Pathogenic bacteria induce aversive olfactory learning in Caenorhabditis elegans
Pathogenic bacteria induce aversive olfactory learning in Caenorhabditis elegans
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DOI：
10.1038/nature04216
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发表时间：
2005-11-10
期刊：
影响因子：
64.8
通讯作者：
Bargmann, CI
中科院分区：
文献类型：
--
作者：
Zhang, Y;Lu, H;Bargmann, CI
食物可能是危险的，无论是通过毒性还是通过摄入受污染的食物源后的细菌感染。因为了解食物质量可以提高生存率，所以嗅觉学习最有力的形式之一就是条件性地回避与内脏不适相关的味道。线虫秀丽隐杆线虫以细菌为食，但在自然环境中很容易受到病原菌的感染。在这里，我们表明，线虫在接触致病菌后会改变其嗅觉偏好，避免来自病原体的气味，并增加其对熟悉的非致病菌气味的吸引力。特定的细菌会引起嗅觉偏好的特定变化，这暗示着联想学习。暴露于致病细菌会通过转录和转录后机制增加 ADF 化学感应神经元中的血清素。血清素通过 MOD-1（一种在感觉中间神经元中表达的血清素门控氯离子通道）发挥作用，促进厌恶性学习。血清素的增加可能代表病原体感染的负强化刺激。
Food can be hazardous, either through toxicity or through bacterial infections that follow the ingestion of a tainted food source. Because learning about food quality enhances survival, one of the most robust forms of olfactory learning is conditioned avoidance of tastes associated with visceral malaise. The nematode Caenorhabditis elegans feeds on bacteria but is susceptible to infection by pathogenic bacteria in its natural environment. Here we show that C. elegans modifies its olfactory preferences after exposure to pathogenic bacteria, avoiding odours from the pathogen and increasing its attraction to odours from familiar nonpathogenic bacteria. Particular bacteria elicit specific changes in olfactory preferences that are suggestive of associative learning. Exposure to pathogenic bacteria increases serotonin in ADF chemosensory neurons by transcriptional and post-transcriptional mechanisms. Serotonin functions through MOD-1, a serotonin-gated chloride channel expressed in sensory interneurons, to promote aversive learning. An increase in serotonin may represent the negative reinforcing stimulus in pathogenic infection.