Behavioral and Physiological Mechanisms of Olfaction

描述（由申请人提供）：本提案将专注于使用蜜蜂（Apis mellifera）作为模型动物物种来理解对气味的行为可塑性机制。这些动物面临着与哺乳动物相同的嗅觉问题。它们需要探测和响应大量气味的能力，因为它们依赖于定位许多不同类型的花来收获花蜜中的碳水化合物资源。在一个人的一生中，这些气味与花蜜的联系会发生很多次变化，这也要求动物了解这些联系。像哺乳动物一样，昆虫也有多种方法来学习和编码花香的记忆。比较证据表明，昆虫和哺乳动物之间的行为和系统级神经处理相似性是独立进化的。这表明可能只有一种通用的神经解决方案可用于编码有关气味的信息。因此，作为比较模型，昆虫对于揭示气味是如何在中枢神经系统中学习和编码的，以及这种机制是否是嗅觉处理的基础，是至关重要的。本提案的目的是评估存在于昆虫触角叶（AL）中的神经可塑性机制，触角叶是哺乳动物嗅球的神经类似物（Hildebrand & Shepherd 1997）。本研究的中心主题是，记录在案的神经机制和AL中的调节途径代表了强化的存在（或不存在），作为过滤掉不重要的、可变的背景气味的手段。这使得生物学上相关的、习得的气味很容易被检测到。将有三个目标。首先，行为调查将详细研究习得性注意力不集中（CS预暴露效应）和气味-气味混合物阻塞的机制。特别是，条件作用背景的操纵将揭示CS预暴露的具体理论处理在多大程度上可以解释昆虫的这种情况。其次，多通道记录技术将用于研究这些行为机制是否以及如何在AL中作为过滤机制实现。第三，通过RNA干扰的药理学和分子操作将用于研究调节途径如何通过调节生物胺（5 -羟色胺和章鱼胺）的释放来代表AL中的强化。

DESCRIPTION (provided by applicant): This proposal will focus on using the honeybee (Apis mellifera) as a model animal species for understanding mechanisms of behavioral plasticity toward odors. These animals are faced with the same types of olfactory problems as mammals. They require the capability to detect and respond to a very large number of odors because they depend on locating many different types of flowers to harvest carbohydrate resources in nectars. Association of these odors with nectar changes many times within an individual's lifetime, which also requires that animals learn about these associations. Like mammals, insects exhibit a variety of means to learn about and encode memories for floral odors. Comparative evidence indicates that behavioral and systems-level neural processing similarities between insects and mammals have evolved independently. That suggests that there may only be one general neural solution available to encode information about odors. Therefore, as comparative models, insects can be critical for revealing how odors are learned and encoded in the CNS, and whether this mechanism is fundamental to olfactory processing. The aims of this proposal are to evaluate mechanisms of neural plasticity that exist in the insect Antennal Lobes (AL), which are the neural analogs to the mammalian Olfactory Bulb (Hildebrand & Shepherd 1997). The central theme is that documented neural mechanisms and modulatory pathways in the AL that represent the presence (or absence) of reinforcement serve as a means to filter out unimportant, variable background odors. This allows biologically relevant, learned odors to be readily detected. There will be three aims. First, behavioral investigations will examine in detail mechanisms that underlie a learned inattention (CS preexposure effect) toward odors and blocking in odor-odor mixtures. In particular, manipulations of the conditioning context will reveal the extent to which specific theoretical treatments of CS preexposure can account for it in insects. Second, multichannel recording techniques will be employed to investigate whether and how these behavioral mechanisms may be implemented as a filtering mechanism in the AL. Third, pharmacological and molecular manipulation by way of RNA interference will be used to examine how modulatory pathways represent reinforcement in the AL by regulating biogenic amine (serotonin and octopamine) release.