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Cortical column

January 12, 2023

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 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]

Mammalian cerebral cortex

Main article: Cerebral cortex

The mammalian cerebral cortex, the grey matter encapsulating the white matter, is composed of layers. The human cortex is between 2 and 3 mm thick.[11] The number of layers is the same in most mammals, but varies throughout the cortex. In the neocortex 6 layers can be recognized although many regions lack one or more layers, fewer layers are present in the archipallium and the paleopallium.[12]

Columnar functional organization

The columnar functional organization, as originally framed by Vernon Mountcastle,[1] suggests that neurons that are horizontally more than 0.5 mm (500 µm) from each other do not have overlapping sensory receptive fields, and other experiments give similar results: 200–800 µm.[4][13][14] Various estimates suggest there are 50 to 100 cortical minicolumns in a hypercolumn, each comprising around 80 neurons. Their role is best understood as 'functional units of information processing.'

An important distinction is that the columnar organization is functional by definition, and reflects the local connectivity of the cerebral cortex. Connections "up" and "down" within the thickness of the cortex are much denser than connections that spread from side to side.

Hubel and Wiesel studies

David Hubel and Torsten Wiesel followed up on Mountcastle's discoveries in the somatic sensory cortex with their own studies in vision. A part of the discoveries that resulted in them winning the 1981 Nobel Prize[15] was that there were cortical columns in vision as well, and that the neighboring columns were also related in function in terms of the orientation of lines that evoked the maximal discharge. Hubel and Wiesel followed up on their own studies with work demonstrating the impact of environmental changes on cortical organization, and the sum total of these works resulted in their Nobel Prize.

Number of cortical columns

There are about 200 million (2×108) cortical minicolumns in the human neocortex with up to about 110 neurons each,[16] and with estimates of 21–26 billion (2.1×1010–2.6×1010) neurons in the neocortex. With 50 to 100 cortical minicolumns per cortical column a human would have 2–4 million (2×106–4×106) cortical columns. There may be more if the columns can overlap, as suggested by Tsunoda et al.[17]

There are claims that minicolumns may have as many as 400 principal cells,[18] but it is not clear if that includes glia cells.

Some contradicts the previous estimates,[19] claiming the original research is too arbitrary.[20] The authors propose a uniform neocortex, and chose a fixed width and length to calculate the cell numbers. Later research pointed out that the neocortex is indeed not uniform for other species,[21] and studying nine primate species they found that “the number of neurons underneath 1 mm2 of the cerebral cortical surface … varies by three times across species." The neocortex is not uniform across species.[20][22][23] The actual number of neurons within a single column is variable, and depends on the cerebral areas and thus the function of the column.

