Olfactory Coding in the Drosophila Brain

描述（由申请人提供）：我们的长期目标是了解中枢神经系统的嗅觉编码。在本研究中，我们将研究果蝇蘑菇体的刻板气味表征，并验证活动的空间模式编码气味信息的假设。果蝇和哺乳动物早期嗅觉系统的组织和功能逻辑具有显著的相似性。该系统的一个突出特征是肾小球中受体活性分离的地形图。然而，这种活动的空间模式如何转化到更高的中枢，然后转化为气味感知，仍然是一个谜。利用相对简单的神经系统和我们新开发的成像方法，我们已经能够揭示气味诱发的高级中枢之一蘑菇体的刻板活动模式。在本研究中，我们将利用活蝇的ca2 +成像技术来监测气味诱导的蘑菇体细胞体和树突区域的神经元活动。在本研究中，利用常规显微镜观察神经元活动的整体空间格局，同时利用双光子激光显微镜分析单个神经元的活动。我们将研究这种刻板气味表征的基本特性，包括单一气味、混合气味和气味浓度如何在活动的空间模式中表征。然后，我们将通过比较成像分析和行为测试的结果来检验空间活动模式在气味识别中的生理意义。最后，我们将使用遗传操作来帮助剖析气味信息是如何组织在蘑菇体活动的空间模式。

DESCRIPTION (provided by applicant): Our long-term goal is to understand olfactory coding in the central nervous system. In this proposal, we will investigate stereotyped odor representation in Drosophila mushroom body and test the hypothesis that spatial patterns of activity examined encode odor information. The organization and functional logic of early olfactory system appears remarkably similar in Drosophila and mammals. An outstanding feature of this system is the topographic map of receptor activity segregated in glomeruli. Yet, how such spatial patterns of activity are transformed to higher centers and then translated into odor perception remains illusive. Taking advantage of a relatively simple nervous system and our newly developed imaging method, we have been able to reveal odor-evoked stereotyped activity patterns in one of the higher centers, mushroom body. In this proposal, odor-induced neuronal activity in the regions of cell bodies and dendrites of mushroom body will be monitored via Ca 2+ imaging from living flies. In this preparation, a global view of spatial patterns of activity is obtained by conventional microscope while activity in individual neurons is analyzed by 2-photon laser microscope. We will investigate the basic properties of this stereotyped odor representation, including how single odorants, mixed odorants, and concentrations of odorants are represented in spatial patterns of activity. Then, we will examine physiological significance of spatial patterns of activity in odor discrimination by comparing results of imaging analysis with behavioral tests. Finally, we will use genetic manipulation to help to dissect how odor information is organized in spatial patterns of activity in mushroom body.