Molecular and neural mechanisms of predator cue sensation

了解动物如何做出行为决定是神经科学中最大的问题之一。这个 拟议的研究旨在了解先天防御行为背后的分子和神经机制 是由捕食者物种的化学线索引起的。对掠夺性威胁的防御性反应是通过 预先编程的防御大脑回路，它有能力立即做出适当的行为决定 在感觉到捕食者衍生的感官刺激时。人们普遍认为，嗅觉是人类的主要感官之一。 捕食者衍生的化学线索在被捕食物种中引发行为反应的方式。什么时候 被捕食的动物从捕食者的暗示中察觉到直接的危险，它们表现出敏锐的防御行为，如冻结 或者逃亡。另一方面，当被捕食的动物在捕食者的线索中只检测到潜在的危险时，它们表现出 警觉和风险评估行为，如重复伸展嗅探。行为学中的一个重要问题 神经科学是关于这些捕食性威胁的防御决定是否通过不同的神经回路做出的 或者是一个共享的神经种群。我们的初步数据建立了拟议研究的框架，以剖析 由捕食者通过犁鼻化学感觉器(VNO)提示激活的防御行为回路， 这会引发小鼠的冰冻或风险评估行为。在这项建议中，我们的目标是确定 冰冻和风险评估诱导的捕食者线索及其在VNO中的感觉受体，并评估 感觉信号是否通过独立的、平行的电路诱导行为输出，或者它们是 整合在大脑中以诱导适当的行为。我们的中心假设是不同的捕食者线索 被不同的感觉感受器回路检测到，并引发不同的防御行为输出。至 验证这一假设，我们将在分子水平上研究捕食者线索感觉的机制；更多 具体地说，我们将首先识别感觉刺激(目标1)和感觉受体(目标2)。此外，使用 冰冻和风险评估诱导的感官线索作为工具，我们将进一步检查防御 对捕食者线索的决定是由独立的神经回路做出的(目标3)。这些研究的结果 实验将为人类感觉加工的分子机制提供新的见解。 捕食者提示感觉，并将揭示情感决策回路的操作原理 行为。这将有助于我们理解作为基础的预先编程的大脑机制 多层次的恐惧和压力处理，以应对威胁。

Understanding how animals make behavioral decisions is one of the biggest problems in neuroscience. The proposed study aims to understand molecular and neural mechanisms underlying innate defensive behaviors elicited by chemical cues from predator species. Defensive responses to predatory threats are made through a pre-programmed defensive brain circuit, which has an ability to instantly make an appropriate behavioral decision upon sensing predator-derived sensory stimuli. It is widely appreciated that olfaction is one of the major sensory modalities through which predator-derived chemical cues trigger behavioral responses in prey species. When prey animals detect immediate danger in predator cues, they exhibit acute defense behaviors such as freezing or flight. On the other hand, when prey animals detect only potential danger in predator cues, they exhibit vigilance and risk assessment behaviors such as repetitive stretched sniffing. An important question in behavioral neuroscience is whether these defensive decisions for predatory threats are made through distinct neural circuits or by a shared neural population. Our preliminary data establish a framework of the proposed study to dissect defensive behavioral circuitries activated by predator cues through the vomeronasal chemosensory organ (VNO), which trigger either freezing or risk assessment behaviors in mice. In this proposal, we aim to identify the freezing- and risk assessment-inducing predator cues and their sensory receptors in the VNO, and to assess whether the sensory signals induce behavioral outputs through independent, parallel circuitries, or they are integrated in the brain to induce an appropriate behavior. Our central hypothesis is that different predator cues are detected by distinct sensory receptor circuitries and elicit distinct defensive behavioral outputs in parallel. To test this hypothesis, we will investigate mechanisms of the predator cue sensation at molecular levels; more specifically, we will first identify the sensory stimuli (Aim 1) and the sensory receptors (Aim 2). Moreover, using freezing- and risk assessment-inducing sensory cues as tools, we will further examine whether the defensive decision towards predator cues is made by independent neural circuitries or not (Aim 3). The results from these experiments will provide new insights into the molecular mechanisms underlying the sensory processing in predator cue sensation, and will reveal an operational principle of decision making circuitries for emotional behaviors. This will critically contribute to our understanding of pre-programmed brain machinery that underlies multiple levels of fear and stress processing in response to threat.