Integrative Physiological Approaches to Thermoregulatory and Thermosensory Biology

温度调节和热感觉生物学的综合生理学方法

• 批准号: RGPIN-2014-05814
• 负责人: Tattersall, Glenn
• 金额: $ 2.91万
• 依托单位: Brock University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=588635
• 关键词: Integrative; Physiological; Approaches; Thermoregulatory; Thermosensory

As a complex biological trait, animal thermal physiology involves the co-evolution of thermal sensation along with biochemical mechanisms of thermal tolerance. Therefore, animals with different body temperatures should show functional differences in the properties of their molecular thermal sensors that coincide with their optimal temperatures. Understanding the thermal physiology of animals is important from a basic and an applied perspective, particularly as climate change models predict steep changes in environmental temperatures. The volitional thermal choices made by animals will play an important role in mitigating the effects of climate warming, especially if temperatures rise at rates faster than physiological tolerances evolve. Therefore, understanding how organisms regulate their body temperature is important since it illustrates their potential to respond to change in the environment. Indeed, recent studies suggest that species with narrow behavioural niches will be more adversely affected by rising temperatures; conversely, species with narrow thermal optimalities will be forced to compensate behaviourally in the future in order to achieve body temperatures within this narrow range. Traditionally, much thermal biology research focuses on the effects that temperature pose on animals rather than the influence animals have on their own temperature. My laboratory focuses on both the conserved as well as the unique mechanisms available to animals that bestow their abilities to modify and regulate their internal body temperature; these include behavioural, physiological, molecular and biochemical. In order to control body temperature, animals require: an ability to sense temperature, a central organizer to process and direct thermoeffector responses, and an array of effectors to bring out changes in temperature. This diffusively organized control system is phylogenetically ancient and exhibits remarkable variability. Yet certain elements seem relatively preserved, namely the sensation of temperature, which appears to derive from molecular thermosensors sharing similar biochemical properties and the integration of these signals in the brain, which seem to share dual set-point like behaviour. Below the brain is where the thermoregulatory systems diverge, with various anatomical, biochemical, physiological and behavioural adaptations responsible for effecting thermally relevant changes. The sensory system is the first filtering mechanism available to animals in responding to their thermal environment. Recent advances have used genetic, molecular and in vitro approaches to understand an ever burgeoning array of putative temperature sensors, yet definitive information that these sensors are necessary and sufficient to produce real-life thermosensory behaviours in vivo are lacking. Knock-out models show some promise in this regard, yet suffer from the usual problems in that pleiotropic effects of genes are masked or the ability of the organism to compensate with other pathways is assumed to be absent. Over the next five years we will: 1) study the regulatory pathways (behavioural and physiological) that control Tb in animals by examining the physiological relevance of altered thermoregulatory states (e.g. hypoxia, hydrogen sulfide); 2) examine the mechanisms of warm and cold thermosensation and establish their roles in thermoregulatory behaviours through a comparative analysis of animals with different thermoregulatory preferences; 3) study the development and plasticity of thermoregulatory "appendages" and the interactions between water conservation and temperature regulation.

动物热生理学是一个复杂的生物学特性，涉及热感觉沿着热耐受生化机制的共同进化。 因此，具有不同体温的动物应该在其分子热传感器的特性中显示出功能差异，这些特性与其最佳温度相一致。 从基础和应用的角度来看，了解动物的热生理学非常重要，特别是当气候变化模型预测环境温度的急剧变化时。 动物自愿作出的热选择将在减轻气候变暖的影响方面发挥重要作用，特别是如果温度上升的速度快于生理耐受力的发展。 因此，了解生物体如何调节体温是很重要的，因为它说明了它们对环境变化做出反应的潜力。 事实上，最近的研究表明，具有狭窄行为生态位的物种将受到温度上升的不利影响;相反，具有狭窄热最佳状态的物种将被迫在未来进行行为补偿，以使体温在这个狭窄的范围内。 传统上，许多热生物学研究集中在温度对动物的影响，而不是动物对自身温度的影响。 我的实验室专注于保守的以及独特的机制提供给动物，赋予他们的能力来修改和调节他们的内部体温;这些包括行为，生理，分子和生化。 为了控制体温，动物需要：感知温度的能力，处理和指导热效应器反应的中央组织者，以及一系列效应器来引起温度变化。 这种扩散性组织的控制系统在遗传学上是古老的，并且表现出显著的可变性。然而，某些元素似乎相对保存，即温度的感觉，这似乎来自分子热传感器共享类似的生物化学性质， 这些信号在大脑中的整合，似乎共享双重设定点一样的行为。 大脑下方是温度调节系统的分叉处，具有各种解剖学，生物化学，生理学和行为适应性，负责影响热相关变化。 感觉系统是动物对热环境作出反应的第一个过滤机制。 最近的进展已经使用遗传，分子和体外方法来了解一个不断发展的阵列推定的温度传感器，但缺乏明确的信息，这些传感器是必要的，足以产生现实生活中的热敏行为在体内。 敲除模型在这方面显示出一些希望，但遭受常见的问题，即基因的多效性效应被掩盖或生物体补偿其他途径的能力被认为是不存在的。 在未来五年，我们将：1）研究监管途径通过检查改变的体温调节状态的生理相关性来控制动物中的Tb（例如缺氧、硫化氢）; 2）通过对具有不同温度调节偏好的动物的比较分析，研究热和冷温度感觉的机制，并确定它们在温度调节行为中的作用; 3）研究温度调节“附属物”的发育和可塑性，以及水分保持和温度调节之间的相互作用。