Movatterモバイル変換


[0]ホーム

URL:


Jump to content
WikipediaThe Free Encyclopedia
Search

Brodmann area

From Wikipedia, the free encyclopedia
52 distinct regions of the brain's cerebral cortex

Brodmann area
3D representation of Brodmann areas
Details
Part ofCerebrum
Identifiers
NeuroNames427
FMA68596
Anatomical terms of neuroanatomy

ABrodmann area is a region of thecerebral cortex, in thehuman or otherprimatebrain, defined by itscytoarchitecture, orhistological structure and organization ofcells. The concept was first introduced by the German anatomistKorbinian Brodmann in the early 20th century. Brodmann mapped the human brain based on the varied cellular structure across the cortex and identified 52 distinct regions, which he numbered 1 to 52. These regions, or Brodmann areas, correspond with diverse functions including sensation, motor control, and cognition.[1]

History

[edit]

Brodmann areas were originally defined and numbered by theGermananatomistKorbinian Brodmann based on thecytoarchitectural organization ofneurons he observed in the cerebral cortex using theNissl method of cell staining. Brodmann published his maps of cortical areas in humans, monkeys, and other species in 1909,[2] along with many other findings and observations regarding the general cell types andlaminar organization of the mammaliancortex. The same Brodmann area number in different species does not necessarily indicatehomologous areas.[3] A similar, but more detailed cortical map was published byConstantin von Economo andGeorg N. Koskinas in 1925.[4]

Present importance

[edit]

Brodmann areas have been discussed, debated, refined, and renamed exhaustively for nearly a century and remain the most widely known and frequently cited cytoarchitectural organization of the human cortex.

Many of the areas Brodmann defined based solely on their neuronal organization have since been correlated closely to diverse cortical functions. For example, Brodmann areas 1, 2 and 3 are theprimary somatosensory cortex; area 4 is theprimary motor cortex; area 17 is theprimary visual cortex; and areas 41 and 42 correspond closely toprimary auditory cortex.Higher order functions of theassociation cortical areas are also consistently localized to the same Brodmann areas byneurophysiological,functional imaging, and other methods (e.g., the consistent localization ofBroca's speech and language area to the leftBrodmann areas 44 and 45). However, functional imaging can only identify the approximate localization of brain activations in terms of Brodmann areas since their actual boundaries in any individual brain require itshistological examination.

Overview

[edit]
Brodmann's classification of areas of the cortex

Different parts of the cerebral cortex are involved in different cognitive and behavioral functions. The differences show up in a number of ways: the effects of localized brain damage, regional activity patterns exposed when the brain is examined using functional imaging techniques, connectivity with subcortical areas, and regional differences in the cellular architecture of the cortex.Neuroscientists describe most of the cortex—the part they call theneocortex—as having six layers, but not all layers are apparent in all areas, and even when a layer is present, its thickness and cellular organization may vary. Scientists haveconstructed maps of cortical areas on the basis of variations in the appearance of the layers as seen with a microscope. One of the most widely used schemes came fromKorbinian Brodmann, who split the cortex into 52 different areas and assigned each a number (many of these Brodmann areas have since been subdivided). For example, Brodmann area 1 is the primary somatosensory cortex, Brodmann area 17 is the primary visual cortex, and Brodmann area 25 is the anterior cingulate cortex.[5]

This sectiondoes notcite anysources. Please helpimprove this section byadding citations to reliable sources. Unsourced material may be challenged andremoved.(July 2014) (Learn how and when to remove this message)
Topography of the primary motor cortex, showing which zone controls each body part

Many of the brain areas defined by Brodmann have their own complex internal structures. In a number of cases, brain areas are organized intotopographic maps, where adjoining bits of the cortex correspond to adjoining parts of the body, or of some more abstract entity. A simple example of this type of correspondence is the primary motor cortex, a strip of tissue running along the anterior edge of thecentral sulcus. Motor areas innervating each part of the body arise from a distinct zone, with neighboring body parts represented by neighboring zones[6]. Electrical stimulation of the cortex at any point causes a muscle-contraction in the represented body part. This "somatotopic" representation is not evenly distributed, however; the head, for example, is represented by a region about three times as large as the zone for the entire back and trunk. The size of any zone correlates to the precision of motor control and sensory discrimination possible. The areas for the lips, fingers, and tongue are particularly large, considering the proportional size of their represented body parts.

The maps for visual areas areretinotopic[7][8], meaning that they reflect the topography of theretina: the layer oflight-activated neurons lining the back of the eye. In this case too, the representation is uneven: thefovea—the area at the center of the visual field—is greatly overrepresented compared to the periphery. The visual circuitry in the human cerebral cortex contains several dozen distinct retinotopic maps, each devoted to analyzing the visual input stream in a particular way. The primary visual cortex (Brodmann area 17), which is the main recipient of direct input from the visual part of the thalamus, contains many neurons that are most easily activated by edges with a particular orientation moving across a particular point in the visual field. Visual areas farther downstream extract features such as color, motion, and shape.

