Guillery R W, Polley E H, Torrealba F
J Neurosci. 1982 Jun;2(6):714-21. doi: 10.1523/JNEUROSCI.02-06-00714.1982.
The topographic distribution of axons according to diameter classes in the optic tract of the cat has been studied by light and electron microscopic methods. The subdivision of the tract into a ventral and a dorsal sector, with the former containing the thickest fibers of the tract, has been confirmed. In addition, there is a ventrolateral marginal zone of the tract which contains many of the finest axons and there are gradients of fiber diameters definable for thick and intermediate axons. The gradients show the thinner fibers lying rostral to the thicker fibers. The major points demonstrable by fiber diameter measurements have been confirmed by counts of myelin lamellae. Comparison of fiber distributions in the optic tract with the distributions in the optic nerve on the one hand and with the geniculate terminations on the other shows that, in the region of the optic chiasm, retinofugal axons are sorted not only according to their crossed or uncrossed pathway but also according to their fiber diameter class and thus are presorted in terms of their final destinations.
利用光学显微镜和电子显微镜方法，研究了猫视束中不同直径类别的轴突的地形分布。视束分为腹侧和背侧部分，前者包含视束中最粗的纤维，这一点已得到证实。此外，视束有一个腹外侧边缘区，其中包含许多最细的轴突，并且对于粗轴突和中等轴突可确定纤维直径梯度。这些梯度表明较细的纤维位于较粗纤维的前方。通过纤维直径测量所证实的主要要点已通过髓鞘板计数得到确认。对视束中的纤维分布与一方面的视神经中的分布以及另一方面的膝状体终末的分布进行比较表明，在视交叉区域，视网膜传出轴突不仅根据其交叉或不交叉路径进行分类，而且还根据其纤维直径类别进行分类，因此就其最终目的地而言是预先分类的。
