Neural Mechanisms for Olfactory and Gustatory Integration in the Drosophila Larva

项目摘要 整合来自不同感官系统的信息对于动物形成准确的 他们对周围环境的感知，并对环境线索采取果断和迅速的行动。 传统上，多感官整合被认为只发生在较高阶联结区 大脑的一部分。然而，最近的研究发现，早期“单一感觉”大脑区域的神经元，如 初级嗅觉皮质，对多种感官形式作出反应，如气味和味觉刺激。 生理和行为观察表明，单感觉和多感觉整合 不同的基础计算。此外，人类多感官整合的失败是一种 自闭症和精神分裂症等疾病的常见症状，这些症状加在一起影响约7000万人 世界各地的人们。然而，我们对多感官整合如何发生以及在哪里发生，如何发生，我们知之甚少。 改变神经元的反应特性，以及在此基础上的突触和细胞机制 整合。 本研究的目标是将定量行为分析和视觉神经生理学结合起来 用果蝇幼虫来解释多感官整合是如何在行为水平和在 幼虫大脑的第一个嗅觉处理中心，称为触角叶(AL)。幼虫是一种 研究这些问题的理想系统，因为它有少量(~20)个唯一可识别的， 推测AL中的多感觉神经元对气味和味道做出反应。此外，还有可能 在分娩时非侵入性地监测和操纵清醒幼虫个体神经元的活动 控制气味和味觉刺激，并量化自由行为的幼虫在航行时的反应 嗅觉和味觉环境。第一个目标是描述和比较幼虫的行为 在并发嗅觉和味觉梯度中导航时会修改要素，而不是 感觉梯度。第二个目标将从功能上识别AL中对味觉和 并描述这些神经元对单峰刺激的反应。第三个目标将定义 通过传递气味-味觉序列实现AL多感觉神经元整合的时间动力学 具有不同的时间延迟和浓度。这些实验将开始解决以下问题 多感觉输入如何相互作用来改变感觉过程并产生多感觉知觉 和行为。负责嗅觉-味觉整合的神经机制可能会告诉我们 其他感官系统的整合会发生，并且可能在不同物种之间也是如此。

Project Abstract The integration of information from different sensory systems is critical for animals to form an accurate perception of their surroundings and to act decisively and rapidly in response to environmental cues. Traditionally, it was assumed that multisensory integration only occurs in higher-order association areas of the brain. However, recent studies have found neurons in early “unisensory” brain areas, such as the primary olfactory cortex, that respond to multiple sensory modalities, such as odor and taste stimuli. Physiological and behavioral observations suggest that unisensory and multisensory integration engage different underlying computations. Furthermore, the failure of multisensory integration in humans is a common symptom of disorders such as autism and schizophrenia, which combined affect ~70 million people worldwide. Yet, we know very little about how and where multi-sensory integration occurs, how it modifies the response properties of neurons, and the synaptic and cellular mechanisms underlying this integration. The goal of this research is to combine quantitative behavioral analysis and optical neurophysiology in the Drosophila larva to elucidate how multisensory integration occurs both at the behavioral level and in the first olfactory processing center of the larval brain, called the antennal lobe (AL). The larva is an ideal system to study these questions in because it has a small number (~20) of uniquely identifiable, putative multisensory neurons in the AL that respond to odors and tastes. Furthermore, it is possible to non-invasively monitor and manipulate activity in individual neurons of awake larvae while delivering controlled odor and taste stimuli, and to quantify responses of freely behaving larvae while navigating in olfactory and gustatory environments. The first aim will characterize and compare how larval behavioral features are modified while navigating in concurrent olfactory and gustatory gradients versus a single sensory gradient. The second aim will functionally identify neurons in the AL that respond to tastes and odors and characterize the responses of these neurons to unimodal stimuli. The third aim will define the temporal dynamics of integration in multisensory neurons of the AL by delivering odor-taste sequences with varying time delays and concentrations. These experiments will begin to address the question of how multisensory inputs interact to modify sensory processing and give rise to multisensory perception and behavior. Neural mechanisms responsible for olfactory-gustatory integration will likely inform how integration of other sensory systems occurs and may hold true across species.