Editing Cortical column (section)

{{Short description|Group of neurons in the cortex of the brain}}
A '''cortical column''' is a group of [[neuron]]s forming a cylindrical structure through the [[cerebral cortex]] of the brain perpendicular to the cortical surface.<ref name="Mountcastle1957">{{cite journal |last1=Mountcastle |first1=Vernon |title=Modality and topographic properties of single neurons of cat's somatic sensory cortex |journal=Journal of Neurophysiology |volume=20 |issue=4 |pages=408–34 |date=July 1957 |doi=10.1152/jn.1957.20.4.408 |pmid=13439410 |doi-access=free }}</ref> The structure was first identified by [[Vernon Benjamin Mountcastle]] in 1957. He later identified [[cortical minicolumn|minicolumns]] as the basic units of the neocortex which were arranged into columns.<ref>{{cite journal |last1=Mountcastle |first1=Vernon |title=The columnar organization of the neocortex |journal=Brain |date=1997 |volume=120 |issue=4 |pages=701–722 |doi=10.1093/brain/120.4.701 |pmid=9153131 |doi-access=free }}</ref> Each contains the same types of neurons, connectivity, and firing properties.<ref name="Bennett2020">{{cite journal |last1=Bennett |first1=Max |title=An Attempt at a Unified Theory of the Neocortical Microcircuit in Sensory Cortex |journal=Frontiers in Neural Circuits |date=2020 |volume=14 |page=40 |doi=10.3389/fncir.2020.00040 |pmid=32848632 |pmc=7416357 |doi-access=free }}</ref> Columns are also called '''hypercolumn''', '''macrocolumn''',<ref name=":0">{{Cite journal|last=Buxhoeveden|first=D. P.|date=2002-05-01|title=The minicolumn hypothesis in neuroscience|journal=Brain|volume=125|issue=5|pages=935–951|doi=10.1093/brain/awf110|pmid=11960884|issn=0006-8950|doi-access=free}}</ref> '''functional column'''<ref name=":1">{{Cite journal|last1=Lodato|first1=Simona|last2=Arlotta|first2=Paola|date=2015-11-13|title=Generating Neuronal Diversity in the Mammalian Cerebral Cortex|journal=Annual Review of Cell and Developmental Biology|volume=31|issue=1|pages=699–720|doi=10.1146/annurev-cellbio-100814-125353|pmc=4778709|pmid=26359774|quote=Functional columns were first defined in the cortex by Mountcastle (1957), who proposed the columnar hypothesis, which states that the cortex is composed of discrete, modular columns of neurons, characterized by a consistent connectivity profile.}}</ref> or sometimes '''cortical module'''.<ref>{{cite book |author1=Kolb, Bryan |author2=Whishaw, Ian Q. |title=Fundamentals of human neuropsychology |publisher=Worth |location=New York |year=2003 |isbn=978-0-7167-5300-1}}</ref> Neurons within a minicolumn (microcolumn) encode similar features, whereas a hypercolumn "denotes a unit containing a full set of values for any given set of receptive field parameters".<ref name="horton">{{cite journal |vauthors=Horton JC, Adams DL |title=The cortical column: a structure without a function |journal=Philos. Trans. R. Soc. Lond. B Biol. Sci. |volume=360 |issue=1456 |pages=837–862 |year=2005 |pmid=15937015 |doi=10.1098/rstb.2005.1623 |pmc=1569491}}</ref> A cortical module is defined as either synonymous with a hypercolumn [[Vernon Benjamin Mountcastle|(Mountcastle)]] or as a tissue block of multiple overlapping hypercolumns.<ref>{{cite journal|pmid=13955384 | volume=165 | issue=3 | title=Shape and arrangement of columns in cat's striate cortex |date=Mar 1963 | journal=J Physiol | pages=559–68 | pmc=1359325 | last1 = Hubel | first1 = DH | last2 = Wiesel | first2 = TN | doi=10.1113/jphysiol.1963.sp007079}}</ref>

Cortical columns are proposed to be the canonical microcircuits for [[predictive coding]],<ref>{{cite journal |last1=Bastos |first1=AM |last2=Usrey |first2=WM |last3=Adams |first3=RA |last4=Mangun |first4=GR |last5=Fries |first5=P |last6=Friston |first6=Karl |title=Canonical microcircuits for predictive coding |journal=Neuron |date=2012 |volume=76 |issue=4 |pages=695–711 |doi=10.1016/j.neuron.2012.10.038 |pmid=23177956 |pmc=3777738 |doi-access=free }}</ref> in which the process of cognition is implemented through a hierarchy of identical microcircuits.<ref name="Bennett2020" /> The evolutionary benefit to this duplication allowed human neocortex to increase in size by almost 3-fold over just the last 3 million years.<ref name="Bennett2020" />

[[File:Cortical Columns.jpg|thumb|3D reconstruction of five cortical columns in rat vibrissal cortex]]

The columnar hypothesis states that the cortex is composed of discrete, modular columns of neurons, characterized by a consistent connectivity profile.<ref name=":1" /> The columnar organization hypothesis is currently the most widely adopted to explain the cortical processing of information.<ref>{{cite journal |doi=10.3389/fnana.2012.00022|title=The neocortical column|journal=Frontiers in Neuroanatomy|volume=6|pages=5|year=2012|last1=Defelipe|first1=Javier|pmid=22347848|pmc=3278674|doi-access=free}}</ref>