Kaas J H, Huerta M F, Weber J T, Harting J K
J Comp Neurol. 1978 Dec 1;182(3):517-53. doi: 10.1002/cne.901820308.
Autoradiographic tracing procedures have been used to study the organization of retinogeniculate axons in seven primates, i.e., four species of New World monkeys, one species of Old World monkeys and two species of prosimians. These data suggest that the basic primate pattern of geniculate lamination consists of two parvocellular layers, two magnocellular layers, and two poorly developed and highly variable superficial (S) layers which are ventrally located. Ocular input to each member of each of the three pairs differs. In the macaque, the squirrel, and the saki monkey, the parvocellular layers subdivide and interdigitate into four leaflets so as to give the appearance of four parvocellular "layers." These leaflets are much less extensive in the owl and marmoset monkeys. In some individual macaque monkeys, there is further splitting of the parvocellular leaflets into subleaflets, giving the appearance of six parvocellular "layers." The prosimians (galago and slow loris) have two additional layers that are not found in pithecoid primates, and only one superficial layer is apparent. The two additional layers are termed "koniocellular" since they consist of very small cells. Finally, New and Old World monkeys have both ipsilateral and contralateral retinal input to the interlaminar zones. We conclude that the basic pattern of lateral geniculate organization is six layers, but not the traditional six. Prosimians have evolved two additional layers, the koniocellular layers, and have possibly lost one superficial layer. Both New World and Old World monkeys have elaborated the parvocellular layers by forming leaflets to varying extents. With the possible exception of the single S layer in prosimians, layers form pairs that are similar in cell types, but different in ocular input.
放射自显影追踪程序已被用于研究七种灵长类动物视网膜神经节细胞轴突的组织情况，即四种新大陆猴、一种旧大陆猴和两种原猴亚目动物。这些数据表明，灵长类动物外侧膝状体分层的基本模式由两个小细胞层、两个大细胞层以及两个发育不良且高度可变的腹侧浅层（S）层组成。每三对中的每一个成员的眼输入都不同。在猕猴、松鼠猴和僧面猴中，小细胞层细分并相互交错形成四个小叶，从而呈现出四个小细胞“层”的外观。在枭猴和狨猴中，这些小叶的范围要小得多。在一些个体猕猴中，小细胞小叶进一步分裂成亚小叶，呈现出六个小细胞“层”的外观。原猴亚目动物（婴猴和懒猴）有两个在类人猿灵长类动物中未发现的额外层，并且只有一个浅层明显可见。这两个额外的层被称为“侏儒细胞层”，因为它们由非常小的细胞组成。最后，新大陆猴和旧大陆猴在层间区都有同侧和对侧视网膜输入。我们得出结论，外侧膝状体组织的基本模式是六层，但不是传统的六层。原猴亚目动物进化出了两个额外的层，即侏儒细胞层，并且可能失去了一个浅层。新大陆猴和旧大陆猴都通过不同程度地形成小叶来细化小细胞层。除了原猴亚目动物中单一的S层可能例外，各层形成细胞类型相似但眼输入不同的成对结构。
