我们熟悉那些与酸有关的不好的、经常是刺激性的气味，但虽然酸受体已知决定对酸味的检测，而在嗅觉系统中却没有酸传感神经元。现在，Greg Suh及其同事在果蝇的嗅觉系统中识别出了这样的神经元。酸传感还要求跨膜蛋白IR64a在这些神经元中表达。IR64a本身不足以决定酸识别，但（在这个方面）对它的需求，是最近发现的（假定存在的）气味受体的亲离子受体家族中一个成员的第一个已知功能。（生物谷Bioon.com）
生物谷推荐原文出处：
Nature doi:10.1038/nature09537
Acid sensing by the Drosophila olfactory system
Minrong Ai1,3, Soohong Min1,3, Yael Grosjean2,4, Charlotte Leblanc1,4, Rati Bell2, Richard Benton2 & Greg S. B. Suh1
Molecular Neurobiology Program, Skirball Institute of Biomolecular Medicine, Department of Cell Biology, New York University, School of Medicine, New York, New York 10016, USA
Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
These authors contributed equally to this work.
Present addresses: Centre des Sciences du Goût et de l’Alimentation, UMR-6265 CNRS, UMR-1324 INRA, Université de Bourgogne, 6 Boulevard Gabriel, 21000 Dijon, France (Y.G.); Université Paris Diderot – Paris 7, 16 rue Marguerite Duras, 75013 Paris, France (C.L.).
The odour of acids has a distinct quality that is perceived as sharp, pungent and often irritating1. How acidity is sensed and translated into an appropriate behavioural response is poorly understood. Here we describe a functionally segregated population of olfactory sensory neurons in the fruitfly, Drosophila melanogaster, that are highly selective for acidity. These olfactory sensory neurons express IR64a, a member of the recently identified ionotropic receptor (IR) family of putative olfactory receptors2. In vivo calcium imaging showed that IR64a+ neurons projecting to the DC4 glomerulus in the antennal lobe are specifically activated by acids. Flies in which the function of IR64a+ neurons or the IR64a gene is disrupted had defects in acid-evoked physiological and behavioural responses, but their responses to non-acidic odorants remained unaffected. Furthermore, artificial stimulation of IR64a+ neurons elicited avoidance responses. Taken together, these results identify cellular and molecular substrates for acid detection in the Drosophila olfactory system and support a labelled-line mode of acidity coding at the periphery.
