A cortical minicolumn (also called cortical microcolumn[1]) is a vertical column through the cortical layers of the brain. Neurons within the microcolumn "receive common inputs, have common outputs, are interconnected, and may well constitute a fundamental computational unit of the cerebral cortex".[2][3] Minicolumns comprise perhaps 80–120 neurons, except in the primateprimary visual cortex (V1), where there are typically more than twice the number. There are about 2×108 minicolumns in humans.[4] From calculations, the diameter of a minicolumn is about 28–40 μm.[2] Minicolumns grow from progenitor cells within the embryo and contain neurons within multiple layers (2–6) of the cortex.[5]
Visualization of cortical minicolumns within a macrocolumn
Many sources support the existence of minicolumns, especially Mountcastle,[2] with strong evidence reviewed by Buxhoeveden and Casanova[6] who conclude "... the minicolumn must be considered a strong model for cortical organization" and "[the minicolumn is] the most basic and consistent template by which the neocortex organizes its neurones, pathways, and intrinsic circuits".
Cells in 50 μm minicolumn all have the same receptive field; adjacent minicolumns may have different fields.[7]
Estimates of number of neurons in a minicolumn range from 80–100 neurons.[6][2][8]
Jones[7] describes a variety of observations that may be interpreted as mini- or micro-columns and gives example numbers from 11 to 142 neurons per minicolumn.
3D render of a cortical minicolumn in the mouse visual cortex
Number of minicolumnsedit
Estimates of the number of neurons in cortex or in neocortex are on the order of 2×1010.[9][10] Most[11] (perhaps 90%[citation needed]) of cortical neurons are neocortical neurons.
Johansson and Lansner[4] use an estimate of 2×1010 neurons in the neocortex and an estimate of 100 neurons per minicolumn, yielding an estimate of 2×108 minicolumns.
Sporns et al. give an estimate of 2×107 – 2×108 minicolumns.[12]
Size of minicolumnsedit
The minicolumn measures of the order of 40–50 μm in transverse diameter;[2][6] 35–60 μm;[citation needed] 50 μm with 80 μm spacing,[citation needed] or 30 μm with 50 μm.[citation needed] Larger sizes may not be of human minicolumns, for example macaque monkey V1 minicolumns are 31 μm diameter, with 142 pyramidal cells[citation needed] — 1270 columns per mm2. Similarly, the cat V1 has much bigger minicolumns, ~56 μm.[citation needed]
The size can also be calculated from area considerations. If cortex (both hemispheres) is 1.27×1011 μm2 then if there are 2×108 minicolumns in the neocortex then each is 635 μm2, giving a diameter of 28 μm (if the cortex area were doubled to the commonly quoted value, this would rise to 40 μm). Johansson and Lansner[4] do a similar calculation and arrive at 36 μm (p51, last para).
Downwards projecting axons in minicolumns are ≈10 μm in diameter, periodicity and density similar to those within the cortex, but not necessarily coincident.[citation needed]
^Cruz, Luis; Buldyrev, Sergey; Peng, Shouyong; Roe, Daniel; Urban, Brigita; Stanley, HE; Rosene, Douglas (February 2005). "A statistically based density map method for identification and quantification of regional differences in microcolumnarity in the monkey brain". Journal of Neuroscience Methods. 141 (3): 321–332. doi:10.1016/j.jneumeth.2004.09.005. PMID 15661314. S2CID 6316809 – via Elsevier Science Direct.
^ abcdeMountcastle, 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.
^Bennett, Max (July 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. PMC7416357. PMID 32848632.
^ abcBuxhoeveden, Daniel P.; Casanova, Manuel F. (May 2002). "The minicolumn hypothesis in neuroscience". Brain. 125 (Pt 5): 935–951. doi:10.1093/brain/awf110. ISSN 0006-8950. PMID 11960884.
