insights into how mild temperatures trigger neuropathic pain in clinical disorders such as fibromyalgia, multiple sclerosis, and stroke.