Neural circuits mediating food, pherome, and repulsive odor behaviors

描述（由申请人提供）：嗅觉是由气味剂激活鼻子中的嗅觉感觉神经元引起的。该领域的一个关键问题是这些神经元活动如何引起气味感知。由于昆虫和哺乳动物的嗅觉系统的神经元结构非常相似，因此研究果蝇大脑如何处理嗅觉信息可以揭示其他生物体嗅觉的基本原理。我们之前证明，嗅觉皮层（侧角）分为两大区域，一代表食物气味，一代表信息素。因此，这个肉眼看起来是同质的嗅觉区域可能被组织成反映生物学相关信息的嗅觉处理中心。这些研究基于将气味剂简单分类为食物或信息素，但没有考虑气味剂的化合价，即它在行为上是否有吸引力或令人厌恶。我们最近工作的初步数据表明，令人厌恶的气味可能代表嗅觉皮层中的一个新的处理中心。结合遗传学、行为分析、轴突追踪和脑成像研究，我们将检验以下假设：(1) 嗅觉皮层根据果蝇生命的三个重要方面组织成多个域：食物、信息素和回避。这项工作的结果将使我们能够将排斥行为与其潜在的神经元成分联系起来，从而模拟新识别和已知的厌恶信号如何在高级嗅觉皮层中表示。为了了解有吸引力的信号（例如有吸引力的食物气味和有吸引力的信息素）如何在嗅觉皮层中呈现，以及嗅觉系统如何利用它们来传达有关动物环境的相关信息，我们研究了我们已经确定的一种新型信息素信号系统。我们的初步数据表明，果蝇的这种信号系统代表了食物和信息素信号之间的行为联系。结合遗传学、分子生物学、GC-MS、钙成像和电生理记录，我们将检验以下假设：(2) 果蝇在受到诱人食物气味刺激时会分泌一种有吸引力的信息素，以标记积极社会行为（如产卵或求偶）的位点。这种新信息素信号机制的表征结果将丰富我们对如何使用嗅觉通信来指导对不断变化的环境的行为反应的理解。拟议的研究意义重大，因为我们将深入了解厌恶和有吸引力的嗅觉信息如何在嗅觉系统的高级处理中心中表示，该嗅觉系统可以作为嗅觉感知如何在其他动物的大脑中编码的模型。 ！

DESCRIPTION (provided by applicant): The sense of smell is caused by odorants activating olfactory sensory neurons in the nose. A pivotal question in the field is how these neuronal activities give rise to odor perceptions. Since the neuronal architecture of the olfactory system i remarkably similar between insects and mammals, studying how the fly brain processes olfactory information could shed light on principles underlying olfaction in other organisms. We previously demonstrated that the olfactory cortex (lateral horn) is divided into two broad domains, one representing food odors and one representing pheromones. Therefore, this olfactory region, which to the naked eye looks homogenous, might be organized into olfactory processing centers that reflect biologically relevant information. These studies were based on simple classifications of odorants as being food or pheromone, but did not take into account the valence of the odorant - that is if it is behaviorally attractive or repulsive. Preliminary data frm our recent work suggests that aversive odors might represent a new processing center in the olfactory cortex. Using a combination of genetics, behavioral analyses, axon tracing, and brain imaging studies, we will test the hypothesis that (1) the olfactory cortex is organized into domains based on three important aspects of a fly's life: food, pheromones, and avoidance. Results from this work will allow us to link repulsive behaviors to their underlying neuronal components and thus model how newly identified and known aversive signals might be represented in the higher olfactory cortex. To understand how attractive signals such as attractive food odors and attractive pheromones are represented in the olfactory cortex, as well as how the olfactory system utilizes them to communicate relevant information regarding an animal's environment, we investigate a novel pheromone signaling system that we have identified. Our preliminary data suggests that this signaling system in Drosophila represents a behavioral link between food and pheromone signaling. Using a combination of genetics, molecular biology, GC-MS, calcium imaging, and electrophysiological recordings, we will test the hypothesis that (2) Drosophila secrete an attractive pheromone when stimulated by attractive food odors to tag sites for positive social behaviors such as egg laying or courtship. Results from the characterization of this new pheromone signaling mechanism will enrich our understanding of how olfactory communications are used to guide behavioral responses to a changing environment. The proposed studies are significant because we will gain insights into how aversive and attractive olfactory information is represented in higher processing centers of an olfactory system that could serve as a model for how olfactory perceptions are encoded in the brains of other animals. !