Maxillary palps are broad spectrum odorant detectors in Culex quinquefasciatus
Maxillary palps are broad spectrum odorant detectors in Culex quinquefasciatus
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DOI：
10.1093/chemse/bjm040
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发表时间：
2007-10-01
期刊：
影响因子：
3.5
通讯作者：
Leal, Walter S.
中科院分区：
文献类型：
--
作者：
Syed, Zainulabeuddin;Leal, Walter S.
许多蚊子物种的下颚须上都有一种单一类型的嗅觉感受器，其中有一个非常敏感的嗅觉受体神经元（ORN），用于接收二氧化碳。我们进行了广泛的单感器记录，从这个钉感器致倦库蚊，其特征在于响应阈值和动力学的CO2接收，检测阈值小于大气中的CO2浓度。该ORN以强直模式响应于较低浓度的CO2，而较高浓度产生动作电位放电的相位强直模式。感觉器电位准确地代表了二氧化碳引起的兴奋性反应的反应幅度和动力学。刺激这些ORN与人类的呼吸，蚊子利它素和高达4.5%的CO2的复杂混合物，引起兴奋性反应，可靠地检测到CO2敏感的ORN。另一个ORN安置在这些感器1-辛烯-3-醇和各种植物衍生的化合物，特别是花和绿色叶挥发物。该ORN对天然对映体（R）-（-）-1-辛烯-3-醇表现出显著的敏感性，可与蛾类中检测信息素的ORN相媲美。10 ng剂量引起最大神经元反应。生物学，生态学的作用，下颚须在检测植物和花蜜相关的来源提出。
A single type of olfactory sensilla on maxillary palps in many species of mosquitoes houses a very sensitive olfactory receptor neuron (ORN) for carbon dioxide reception. We performed extensive single sensillum recordings from this peg sensillum in Culex quinquefasciatus and have characterized the response threshold and kinetics for CO2 reception, with a detection threshold less than the CO2 concentration in the atmosphere. This ORN responded in a tonic mode to lower concentrations of CO2, whereas higher concentrations generated a phasic-tonic mode of action potential firing. Sensillum potentials accurately represented the response magnitude and kinetics of carbon dioxide-elicited excitatory responses. Stimulation of these ORNs with human breath, a complex mixture of mosquito kairomones and up to 4.5% CO2, elicited excitatory responses that were reliably detected by CO2-sensitive ORNs. Another ORN housed in these sensilla responded to 1-octen-3-ol and to various plant-derived compounds, particularly floral and green leaf volatiles. This ORN showed remarkable sensitivity to the natural enantiomer, (R)-(-)-1-octen-3-ol, rivaling pheromone-detecting ORNs in moths. Maximum neuronal response was elicited with a 10 ng dose. A biological, ecological role of maxillary palps in detection of plant- and nectar-related sources is proposed.