Midget cell

A midget cell is one type of retinal ganglion cell. Midget cells originate in the ganglion cell layer of the retina, and project to the parvocellular layers of the lateral geniculate nucleus (LGN). The axons of midget cells travel through the optic nerve and optic tract, ultimately synapsing with parvocellular cells in the LGN. These cells are known as midget retinal ganglion cells due to the small sizes of their dendritic trees and cell bodies. About 80% of RGCs are midget cells. They receive inputs from relatively few rods and cones. In many cases, they are connected to midget bipolar cells, which are linked to one cone each.^[1] They have slow conduction velocity, and respond to changes in color but respond only weakly to changes in contrast unless the change is great.^[2] They have simple center-surround receptive fields, where the center may be either ON or OFF while the surround is the opposite.

References

↑ "Eye, human."Encyclopædia Britannica. 2008. Encyclopædia Britannica 2006 Ultimate Reference Suite DVD
↑ Principles of Neural Science 4th Ed. Kandel et al.

Anatomy of the globe of the eye

Fibrous tunic (outer)

Sclera	Episcleral layer Schlemm's canal Trabecular meshwork

Cornea	Limbus layers Epithelium Bowman's Stroma Dua's layer Descemet's Endothelium

1:posterior segment 2:ora serrata 3:ciliary muscle 4:ciliary zonules 5:Schlemm's canal 6:pupil 7:anterior chamber 8:cornea 9:iris 10:lens cortex 11:lens nucleus 12:ciliary process 13:conjunctiva 14:inferior oblique muscule 15:inferior rectus muscule 16:medial rectus muscle 17:retinal arteries and veins 18:optic disc 19:dura mater 20:central retinal artery 21:central retinal vein 22:optic nerve 23:vorticose vein 24:bulbar sheath 25:macula 26:fovea 27:sclera 28:choroid 29:superior rectus muscle 30:retina

Uvea/vascular tunic (middle)

Choroid	Capillary lamina of choroid Bruch's membrane Sattler's layer

Ciliary body	Ciliary processes Ciliary muscle Pars plicata Pars plana

Iris	Stroma Pupil Iris dilator muscle Iris sphincter muscle

Retina (inner)

Layers	Inner limiting membrane Nerve fiber layer Ganglion cell layer Inner plexiform layer Inner nuclear layer Outer plexiform layer Outer nuclear layer External limiting membrane Layer of rods and cones Retinal pigment epithelium

Cells	Photoreceptor cells (Cone cell, Rod cell) → (Horizontal cell) → Bipolar cell → (Amacrine cell) → Retina ganglion cell (Midget cell, Parasol cell, Bistratified cell, Giant retina ganglion cells, Photosensitive ganglion cell) → Diencephalon: P cell, M cell, K cell, Muller glia

Other	Macula Foveola Fovea centralis Parafovea Perifovea Optic disc Optic cup Ora serrata

Anatomical regions of the eye

Anterior segment	Adnexa Fibrous tunic Anterior chamber Aqueous humor Iris Posterior chamber Ciliary body Lens Capsule of lens Zonule of Zinn

Posterior segment	Vitreous chamber Vitreous humor Retina Choroid

Other

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Midget cell

See also

References