Gaze R M, Wilson M A, Taylor J S
Institute of Cell, Animal and Population Biology, University of Edinburgh, Ashworth Laboratories, U.K.
Anat Embryol (Berl). 1993 Jan;187(1):27-35. doi: 10.1007/BF00208194.
The position of the earliest optic synapses in Xenopus and the stage at which they developed were studied with the electron microscope after labelling of optic axons with horseradish peroxidase. In addition, tritiated thymidine autoradiography and bromodeoxyuridine immunohistology were used to identify the birth dates of cells in the regions where the synapses had been found. The earliest mature optic synapses were found in the mid-diencephalic region, where the major diencephalic optic neuropils were beginning to develop. These synapses were seen at stage 35/36, before cells in the tectal precursor region had become postmitotic. In other animals labelling with tritiated thymidine or bromodeoxyuridine showed that cells in the diencephalon, close to where the synapses had been seen, were becoming postmitotic at the time the earliest optic axons arrived. The first optic synapses to form in the developing Xenopus visual system thus appeared to do so in the neuropil of Bellonci and the rostral visual nucleus.
在用辣根过氧化物酶标记视轴突后，利用电子显微镜研究了非洲爪蟾最早的视突触位置及其发育阶段。此外，还使用了氚标记胸腺嘧啶核苷放射自显影术和溴脱氧尿苷免疫组织学方法来确定在发现突触的区域中细胞的出生日期。最早的成熟视突触出现在中脑间脑区域，主要的间脑视神经纤维网开始在此处发育。这些突触在第35/36阶段被观察到，此时顶盖前体细胞区域的细胞尚未进入有丝分裂后期。在其他动物中，用氚标记胸腺嘧啶核苷或溴脱氧尿苷标记显示，在最早的视轴突到达时，间脑中靠近已观察到突触位置的细胞正进入有丝分裂后期。因此，在发育中的非洲爪蟾视觉系统中形成的第一批视突触似乎是在贝隆奇神经纤维网和吻侧视核中形成的。
