Peptidergic mediation of the stress response: relationship between aversive and appetitive brain circuits

应激反应的肽能介导：厌恶和食欲脑回路之间的关系

• 批准号: RGPIN-2015-05388
• 负责人: Merali, Zul
• 金额: $ 2.4万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=659591
• 关键词: Peptidergic; mediation; stress; response; relationship

The long-term objective of this research program is to better understand how the brain interprets various types of stressors or salient stimuli (including appetitive events) and coordinates internal bodily responses as well as behavioral outputs in response to these events. This is based on the observation that exposure to threatening (or aversive) stimuli or to appetitive (or rewarding) stimuli can activate some of the same neural circuits. In this project, we will explore the behavioral, neurochemical and neuroanatomical substrates underlying responses to 1) `classic stressors' including naturalistic psychogenic (psychological) stressors (exposure to a larger `bully' leading to social defeat), neurogenic stressors (physical restraint), which have psychological and physical attributes and pure physiological stressors (e.g. exposure to immune-type stressors) and 2) appetitive stimuli (sexual behavior, palatable snack). We have deliberately selected to study these types of naturalistic stressors, as they are ethologically sound and more likely to yield heuristically and practically useful information. Moreover, the selection of the appetitive stimuli was based on data showing comparable activation of the hypothalamic-pituitary adrenal axis to social defeat and restraint making these stressors of opposite valence well suited for comparative studies. The brain utilizes various chemical signals (neurotransmitters) to communicate not only with the rest of the body but also between different regions of the brain itself. One particular class of such transmitter molecules that seem important in responding to stress are small hormone-like molecules called peptides. We are able to monitor the release of various brain transmitters/peptides, in freely behaving animals - without them being 'aware' of this process. We will also monitor the release of various hormones and assess levels of motivation and emotional responses in these animals as stressor exposure is known to affect these behavioral processes. It is hoped that this work will shed new light on the stressor-specific neurochemical mechanisms that link perception of stress to its translation into the classical stress response. Moreover, we hope to uncover the links between stress and reward systems, which may have bearing on adaptive responses to stressors, and potentially uncover how stressful events come to influence motivational behavior and cognitive appraisal.**

该研究计划的长期目标是更好地了解大脑如何解释各种类型的压力源或显着刺激（包括食欲事件）并协调内部身体反应以及响应这些事件的行为输出。这是基于这样的观察：暴露于威胁性（或厌恶性）刺激或食欲性（或奖励性）刺激可以激活一些相同的神经回路。在这个项目中，我们将探讨对以下反应的行为、神经化学和神经解剖学基础：1）“经典压力源”，包括自然心因性（心理）压力源（暴露于更大的“欺凌”导致社会失败）、神经源性压力源（身体约束），其具有心理和物理属性以及纯生理压力源（例如暴露于免疫型压力源）和2） 食欲刺激（性行为、美味小吃）。我们特意选择研究这些类型的自然压力源，因为它们在行为学上是合理的，并且更有可能产生启发式和实用的有用信息。此外，食欲刺激的选择是基于数据显示下丘脑-垂体肾上腺轴的激活与社会失败和克制的相似性，使得这些相反价的压力源非常适合比较研究。大脑利用各种化学信号（神经递质）不仅与身体的其他部分进行通信，而且还与大脑本身的不同区域进行通信。在应对压力方面似乎很重要的一类特殊的递质分子是称为肽的类激素小分子。我们能够监测自由行为的动物中各种大脑递质/肽的释放 - 而无需它们“意识到”这个过程。我们还将监测各种激素的释放，并评估这些动物的动机和情绪反应水平，因为众所周知，压力源暴露会影响这些行为过程。希望这项工作能够为压力源特异性神经化学机制提供新的线索，该机制将压力感知与其转化为经典压力反应联系起来。此外，我们希望揭示压力和奖励系统之间的联系，这可能会影响对压力源的适应性反应，并可能揭示压力事件如何影响动机行为和认知评估。**