We describe an integrated theory of olfactory systems operation that incorporates experimental findings across scales, stages, and methods of analysis into a common framework. In particular, we consider the multiple stages of olfactory signal processing as a collective system, in which each stage samples selectively from its antecedents. We propose that, following the signal conditioning operations of the nasal epithelium and glomerular-layer circuitry, the plastic external plexiform layer of the olfactory bulb effects a process of category learning—the basis for extracting meaningful, quasi-discrete odor representations from the metric space of undifferentiated olfactory quality. Moreover, this early categorization process also resolves the foundational problem of how odors of interest can be recognized in the presence of strong competitive interference from simultaneously encountered background odorants. This problem is fundamentally constraining on early-stage olfactory encoding strategies and must be resolved if these strategies and their underlying mechanisms are to be understood. Multiscale general theories of olfactory systems operation are essential in order to leverage the analytical advantages of engineered approaches together with our expanding capacity to interrogate biological systems.

中文翻译：

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嗅球信号转换的系统框架

我们描述了嗅觉系统运作的综合理论，它将跨尺度、阶段和分析方法的实验结果纳入一个共同的框架中。特别是，我们将嗅觉信号处理的多个阶段视为一个集体系统，其中每个阶段都有选择地从其前因中进行采样。我们提出，在鼻上皮和肾小球层电路的信号调节操作之后，嗅球的塑料外部丛状层会影响类别学习的过程——这是从度量空间中提取有意义的、准离散气味表示的基础具有未分化的嗅觉质量。此外，这种早期分类过程还解决了在同时遇到的背景气味剂存在强烈竞争干扰的情况下如何识别感兴趣的气味的基本问题。这个问题从根本上限制了早期嗅觉编码策略，如果要理解这些策略及其潜在机制，就必须解决这个问题。为了利用工程方法的分析优势以及我们不断扩大的询问生物系统的能力，嗅觉系统运作的多尺度一般理论至关重要。