Editing Cerebral cortex (section)

===Columns===
The cortical layers are not simply stacked one over the other; there exist characteristic connections between different layers and neuronal types, which span all the thickness of the cortex. These cortical microcircuits are grouped into [[cortical column]]s and [[Cortical minicolumn|minicolumns]].<ref name="Suzuki">{{cite journal | vauthors = Suzuki IK, Hirata T | title = Neocortical neurogenesis is not really "neo": a new evolutionary model derived from a comparative study of chick pallial development | journal = Development, Growth & Differentiation | volume = 55 | issue = 1 | pages = 173–187 | date = January 2013 | pmid = 23230908 | doi = 10.1111/dgd.12020 | s2cid = 36706690 | doi-access = free }}</ref> It has been proposed that the minicolumns are the basic functional units of the cortex.<ref>{{cite journal | vauthors = Mountcastle VB | title = The columnar organization of the neocortex | journal = Brain | volume = 120 ( Pt 4) | issue = 4 | pages = 701–722 | date = April 1997 | pmid = 9153131 | doi = 10.1093/brain/120.4.701 | doi-access = free }}</ref> In 1957, [[Vernon Benjamin Mountcastle|Vernon Mountcastle]] showed that the functional properties of the cortex change abruptly between laterally adjacent points; however, they are continuous in the direction perpendicular to the surface. Later works have provided evidence of the presence of functionally distinct cortical columns in the visual cortex (Hubel and [[Torsten Wiesel|Wiesel]], 1959),<ref name="pmid14403679">{{cite journal | vauthors = Hubel DH, Wiesel TN | title = Receptive fields of single neurones in the cat's striate cortex | journal = The Journal of Physiology | volume = 148 | issue = 3 | pages = 574–591 | date = October 1959 | pmid = 14403679 | pmc = 1363130 | doi = 10.1113/jphysiol.1959.sp006308 }}</ref> auditory cortex,
and associative cortex.

Cortical areas that lack a layer IV are called [[agranular cortex|agranular]]. Cortical areas that have only a rudimentary layer IV are called dysgranular.<ref>S.M. Dombrowski, C.C. Hilgetag, and H. Barbas. [http://cercor.oxfordjournals.org/cgi/content/full/11/10/975 Quantitative Architecture Distinguishes Prefrontal Cortical Systems in the Rhesus Monkey] {{webarchive|url=https://web.archive.org/web/20080829143033/http://cercor.oxfordjournals.org/cgi/content/full/11/10/975 |date=2008-08-29 }}.Cereb. ''Cortex'' 11: 975–988. "...they either lack (agranular) or have only a rudimentary granular layer IV (dysgranular)."</ref> Information processing within each layer is determined by different temporal dynamics with that in layers II/III having a slow 2&nbsp;[[Hertz|Hz]] [[Neural oscillation|oscillation]] while that in layer V has a fast 10–15&nbsp;Hz oscillation.<ref>{{cite journal | vauthors = Sun W, Dan Y | title = Layer-specific network oscillation and spatiotemporal receptive field in the visual cortex | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 106 | issue = 42 | pages = 17986–17991 | date = October 2009 | pmid = 19805197 | pmc = 2764922 | doi = 10.1073/pnas.0903962106 | doi-access = free | bibcode = 2009PNAS..10617986S }}</ref>