Figure 1. Laminar organization of the LGN in five different primates: galago, squirrel monkey, macaque monkey, chimpanzee, and human.

In each, neurones in the magnocellular, parvocellular and koniocellular streams occupy distinct laminae. In the galago, magnocellular neurones occupy layers 1 and 2, parvocellular neurones occupy layers 3 and 6, and koniocellular neurones occupy layers 4 and 5 and the intercalated zones. In the squirrel monkey, macaque monkey, chimpanzee and human, magnocellular neurones occupy layers 1 and 2, parvocellular neurones occupy layers 3, 4, 5 and 6, and koniocellular neurones occupy the intercalated layers below and between each of the magnocellular and parvocellular layers. Although the squirrel monkey lacks clear intercalated zones between the parvocellular layers, koniocellular neurones have been reported between the layers.