Cortical column

A cortical column is a group of neurons forming a cylindrical structure through the cerebral cortex of the brain perpendicular to the cortical surface.[1] The structure was first identified by Vernon Benjamin Mountcastle in 1957. He later identified minicolumns as the basic units of the neocortex which were arranged into columns.[2] Each contains the same types of neurons, connectivity, and firing properties.[3] Columns are also called hypercolumn, macrocolumn,[4] functional column[5] or sometimes cortical module.[6] 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".[7] A cortical module is defined as either synonymous with a hypercolumn (Mountcastle) or as a tissue block of multiple overlapping hypercolumns.[8]

Cortical columns are proposed to be the canonical microcircuits for predictive coding,[9] in which the process of cognition is implemented through a hierarchy of identical microcircuits.[3] The evolutionary benefit to this duplication allowed human neocortex to increase in size by almost 3-fold over just the last 3 million years.[3]

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.[5] The columnar organization hypothesis is currently the most widely adopted to explain the cortical processing of information.[10]

  1. ^ Mountcastle, Vernon (July 1957). "Modality and topographic properties of single neurons of cat's somatic sensory cortex". Journal of Neurophysiology. 20 (4): 408–34. doi:10.1152/jn.1957.20.4.408. PMID 13439410.
  2. ^ Mountcastle, Vernon (1997). "The columnar organization of the neocortex". Brain. 120 (4): 701–722. doi:10.1093/brain/120.4.701. PMID 9153131.
  3. ^ a b c Bennett, Max (2020). "An Attempt at a Unified Theory of the Neocortical Microcircuit in Sensory Cortex". Frontiers in Neural Circuits. 14: 40. doi:10.3389/fncir.2020.00040. PMC 7416357. PMID 32848632.
  4. ^ Buxhoeveden, D. P. (2002-05-01). "The minicolumn hypothesis in neuroscience". Brain. 125 (5): 935–951. doi:10.1093/brain/awf110. ISSN 0006-8950. PMID 11960884.
  5. ^ a b Lodato, Simona; Arlotta, Paola (2015-11-13). "Generating Neuronal Diversity in the Mammalian Cerebral Cortex". Annual Review of Cell and Developmental Biology. 31 (1): 699–720. doi:10.1146/annurev-cellbio-100814-125353. PMC 4778709. PMID 26359774. 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.
  6. ^ Kolb, Bryan; Whishaw, Ian Q. (2003). Fundamentals of human neuropsychology. New York: Worth. ISBN 978-0-7167-5300-1.
  7. ^ Horton JC, Adams DL (2005). "The cortical column: a structure without a function". Philos. Trans. R. Soc. Lond. B Biol. Sci. 360 (1456): 837–862. doi:10.1098/rstb.2005.1623. PMC 1569491. PMID 15937015.
  8. ^ Hubel, DH; Wiesel, TN (Mar 1963). "Shape and arrangement of columns in cat's striate cortex". J Physiol. 165 (3): 559–68. doi:10.1113/jphysiol.1963.sp007079. PMC 1359325. PMID 13955384.
  9. ^ Bastos, AM; Usrey, WM; Adams, RA; Mangun, GR; Fries, P; Friston, Karl (2012). "Canonical microcircuits for predictive coding". Neuron. 76 (4): 695–711. doi:10.1016/j.neuron.2012.10.038. PMC 3777738. PMID 23177956.
  10. ^ Defelipe, Javier (2012). "The neocortical column". Frontiers in Neuroanatomy. 6: 5. doi:10.3389/fnana.2012.00022. PMC 3278674. PMID 22347848.