荧光染料在视神经脊髓鞘形成期从轴突至少突胶质细胞的扩散

将真蓝(true blue)混悬液注入出生后7、14、28d大鼠眼球内,经过一定时间后,视神经内的轴突和少突胶质细胞被荧光标记。荧光强度在视神经眼球端强于视神经交叉端;出生后14～28d的幼鼠荧光标记明显强于出生后7d的幼鼠;不同年龄组的动物荧光标记普遍在注射荧光染料后的第5d显著增强。本研究表明,荧光染料可被视网膜的节细胞吸收,经轴突输送,然后,横向扩散到少突胶质细胞,扩散的通路可能是朗氏结旁区的轴胶连接。

Transcellular Transport of Fluorescent Dye from Axons to Oligodendroglia in Developing Optic Nerve

A suspension of True Blue (TB) in physiological saline was injected into the posterior chamber of the eye in rats aged 7 days, 14 days, and 28 days. Animals were killed at 1, 3, 5, 7 or 9 days post injection. Axons and oligodendroglia were labeled. Fluorescence in the optic nerve was greatest near the orbit and declined toward the optic chiasm. During rapid myelination (14 days) and late myelination (28 days) period. fluorescence labeled glias were especially abundant. The labeled glia were characteristically arranged in rows running longitudinally throughout the optic nerve. Fluorescence in the glia increased from the fifth days after the injection of the dye. The evidence supports a hypothesis that the fluorescent dye entered the oligodendroglia directly by axonal transport mechanism, possibly at the paranodal, axo-glial junction.