El Jundi Basil, Huetteroth Wolf, Kurylas Angela E, Schachtner Joachim
Department of Biology, Animal Physiology, Philipps-University, Marburg, Germany.
J Comp Neurol. 2009 Nov 10;517(2):210-25. doi: 10.1002/cne.22150.
Lepidopterans like the giant sphinx moth Manduca sexta are known for their conspicuous sexual dimorphism in the olfactory system, which is especially pronounced in the antennae and in the antennal lobe, the primary integration center of odor information. Even minute scents of female pheromone are detected by male moths, facilitated by a huge array of pheromone receptors on their antennae. The associated neuropilar areas in the antennal lobe, the glomeruli, are enlarged in males and organized in the form of the so-called macroglomerular complex (MGC). In this study we searched for anatomical sexual dimorphism more downstream in the olfactory pathway and in other neuropil areas in the central brain. Based on freshly eclosed animals, we created a volumetric female and male standard brain and compared 30 separate neuropilar regions. Additionally, we labeled 10 female glomeruli that were homologous to previously quantitatively described male glomeruli including the MGC. In summary, the neuropil volumes reveal an isometric sexual dimorphism in M. sexta brains. This proportional size difference between male and female brain neuropils masks an anisometric or disproportional dimorphism, which is restricted to the sex-related glomeruli of the antennal lobes and neither mirrored in other normal glomeruli nor in higher brain centers like the calyces of the mushroom bodies. Both the female and male 3D standard brain are also used for interspecies comparisons, and may serve as future volumetric reference in pharmacological and behavioral experiments especially regarding development and adult plasticity. J. Comp. Neurol. 517:210-225, 2009. (c) 2009 Wiley-Liss, Inc.
像烟草天蛾这样的鳞翅目昆虫，其嗅觉系统存在明显的两性异形，这在触角和触角叶（气味信息的主要整合中心）中尤为显著。雄性蛾类能够检测到雌性信息素的细微气味，这得益于其触角上大量的信息素受体。触角叶中相关的神经纤维区域，即嗅觉小球，在雄性中会扩大，并以所谓的大嗅觉球复合体（MGC）的形式组织起来。在本研究中，我们在嗅觉通路的更下游以及中枢脑的其他神经纤维区域寻找解剖学上的两性异形。基于刚羽化的动物，我们创建了雌性和雄性标准脑的三维模型，并比较了30个不同的神经纤维区域。此外，我们标记了10个与先前定量描述的雄性嗅觉小球（包括MGC）同源的雌性嗅觉小球。总之，神经纤维体积揭示了烟草天蛾大脑中存在等比例的两性异形。雄性和雌性大脑神经纤维之间这种成比例的大小差异掩盖了一种非等比例或不成比例的两性异形，这种异形仅限于触角叶中与性别相关的嗅觉小球，在其他正常嗅觉小球或更高的脑中枢如蘑菇体的萼中并未体现。雌性和雄性三维标准脑还用于种间比较，并可作为未来药理学和行为实验中的体积参考，特别是关于发育和成年可塑性方面的实验。《比较神经学杂志》517:210 - 225, 2009。(c) 2009威利 - 利斯公司。
