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: 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=666571
• 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.

动物热生理是一种复杂的生物学特性，涉及热感觉和热耐受生化机制的共同进化。因此，不同体温的动物在其分子热传感器的特性上应该表现出功能上的差异，这与它们的最佳温度相一致。从基础和应用的角度来看，理解动物的热生理是很重要的，特别是在气候变化模型预测环境温度急剧变化的情况下。动物自愿做出的热选择将在减轻气候变暖的影响方面发挥重要作用，特别是在温度上升速度超过生理耐受性进化的情况下。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，行为生态位狭窄的物种受到气温上升的不利影响更大；相反，具有较窄热最优的物种将被迫在未来进行行为补偿，以达到在这一狭窄范围内的体温。**传统上，许多热生物学研究关注的是温度对动物的影响，而不是动物对自身温度的影响。我的实验室既关注动物的保守机制，也关注动物的独特机制，这些机制赋予了它们改变和调节内部体温的能力；这些包括行为、生理、分子和生物化学。为了控制体温，动物需要：感知温度的能力，处理和指导热效应反应的中央组织者，以及引起温度变化的一系列效应器。这种扩散组织的控制系统在系统发育上是古老的，并表现出显著的可变性。然而，某些元素似乎相对保存了下来，即温度的感觉，似乎来自具有相似生化特性的分子热传感器，以及这些信号在大脑中的整合，它们似乎具有双重设定点行为。在大脑下方是体温调节系统分化的地方，各种解剖、生化、生理和行为适应负责影响与热相关的变化。* *感觉系统是动物对热环境作出反应的第一种过滤机制。最近的进展是利用遗传、分子和体外方法来了解不断涌现的一系列假定的温度传感器，但这些传感器对于在体内产生真实的热感觉行为是必要的和足够的明确信息缺乏。基因敲除模型在这方面显示出一些希望，但也存在一些常见的问题，即基因的多效性效应被掩盖，或者生物体用其他途径进行补偿的能力被认为不存在。* *在未来五年内，我们将：1)通过检查改变的体温调节状态（例如缺氧，硫化氢）的生理相关性，研究控制动物结核病的调节途径（行为和生理）；2)通过对具有不同体温调节偏好的动物的比较分析，研究热感觉和冷感觉的机制，并确定它们在体温调节行为中的作用；3)研究温度调节“附属物”的发育和可塑性以及保水和温度调节之间的相互作用。