Transduction in Drosophila olfactory receptor neurons is invariant to air speed.
Transduction in Drosophila olfactory receptor neurons is invariant to air speed.
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DOI：
10.1152/jn.01146.2011
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发表时间：
2012-10
影响因子：
2.5
通讯作者：
Yi Zhou;Rachel I. Wilson
中科院分区：
文献类型：
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作者：
Yi Zhou;Rachel I. Wilson
在脊椎动物的鼻子中，在气味浓度和持续时间不变的情况下，增加空气速度往往会增加嗅觉感受器神经元(ON)的气味诱发活动的幅度。人们通常认为昆虫的嗅觉器官也是如此，但这一点还没有得到直接测试。在这项研究中，我们研究了空气速度对果蝇ORN反应的影响。我们构建了一种气味传递设备，使我们能够独立地改变浓度和空气速度，我们使用快速光电离探测器来精确测量天线上的实际气味浓度，同时记录体内Orns的尖峰信号。我们的结果表明，只要气味浓度保持不变，果蝇的ORN气味反应就不会随着空气速度的变化而变化。在100倍的空速范围内，这一发现是正确的。由于气味疏水性已被提出影响嗅觉传导的空气速度依赖性，我们测试了1000倍的疏水性数值范围，发现ORN反应在整个范围内不随空气速度而变化。这些结果对气味向果蝇角传递的机制有一定的意义。我们的发现也很重要，因为与陆生脊椎动物不同，苍蝇控制通过触角的气流的能力有限，陆生脊椎动物可以控制鼻腔内的气流。因此，对于苍蝇来说，对空气速度的不变性可能是自适应的，因为它赋予了对变化的风条件的稳健性。
In the vertebrate nose, increasing air speed tends to increase the magnitude of odor-evoked activity in olfactory receptor neurons (ORNs), given constant odor concentration and duration. It is often assumed that the same is true of insect olfactory organs, but this has not been directly tested. In this study, we examined the effect of air speed on ORN responses in Drosophila melanogaster. We constructed an odor delivery device that allowed us to independently vary concentration and air speed, and we used a fast photoionization detector to precisely measure the actual odor concentration at the antenna while simultaneously recording spikes from ORNs in vivo. Our results demonstrate that Drosophila ORN odor responses are invariant to air speed, as long as odor concentration is kept constant. This finding was true across a >100-fold range of air speeds. Because odor hydrophobicity has been proposed to affect the air speed dependence of olfactory transduction, we tested a >1,000-fold range of hydrophobicity values and found that ORN responses are invariant to air speed across this full range. These results have implications for the mechanisms of odor delivery to Drosophila ORNs. Our findings are also significant because flies have a limited ability to control air flow across their antennae, unlike terrestrial vertebrates, which can control air flow within their nasal cavity. Thus, for the fly, invariance to air speed may be adaptive because it confers robustness to changing wind conditions.