Elekes K, Hustert R, Geffard M
Fakultät für Biologie, Universität Konstanz, Konstanz, Bundesrepublik Deutschland.
Cell Tissue Res. 1987 Oct;250(1):167-80. doi: 10.1007/BF00214668.
The distribution and ultrastructure of serotonin- and dopamine-immunoreactive (5-HTi and DAi) neurones have been investigated in the terminal ganglion of the cricket, Acheta domestica, using a pre-embedding chopper technique. Special attention has been paid to the immunoreactive structures in the neuropil. 5-HTi structures are extensively distributed and densely packed throughout the 5 neuromeres of the terminal ganglion and originate from several interneurones and efferent neurones. In contrast, DAi fibres are distributed sparsely although they extend to all neuromeres of the ganglion and originate from 6 interneurons only. For both 5-HTi and DAi neurones characteristic axonal projections and branching patterns can be distinguished. The 5-HTi axons exhibit rich varicose arborizations, whereas DAi neurones possess fewer varicosities in the neuropil. Electron microscopy shows that 5-HTi varicosities contain small (∼ 60 nm) and large (∼ 100 nm) agranular vesicles, and large (∼ 100 nm) granular vesicles, whereas in DAi varicosities small (∼ 60 nm) agranular and large (∼ 100 nm) granular vesicles are seen. Both 5-HTi and DAi varicosities form synaptic contacts. We conclude that both serotonin and dopamine may be used as neurotransmitters in the terminal ganglion of the cricket.
采用包埋前切片技术，研究了家蟋蟀终末神经节中5-羟色胺免疫反应性（5-HTi）和多巴胺免疫反应性（DAi）神经元的分布及超微结构。特别关注了神经纤维网中的免疫反应性结构。5-HTi结构广泛分布于终末神经节的所有5个神经节段，密集排列，起源于多个中间神经元和传出神经元。相比之下，DAi纤维分布稀疏，尽管它们延伸至神经节的所有神经节段，且仅起源于6个中间神经元。对于5-HTi和DAi神经元，均可区分出特征性的轴突投射和分支模式。5-HTi轴突呈现丰富的曲张分支，而DAi神经元在神经纤维网中的曲张较少。电子显微镜显示，5-HTi曲张体含有小（约60nm）和大（约100nm）的无颗粒囊泡以及大（约100nm）的颗粒囊泡，而在DAi曲张体中可见小（约60nm）的无颗粒囊泡和大（约100nm）的颗粒囊泡。5-HTi和DAi曲张体均形成突触联系。我们得出结论，5-羟色胺和多巴胺在蟋蟀终末神经节中均可能作为神经递质。
