What is "lateral geniculate nucleus"

n. 1 The nucleus of the thalamus which received input from the optic tract. 2 The nucleus which is organized into magnocellular, parvocellular and koniocellular 3 This nucleus projects to the Striate cortex, or primary visual cortex

The lateral geniculate nucleus (LGN) (also called the lateral geniculate body or lateral geniculate complex) is a relay center in the thalamus for the visual pathway. It receives a major sensory input from the retina. The LGN is the main central connection for the optic nerve to the occipital lobe. In humans, each LGN has six layers of neurons (grey matter) alternating with optic fibers (white matter).

The LGN is small, ovoid, ventral projection at the termination of optic tract on each side of the brain. The LGN and the medial geniculate nucleus which deals with auditory information are both thalamic nuclei and so are present in both hemispheres.

The LGN receives information directly from the ascending retinal ganglion cells via the optic tract and from the reticular activating system. Neurons of the LGN send their axons through the optic radiation, a direct pathway to the primary visual cortex. In addition, the LGN receives many strong feedback connections from the primary visual cortex. In humans as well as other mammals, the two strongest pathways linking the eye to the brain are those projecting to the dorsal part of the LGN in the thalamus, and to the superior colliculus.