^ abJones, Edward G. (2000-05-09). "Microcolumns in the cerebral cortex". Proceedings of the National Academy of Sciences. 97 (10): 5019–5021. Bibcode:2000PNAS...97.5019J. doi:10.1073/pnas.97.10.5019. ISSN 0027-8424. PMC33979. PMID 10805761.
^Sporns O, Tononi G, Kötter R. The human connectome: A structural description of the human brain. PLoS Comput. Biol. 2005 Sep1(4):e42.
^Pakkenberg B., Gundersen H. J. G. (1997). "Neocortical Neuron Number in Humans: Effect of Sex and Age". The Journal of Comparative Neurology. 384 (2): 312–320. doi:10.1002/(sici)1096-9861(19970728)384:2<312::aid-cne10>3.3.co;2-g. PMID 9215725.
^Azevedo, Frederico A.C.; Carvalho, Ludmila R.B.; Grinberg, Lea T.; Farfel, José Marcelo; Ferretti, Renata E.L.; Leite, Renata E.P.; Filho, Wilson Jacob; Lent, Roberto; Herculano-Houzel, Suzana (2009). "Equal numbers of neuronal and nonneuronal cells make the human brain an isometrically scaled-up primate brain" (PDF). J. Comp. Neurol. 513 (5): 532–541. doi:10.1002/cne.21974. PMID 19226510. S2CID 5200449.
^Claudia Krebs MD PhD, Joanne Weinberg PhD, Elizabeth Akesson MSc. Lippincott’s Illustrated Reviews: Neuroscience, accessed Nov 10 2013. Chapter 13, II.A, "Histological organization of the cortex"
^Sporns O, Tononi G, Kötter R. The human connectome: A structural description of the human brain. PLoS Comput. Biol. 2005 Sep1(4):e42
External linksedit
"W. H. Calvin's "Cortical Columns, Modules, and Hebbian Cell Assemblies" (MIT Press 1995)". williamcalvin.com. Retrieved 2017-12-31.
May 04, 2024
cortical, minicolumn, cortical, minicolumn, also, called, cortical, microcolumn, vertical, column, through, cortical, layers, brain, neurons, within, microcolumn, receive, common, inputs, have, common, outputs, interconnected, well, constitute, fundamental, co. A cortical minicolumn also called cortical microcolumn 1 is a vertical column through the cortical layers of the brain Neurons within the microcolumn receive common inputs have common outputs are interconnected and may well constitute a fundamental computational unit of the cerebral cortex 2 3 Minicolumns comprise perhaps 80 120 neurons except in the primate primary visual cortex V1 where there are typically more than twice the number There are about 2 108 minicolumns in humans 4 From calculations the diameter of a minicolumn is about 28 40 mm 2 Minicolumns grow from progenitor cells within the embryo and contain neurons within multiple layers 2 6 of the cortex 5 Visualization of cortical minicolumns within a macrocolumn Many sources support the existence of minicolumns especially Mountcastle 2 with strong evidence reviewed by Buxhoeveden and Casanova 6 who conclude the minicolumn must be considered a strong model for cortical organization and the minicolumn is the most basic and consistent template by which the neocortex organizes its neurones pathways and intrinsic circuits Cells in 50 mm minicolumn all have the same receptive field adjacent minicolumns may have different fields 7 Contents 1 Number of neurons 2 Number of minicolumns 3 Size of minicolumns 4 See also 5 References 6 External linksNumber of neurons editEstimates of number of neurons in a minicolumn range from 80 100 neurons 6 2 8 Jones 7 describes a variety of observations that may be interpreted as mini or micro columns and gives example numbers from 11 to 142 neurons per minicolumn nbsp 3D render of a cortical minicolumn in the mouse visual cortexNumber of minicolumns editEstimates of the number of neurons in cortex or in neocortex are on the order of 2 1010 9 10 Most 11 perhaps 90 citation needed of cortical neurons are neocortical neurons Johansson and Lansner 4 use an