Editing Lateral geniculate nucleus (section)

== Input ==
The LGN receives input from the retina and many other brain structures, especially visual cortex.

The principal neurons in the LGN receive strong inputs from the retina. However, the retina only accounts for a small percentage of LGN input. As much as 95% of input in the LGN comes from the visual cortex, superior colliculus, pretectum, thalamic reticular nuclei, and local LGN interneurons. Regions in the brainstem that are not involved in visual perception also project to the LGN, such as the mesencephalic reticular formation, dorsal raphe nucleus, periaqueuctal grey matter, and the locus coeruleus.<ref name="Guillery 163–75">{{cite journal|last=Guillery|first=R|author2=SM Sherman |title=Thalamic relay functions and their role in corticocortical communication: generalizations from the visual system|journal=Neuron|date=Jan 17, 2002|volume=33|issue=2|pages=163–75|doi=10.1016/s0896-6273(01)00582-7 |pmid=11804565|doi-access=free}}</ref>  The LGN also receives some inputs from the [[optic tectum]] (known as the [[superior colliculus]] in mammals).<ref>In Chapter 7, section "The Parcellation Hypothesis" of "Principles of Brain Evolution", [[Georg F. Striedter]] (Sinauer Associates, Sunderland, MA, USA, 2005) states, "...we now know that the LGN receives at least some inputs from the optic tectum (or superior colliculus) in many amniotes". He cites "{{cite journal | last1 = Wild | first1 = J.M. | year = 1989 | title = Pretectal and tectal projections to the homolog of the dorsal lateral geniculate nucleus in the pigeon—an anterograde and retrograde tracing study with cholera-toxin conjugated to horseradish-peroxidase | doi = 10.1016/0006-8993(89)91342-5 | journal = Brain Res | volume = 479 | issue = 1 | pages = 130–137 | pmid = 2924142 | s2cid = 29034684 }}" and also "Kaas, J.H., and Huerta, M.F. 1988. The subcortical visual system of primates. In: Steklis H. D., Erwin J., editors. Comparative primate biology, vol 4: neurosciences. New York: Alan Liss, pp. 327–391.</ref> These non-retinal inputs can be excitatory, inhibitory, or modulatory.<ref name="Guillery 163–75"/>