Optic radiation 681106 222922907 2008-07-01T19:27:36Z DOI bot 6652755 Citation maintenance. Formatted: title. You can [[WP:DOI|use this bot]] yourself! Please [[User:DOI_bot/bugs|report any bugs]]. {{Infobox Brain| Name = {{PAGENAME}} | Latin = radiatio optica | GraySubject = | GrayPage = | Image = Gray753.png | Caption = Deep dissection of cortex and brain-stem. (Optic radiation labeled at center left.) | Image2 = | Caption2 = | IsPartOf = | Components = | Artery = | Vein = | BrainInfoType = ancil | BrainInfoNumber = 529 | MeshName = | MeshNumber = | DorlandsPre = r_01 | DorlandsSuf = 12686139 | }} The '''optic radiation''' (also known as the '''geniculo-calcarine tract''' or as the '''geniculostriate pathway''') is a collection of [[axon]]s from [[relay neuron]]s in the [[lateral geniculate nucleus]] of the [[thalamus]] carrying visual information to the [[visual cortex]] (also called ''striate cortex'') along the [[calcarine fissure]]. There is one such tract on each side of the [[brain]]. ==Parts== A distinctive feature of the optic radiations is that they split into two parts on each side: {| class="wikitable" | '''Source''' || '''Path''' || '''Information''' || '''Damage''' |- | Fibers from the ''inferior [[retina]]'' (also called "Meyer's loop" or "Archambault's loop") || must pass into the [[temporal lobe]] by looping around the [[Lateral ventricles|inferior horn of the lateral ventricle]]. || Carry information from the ''superior part'' of the [[visual field]] || A lesion in the temporal lobe that results in damage to Meyer's loop causes a characteristic loss of [[Visual perception|vision]] in a superior quadrant ([[quadrantanopia]].) |- | Fibers from the ''superior retina'' || travel straight back to the [[occipital lobe]] in the [[internal capsule|retrolenticular limb of the internal capsule]] to the visual cortex. || Carry information from the ''inferior part'' of the visual field || Taking the shorter path, these fibers are less susceptible to damage. |} [[Image:Right_superior_quadrantanopia.png|thumb|400px|center|'''Right superior [[quadrantanopia]]'''. The areas of the visual field lost in each eye are shown as black areas. This visual field defect is characteristic of damage to ''Meyer's loop'' on the left side of the brain. ]] ==Additional images== <gallery> Image:Telencephalon-Horiconatal.jpg|Horizontal section of right cerebral hemisphere. Image:Gray746.png|Diagram of the tracts in the internal capsule. Image:ERP_-_optic_cabling.jpg‎|3D schematic representation of optic tracts </gallery> ==External links== * {{eMedicineDictionary|Optic+radiation}} * {{cite journal | author=Kier LE, Staib LH, Davis, LM, Bronen, RA | title=MR Imaging of the Temporal Stem: Anatomic Dissection Tractography of the Uncinate Fasciculus, Inferior Occipitofrontal Fasciculus, and Meyer’s Loop of the Optic Radiation| journal=Am J Neuroradiology | volume=25 | pages=677–691 | year=2004 | pmid=15140705 | url = http://www.ajnr.org/cgi/content/abstract/25/5/677 | accessdate= 2007-12-19 }} * http://www2.umdnj.edu/~neuro/studyaid/Practical2000/Q34.htm {{Visual_system}} {{Sensory_system}} {{White matter}} {{neuroscience-stub}} [[Category:Nervous system]] [[Category:Visual system]] [[fr:Radiation optique]] [[nl:Geniculostriate route]]