Department of Crop Protection, Centre UdL-IRTA, University of Lleida, Lleida, Spain.
J Exp Biol. 2011 Feb 15;214(Pt 4):637-45. doi: 10.1242/jeb.047316.
Both sexes of Grapholita molesta, a key pest of stone fruits, are able to detect host-plant volatiles and the sex pheromone emitted by females, and to modify their behaviour accordingly. How olfactory information is processed in the central nervous system is unknown. Intracellular recordings and stainings were used to characterize antennal lobe (AL) neuron responses to single pheromone components, a behaviourally active blend of five peach volatiles and a pear-fruit ester. AL neurons with different response patterns responded to pheromone components and plant volatiles. In males more neurons responded specifically to the main pheromone component than in females, whereas neurons responding to all three pheromone components were more abundant in females. Neurons responding to all three pheromone components often responded also to the tested plant volatiles in both sexes. Responses to all pheromone components were dose dependent in males and females, but dose-response relationships differed between neurons and tested pheromone components. Among the five AL projection neurons identified neuroanatomically in males, no arborizations were observed in the enlarged cumulus (Cu), although all of them responded to pheromone compounds. In one of two stained projection neurons in females, however, the glomerulus, which is thought to be homologous to the Cu, was targeted. The processing of pheromone information by ordinary glomeruli rather than by the macroglomerular complex is thus a striking feature of this species, indicating that pheromone and plant volatile processing are not entirely separate in this tortricid moth AL. However, the absence of recorded pheromone responses in the Cu needs to be confirmed.
雌雄两性的桃小食心虫 Grapholita molesta 均能够探测到寄主植物挥发物和雌性昆虫释放的性信息素，并相应地改变行为。然而，目前尚不清楚嗅觉信息在中枢神经系统中是如何被处理的。本研究采用细胞内记录和染色技术来描述触角叶（AL）神经元对单个信息素成分、五种桃挥发物和一种梨果酯的行为活性混合物的反应，结果表明具有不同反应模式的 AL 神经元对信息素成分和植物挥发物均有反应。与雌性相比，雄性中对主要信息素成分有特异性反应的神经元更多，而对所有三种信息素成分都有反应的神经元在雌性中更为丰富。对所有三种信息素成分都有反应的神经元通常也对两性测试的植物挥发物有反应。在雄性和雌性中，所有信息素成分的反应均呈剂量依赖性，但神经元和测试信息素成分之间的剂量-反应关系存在差异。在雄性中，通过神经解剖学鉴定的 5 个 AL 投射神经元中，没有观察到在增大的 cumulus（Cu）中的分支，尽管所有神经元都对信息素化合物有反应。然而，在雌性中的两个染色投射神经元中的一个中，观察到了被认为与 Cu 同源的肾小球被靶向。因此，信息素处理不是通过普通的肾小球，而是通过宏观肾小球复合体来完成的，这在该卷蛾科昆虫的 AL 中是一个显著特征，表明信息素和植物挥发物的处理并非完全分离。然而，需要进一步确认在 Cu 中未记录到的信息素反应的情况。
