Grafstein B
Science. 1967 Jul 14;157(3785):196-8. doi: 10.1126/science.157.3785.196.
After tritiated leucine was injected into the eye of goldfish, radio-active protein synthesized by the ganglion cell bodies moved down the optic axons at an average rate of 0.4 mm per day. Radioautograms of the optic tectum in which these axons end show that, as early as 24 hours after the injection, before the radioactivity in the tectal layer containing the optic axons had risen above background level, the layer containing the axon terminals was already heavily labeled. The radioactivity in the terminals reached a maximum about 48 hours after the injection and remained approximately constant for at least 23 days thereafter, whereas the radioactivity in the fiber layer increased significantly during the same interval, as the slowly moving protein component entered it. Thus there appears to be a special mechanism for rapid transport of protein from the cell body to the synaptic terminals, as well as a slower movement of protein down the axon.
将氚标记的亮氨酸注入金鱼眼中后，神经节细胞体合成的放射性蛋白质以平均每天0.4毫米的速度沿视神经轴突向下移动。这些轴突末端所在的视顶盖放射自显影片显示，早在注射后24小时，在含有视神经轴突的顶盖层放射性升至背景水平之上之前，含有轴突终末的层就已被大量标记。注射后约48小时，终末中的放射性达到最大值，此后至少23天保持大致恒定，而在同一时间段内，随着缓慢移动的蛋白质成分进入纤维层，纤维层中的放射性显著增加。因此，似乎存在一种将蛋白质从细胞体快速运输到突触终末的特殊机制，以及蛋白质沿轴突的较慢移动。
