Winnington A P, Napper R M, Mercer A R
Department of Zoology, University of Otago, Dunedin, New Zealand.
J Comp Neurol. 1996 Feb 12;365(3):479-90. doi: 10.1002/(SICI)1096-9861(19960212)365:3<479::AID-CNE10>3.0.CO;2-M.
Adult worker honey bees alter their behaviour with age but retain a strong reliance on sensory information from the antennae. The antennae house a diverse array of receptors, including mechanoreceptors, hygroreceptors, olfactory receptors, and contact chemoreceptors, which relay information to the brain. Antennal sensory neurons that project to the antennal lobes of the brain converge onto second-order interneurones to form discrete spheres of neuropil, called glomeruli. The spatial organisation of glomeruli in the antennal lobes of the honey bee is constant, but the central distribution of information from receptors tuned to different sensory modalities is unknown. Here we show that the glomerular neuropil of the antennal lobes undergoes constant modification during the lifetime of the adult worker bee. Changes in morphology are site specific and highly predictable. The total volume of the glomerular neuropil of the antennal lobe increased significantly during the first 4 days of adult life. Each of the five readily identifiable glomeruli examined in this study exhibited a unique pattern of growth. The growth of two of the five glomeruli changed dramatically with the shift to foraging duties. Furthermore, significant differences were identified between the antennal lobes of bees performing nectar- and pollen-foraging tasks. The highly compartmentalized nature of the antennal lobes, the ease with which specific glomeruli can be identified, and the predictability of changes to the antennal lobe neuropil make this an ideal system for examining the mechanisms and behavioural consequences of structural plasticity in primary sensory centres of the brain.
成年工蜂的行为会随着年龄而改变，但它们仍然高度依赖来自触角的感官信息。触角中有各种各样的感受器，包括机械感受器、湿感受器、嗅觉感受器和接触化学感受器，这些感受器将信息传递给大脑。投射到脑触角叶的触角感觉神经元汇聚到二级中间神经元上，形成称为神经小球的离散神经毡球。蜜蜂触角叶中神经小球的空间组织是恒定的，但来自调谐到不同感觉模式的感受器的信息在中枢的分布尚不清楚。在这里，我们表明成年工蜂一生中触角叶的神经小球神经毡会不断发生变化。形态变化具有位点特异性且高度可预测。触角叶神经小球神经毡的总体积在成年后的头4天显著增加。在本研究中检查的五个易于识别的神经小球中每个都表现出独特的生长模式。五个神经小球中的两个的生长随着转向觅食任务而发生显著变化。此外，在执行采蜜和采粉任务的蜜蜂的触角叶之间发现了显著差异。触角叶高度分隔的性质、特定神经小球易于识别的特性以及触角叶神经毡变化的可预测性，使其成为研究大脑初级感觉中枢结构可塑性的机制和行为后果的理想系统。