See also

References

  1. ^ a b 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. 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. doi:10.3389/fncir.2020.00040. PMID 32848632. Retrieved 7 November 2022.
  4. ^ a b 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. doi:10.1016/j.neuron.2012.10.038. PMID 23177956. Retrieved 7 November 2022.
  10. ^ Defelipe, Javier (2012). "The neocortical column". Frontiers in Neuroanatomy. 6: 5. doi:10.3389/fnana.2012.00022. PMC 3278674. PMID 22347848.
  11. ^ Saladin, Kenneth (2011). Human anatomy (3rd ed.). McGraw-Hill. p. 416. ISBN 9780071222075.
  12. ^ R Nieuwenhuys; HJ Donkelaar; C Nicholson; WJAJ Smeets; H Wicht (1998). The central nervous system of vertebrates. Berlin [u.a.]: Springer. ISBN 978-3540560135.
  13. ^ Hubel DH, Wiesel TN, Stryker MP (September 1977). "Orientation columns in macaque monkey visual cortex demonstrated by the 2-deoxyglucose autoradiographic technique". Nature. 269 (5626): 328–30. Bibcode:1977Natur.269..328H. doi:10.1038/269328a0. PMID 409953. S2CID 4246375.
  14. ^ Leise EM (1990). "Modular construction of nervous systems: a basic principle of design for invertebrates and vertebrates" (PDF). Brain Research. Brain Research Reviews. 15 (1): 1–23. doi:10.1016/0165-0173(90)90009-d. PMID 2194614. S2CID 4996690.
  15. ^ "The Nobel Prize in Medicine 1981". Retrieved 2008-04-13.
  16. ^ Krueger, James M.; et al. (2008). "Sleep as a fundamental property of neuronal assemblies". Nature Reviews Neuroscience. 9 (12): 910–919. doi:10.1038/nrn2521. PMC 2586424. PMID 18985047.
  17. ^ Kazushige Tsunoda; Yukako Yamane; Makoto Nishizaki; Manabu Tanifuji (August 2001). "Complex objects are represented in macaque inferotemporal cortex by the combination of feature columns". Nat. Neurosci. 4 (8): 832–838. doi:10.1038/90547. PMID 11477430. S2CID 14714957.
  18. ^ O. David, in Brain Mapping (2015). "Acquisition Methods, Methods and Modeling". In Arthur W. Toga (ed.). Brain Mapping – An Encyclopedic Reference. ISBN 9780123973160.
  19. ^ Powell, T. P.; Hiorns, R. W.; Rockel, A. J. (June 1980). "The basic uniformity in structure of the neocortex". Brain: A Journal of Neurology. 103 (2): 221–244. doi:10.1093/brain/103.2.221. ISSN 0006-8950. PMID 6772266.
  20. ^ a b Rakic, Pasko (2008-08-26). "Confusing cortical columns". Proceedings of the National Academy of Sciences. 105 (34): 12099–12100. Bibcode:2008PNAS..10512099R. doi:10.1073/pnas.0807271105. ISSN 0027-8424. PMC 2527871. PMID 18715998.
  21. ^ Lent, Roberto; Kaas, Jon H.; Wong, Peiyan; Collins, Christine E.; Herculano-Houzel, Suzana (2008-08-26). "The basic nonuniformity of the cerebral cortex". Proceedings of the National Academy of Sciences. 105 (34): 12593–12598. doi:10.1073/pnas.0805417105. ISSN 0027-8424. PMC 2527956. PMID 18689685.
  22. ^ Lent, Roberto; Azevedo, Frederico A. C.; Andrade‐Moraes, Carlos H.; Pinto, Ana V. O. (2012). "How many neurons do you have? Some dogmas of quantitative neuroscience under revision". European Journal of Neuroscience. 35 (1): 1–9. doi:10.1111/j.1460-9568.2011.07923.x. ISSN 1460-9568. PMID 22151227. S2CID 20365568.
  23. ^ Molnár, Z. (January 2013). "Chapter 7 - Cortical Columns". Neural Circuit Development and Function in the Brain: 109–129. doi:10.1016/B978-0-12-397267-5.00137-0.

External links

  • Graham-Rowe, Duncan (6 June 2005). "Mission to build a simulated brain begins". New Scientist. [...] the initial phase of Blue Brain will model the electrical structure of neocortical columns - neural circuits that are repeated throughout the brain. These are the network units of the brain, says Markram. Measuring just 0.5 millimetres by 2 mm, these units contain between 10 and 70,000 neurons, depending upon the species. Once this is complete, the behaviour of columns can be mapped and modelled [...]
  • The Blue Brain Project aims to
  • On Intelligence—a popular science book about column function by Jeff Hawkins
  • Rakic, P. (August 2008). "Confusing cortical columns". Proceedings of the National Academy of Sciences. 105 (34): 12099–12100. Bibcode:2008PNAS..10512099R. doi:10.1073/pnas.0807271105. PMC 2527871. PMID 18715998. Summarizes what is known and corrects some misconceptions.

