Lateral Geniculate Nucleus

Abstract

The lateral geniculate nucleus is remarkably stable across mammals and can be recognized even in those such as moles in which the eyes are congenitally absent or greatly reduced in size. It is stricly a nuclear complex, rather than a single nucleus, for in virtually every mammal two or more components can be recognized. One of these, the dorsal lateral geniculate nucleus, is developmentally a derivative of the dorsal thalamus and projects to the cerebral cortex. In a number of species it is laminated and may contain a number of subsidiary nuclei. The other component, the ventral lateral geniculate nucleus, is developmentally a part of the ventral thalamus and does not project to the cortex. In primates, seemingly on account of the descent and rotation of the dorsal lateral geniculate nucleus during development (Le Gros Clark, 1932b) (Fig. 9.1), the ventral nucleus has come to lie dorsal to the dorsal nucleus; in this position it is often referred to as the pregeniculate nucleus.

⋯nor doth the eye itself, That most pure spirit of sense, behold itself, Not going from itself; but eye to eye opposed Salute each other with each others’ form.⋯

Shakespeare, Troilus and Cressida III, 3, 112-115