Watson A H, Burrows M, Hale J P
J Comp Neurol. 1985 Sep 15;239(3):341-59. doi: 10.1002/cne.902390307.
The morphologies of three common inhibitory motor neurones which innervate muscles of a hind leg and the homologous three neurones which innervate muscles in a middle leg are described in relation to known commissures, tracts, and areas of neuropile in their ganglia. The neurones were stained individually by the intracellular injection of cobalt, and the ultrastructure of common inhibitor 1 (CI1) in the metathoracic ganglion was revealed by the intracellular injection of horseradish peroxidase. Homologous inhibitory motor neurones in the meso- and metathoracic ganglia have similar shapes. CI1 has axons in nerves 3, 4, and 5, but common inhibitors 2 and 3 (CI2, CI3) have only a single axon in nerve 5. They nevertheless all share many features in common. All have large (60 70 micron diameter) cell bodies in the ventral cortex near the midline, well separated from those of the excitatory leg motor neurones. Their primary neurites run dorsally and laterally and send many fine branches into the dorsal and lateral neuropile, and some fine branches medially. None enter the ventral neuropile. CI1 and CI2 have a small branch that arises close to the cell body and arborises on either side of the midline. When examined with the electron microscope, CI1 was not found to make any output synapses, even though some of its fine branches are varicose and end in bulbous swellings. These were seen to be packed with mitochondria but not vesicles. Input synapses tend to be grouped together on the secondary neurites and, more especially, on the finer branches and their spines. The majority of processes presynaptic to CI1 contain round agranular vesicles.
描述了支配后肢肌肉的三种常见抑制性运动神经元以及支配中肢肌肉的同源三种神经元的形态，这些形态与它们神经节中已知的连合、神经束和神经毡区域相关。通过细胞内注射钴对神经元进行单独染色，通过细胞内注射辣根过氧化物酶揭示了后胸神经节中常见抑制剂1（CI1）的超微结构。中胸和后胸神经节中的同源抑制性运动神经元具有相似的形状。CI1在神经3、4和5中有轴突，但常见抑制剂2和3（CI2、CI3）在神经5中只有单个轴突。然而，它们都有许多共同特征。所有神经元在中线附近的腹侧皮质都有大的（直径60 - 70微米）细胞体，与兴奋性腿部运动神经元的细胞体分隔良好。它们的初级神经突向背侧和外侧延伸，并向背侧和外侧神经毡发出许多细分支，还有一些细分支向内侧延伸。没有一个进入腹侧神经毡。CI1和CI2有一个靠近细胞体发出的小分支，在中线两侧分支。用电子显微镜检查时，即使CI1的一些细分支有曲张并末端呈球状膨大，也未发现其形成任何输出突触。这些球状膨大充满线粒体但没有囊泡。输入突触倾向于聚集在次级神经突上，尤其是在更细的分支及其棘突上。大多数与CI1形成突触前联系的突起含有圆形无颗粒囊泡。
