期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2017
卷号：114
期号：23
页码：E4658-E4665
DOI：10.1073/pnas.1614596114
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Sensory receptor neurons match their dynamic range to ecologically relevant stimulus intensities. How this tuning is achieved is poorly understood in most receptors. The roundworm Caenorhabditis elegans avoids 21% O2 and hypoxia and prefers intermediate O2 concentrations. We show how this O2 preference is sculpted by the antagonistic action of a neuroglobin and an O2-binding soluble guanylate cyclase. These putative molecular O2 sensors confer a sigmoidal O2 response curve in the URX neurons that has highest slope between 15 and 19% O2 and approaches saturation when O2 reaches 21%. In the absence of the neuroglobin, the response curve is shifted to lower O2 values and approaches saturation at 14% O2. In behavioral terms, neuroglobin signaling broadens the O2 preference of Caenorhabditis elegans while maintaining avoidance of 21% O2. A computational model of aerotaxis suggests the relationship between GLB-5–modulated URX responses and reversal behavior is sufficient to broaden O2 preference. In summary, we show that a neuroglobin can shift neural information coding leading to altered behavior. Antagonistically acting molecular sensors may represent a common mechanism to sharpen tuning of sensory neurons.