January 12, 2023
cortical, column, cortical, column, group, neurons, forming, cylindrical, structure, through, cerebral, cortex, brain, perpendicular, cortical, surface, structure, first, identified, mountcastle, 1957, later, identified, minicolumns, basic, units, neocortex, w. 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 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 Contents 1 Mammalian cerebral cortex 1 1 Columnar functional organization 2 Hubel and Wiesel studies 3 Number of cortical columns 4 See also 5 References 6 External linksMammalian cerebral cortex EditMain article Cerebral cortex The mammalian cerebral cortex the grey matter encapsulating the white matter is composed of layers The human cortex is between 2 and 3 mm thick 11 The number of layers is the same in most mammals but varies throughout the cortex In the neocortex 6 layers can be recognized although many regions lack one or more layers fewer layers are present in the archipallium and the paleopallium 12 Columnar functional organization Edit The columnar functional organization as originally framed by Vernon Mountcastle 1 suggests that neurons that are horizontally more than 0 5 mm 500 µm from each other do not have overlapping sensory receptive fields and other experiments give similar results 200 800 µm 4 13 14 Various estimates suggest there are 50 to 100 cortical minicolumns in a hypercolumn each comprising around 80 neurons Their role is best understood as functional units of information processing An important distinction is that the columnar organization is functional by definition and reflects the local connectivity of the cerebral cortex Connections up and down within the thickness of the cortex are much denser than connections that spread from side to side Hubel and Wiesel studies EditDavid Hubel and Torsten Wiesel followed up on Mountcastle s discoveries in the somatic sensory cortex with their own studies in vision A part of the discoveries that resulted in them winning the 1981 Nobel Prize 15 was that there were cortical columns in vision as well and that the neighboring columns were also related in function in terms of the orientation of lines that evoked the maximal discharge Hubel and Wiesel followed up on their own studies with work demonstrating the impact of environmental changes on cortical organization and the sum total of these works resulted in their Nobel Prize Number of cortical columns EditThere are about 200 million 2 108 cortical minicolumns in the human neocortex with up to about 110 neurons each 16 and with estimates of 21 26 billion 2 1 1010 2 6 1010 neurons in the neocortex With 50 to 100 cortical minicolumns per cortical column a human would have 2 4 million 2 106 4 106 cortical columns There may be more if the columns can overlap as suggested by Tsunoda et al 17 There are claims that minicolumns may have as many as 400 principal cells 18 but it is not clear if that includes glia cells Some contradicts the previous estimates 19 claiming the original research is too arbitrary 20 The authors propose a uniform neocortex and chose a fixed width and length to calculate the cell numbers Later research pointed out that the neocortex is indeed not uniform for other species 21 and studying nine primate species they found that the number of neurons underneath 1 mm2 of the cerebral cortical surface varies by three times across species The neocortex is not uniform across species 20 22 23 The actual number of neurons within a single column is variable and depends on the cerebral areas and thus the function of the column See also EditCortical minicolumn Ocular dominance column Predictive coding Radial unit hypothesisReferences Edit a b 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 Mountcastle Vernon 1997 The columnar organization of the neocortex Brain doi 10 1093 brain 120 4 701 PMID 9153131 a b c Bennett Max 2020 An Attempt at a Unified Theory of the Neocortical Microcircuit in Sensory Cortex Frontiers in Neural Circuits doi 10 3389 fncir 2020 00040 PMID 32848632 Retrieved 7 November 2022 a b 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 