Editing Pretectal area (section)

==Location and structure==
The pretectum is a bilateral group of highly interconnected nuclei located near the junction of the [[midbrain]] and [[forebrain]].<ref name="Millodot">{{cite book|last=Millodot|first=Michel | name-list-style = vanc |title=Dictionary of optometry and visual science|year=2009|publisher=Elsevier/Butterworth-Heinemann|location=Edinburgh|isbn=978-0-7020-2958-5|edition=7th}}</ref> The pretectum is generally classified as a midbrain structure, although because of its proximity to the forebrain it is sometimes classified as part of the caudal diencephalon (forebrain).<ref name="Ramachandran">{{cite book|last=Ramachandran|first=Vilayanur S.| name-list-style = vanc |title=Encyclopedia of the human brain|year=2002|publisher=Acad. Press|location=Amsterdam|isbn=978-0122272103}}</ref> Within [[vertebrates]], the pretectum is located directly anterior to the [[superior colliculus]] and posterior to the [[thalamus]]. It is situated above the [[periaqueductal grey]] and [[posterior commissure|nucleus of the posterior commissure]].<ref name="Nicholson">{{cite book| first1 = Rudolf | last1 = Nieuwenhuys | first2 = HJ | last2 = ten Donkelaar | first3 = Charles | last3 = Nicholson | name-list-style = vanc |title=The central nervous system of vertebrates|year=1998|publisher=Springer|location=Berlin [u.a.]|isbn=978-3540560135|pages=1812–1817}}</ref>

Several nuclei have been identified within the pretectum, although their borders can be difficult to define and there has been debate over which regions should be included and their precise names.<ref name="Gamlin" /><ref name="Nicholson" /><ref>{{cite journal | vauthors = Borostyánkoi-Baldauf Z, Herczeg L | title = Parcellation of the human pretectal complex: a chemoarchitectonic reappraisal | journal = Neuroscience | volume = 110 | issue = 3 | pages = 527–40 | date = 1 March 2002 | pmid = 11906791 | doi = 10.1016/S0306-4522(01)00462-6 | s2cid = 45807167 }}</ref> The five primary nuclei are: the olivary pretectal nucleus (ON), the nucleus of the optic tract (NOT), and the anterior (NPA), medial (NPM), and posterior (NPP) pretectal nuclei. The NOT consists of relatively large cells and is located between the superior colliculi. The ON is located medial to the NOT and has a tail that extends between the NOT and NPP, which is ventral to the ON.<ref name="Nicholson" /> Two additional nuclei have also been identified: the posterior limitans (PLi) and the commisural pretectal area (CPA).<ref name="Prichard">{{cite journal | vauthors = Prichard JR, Stoffel RT, Quimby DL, Obermeyer WH, Benca RM, Behan M | title = Fos immunoreactivity in rat subcortical visual shell in response to illuminance changes | journal = Neuroscience | volume = 114 | issue = 3 | pages = 781–93 | date = 1 October 2002 | pmid = 12220578 | doi = 10.1016/S0306-4522(02)00293-2 | s2cid = 32888470 }}</ref> While these two regions have not been examined to the same extent as the five primary nuclei, research has shown both the PLi and CPA to receive retinal input, which suggests a role in processing visual information.<ref name="Morin">{{cite journal | vauthors = Morin LP, Blanchard JH | title = Neuropeptide Y and enkephalin immunoreactivity in retinorecipient nuclei of the hamster pretectum and thalamus | journal = Visual Neuroscience | volume = 14 | issue = 4 | pages = 765–77 | date = Jul–Aug 1997 | pmid = 9279004 | doi = 10.1017/s0952523800012712 | s2cid = 25125769 }}</ref>

===Inputs===
The pretectum receives significant [[binocular vision|binocular]] input from [[photosensitive ganglion cell]]s in the retina. In primates these afferents are bilateral<ref name=":0">{{cite journal | vauthors = Hutchins B, Weber JT | title = The pretectal complex of the monkey: a reinvestigation of the morphology and retinal terminations | journal = The Journal of Comparative Neurology | volume = 232 | issue = 4 | pages = 425–42 | date = February 1985 | pmid = 3980762 | doi = 10.1002/cne.902320402 | s2cid = 25656241 }}</ref> while in rodents they project from the contralateral retina. The majority of these retino-pretectal projections go to the ON and NOT<ref name=":0" /> while other pretectal nuclei receive minor retinal input in mammals including the posterior, medial, and anterior pretectal nuclei.<ref name="Gamlin" /><ref name="Nicholson" /><ref>{{cite journal | vauthors = Hutchins B | year = 1991 | title = Evidence for a direct retinal projection to the anterior pretectal nucleus in the cat | journal = Brain Research | volume = 561 | issue = 1 | pages = 169–173 | doi=10.1016/0006-8993(91)90764-m| pmid = 1797344 | s2cid = 2584102 }}</ref><ref>{{cite journal |vauthors=Weber JT, Hutchins B | year = 1982 | title = The demonstration of a retinal projection to the medial pretectal nucleus in the domestic cat and the squirrel monkey: anautoradiographic analysis | journal = Brain Research | volume = 232 | issue = 1 | pages = 181–186 | doi=10.1016/0006-8993(82)90622-9| pmid = 6173098 | s2cid = 8118675 }}</ref>

The NOT receives input from several regions. From the thalamus the NOT receives inhibitory projections from [[gamma-Aminobutyric acid|GABA]]-producing neurons in the ipsilateral [[lateral geniculate nucleus]] and bilateral intergeniculate leaflets. The ipsilateral superficial [[suprachiasmatic nucleus]] and the medial, dorsal, and lateral terminal nuclei in the midbrain project onto the NOT. Fibers also project to the NOT from the [[nucleus prepositus hypoglossi]] in the medulla, the contralateral NOT, and from various cortical regions.<ref name="Gamlin" /><ref name="Ono">{{cite journal | vauthors = Ono S, Mustari MJ | title = Visual error signals from the pretectal nucleus of the optic tract guide motor learning for smooth pursuit | journal = Journal of Neurophysiology | volume = 103 | issue = 5 | pages = 2889–99 | date = May 2010 | pmid = 20457849 | pmc = 2867559 | doi = 10.1152/jn.01024.2009 }}</ref>

===Outputs===
Many pretectal nuclei share targets of efferent projections. All pretectal nuclei, except for the ON, project to nuclei in the thalamus, subthalamus, [[superior colliculus]], [[reticular formation]], [[pons]], and [[inferior olive]].<ref name="Nicholson" /> Both the ON and the CPA have efferent projections to the  [[Edinger-Westphal nucleus]]. The NPP and NPA both project to the pulvinar, the lateral posterior nucleus of the thalamus, and several precerebellar nuclei.<ref name="Gamlin" />

The NOT has efferent projections to the zona incerta of the subthalamus, several nuclei of the pons, medulla, intralaminar nuclei, midbrain, and dorsal and ventral thalamic nuclei. Its bilateral inhibitory projections to the accessory optic system include connections to the lateral and medial terminal nuclei. Projections to the subthalamus are target toward the lateral geniculate nucleus and [[pulvinar nuclei|pulvinar]].  The NOT projects bilaterally to the [[superior colliculus]], although the ipsilateral connections appear to be more dominant. In addition to these projections, the NOT projects to the [[Vestibular system|vestibular]] and [[Anatomy of the cerebellum#Phylogenetic and functional divisions|vestibulocerebellar]] relay nuclei.<ref name="Gamlin" />