Taste representations in the Drosophila brain

描述（由申请人提供）：本提案的长期目标是增加对味觉识别和味觉感知的理解。拟议的实验将在果蝇（Drosophila melanogaster）中进行，果蝇是一种具有简单的味觉系统和强大的味觉行为的生物，可适用于分子，遗传和电生理方法。果蝇的味觉识别是由长鼻、内部口器、腿、翅膀和产卵器上的感觉神经元介导的。初步研究鉴定了一个由56个候选味觉受体基因组成的大家族，并揭示了每个味觉神经元表达一个或几个受体。

DESCRIPTION (provided by applicant): The long-term objectives of this proposal are to increase understanding of taste recognition and taste perception. The proposed experiments will be conducted in the fruit fly, Drosophila melanogaster, an organism with a simple gustatory system and robust gustatory behaviors that is amenable to molecular, genetic and electrophysiological approaches. Taste recognition in Drosophila is mediated by sensory neurons on the proboscis, internal mouthparts, legs, wings, and ovipositor. Preliminary studies have characterized a large family of 56 candidate gustatory receptor genes (GRs) and revealed that each gustatory neuron expresses one or a few receptors. How are these different gustatory neurons represented in the brain? In the somatosensory and visual systems, sensory projections are segregated according to the location of the neuron in the periphery to provide a topographic map of stimulus position in the brain. In the olfactory system, projections are segregated according to the odorant receptor that the neuron expresses, such that the quality of an odor is mapped rather than its peripheral position. The proposed experiments are designed to determine the molecular and positional representations of tastes in the brain. The following aims are proposed: (1) to determine if gustatory projections are segregated according to the receptor they express; (2) to determine if they are segregated according to their location in the periphery; (3) to compare gustatory maps with mechanosensory maps; (4) to identify synaptic connections of gustatory neurons. The proposed experiments will provide insight into the logic of taste representations in the brain, with the ultimate aim of understanding how sensory perception is encoded in neural circuits.