Guillery R W
Department of Human Anatomy, South Parks Road, Oxford, England.
Rev Bras Biol. 1995 Dec;55 Suppl 1:1-10.
There are four fiber components in the mammalian optic chiasm. Two crossed and two uncrossed components, one of each from each eye. The two crossed components meet at the midline, forming coarse interdigitating bundles in some species, and extremely fine crossing bundles in others. The two components from one eye mingle in the optic nerve. Then in some species they separate, before reaching the chiasm, but in others they do not separate until they reach the midline of the chiasm. Once past the chiasm, the two components that form the tract reunite and one more, the crossed and the uncrossed fibers mingle. The review considers that difference between the marsupial and the eutherian mammals that have been studied, and looks at the developmental changes that are likely to underlie these different types of chiasmatic organization.
哺乳动物的视交叉中有四种纤维成分。两种交叉成分和两种不交叉成分，每种成分各来自一只眼睛。两种交叉成分在中线处交汇，在某些物种中形成粗大的相互交错的束状结构，而在其他物种中则形成极其纤细的交叉束状结构。来自一只眼睛的两种成分在视神经中混合。然后在某些物种中，它们在到达视交叉之前分开，但在其他物种中，它们直到到达视交叉的中线才分开。一旦越过视交叉，形成视束的两种成分重新汇合，此外，交叉纤维和不交叉纤维也会混合。这篇综述考虑了已研究的有袋类动物和真兽类哺乳动物之间的差异，并探讨了可能是这些不同类型视交叉组织基础的发育变化。
