Central thermoregulatory mechanisms during heat stress

摘要 体温调节在中枢神经系统中受到控制，中枢神经系统整合了外周热信息， 体温调节反应被激活。核心体温调节网络包括外侧 臂旁核、视前区、下丘脑背内侧核和苍白中缝吻侧核， 参与适应性体温调节和发热反应的大多数机制。体温调节 当核心体温（CBT）达到40.5 ℃时， 更多的是没有被完全理解。我们已经确定了大脑区域，这些区域只在这种情况下被特别激活。 条件和我们的初步数据表明，这些神经元是热敏性的，并投射到视前区。 体温调节神经元我们的初步研究还表明，这些细胞群的激活 神经元会导致体温过低这项提议的首要假设是， 的神经元在高核心体温下被激活，它们刺激下游的体温调节 视前神经元触发热损失机制。在具体目标1中，我们将使用遗传工具确定 神经元在热应激过程中激活，并表征其生理和神经化学特性。在 具体目标2，我们将使用转基因模型，病毒载体和光遗传学研究网络连接， 这些神经元及其在体温调节中的作用。通过使用药理学工具，电生理学和 转基因模型，我们将研究参与神经元热敏放电的离子通道 在高CBT时被激活，并将决定它们在体温调节中的作用（具体目标3）。研究 温度调节神经元网络和细胞机制激活的极端热暴露可能会导致 更好的治疗中暑，并提供中枢药理学目标的发展， 剂.

ABSTRACT Thermoregulation is controlled in the CNS where peripheral thermal information is integrated and thermoregulatory responses are activated. The core thermoregulatory network comprises the lateral parabrachial nucleus, the preoptic area, the dorsomedial hypothalamus and the rostral raphe pallidus and is involved in the most mechanisms of adaptive thermoregulation and in the fever response. The thermoregulatory mechanisms activated during extreme heat exposure, when core body temperature (CBT) reaches 40.5 C or more, are not fully understood. We have identified brain regions that are specifically activated only in such conditions and our preliminary data indicate that these neurons are thermosensitive and are projecting to preoptic thermoregulatory neurons. Our preliminary studies have also revealed that activation of these population of neurons induces a potent hypothermia. The overarching hypothesis of this proposal is that a specific population of neurons are activated at high core body temperature and that they stimulate downstream thermoregulatory preoptic neurons triggering heat loss mechanisms. In Specific Aim 1 we will identify, using genetic tools, the neurons activated during heat stress and characterize their physiological and neurochemical properties. In Specific Aim 2 we will study using transgenic models, viral vectors and optogenetics the network connectivity of these neurons and their role in thermoregulation. By employing pharmacological tools, electrophysiology and transgenic models we will then study the ion channels involved in the thermosensitive firing of the neurons activated at high CBT and will determine their role in thermoregulation (Specific Aim 3). Studying the thermoregulatory neuronal networks and cellular mechanisms activated by extreme heat exposure may lead to better therapies for heat stroke and provide central pharmacological targets for the development of hypothermic agents.