Touhara Kazushige, Vosshall Leslie B
Department of Integrated Biosciences, The University of Tokyo, Chiba, 277-8562 Japan.
Annu Rev Physiol. 2009;71:307-32. doi: 10.1146/annurev.physiol.010908.163209.
Olfaction is a critical sensory modality that allows living things to acquire chemical information from the external world. The olfactory system processes two major classes of stimuli: (a) general odorants, small molecules derived from food or the environment that signal the presence of food, fire, or predators, and (b) pheromones, molecules released from individuals of the same species that convey social or sexual cues. Chemosensory receptors are broadly classified, by the ligands that activate them, into odorant or pheromone receptors. Peripheral sensory neurons expressing either odorant or pheromone receptors send signals to separate odor- and pheromone-processing centers in the brain to elicit distinct behavioral and neuroendocrinological outputs. General odorants activate receptors in a combinatorial fashion, whereas pheromones activate narrowly tuned receptors that activate sexually dimorphic neural circuits in the brain. We review recent progress on chemosensory receptor structure, function, and circuitry in vertebrates and invertebrates from the point of view of the molecular biology and physiology of these sensory systems.
嗅觉是一种至关重要的感觉方式，它使生物能够从外部世界获取化学信息。嗅觉系统处理两类主要刺激：（a）普通气味剂，即源自食物或环境的小分子，它们表明食物、火灾或捕食者的存在；（b）信息素，即同一物种个体释放的分子，其传达社会或性信号。化学感应受体根据激活它们的配体大致分为气味剂受体或信息素受体。表达气味剂或信息素受体的外周感觉神经元将信号发送到大脑中不同的气味和信息素处理中心，以引发不同的行为和神经内分泌输出。普通气味剂以组合方式激活受体，而信息素激活调谐范围狭窄的受体，这些受体激活大脑中具有性别差异的神经回路。我们从这些感觉系统的分子生物学和生理学角度，综述了脊椎动物和无脊椎动物在化学感应受体结构、功能和神经回路方面的最新进展。