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 Kolb Bryan Whishaw Ian Q 2003 Fundamentals of human neuropsychology New York Worth ISBN 978 0 7167 5300 1 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 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 Bastos AM Usrey WM Adams RA Mangun GR Fries P Friston Karl 2012 Canonical microcircuits for predictive coding Neuron doi 10 1016 j neuron 2012 10 038 PMID 23177956 Retrieved 7 November 2022 Defelipe Javier 2012 The neocortical column Frontiers in Neuroanatomy 6 5 doi 10 3389 fnana 2012 00022 PMC 3278674 PMID 22347848 Saladin Kenneth 2011 Human anatomy 3rd ed McGraw Hill p 416 ISBN 9780071222075 R Nieuwenhuys HJ Donkelaar C Nicholson WJAJ Smeets H Wicht 1998 The central nervous system of vertebrates Berlin u a Springer ISBN 978 3540560135 Hubel DH Wiesel TN Stryker MP September 1977 Orientation columns in macaque monkey visual cortex demonstrated by the 2 deoxyglucose autoradiographic technique Nature 269 5626 328 30 Bibcode 1977Natur 269 328H doi 10 1038 269328a0 PMID 409953 S2CID 4246375 Leise EM 1990 Modular construction of nervous systems a basic principle of design for invertebrates and vertebrates PDF Brain Research Brain Research Reviews 15 1 1 23 doi 10 1016 0165 0173 90 90009 d PMID 2194614 S2CID 4996690 The Nobel Prize in Medicine 1981 Retrieved 2008 04 13 Krueger James M et al 2008 Sleep as a fundamental property of neuronal assemblies Nature Reviews Neuroscience 9 12 910 919 doi 10 1038 nrn2521 PMC 2586424 PMID 18985047 Kazushige Tsunoda Yukako Yamane Makoto Nishizaki Manabu Tanifuji August 2001 Complex objects are represented in macaque inferotemporal cortex by the combination of feature columns Nat Neurosci 4 8 832 838 doi 10 1038 90547 PMID 11477430 S2CID 14714957 O David in Brain Mapping 2015 Acquisition Methods Methods and Modeling In Arthur W Toga ed Brain Mapping An Encyclopedic Reference ISBN 9780123973160 Powell T P Hiorns R W Rockel A J June 1980 The basic uniformity in structure of the neocortex Brain A Journal of Neurology 103 2 221 244 doi 10 1093 brain 103 2 221 ISSN 0006 8950 PMID 6772266 a b Rakic Pasko 2008 08 26 Confusing cortical columns Proceedings of the National Academy of Sciences 105 34 12099 12100 Bibcode 2008PNAS 10512099R doi 10 1073 pnas 0807271105 ISSN 0027 8424 PMC 2527871 PMID 18715998 Lent Roberto Kaas Jon H Wong Peiyan Collins Christine E Herculano Houzel Suzana 2008 08 26 The basic nonuniformity of the cerebral cortex Proceedings of the National Academy of Sciences 105 34 12593 12598 doi 10 1073 pnas 0805417105 ISSN 0027 8424 PMC 2527956 PMID 18689685 Lent Roberto Azevedo Frederico A C Andrade Moraes Carlos H Pinto Ana V O 2012 How many neurons do you have Some dogmas of quantitative neuroscience under revision European Journal of Neuroscience 35 1 1 9 doi 10 1111 j 1460 9568 2011 07923 x ISSN 1460 9568 PMID 22151227 S2CID 20365568 Molnar Z January 2013 Chapter 7 Cortical Columns Neural Circuit Development and Function in the Brain 109 129 doi 10 1016 B978 0 12 397267 5 00137 0 External links EditGraham Rowe Duncan 6 June 2005 Mission to build a simulated brain begins New Scientist the initial phase of Blue Brain will model the electrical structure of neocortical columns neural circuits that are repeated throughout the brain These are the network units of the brain says Markram Measuring just 0 5 millimetres by 2 mm these units contain between 10 and 70 000 neurons depending upon the species Once this is complete the behaviour of columns can be mapped and modelled The Blue Brain Project aims to simulate a cortical column On Intelligence a popular science book about column function by Jeff Hawkins Rakic P August 2008 Confusing cortical columns Proceedings of the National Academy of Sciences 105 34 12099 12100 Bibcode 2008PNAS 10512099R doi 10 1073 pnas 0807271105 PMC 2527871 PMID 18715998 Summarizes what is known and corrects some misconceptions Retrieved from https en wikipedia org w index php title Cortical column amp oldid 1120843307, wikipedia, wiki, book, books, library,

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