Amygdalar Modulation of Fear-Conditioned Changes in REM Sleep

描述（由申请人提供）：该项目的总体目标是了解杏仁核处理感觉输入调节基本睡眠-觉醒机制的方式。我们建议使用线索恐惧条件反射（CFC）作为实验范式来研究杏仁核（AMY）在决定生物体对环境的反应性方面的更一般作用。具体来说，我们将研究恐惧条件反射后大鼠快速眼动睡眠（REM）的变化，以及清醒时相关的行为变化(W)。在目前的提议中，我们关注的是AMY的外侧核（LA）。作为第一个目标，我们将根据标准的氯氟烃协议研究一组大鼠。我们将扩大我们对这些动物的神经行为评估，包括睡眠期间的REM相活动和超声发声（USV），新奇检测和W期间的冻结行为。作为第二个目标，我们将在一组LA完全双侧电解损伤的大鼠中研究睡眠和W期间相同的措施。我们将重复病变研究，用伊博tenic酸制作细胞毒性病变，以确定在前病变中观察到的变化是否源于细胞破坏而不是纤维损伤。为了证明左脑损伤干扰睡眠-清醒的恐惧条件反射，特别是通过在训练期间中断条件刺激(CS)-非条件刺激（US）的关联，我们将在另一组大鼠中，在CFC方案训练前立即使用局部麻醉剂利多卡因对左脑造成临时双侧损伤。有证据表明5-羟色胺（5-HT）在LA的激活和抑制机制中起重要作用，可能是通过刺激在LA主细胞上突触的gaba能中间神经元。作为第三个目标，我们将探索5-羟色胺在CFC协议训练期间发生的CS-US关联过程中的调节作用，并改变睡眠-觉醒行为。在1个实验中，我们在训练一组大鼠之前立即将5-HT注射到LA双侧。在第二个实验中，我们将注射5-羟色胺和非特异性5-羟色胺能拮抗剂。为了开始描述5-HT作用的细胞机制，我们将在第三个实验中，将5-HT与GABAA拮抗剂一起注射。这一建议与人类精神障碍特别相关，这些精神障碍是在心理压力经历之后出现的，涉及睡眠-觉醒行为和睡眠微结构的显着异常。特别是，我们希望深入了解创伤后应激障碍（PTSD）的睡眠障碍，这通常是目前可用的心理治疗和药物治疗难以解决的问题。原发性失眠也可能是压力经历的后遗症，一些PTSD患者也可能出现REM中断失眠。由于影响5-羟色胺功能的药物已被广泛接受用于治疗PTSD，但在相关动物模型中对其作用知之甚少，因此研究CFC在动物体内的5-羟色胺能调节非常重要。

DESCRIPTION (provided by applicant): The overall objective of this project is to understand the manner in which amygdalar processing of sensory inputs modulates basic sleep-wake mechanisms. We propose to use cued fear conditioning (CFC) as an experimental paradigm for studying the more general role of the amygdala (AMY) in determining an organism's responsiveness to its environment. Specifically, we shall study changes in REM sleep (REM) after fear conditioning in rats, and related behavioral changes during wakefulness (W). In the current proposal, we focus on the lateral nucleus (LA) of AMY. As a first aim, we shall study a group of rats according to a standard CFC protocol. We shall expand our neurobehavioral assessment of these animals to include REM phasic activity during sleep and ultrasonic vocalizations (USV), novelty detection and freezing behavior during W. As a second aim, we shall study the same measures during sleep and W in a group of rats with complete bilateral electrolytic lesions of LA. We shall repeat the lesion study by making cytotoxic lesions with ibotenic acid in order to determine whether the changes observed with the former lesions originate from cellular destruction and not fiber damage. To demonstrate that LA lesions interfere with the fear conditioning of sleep-wake specifically by interrupting conditioned stimulus (CS)-unconditioned stimulus (US) associations during training, we shall, in another group of rats, make temporary bilateral lesions of LA using a local anesthetic, lidocaine, immediately before training in the CFC protocol. There is evidence that serotonin (5-HT) plays an important role in mechanisms of LA activation and inhibition, possibly by exciting GABAergic interneurons that synapse on LA principal cells. As a third aim we shall explore the modulatory role of 5-HT in the CS-US association process that occurs during training in the CFC protocol and alters sleep-wake behavior. In 1 experiment, we will inject 5-HT into LA bilaterally immediately before training a group of rats. In a second experiment, we shall inject 5-HT together with a nonspecific serotonergic antagonist. In order to begin to delineate the cellular mechanisms of 5-HT's actions, we will, in a third experiment, inject 5-HT together with a GABAA antagonist. This proposal has particular relevance to human mental disorders that arise in the aftermath of a psychologically stressful experience and involve significant abnormalities in sleep-wake behavior and the microarchitecture of sleep. In particular, we expect to gain insight into the sleep disturbance in posttraumatic stress disorder (PTSD), which is often intractable to currently available psychotherapeutic and pharmacological treatments. Primary insomnia also may be a sequel to a stressful experience, and REM interruption insomnia may occur in some individuals with PTSD. It is very important to investigate the serotonergic modulation of CFC in animals because drugs that influence 5-HT function have widespread acceptance for treating PTSD yet little is known about their actions in related animal models.