Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Avda Gran Bretaña 1111, 2360102 Playa Ancha, Valparaíso, Chile.
J Exp Biol. 2012 May 15;215(Pt 10):1740-8. doi: 10.1242/jeb.067264.
Teleost fish lack independent olfactory organs for odorant and pheromone detection. Instead, they have a single sensory epithelium with two populations of receptor neurons, ciliated and microvillous, that are conserved among vertebrates, and a unique receptor cell type named the olfactory crypt cell. Crypt cells were shown to be chemosensory neurons that project to specific areas in the olfactory bulb, but their odorant tuning and overall function remain unclear. Reproduction in fish is generally synchronized by sex pheromonal signaling between males and females, but the sensors responsible for pheromone detection remain unknown. In crucian carp, a seasonal variation in the population of olfactory crypt cells and their brain projections pathways, involved in reproduction, led to the hypothesis of a role as sex pheromone detectors. In the present study, morphology and localization of olfactory crypt cells were compared between juvenile and mature rainbow trout of both sexes, and calcium imaging was used to visualize responses of crypt cells from the three groups to common social and food-related odorants, sex hormones and conspecific tissue extracts. Crypt cells from mature trout were found to be larger than those of juvenile specimens, and preferentially localized to the apical surface of the olfactory epithelium. Although a fraction of crypt cells of all groups responded to common odorants such as amino acids and bile salts, cells from mature trout showed a characteristic preference for gonadal extracts and hormones from the opposite sex. These results support an involvement of olfactory crypt cells in reproduction-related olfactory signaling in fishes.
硬骨鱼类缺乏独立的嗅觉器官来感知气味和信息素。相反，它们有一个单一的感觉上皮，其中有两种受体神经元，纤毛和微绒毛，这在脊椎动物中是保守的，还有一种独特的受体细胞类型，称为嗅觉隐窝细胞。隐窝细胞被证明是化学感觉神经元，它们投射到嗅球的特定区域，但它们的气味调谐和整体功能仍不清楚。鱼类的繁殖通常是通过雌雄之间的性信息素信号同步进行的，但负责检测信息素的传感器仍然未知。在鲫鱼中，嗅觉隐窝细胞及其脑投射途径的数量在繁殖过程中存在季节性变化，这导致了它们作为性信息素探测器的假说。在本研究中，比较了雌雄幼鱼和成鱼的嗅觉隐窝细胞的形态和定位，并使用钙成像技术来可视化来自三组的隐窝细胞对常见的社交和食物相关气味、性激素和同种组织提取物的反应。成熟鳜鱼的隐窝细胞比幼鱼的大，并且优先定位于嗅觉上皮的顶端表面。尽管所有组的隐窝细胞都对常见的气味物质如氨基酸和胆汁盐有反应，但成熟鳜鱼的细胞对性腺提取物和异性的激素表现出特征性的偏好。这些结果支持嗅觉隐窝细胞参与鱼类与繁殖相关的嗅觉信号传递。