estimate of 2 1010 neurons in the neocortex and an estimate of 100 neurons per minicolumn yielding an estimate of 2 108 minicolumns Sporns et al give an estimate of 2 107 2 108 minicolumns 12 Size of minicolumns editThe minicolumn measures of the order of 40 50 mm in transverse diameter 2 6 35 60 mm citation needed 50 mm with 80 mm spacing citation needed or 30 mm with 50 mm citation needed Larger sizes may not be of human minicolumns for example macaque monkey V1 minicolumns are 31 mm diameter with 142 pyramidal cells citation needed 1270 columns per mm2 Similarly the cat V1 has much bigger minicolumns 56 mm citation needed The size can also be calculated from area considerations If cortex both hemispheres is 1 27 1011 mm2 then if there are 2 108 minicolumns in the neocortex then each is 635 mm2 giving a diameter of 28 mm if the cortex area were doubled to the commonly quoted value this would rise to 40 mm Johansson and Lansner 4 do a similar calculation and arrive at 36 mm p51 last para Downwards projecting axons in minicolumns are 10 mm in diameter periodicity and density similar to those within the cortex but not necessarily coincident citation needed See also editCortical columnReferences edit Cruz Luis Buldyrev Sergey Peng Shouyong Roe Daniel Urban Brigita Stanley HE Rosene Douglas February 2005 A statistically based density map method for identification and quantification of regional differences in microcolumnarity in the monkey brain Journal of Neuroscience Methods 141 3 321 332 doi 10 1016 j jneumeth 2004 09 005 PMID 15661314 S2CID 6316809 via Elsevier Science Direct a b c d e 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 Bennett Max July 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 a b c Johansson Christopher Lansner Anders 2007 Towards cortex sized artificial neural systems Neural Networks 20 1 48 61 doi 10 1016 j neunet 2006 05 029 PMID 16860539 Jeff Hawkins Sandra Blakeslee On Intelligence p 94 a b c Buxhoeveden Daniel P Casanova Manuel F May 2002 The minicolumn hypothesis in neuroscience Brain 125 Pt 5 935 951 doi 10 1093 brain awf110 ISSN 0006 8950 PMID 11960884 a b Jones Edward G 2000 05 09 Microcolumns in the cerebral cortex Proceedings of the National Academy of Sciences 97 10 5019 5021 Bibcode 2000PNAS 97 5019J doi 10 1073 pnas 97 10 5019 ISSN 0027 8424 PMC 33979 PMID 10805761 Sporns O Tononi G Kotter R The human connectome A structural description of the human brain PLoS Comput Biol 2005 Sep1 4 e42 Pakkenberg B Gundersen H J G 1997 Neocortical Neuron Number in Humans Effect of Sex and Age The Journal of Comparative Neurology 384 2 312 320 doi 10 1002 sici 1096 9861 19970728 384 2 lt 312 aid cne10 gt 3 3 co 2 g PMID 9215725 Azevedo Frederico A C Carvalho Ludmila R B Grinberg Lea T Farfel Jose Marcelo Ferretti Renata E L Leite Renata E P Filho Wilson Jacob Lent Roberto Herculano Houzel Suzana 2009 Equal numbers of neuronal and nonneuronal cells make the human brain an isometrically scaled up primate brain PDF J Comp Neurol 513 5 532 541 doi 10 1002 cne 21974 PMID 19226510 S2CID 5200449 Claudia Krebs MD PhD Joanne Weinberg PhD Elizabeth Akesson MSc Lippincott s Illustrated Reviews Neuroscience accessed Nov 10 2013 Chapter 13 II A Histological organization of the cortex Sporns O Tononi G Kotter R The human connectome A structural description of the human brain PLoS Comput Biol 2005 Sep1 4 e42External links edit W H Calvin s Cortical Columns Modules and Hebbian Cell Assemblies MIT Press 1995 williamcalvin com Retrieved 2017 12 31 Retrieved from https en wikipedia org w index php title Cortical minicolumn amp oldid 1215662439, wikipedia, wiki, book, books, library,
