Activation of Thermonociceptors by Infrared Diode Laser

红外二极管激光激活热痛感受器

• 批准号: 6869993
• 负责人: David Clifford Yeomans
• 金额: $ 20.53万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-01-20 至 2006-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6869993
• 关键词: biological models; heat stimulus; infrared radiation; laboratory rat; lasers; model design /development; receptor sensitivity; single cell analysis; skin; thermodynamics; thermoreceptors

DESCRIPTION (provided by applicant): One of the main determinants of the temperature at which C or Adelta thermonociceptors are excited appears to be the rate at which the peripheral terminals of nociceptors are heated. The relationship between rate and threshold temperature is not simple however, and is likely modulated by other direct factors, such as intensity and duration of stimulation, and surface area stimulated, as well as numerous indirect factors, including body, skin and air temperature, depth of the receptor in the skin, density of the skin, and specific characteristics of the heat source (thermode, normal radiant, various kinds of lasers). Perhaps the greatest advance in investigating these issues has been the development of standardized laser stimulation. However, there are great differences in the types of laser used, which can complicate comparisons between laboratories. We have chosen to investigate the use of a diode infrared laser, which should give optimal heating characteristics, in terms of direct heating of nociceptors in the skin, and which should inherently produce an extremely stable output. In addition, we will use a thermal camera to precisely measure temperature changes in the skin with an extremely precise temporal accuracy, so that the very rapid changes that can occur with lasers can be measured. Finally, we will combine these technologies with single unit peripheral nerve recordings in rats. In this way, we hope to determine optimal laser heating protocol for selective activation of either C or Adelta thermonociceptors. Based on our preliminary work, as well as our examination of the literature, we hypothesize that very rapid rise times with this laser will allow for selective activation of Adelta nociceptors, whereas lower rise time stimuli will selectively excite C nociceptors. Thus, we hope to show that temperatures of activation are not absolute, but rather are modulated by heating rate (dictated by laser power) and duration, and size of area stimulated. We also intend to use the basic data gleaned from these studies to generate predictive modeling of temperature response functions at different depths of skin In this way, we hope, with this R21 early stage project, to develop a method which will allow future studies in terms of nociceptimetric testing in rats, examining the biomolecular mechanisms underlying selective nociceptor activation, and finally in the examination of central nervous system consequences, in humans, of specific activation of these different nociceptor types.

描述（由申请人提供）：C或Adelta热感受器被激发的温度的主要决定因素之一似乎是伤害感受器的外周末端被加热的速率。然而，速率和阈值温度之间的关系并不简单，而且可能受到其他直接因素的调节，例如刺激的强度和持续时间、受刺激的表面积，以及许多间接因素，包括身体、皮肤和空气温度、皮肤中受体的深度、皮肤的密度和热源的特定特性（热模、正常辐射、各种激光器）。