Forebrain Processing of Biologically Relevant Odor Information

嗅觉信息从嗅觉感受器神经元进入大脑，到达前脑的第一个处理中心，即嗅球。然而，关于气味是如何在更多的中枢神经水平上处理的功能信息充其量是零散的。一个关键的问题是，有关生物相关气味的信息是如何被大脑小叶处理的，这些信息是从嗅球通过嗅束到达的。斑点叉尾鱼是一种硬骨鱼，是唯一一种脊椎动物，在嗅觉感受器神经元的形态类型、特定的分子转导系统、检测到的生物相关气味类型以及用于处理这些信息的嗅球的局部部分之间存在明显的相关性。该项目使用多电极和单电极的电生理记录方法，以确定氨基酸、胆盐和核苷酸的生物相关气味是否在脑叶中由局部活动表示，如它们在嗅球中一样；确定大脑叶内对气味有反应的神经元的反应特性；以及确定在嗅觉感受器神经元中看到的气味诱导的同步性是否调节脑叶内的气味反应。这些结果将为理解脊椎动物嗅觉信息的高级处理提供一个新的水平，并将为皮质神经元如何处理气味提供一个进化和比较的视角。同步振荡活动的问题与脑功能的计算模型和理论模型有关。由于硬骨鱼是脊椎动物中数量最多的物种，在世界范围内具有重要的经济意义，因此这项工作的重要性不仅限于神经科学，还包括比较生理学和生态学，以及水产养殖。最后，该项目在EPSCoR指定的状态下促进博士后、研究生和本科生的教学和培训，包括那些来自服务不足群体的学生。

Olfactory information comes into the brain from the level of the olfactory receptor neurons to the first processing center of the forebrain, the olfactory bulb. However, functional information as to how odors are processed at more central neural levels is fragmentary at best. A key question is how information about biologically relevant odors is handled by the cerebral lobes, after arriving via the olfactory tracts from the olfactory bulbs. The channel catfish, Ictalurus punctatus, a teleost fish, is the only vertebrate species for which there is a clear correlation across the morphological type of olfactory receptor neuron, the specific molecular transduction system, the type of biologically relevant odor detected, and the local portion of the olfactory bulb used to process this information. This project uses electrophysiological recording by multi-electrode methods as well as single electrodes, to determine whether biologically relevant odors of amino acids, bile salts, and nucleotides are represented in by local activity showing an 'odotopic' map in the cerebral lobes as they are in the olfactory bulb; to determine the response properties of odor-responsive neurons within the cerebral lobes; and to determine whether the odor-induced synchrony of activity seen in olfactory receptor neurons modulates odor responses within the cerebral lobes. Results will provide a new level of understanding higher-level processing of olfactory information in vertebrates, and will provide an evolutionary and comparative perspective on how odors are processed in cortical neurons. The issue of synchronous oscillating activity is relevant to computational and theoretical models of brain function. Because teleost fish comprise the largest number of vertebrate species, and are economically important worldwide, this work has importance beyond neuroscience to comparative physiology and ecology, and to aquaculture. Finally, this project promotes the teaching and training of postdoctoral, graduate and undergraduate students, including those from under-served groups, in an EPSCoR-designated state.