Analysis of a Large Family of Candidate Taste Receptors

项目总结 这个项目的长期目标是阐明苦味剂 被检测和编码。该实验计划利用果蝇作为 一个模型系统，允许对味觉基因和洞察力进行分子遗传分析 味觉功能的电生理分析。 这项提议利用了电生理学的一项重大进步。上一首 通过“笔尖记录”对昆虫味道的电生理分析仅限于 它们的味觉神经元与味觉接触。技术创新现在已经成功了 方便记录刺激前、刺激中、刺激后味觉神经元的活动。现在是时候了 有可能分析口味编码的特征，这些特征以前没有被研究过。 第一个目标将确定味觉神经元的自发放电频率，以及 频率的分子决定因素。它将检验对苦味的抑制 苦味者的神经元广泛存在，代表着味觉的一种新的自由 编码。 第二个目标是对OFF进行精确的、定量的生理分析 常规电生理分析无法观察到的反应。这个 将系统地确定这些反应的普遍程度。这项研究将测试 假设OFF反应的大小和动态携带关于 味觉刺激的同一性和强度。这一目标还应该提供关于蜂窝 以及作为OFF反应基础的分子机制。总而言之，这一分析应该提供 洞察品味编码中一个长期被忽视的特征。 第三个目标将定义品味编码的另一个显著未被研究的特性： 糖对苦味神经元的抑制作用。它将量化对两种自发活动的抑制 和不回应。分析将确定抑制是否取决于质量 和糖刺激的量。该目标还旨在提供对 抑制机制。 昆虫携带的疾病每年折磨着数亿人。这些 昆虫很大程度上是通过它们的化学感觉系统来检测它们的人类宿主。最新进展 了解这些化学感觉系统可能会导致新的方法来操纵它们和 从而控制这些传播人类疾病的昆虫媒介。

PROJECT SUMMARY The long-term goal of this project is to elucidate the mechanisms by which bitter tastants are detected and encoded. The experimental plan takes advantage of the fruit fly Drosophila as a model system, which allows molecular genetic analysis of taste genes and incisive electrophysiological analysis of taste function. The proposal takes advantage of a major advance in electrophysiology. Previous electrophysiological analysis of insect taste via "tip recording" was limited to the period during which taste neurons are in contact with a tastant. Technical innovation has now made it convenient to record the activity of taste neurons before, during, and after stimulation. It is now possible to analyze features of taste coding that have not been examined before. The first aim will determine the spontaneous firing frequency of taste neurons, and the molecular determinants of the frequency. It will examine whether inhibition of bitter taste neurons by bitter tastants occurs widely and represents a new degree of freedom for taste coding. The second aim proposes a precise and quantitative physiological analysis of OFF responses, which could not be observed with conventional electrophysiological analysis. The prevalence of these responses will be determined systematically. The study will test the hypothesis that the magnitude and dynamics of OFF responses carry information about the identity and intensity of taste stimuli. This aim should also provide information about the cellular and molecular mechanisms underlying OFF responses. Together this analysis should provide insight into a long-overlooked feature of taste coding. The third aim will define another remarkably understudied feature of taste coding: the inhibition of bitter neurons by sugars. It will quantify the inhibition of both spontaneous activity and OFF responses. The analysis will determine whether the inhibition depends on the quality and quantity of the sugar stimulus. The aim is also designed to provide insight into the mechanism of inhibition. Diseases carried by insects afflict hundreds of millions of people each year. These insects detect their human hosts largely through their chemosensory systems. Advances in understanding these chemosensory systems may lead to new means of manipulating them and of thereby controlling these insect vectors of human disease.