Spehr Marc, Leinders-Zufall Trese
Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn Street, Baltimore, MD 21201, USA.
Sci STKE. 2005 May 24;2005(285):pe25. doi: 10.1126/stke.2852005pe25.
Olfaction--the sense of smell--is responsible for detecting molecules of immense structural variety. Precise recognition of such diverse stimuli requires a massive receptor repertoire. This functional challenge has been met by simultaneous expression of a multitude of odor-detecting receptors that all belong to the superfamily of heterotrimeric GTP-binding protein (G protein)-coupled receptors. Studies conducted over the past decade have led to the assumption that an individual olfactory sensory neuron expresses only a single odorant receptor, consequently giving rise to the "one receptor-one neuron" hypothesis. This idea is attractive because of its simplicity and has served as the basis for models of olfactory coding. However, recent reports regarding Drosophila have found exceptions to the rule that could have important implications for the logic of olfactory coding.
嗅觉——即味觉——负责检测结构种类繁多的分子。要精确识别如此多样的刺激物，需要大量的受体库。这一功能挑战通过同时表达众多均属于异源三聚体GTP结合蛋白（G蛋白）偶联受体超家族的气味检测受体得以解决。过去十年进行的研究得出这样一种假设，即单个嗅觉感觉神经元仅表达一种气味受体，从而产生了“一个受体—一个神经元”假说。这个观点因其简单性而颇具吸引力，并一直作为嗅觉编码模型的基础。然而，最近有关果蝇的报告发现了该规则的例外情况，这可能对嗅觉编码的逻辑产生重要影响。
