The molecular and cellular basis of cold sensation

描述(申请人提供)：为了补充目前可用的冷行为测试，我们开发了一种新的高通量行为测试来测量不受约束的小鼠对冷刺激的反应。小鼠被安置在一个硼硅酸盐玻璃板上的塑料外壳中，用干冰球快速冷却后后爪正下方的玻璃，直到小鼠收回它的爪子。从干冰刺激中撤退的潜伏期被量化为小鼠对寒冷反应的温度。本实验将用于提供关于TRPM8-/-、TRPA1-/-和TRPM8-TRPA1双基因敲除小鼠冷敏感性的明确信息，从而提供关于TRPM8和TRPA1在冷感中的作用的明确信息。为了更好地了解哪些神经元群对这些信号的传输是重要的，我们使用光遗传学技术在不需要任何手术干预或改变神经元结构的情况下，暂时沉默外围特定的、离散的感觉神经元群。使用这项技术，我们在施加新的冷刺激时使特定的神经元群体沉默，使我们能够测试这些群体中的每一个在对冷刺激的反应中所起的作用。

DESCRIPTION (provided by applicant): To complement the currently available cold behavioral assays, we have developed a novel high- throughput behavioral assay to measure the responses of unrestrained mice to cold stimuli. Mice are acclimated in plastic enclosures on a borosilicate glass plate, and the glass directly underneath the rear hind paw is rapidly cooled with a dry ice pellet until the mouse withdraws its paw. The latency to withdrawal from the dry ice stimulus is quantified as a measure of the temperature at which the mouse responds to cold. This assay will be used to provide unambiguous information about the cold sensitivity of TrpM8-/-, TrpA1-/-, and TrpM8-TrpA1 double knockout mice, and therefore about the roles of TrpM8 and TrpA1 in cold sensation. To better understand which neuronal populations are important for the transmission of these signals, we use optogenetic techniques to transiently silence specific, discrete populations of sensory neurons in the periphery without any surgical intervention or altering the neuronal architecture. Using this technique, we silence specific neuronal populations while applying the cold stimulus from our new assay, allowing us to test the role of each of those populations in the response to the cold stimulus.