Dynamic properties of Drosophila olfactory electroantennograms
Dynamic properties of Drosophila olfactory electroantennograms
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DOI：
10.1007/s00359-008-0322-6
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发表时间：
2008-05-01
影响因子：
2.1
通讯作者：
French, Andrew S.
中科院分区：
文献类型：
--
作者：
Schuckel, Julia;Meisner, Shannon;French, Andrew S.
化学信号的时间依赖性特性可能对许多动物至关重要，但人们对化学感受器的动力学知之甚少。动态敏感性的行为证据包括信息素羽流结构对飞蛾飞行的控制，以及一些吸血昆虫检测不同浓度二氧化碳的能力，可能与宿主呼吸速率相匹配。化学感受器动力学的测量受到在适当宽的幅度和频率范围内产生受控的、精确的嗅觉和味觉化学浓度调节的技术挑战的限制。我们使用新型伺服控制层流系统，结合替代示踪气体的光电离检测，来表征果蝇触角在受到水果气味剂或空气中聚集信息素刺激期间的触角电图（EAG）。在 0-100 Hz 带宽上测量的频率响应函数和相干函数可以通过一阶低通线性滤波器函数很好地表征。过滤时间常数的变化范围几乎是十倍，并且是每种气味剂的特征，表明存在几种动态不同的化学转导机制。信息素反应相对于水果气味来说是延迟的。不同化合物的响应幅度以及由此产生的信噪比也有一致的变化。准确的动态表征有望提供有关化学转导和气味刺激行为的重要新信息。
Time-dependent properties of chemical signals are probably crucially important to many animals, but little is known about the dynamics of chemoreceptors. Behavioral evidence of dynamic sensitivity includes the control of moth flight by pheromone plume structure, and the ability of some blood-sucking insects to detect varying concentrations of carbon dioxide, possibly matched to host breathing rates. Measurement of chemoreceptor dynamics has been limited by the technical challenge of producing controlled, accurate modulation of olfactory and gustatory chemical concentrations over suitably wide ranges of amplitude and frequency. We used a new servo-controlled laminar flow system, combined with photoionization detection of surrogate tracer gas, to characterize electroantennograms (EAG) of Drosophila antennae during stimulation with fruit odorants or aggregation pheromone in air. Frequency response functions and coherence functions measured over a bandwidth of 0-100 Hz were well characterized by first-order low-pass linear filter functions. Filter time constant varied over almost a tenfold range, and was characteristic for each odorant, indicating that several dynamically different chemotransduction mechanisms are present. Pheromone response was delayed relative to fruit odors. Amplitude of response, and consequently signal-to-noise ratio, also varied consistently with different compounds. Accurate dynamic characterization promises to provide important new information about chemotransduction and odorant-stimulated behavior.