Ca2+-activated Cl- current ensures robust and reliable signal amplification in vertebrate olfactory receptor neurons.
Ca2+-activated Cl- current ensures robust and reliable signal amplification in vertebrate olfactory receptor neurons.
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Ca2 激活的 Cl- 电流确保脊椎动物嗅觉受体神经元中强大且可靠的信号放大。
DOI：
10.1073/pnas.1816371116
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发表时间：
2019
影响因子：
11.1
通讯作者：
Reingruber,Jürgen
中科院分区：
文献类型：
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作者：
Reisert,Johannes;Reingruber,Jürgen
大多数初级感觉神经元的激活导致由阳离子携带的转导电流。一个值得注意的例外是脊椎动物嗅觉受体神经元（ORN），其中转导电流主要由阴离子携带。然而，目前还不清楚为什么ORN使用阴离子电流进行信号放大。我们试图通过研究气味反应过程中嗅觉纤毛小空间中迄今被忽视的、、和的动态来澄清这一问题。使用计算建模和仿真，我们比较了基于eitherorcurrents的信号放大的结果。我们发现由流入而不是流出产生的放大是有问题的，原因有几个：首先，电流幅度变化很大，取决于粘膜离子浓度的变化。第二，电流导致在气味反应期间纤毛浓度的大幅增加。这种增加抑制甚至逆转了交换清除，这对反应终止是必不可少的。最后，电流增加纤毛渗透压，这可能导致肿胀，破坏纤毛。相比之下，基于外排的转导途径避免了这些问题，并使气味反应稳健可靠。
Activation of most primary sensory neurons results in transduction currents that are carried by cations. One notable exception is the vertebrate olfactory receptor neuron (ORN), where the transduction current is carried largely by the anion. However, it remains unclear why ORNs use an anionic current for signal amplification. We have sought to provide clarification on this topic by studying the so far neglected dynamics of,,, andin the small space of olfactory cilia during an odorant response. Using computational modeling and simulations we compared the outcomes of signal amplification based on eitherorcurrents. We found that amplification produced byinflux instead of aefflux is problematic for several reasons: First, thecurrent amplitude varies greatly, depending on mucosal ion concentration changes. Second, acurrent leads to a large increase in the ciliaryconcentration during an odorant response. This increase inhibits and even reversesclearance byexchange, which is essential for response termination. Finally, acurrent increases the ciliary osmotic pressure, which could cause swelling to damage the cilia. By contrast, a transduction pathway based onefflux circumvents these problems and renders the odorant response robust and reliable.