Smith C L
Department of Neurobiology, Anatomy and Cell Science, University of Pittsburgh School of Medicine, Pennsylvania 15261.
Dev Biol. 1990 Dec;142(2):476-80. doi: 10.1016/0012-1606(90)90369-t.
Thoracic sensory neurons in bullfrog tadpoles can be induced to form connections typical of brachial sensory neurons by transplanting thoracic ganglia to the branchial level at stages when some thoracic sensory neurons already have formed connections. In order to find out how many postmitotic sensory neurons survive transplantation, [3H]thymidine was administered to tadpoles in which thoracic ganglia were transplanted to the brachial level unilaterally at stages VII to IX. Between 16 and 37% of the neurons in transplanted ganglia were unlabeled, as compared to 46 to 60% in unoperated ganglia. Transplanted ganglia contained fewer unlabeled neurons than corresponding unoperated ganglia, indicating that transplantation caused degeneration of postmitotic neurons. Therefore, a large fraction of the neurons that formed connections typical of brachial sensory neurons probably differentiated while they were at the brachial level.
在牛蛙蝌蚪处于某些胸段感觉神经元已经形成连接的阶段，将胸段神经节移植到鳃部水平，可诱导胸段感觉神经元形成典型的臂部感觉神经元连接。为了弄清楚有多少有丝分裂后的感觉神经元在移植后存活下来，在蝌蚪处于VII至IX期时，对其单侧进行胸段神经节移植到臂部水平的操作，并给这些蝌蚪注射[³H]胸腺嘧啶核苷。与未手术的神经节中46%至60%的神经元未被标记相比，移植神经节中有16%至37%的神经元未被标记。移植神经节中未标记的神经元比相应的未手术神经节少，这表明移植导致了有丝分裂后神经元的退化。因此，形成典型臂部感觉神经元连接的很大一部分神经元可能是在它们处于臂部水平时分化的。
