Neural Ensemble Codes in Drosophila Olfaction

新的实验技术被开发出来，通过光来监测和操纵基因 活体内受限的神经元群体。这些技术将被利用来研究信息 果蝇嗅觉系统的加工。细胞型特异性启动子 增强剂将以基因编码的光学传感器和效应器为靶点，在突触的四个神经元中 耦合处理层：1)到嗅觉感受器神经元，位于感觉表面和 将轴突投射到触角叶，类似于脊椎动物的嗅球；2)局部抑制 触角叶的中间神经元；3)投射神经元，传递来自 触角叶到蘑菇体，类似于脊椎动物的嗅皮层；以及4)到Kenyon 细胞，蘑菇体的内在神经元。气味诱发的神经活动模式将被可视化 通过光学显微镜在这些基因突出的每个加工阶段，和繁殖 将跟踪从加工阶段到加工阶段的活动。凭借这一创新战略，他们 核心，三个具体目标，针对多层神经的基本操作原理 网络将被寻址：1)用于表示四个网络中每一个的气味信息的代码 将描述嗅觉处理阶段以及与这些编码相关的映射规则。2) 表达抽象的神经符号的计算起源、物理形式和语义内容， 分类和行为内涵将在结合光学技术的实验中阐明 用行为分析进行成像。这些实验的重点将放在神经元的底物上 将享乐价(即吸引力或排斥性)附加到气味上，并通过 经验。3)具有确定的神经或行为表型的突变，或将 通过选择性光刺激被插入到遗传指定的靶神经元中，将被用于 扰动神经生理学；这些扰动在系统层面的影响将通过 光学成像。这为了解蜂窝甚至是网络中的集体网络属性提供了机会 分子术语，并由此超越目前将神经科学划分为 MoECU AR、CEU AR和SYSTEM分支。

Novel experimental technologies were developed to monitor and manipulate, through light, genetically circumscribed populations of neurons in vivo. These technologies will be harnessed to study information processing in the olfactory system of the fruit fly, Drosophila melanogaster. Cell-type specific promoters and enhancers will target genetically encoded optical sensors and effectors to neurons in four synaptically coupled processing layers: 1) To olfactory receptor neurons, which are located at the sensory surface and project axons to the antennal lobe, the analog of the vertebrate olfactory bulb; 2) to local inhibitory interneurons of the antennal lobe; 3) to projection neurons that relay olfactory information from the antennal lobe to the mushroom body, the analog of the vertebrate olfactory cortex; and 4) to Kenyon cells, the intrinsic neurons of the mushroom body. Odor-evoked neural activity patterns will be visualized by optical microscopy at each of these genetically highlighted processing stages, and the propagation of activity from processing stage to processing stage will be traced. With this innovative strategy at their core, three specific aims directed at the fundamental operational principles of a multilayered neural network will be addressed: 1) The codes employed to represent odor information at each of the four olfactory processing stages, and the mapping rules that relate these codes, will be characterized. 2) The computational origin, physical form, and semantic content of neural symbols that express abstractions, classifications, and behavioral connotations will be elucidated in experiments that combine optical imaging with behavioral assays. The focus of these experiments will be on the neuronal substrate for attaching hedonic valence (i.e., attractiveness or repulsiveness) to odors, and on its modification by experience. 3) Mutations with defined neural or behavioral phenotypes, or artificial neural signals that will be inserted into genetically designated target neurons by selective photostimulation, will be used to perturb neuronal physiology; the impact of these perturbations at the systems level will be analyzed by optical imaging. This opens an opportunity to understand collective network properties in cellular or even molecular terms, and to transcend thereby some of the boundaries that currently divide neuroscience into mo ecu ar, ce u ar, and systems branches.