Spatial Properties of Cutaneous Temperature Sensitivity

动物模型热感受的生理学、神经生物学和分子生物学研究进展 已经超过了对人体热感受的研究。目前正在进行的项目试图纳入这一点 心理物理学研究的新知识，这些研究测试关于人类基本机制的假设 温度敏感度。之前对该项目的研究发现，有证据表明， 经典定义的冷暖感觉和痛觉之间的敏感性，以及 触觉和温度之间的相互作用，改变了质量和数量维度 温度感知。拟议的研究建立在这些和其他更新的发现的基础上进行调查 无痛体温是如何通过皮肤感觉系统之间的多感官相互作用来感知的。 具体地说，目标1将研究触觉刺激的参数，这些参数是简单接触能力的基础 抑制热敏感，特别是在无害的温度下感觉到的伤害感觉。的 有趣的是，这种抑制是源于触摸对疼痛的一般抑制作用，还是来自于 降低对接触热刺激的敏感性的专门机构。目标2将检验假设 关于新近发现的瞬时受体电位(Trp)通道在非痛性神经系统中的作用 使用局部应用已被证明可以调节的化学试剂来感知寒冷和炎热 这些频道。目标3将测试低阈值热传入纤维如何汇聚和相互作用的模型 脊髓丘脑束内有热和伤害性神经元。对该模型的测试，该模型部分基于 在热纤维和冷纤维范围内敏感的传入纤维的心理物理证据可以 对疼痛通路的接力刺激，将提供关于非痛热机制的基本信息 感知力。目标4将确定局部温度敏感性与全身温度的关系 感知力。重点将放在局部敏感性是否预示着全身敏感性，以及 热刺激的知觉强度与愉悦感之间的关系。这两条线路都是 研究将提供缺失的数据，即皮肤热敏感性如何影响至关重要的动态平衡 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，这项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、 还有中风。

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.