Neural Processes in Olfactory Coding

描述（申请人提供）：哺乳动物的嗅觉系统能够解决化学中的两个重要问题。具体来说，它能区分密切相关的气味化学物质，但它也能探测到化学结构截然不同的气味物质。嗅球对少数相对相似的气味的反应提示了嗅觉系统对气味编码的一些潜在的基本规则。然而，测量到的反应只构成了与正常嗅觉功能有关的大量受体、配体和感知气味的一个微不足道的样本。我们现在可以通过使用2-脱氧葡萄糖摄取技术来评估肾小球对355种气味的反应来测试当前假设的普遍性，这种技术可以进入嗅球的整个结构。这些气味包括一系列分子，这些分子沿着一些尚未测试的分子尺寸逐渐不同。同时，气味剂还包括化学结构差异很大的分子，从而提供了与嗅觉系统的广泛能力更相称的样品。除了测试之前提出的假设外，这个庞大而多样的气味集应该为发现气味编码的新方面提供充足的机会。最后，我们开发了一种方法，将所有肾小球活动数据放入数据库中，我们可以使用该数据库来评估整个肾小球层或该层较小区域模式的定量相似性和差异性。这种方法应该允许我们提取有关气味分子的结构特征的信息，这些特征对于刺激特定的肾小球区域至关重要。这种方法还应该允许我们对气味感知的相似性做出额外的定量预测。我们计划使用这种信息学方法来提取关于气味剂，肾小球活动和气味感知之间关系的新假设。

DESCRIPTION (provided by applicant): The mammalian olfactory system is able to solve two important problems in chemistry. Specifically, it discriminates between closely related odorant chemicals, but it also detects odorants of vastly different chemical structure. The responses of the olfactory bulb to a small number of relatively similar odorants have suggested some potentially fundamental rules for odor coding by the olfactory system. However, the measured responses constitute only a meager sampling of the large number of receptors, ligands, and perceived odors that are involved in normal olfactory function. We are now in a position to test the generality of current hypotheses by assessing glomerular responses to 355 odorants by using a 2-deoxyglucose uptake technique that affords access to the entire structure of the olfactory bulb. These odorants include sets of molecules that differ incrementally along a number of as yet untested molecular dimensions. At the same time, the odorants also include molecules differing very greatly in chemical structure, thereby providing a sample more commensurate with the broad capabilities of the olfactory system. In addition to testing hypotheses that have been advanced previously, this large and varied odorant set should give ample opportunity to uncover novel aspects of odor coding. Finally, we have developed a method to place all of the glomerular activity data in a database that we can use to assess quantitative similarities and differences in patterns either across the entire glomerular layer, or in smaller regions of that lamina. This approach should allow us to extract information about the structural features in odorant molecules that are critical for stimulating specific glomerular areas. The approach also should allow us to make additional quantitative predictions regarding similarities in odor perceptions. We plan to use this informatics approach to extract novel hypotheses regarding the relationships between odorants, glomerular activity and odor perception.