SENSITIZATION--BEHAVIORAL PROPERTIES & NEURAL MECHANISMS

厌恶刺激引起反应的程度，以及 产生了学习，变化很大。在某些情况下， 有害的刺激可能几乎不会被注意到。在其他时候，甚至是温和的 刺激会产生无能为力的疼痛。我们要达到的目的是 是为了 解释这种可变性；生理和心理 系统 调制伤害性信息的加工。过去的研究 有 专注于减少伤害性感受器流动的机制 信息，有效地破坏了其心理影响。 这些 “止痛”系统的研究通常是通过让大鼠暴露于一种 厌恶者 事件(例如，电击)。伤害性信息处理的变化 已评估 通过测量延迟以表现出尾部移动来响应 一个 热刺激(甩尾试验)或 由PAW引导 由化学刺激物(福尔马林试验)引起的行为。 vbl.使用 研究人员发现，这些测试降低了伤害性反应。 但 最近的一项使用其他行为测量的研究表明，疼痛 是 实际上增强了(痛觉过敏)，用于接触电击降低 对各种刺激的发声阈值，并增加 热刺激和电击刺激对巴甫洛夫综合征患者的情感影响 和 操作条件反射范式。我们提出的实验主要集中在 这个 对疼痛的敏感化；什么时候观察到它，它如何影响 伤害性的 以及潜在的神经系统。为了支持我们的 推论 痛觉过敏，并阐明它与其他 行为 现象，将监视多个行为终结点。我们的 行为研究将阐明导致 痛觉过敏，无论它是否与恐惧的诱导有关，它的 对…的影响 其他行为过程(例如，惊吓)以及它如何增强 学习 在巴甫洛夫范式中。随后的实验将探索 牵涉到神经解剖系统。神经化学损伤将是 习惯于 观察大脑背侧区和外侧区的作用 导水管周围 灰质与中央核和基底外侧复合体 杏仁核。 这种损伤方法将通过实验测试加以补充。 这个 化学激活神经系统的影响 导水管周围 Gray和我们的推断将通过获得多个 疼痛反应性的测量。

The degree to which an aversive stimulus elicits responding, and engenders learning, varies tremendously. Under some conditions, a noxious stimulus may be hardly noticed. At other times, even mild stimulation can produce incapacitating pain. The aim of our reach is to explain this variability; how physiological and psychological systems modulate the processing of nociceptive information. Past research has focused on the mechanisms that decrease the flow of nociceptive information, effectively undermining its psychological impact. These "analgesic" systems are commonly studied by exposing rats to an aversive event (e.g., shock). Changes in nociceptive processing are then assessed by measuring the latency to exhibit a tail-movement in response to a thermal stimulus (the tail-flick test) or the amount of paw-directed behavior elicited by a chemical irritant (the formalin test). Using these tests, researchers have found reduced nociceptive reactivity. But recent work, using other behavioral measures, indicates that pain is actually enhanced (hyperalgesia), for exposure to shock lowers vocalization thresholds to a variety of stimuli and increases the affective impact of thermal and shock stimuli in both a Pavlovian and operant conditioning paradigm. The experiments we propose focus on the sensitization of pain; when is it observed, how it affects nociceptive processing, and the underlying neural systems. To bolster our inference of hyperalgesia, and to clarify its relationship to other behavioral phenomena, multiple behavioral endpoints will be monitored. Our behavioral studies will clarify the circumstances that induce hyperalgesia, whether it is tied to the induction of fear, its effect on other behavioral processes (e.g., startle), and how it enhances learning in a Pavlovian paradigm. Subsequent experiments will explore the neuroanatomical systems involved. Neurochemical lesions will be used to examine the role of the dorsal and lateral regions of the periaqueductal gray and the central nucleus and basolateral complex of the amygdala. This lesion approach will be complimented by experiments testing the impact of chemically activating neural systems within the periaqueductal gray and our inferences will be strengthened by obtaining multiple measures of pain reactivity.