RETINOFUGAL FIBERS CHANGE CONDUCTION-VELOCITY AND DIAMETER BETWEEN THE OPTIC-NERVE AND TRACT IN FERRETS
RETINOFUGAL FIBERS CHANGE CONDUCTION-VELOCITY AND DIAMETER BETWEEN THE OPTIC-NERVE AND TRACT IN FERRETS
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DOI：
10.1038/344342a0
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发表时间：
1990-03-22
期刊：
影响因子：
64.8
通讯作者：
STRYKER, MP
中科院分区：
文献类型：
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作者：
BAKER, GE;STRYKER, MP
在早期对中枢神经纤维束的研究中，人们默认单个轴突沿其长度方向是相对均匀的沿着。特别是在离视网膜通路中，轴突直径、髓鞘厚度和相关的传导特性1，2在整个视神经、视交叉和视束中被视为恒定的。我们在这里报告的纤维的传导速度有助于复合动作电位的早期组件是显着更大的视束比在视神经的雪貂，也是最大的离视网膜纤维的直径增加从神经到tract3。这一观察结果提出了关于中枢神经系统中与轴突、轴突直径和与轴突有髓鞘的神经胶质相关的发育机制的重要问题。此外，它表明，依赖于恒定的传导速度沿着视网膜离体course4的研究可能需要重新评估。
IN earlier studies of central nervous fibre tracts, it was tacitly assumed that individual axons are relatively uniform along their length. In the retinofugal pathway in particular, axon diameter, myelin thickness and correlated conduction properties1,2have been treated as constant throughout the optic nerve, chiasm and tract. We report here that the conduction velocities of fibres contributing to the early components of the compound action potential are significantly greater in the optic tract than in the optic nerve of ferrets, and also that the diameters of the largest retinofugal fibres increase from nerve to tract3. This observation raises significant questions about the developmental mechanisms in the central nervous system that relate the axons, their diameters, and the glia with which they are myelinated. In addition, it indicates that studies that have relied on the constancy of conduction velocity along the retinofugal course4may require reappraisal.