López S, Guerrero A, Bleda M J, Quero C
Department of Biological Chemistry and Molecular Modelling, IQAC (CSIC), Barcelona, Spain.
Institute of Advanced Chemistry of Catalonia (IQAC, CSIC), Barcelona, Spain.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2017 Dec;203(12):973-982. doi: 10.1007/s00359-017-1205-5. Epub 2017 Aug 29.
In insects, the olfactory system displays a high degree of plasticity. In Spodoptera littoralis, pre-exposure of males to the sex pheromone has been shown to increase the sensitivity of the olfactory sensory neurons at peripheral level. In this study, we have investigated this sensitization effect by recording the electroantennographic responses of male antennae to the major sex pheromone component (Z,E)-9,11-tetradecadienyl acetate and to the minor components (Z,E)-9,12-tetradecadienyl acetate and (Z)-9-tetradecenyl acetate. Responses to the conjugated diene acetate at 1 and 10 µg and to the unconjugated ester at 10 µg at three different times (11, 22 and 33 min) after pre-exposure (T = 0 min) were significantly higher than those at T = 0, whereas no increase of sensitivity to the pheromone was elicited by any dose of the minor monoene acetate. In addition, pre-exposed antennae to sub-threshold amounts (0.1, 1 and 10 ng) of the major pheromone component also induced an increased response to the chemical at different times (5 and 15 min) after exposure. Our results revealed that pre-exposed isolated antennae display a short-term higher sensitivity at the peripheral level when compared to naive antennae. In addition, we provide evidence of a peripheral sensitization mediated not only by the major pheromone component, but also by the minor unconjugated diene acetate, and the induction of this sensitivity appears to be dependent on the pre-exposure dose and the time span between pre-exposure and subsequent recordings. Possible implications of the sensitization effect displayed by the minor component for a more effective discrimination of the pheromone bouquets of other closely related species are highlighted.
在昆虫中，嗅觉系统表现出高度的可塑性。在棉铃虫中，已证明雄性棉铃虫预先接触性信息素会提高外周水平嗅觉感觉神经元的敏感性。在本研究中，我们通过记录雄性触角对主要性信息素成分（Z,E）-9,11-十四碳二烯乙酸酯以及次要成分（Z,E）-9,12-十四碳二烯乙酸酯和（Z）-9-十四碳烯乙酸酯的触角电图反应，来研究这种致敏效应。在预先接触（T = 0分钟）后的三个不同时间点（11、22和33分钟），对1和10微克的共轭二烯乙酸酯以及10微克的非共轭酯的反应显著高于T = 0时的反应，而任何剂量的次要单烯乙酸酯均未引起对信息素敏感性的增加。此外，预先接触低于阈值量（0.1、1和10纳克）的主要信息素成分的触角，在接触后的不同时间点（5和15分钟）也会对该化学物质产生增强的反应。我们的结果表明，与未接触过的触角相比，预先接触过的离体触角在外周水平表现出短期更高的敏感性。此外，我们提供的证据表明，外周致敏不仅由主要信息素成分介导，还由次要的非共轭二烯乙酸酯介导，并且这种敏感性的诱导似乎取决于预先接触的剂量以及预先接触与后续记录之间的时间跨度。突出了次要成分所表现出的致敏效应对于更有效区分其他密切相关物种的信息素组合的可能影响。
