Amygdalar Modulation of Fear-Conditioned Changes in REM Sleep

描述（由申请人提供）：本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）作为一个实验范式，研究杏仁核（AMY）在决定一个有机体的反应，其环境中的更一般的作用。具体来说，我们将研究大鼠恐惧条件反射后REM睡眠（REM）的变化，以及清醒期间相关的行为变化（W）。在目前的建议中，我们专注于AMY的外侧核（LA）。作为第一个目标，我们将根据标准CFC方案研究一组大鼠。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阶段活动和超声发声（USV），新奇感检测和W期间的冻结行为。作为第二个目标，我们将研究相同的措施，在睡眠和W在一组大鼠完全双边电解病变的LA。我们将通过用鹅膏蕈氨酸造成细胞毒性损伤来重复损伤研究，以确定在前一种损伤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LA病变干扰恐惧条件反射的睡眠-觉醒，特别是通过中断条件刺激（CS）-非条件刺激（US）协会在训练过程中，我们将在另一组大鼠，使临时双边病变的LA使用局部麻醉剂，利多卡因，在CFC协议的培训之前立即。有证据表明，5-羟色胺（5-HT）在LA激活和抑制机制中起着重要作用，可能是通过兴奋与LA主细胞突触的GABA能中间神经元。作为第三个目标，我们将探讨5-HT在CS-US关联过程中的调节作用，该过程发生在CFC协议的训练期间并改变睡眠-觉醒行为。在一个实验中，我们将在训练一组大鼠之前立即将5-HT注入双侧LA。在第二个实验中，我们将注射5-HT和非特异性的肾上腺素能拮抗剂。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著异常。特别是，我们希望深入了解创伤后应激障碍（PTSD）的睡眠障碍，这往往是棘手的，目前可用的心理治疗和药物治疗。原发性失眠也可能是压力经历的后果，一些患有创伤后应激障碍的人可能会发生快速眼动睡眠中断失眠。 研究CFC在动物中的神经元能调节是非常重要的，因为影响5-HT功能的药物被广泛接受用于治疗PTSD，但对它们在相关动物模型中的作用知之甚少。

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.