The term lateral geniculate nucleus refers to one of two components of the lateral geniculate complex in the human ( Mai-2004; Riley-1943 ), the macaque ( Shantha-1968; Martin-2000 ), the rat ( Swanson-2004 ), and the mouse ( Franklin-2008 ), In primates it is a large six-layered nucleus located ventral to a thin pregeniculate nucleus. Separated from the smaller nucleus by fibers of the optic tract, it is composed of two parts: the ventral layers of the lateral geniculate nucleus (layers 1 and 2), and the dorsal layers of the lateral geniculate nucleus (layers 3-5). Many authors refer to it as the dorsal lateral geniculate nucleus or DLG. That poses no problem in the rat ( Swanson-2004 ) and the mouse ( Franklin-2008 ), because the lateral geniculate nucleus lies dorsal to the other component of the lateral geniculate complex, the pregeniculate nucleus.. Applied to the adult primate, however, it causes confusion, because in primates the lateral geniculate nucleus is located ventral to the pregeniculate nucleus.