OSCILLATIONS AND TEMPORAL ENCODING OF OLFACTORY INFO

描述：(改编自申请者摘要)：现代的一个主要目标 神经科学就是理解神经编码的各个方面。当它 人们普遍认为，神经元的放电率通常编码一种 刺激或动物的行为状态，最近的结果来自 哺乳动物、昆虫和软体动物表明，活动的时间特征 单组神经元也可能包含有用的信息。的目标是 因此，这一提议是为了探索特定时间的性质 通过大脑中的嗅觉神经元群的编码方案，来评估其 与感知的潜在相关性，并了解一些机制 这可能会允许下游电路对临时“消息”进行解码。 这项工作将使用昆虫的嗅觉系统进行， 的结构和操作遵循与其 脊椎动物(包括哺乳动物)的对应物，其中刺激诱发 神经元的振荡同步与复杂的时间反应 最近描述了一些模式。昆虫的神经系统包含一种 类似于脊椎动物嗅球的肾小球触角叶，以及 蘑菇体，类似梨状皮质和下游皮质 结构。最近，已经确定了一种去同步的机制 体内气味激活的触角叶神经元。这些知识将被用来 要研究以下内容：1)解码的潜在机制 特别是蘑菇体中神经活动的时间模式 振荡作为选择性过滤器的潜在作用及其灵敏度 中枢神经元对其输入的时间结构的影响；2) 触角叶主叶的时间活动模式的依赖性 神经元对气味浓度和复杂性的影响；3)神经元的出现 气味“学习”过程中的时间模式，通过研究气味“学习”过程中 主神经元从“幼稚”到“熟悉”状态的反应；以及，4) 天线瓣内的局部电路动力学和耦合，通过 检验响应“噪声”之间的相关性 同时记录神经元。对时间编码的理解 专门用于模式识别的复杂大脑电路中的方案( 嗅觉系统)将提供对以下基本原理的重要见解 感官系统中的刺激表示和识别。

DESCRIPTION: (Adapted from applicant's abstract): A major goal of modern neuroscience is to understand the various facets of neural coding. While it is widely accepted that firing rates of neurons usually encode features of a stimulus or of the behavioral state of the animal, recent results from mammals, insects, and mollusks suggest that temporal features of activity in single groups of neurons might also contain useful information. The goal of this proposal is therefore to explore the nature of a specific temporal coding scheme by olfactory neuronal ensembles in the brain, to assess its potential relevance for perception, and to understand some of the mechanisms that might allow decoding of temporal "messages" by downstream circuits. This work will be carried out using the olfactory system of insects, which is structured and operates along the same design principles as its vertebrate (including mammalian) counterpart, and in which stimulus-evoked oscillatory synchronization of neurons and complex temporal response patterns have recently been described. The insect nervous system contains a glomerular antennal lobe, analogous to the vertebrate olfactory bulb, and a mushroom body, analogous to the piriform cortex and downstream cortical structures. Recently a mechanism has been identified to desynchronize odor-activated antennal lobe neurons in vivo. This knowledge will be used to investigate the following: 1) The potential mechanisms for decoding temporal patterns of neural activity in the mushroom bodies, in particular the potential role of oscillations as a selective filter and the sensitivity of central neurons to the temporal structure of their input; 2) The dependence of temporal activity patterns of the antennal lobe's principal neurons on odor concentration and complexity; 3) The emergence of neuronal temporal patterns during odor "learning", by studying the evolution of the responses of principal neurons from a "naive" to a "familiar" state; and, 4) The local circuit dynamics and coupling within the antennal lobes, by examining the degree of correlation between response "noisiness" of simultaneously recorded neurons. An understanding of temporal coding schemes in a complex brain circuit specialized for pattern recognition (the olfactory system) will provide crucial insights into the basic principles of stimulus representation and recognition in sensory systems.