A single identified glomerulus in the zebrafish olfactory bulb carries the high-affinity response to death-associated odor cadaverine
A single identified glomerulus in the zebrafish olfactory bulb carries the high-affinity response to death-associated odor cadaverine
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DOI：
10.1038/srep40892
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发表时间：
2017-01-19
影响因子：
4.6
通讯作者：
Korsching, Sigrun I.
中科院分区：
文献类型：
--
作者：
Dieris, Milan;Ahuja, Gaurav;Korsching, Sigrun I.
死亡相关气味身体碱，由细菌介导的赖氨酸脱羧基产生，已被描述为斑马鱼中一种特定的嗅觉受体TAAR13c的主要激活剂。低浓度的身体碱主要激活表达TAAR13c的嗅觉神经元，提示TAAR13c是连接身体碱刺激和强烈厌恶的先天行为反应的神经元处理通路的重要元件。在这里，我们描述了这条神经通路的初始步骤。首先，我们鉴定了表达TAAR13c的细胞是纤毛神经元，相当于哺乳动物taar基因的情况，这表明尽管硬骨鱼和哺乳动物之间存在很大的进化距离，但它仍然具有高度的保守性。接下来，我们确定了嗅球中身体反应性嗅核的靶区。我们报告说，身体碱剂量依赖地激活一组背外侧肾小球，在最低浓度下直到位于背外侧簇内侧边缘的单个不变的肾小球。这是第一次展示鱼嗅觉系统中针对非信息素气味的单一刻板目标肾小球。不同胺的混合激活了同一背外侧簇中的许多肾小球，表明该区域作为一般的胺反应区发挥作用。
The death-associated odor cadaverine, generated by bacteria-mediated decarboxylation of lysine, has been described as the principal activator of a particular olfactory receptor in zebrafish, TAAR13c. Low concentrations of cadaverine activated mainly TAAR13c-expressing olfactory sensory neurons, suggesting TAAR13c as an important element of the neuronal processing pathway linking cadaverine stimulation to a strongly aversive innate behavioral response. Here, we characterized the initial steps of this neuronal pathway. First we identified TAAR13c-expressing cells as ciliated neurons, equivalent to the situation for mammalian taar genes, which shows a high degree of conservation despite the large evolutionary distance between teleost fishes and mammals. Next we identified the target area of cadaverine-responsive OSNs in the olfactory bulb. We report that cadaverine dose-dependently activates a group of dorsolateral glomeruli, at the lowest concentration down to a single invariant glomerulus, situated at the medial border of the dorsolateral cluster. This is the first demonstration of a single stereotyped target glomerulus in the fish olfactory system for a non-pheromone odor. A mix of different amines activates many glomeruli within the same dorsolateral cluster, suggesting this area to function as a general amine response region.