Duve H, Thorpe A
School of Biological Sciences, Queen Mary, University of London, Mile End Road, London, E1 4NS, UK.
Cell Tissue Res. 2003 Jan;311(1):79-89. doi: 10.1007/s00441-002-0648-2. Epub 2002 Nov 22.
A comparative study of the co-localisation of three different families of neuropeptides, viz. allatostatins of the Y/FXFGL-NH(2) type, Manduca sexta allatostatin (Mas-AS) and allatotropin, in the frontal ganglion of lepidopteran larvae has been carried out by means of immunocytochemistry and confocal laser scanning microscopy. The simultaneous application of three types of fluorochrome-conjugated antibodies reveals triple co-localisation in an anterodorsal pair of neurones in the frontal ganglion of the noctuids Heliothis virescens and Lacanobia oleracea. There is no evidence of differential axonal transport, since all parts of these neurones show complete co-localisation of all three peptides. Prominent axons of the ganglionic neurones project in the recurrent nerve to the foregut and stomodeal valve. Over the crop, lateral and sub-lateral branches follow the course of circular muscle fibres and terminate in varicosities. All three neuropeptides have previously been shown to be myoregulatory on the foregut; the Y/FXFGL-NH(2) allatostatins and Mas-AS are inhibitory, whereas allatotropin is excitatory. The morphological evidence of co-localisation of physiologically antagonistic peptides within the same terminals suggests that an extremely complex mechanism controls the contractile activities of the foregut. A posterodorsal pair of neurones in the frontal ganglion have prominent axons projecting via the frontal connectives to the brain and in the recurrent nerve to the stomodeal valve where extensive branching suggests control over the valve movements. Studies of another noctuid, Spodoptera frugiperda, and the sphingid, M. sexta, show interesting variations in the co-localisation phenomenon.
通过免疫细胞化学和共聚焦激光扫描显微镜技术，对鳞翅目幼虫额神经节中三种不同神经肽家族，即Y/FXFGL-NH₂型咽侧体抑制素、烟草天蛾咽侧体抑制素（Mas-AS）和促咽侧体素的共定位进行了比较研究。同时应用三种荧光染料偶联抗体，揭示了夜蛾科昆虫棉铃虫和甘蓝夜蛾额神经节中一对前背侧神经元存在三重共定位。没有证据表明存在差异轴突运输，因为这些神经元的所有部分都显示出这三种肽完全共定位。神经节神经元的显著轴突通过返神经投射到前肠和口道瓣。在嗉囊上方，外侧和亚外侧分支沿着环肌纤维的走向延伸，并终止于膨体。此前已证明，所有这三种神经肽对前肠都有肌调节作用；Y/FXFGL-NH₂型咽侧体抑制素和Mas-AS具有抑制作用，而促咽侧体素具有兴奋作用。在同一终末内生理拮抗肽共定位的形态学证据表明，存在一种极其复杂的机制控制着前肠的收缩活动。额神经节中一对后背侧神经元有显著的轴突，通过额神经连索投射到脑，并通过返神经投射到口道瓣，在口道瓣处广泛分支表明对瓣膜运动有控制作用。对另一种夜蛾草地贪夜蛾和天蛾科昆虫烟草天蛾的研究显示，共定位现象存在有趣的差异。
