Editing Lateral geniculate nucleus (section)

==Structure==
[[File:Thalmus.png|thumb|240px|Nuclei of the Thalamus]]
Both the left and right [[Cerebral hemisphere|hemisphere]]s of the [[brain]] have a lateral geniculate nucleus, named after its resemblance to a bent knee (''genu'' is Latin for "knee"). In [[human]]s as well as in many other [[primate]]s, the LGN has layers of [[magnocellular cells]] and [[parvocellular cells]] that are interleaved with layers of koniocellular cells.

In humans the LGN is normally described as having six distinctive layers. The inner two layers, (1 and 2) are [[magnocellular cell|magnocellular layers]], while the outer four layers, (3, 4, 5 and 6), are [[parvocellular cell|parvocellular layers]].  An additional set of neurons, known as the [[koniocellular cell|koniocellular layers]], are found ventral to each of the magnocellular and parvocellular layers.<ref name=Brodal2010>{{cite book|last1=Brodal|first1=Per|title=The central nervous system : structure and function|date=2010|publisher=Oxford University Press|location=New York|isbn=978-0-19-538115-3|edition=4th}}</ref>{{rp|227ff}}<ref name="Carlson, N. R. 2007">{{cite book|last1=Carlson|first1=Neil R.|title=Physiology of behavior|date=2007|publisher=Pearson/Allyn & Bacon|location=Boston|isbn=978-0205467242|edition=9th}}</ref>  This layering is variable between primate species, and extra leafleting is variable within species.

The average volume of each LGN in an adult human is about 118mm<math>{}^3</math>. (This is the same volume as a 4.9mm-sided cube.) A study of 24 hemispheres from 15 normal individuals with average age 59 years at autopsy found variation from about 91 to 157mm<math>{}^3</math>.<ref>{{cite journal |last1=Andrews |first1=Timothy J. |last2=Halpern |first2=Scott D. |last3=Purves |first3=Dale |title=Correlated Size Variations in Human Visual Cortex, Lateral Geniculate Nucleus, and Optic Tract |journal=Journal of Neuroscience |date=1997 |volume=17 |issue=8 |pages=2859–2868 |doi=10.1523/JNEUROSCI.17-08-02859.1997 |doi-access=free|pmc=6573115 }}</ref> The same study found that in each LGN, the magnocellular layers comprised about 28mm<math>{}^3</math> in total, and the parvocellular layers comprised about 90mm<math>{}^3</math> in total.