In auditory areas, the primary map istonotopic[9]. Sounds are parsed according to frequency (i.e., high pitch vs. low pitch) by subcortical auditory areas, and this parsing is reflected by the primary auditory zone of the cortex. As with the visual system, there are a number of tonotopic cortical maps, each devoted to analyzing sound in a particular way.

Within a topographic map there can sometimes be finer levels of spatial structure. In the primary visual cortex, for example, where the main organization is retinotopic and the main responses are to moving edges, cells that respond to different edge-orientations are spatially segregated from one another.

For humans and other primates

[edit]

(*) Area only found in non-humanprimates.

Some of the original Brodmann areas have been subdivided further, e.g., "23a" and "23b".[11]

Clickable map: lateral surface

[edit]
Note: the lateral view, or side view, of the brain is denoted the 'lateral surface'
Image mapped Brodmann Areas. Clicking on an area in the picture causes the browser to load the appropriate article.
Image mappedBrodmann Areas. Clicking on an area in the picture causes the browser to load the appropriate article.

Clickable map: medial surface

[edit]
Note: the view of the section between the right and left hemispheres of the brain is denoted the 'medial surface'
Image mapped Brodmann Areas. Clicking on an area in the picture causes the browser to load the appropriate article.
Image mappedBrodmann Areas. Clicking on an area in the picture causes the browser to load the appropriate article.

Criticism

[edit]

When von Bonin and Bailey constructed a brain map for themacaque monkey, they found the description of Brodmann inadequate and wrote: "Brodmann (1907), it is true, prepared a map of the human brain which has been widely reproduced, but, unfortunately, the data on which it was based was never published"[12] They instead used the cytoarchitectonic scheme ofConstantin von Economo andGeorg N. Koskinas published in 1925[4] which had the "only acceptable detailed description of the human cortex".

See also

[edit]

References

[edit]
  1. ^ This article incorporatestext available under theCC BY 4.0 license.Betts, J Gordon; Desaix, Peter; Johnson, Eddie; Johnson, Jody E; Korol, Oksana; Kruse, Dean; Poe, Brandon; Wise, James; Womble, Mark D; Young, Kelly A (14 May 2023).Anatomy & Physiology. Houston: OpenStax CNX. 16.2 Mental status exam.ISBN 978-1-947172-04-3.
  2. ^Brodmann K (1909).Vergleichende Lokalisationslehre der Grosshirnrinde (in German). Leipzig: Johann Ambrosius Barth.[page needed]
  3. ^Garey LJ. (2006).Brodmann's Localisation in the Cerebral Cortex. New York: Springer.ISBN 978-0387-26917-7.[page needed]
  4. ^abEconomo, C.; Koskinas, G.N. (1925).Die Cytoarchitektonik der Hirnrinde des erwachsenen Menschen (in German). Wien & Berlin: Springer.LCCN 31025948.OCLC 14723058.[page needed]
  5. ^Principles of Anatomy and Physiology 12th Edition - Tortora, Page 519-fig. (14.15)
  6. ^Penfield, Wilder; Boldrey, Edwin (1937)."Somatic motor and sensory representation in the cerebral cortex of man as studied by electrical stimulation".Brain.60 (4):389–443.doi:10.1093/brain/60.4.389.
  7. ^Engel, Stephen A.; Rumelhart, David E.; Wandell, Brian A.; Lee, Adrian T.; Glover, Gary H.; Chichilnisky, Eduardo-Jose; Shadlen, Michael N. (16 June 1994)."fMRI of human visual cortex".Nature.369 (6481):525–525.doi:10.1038/369525a0.
  8. ^Holmes, Gordon (1 July 1918)."Disturbances of vision by cerebral lesions".British Journal of Ophthalmology.2 (7):353–384.doi:10.1136/bjo.2.7.353.ISSN 0007-1161.
  9. ^Romani, Gian Luca; Williamson, Samuel J.; Kaufman, Lloyd (18 June 1982)."Tonotopic Organization of the Human Auditory Cortex".Science.216 (4552):1339–1340.doi:10.1126/science.7079770.
  10. ^Fales CL, Barch DM, Rundle MM, Mintun MA, Snyder AZ, Cohen JD, Mathews J, Sheline YI (February 2008)."Altered emotional interference processing in affective and cognitive-control brain circuitry in major depression".Biol. Psychiatry.63 (4):377–84.doi:10.1016/j.biopsych.2007.06.012.PMC 2268639.PMID 17719567.
  11. ^Brent A. Vogt;Deepak N. Pandya; Douglas L. Rosene (August 1987). "Cingulate Cortex of the Rhesus Monkey: I. Cytoarchitecture and Thalamic Afferents".The Journal of Comparative Neurology.262 (2):256–270.doi:10.1002/cne.902620207.PMID 3624554.S2CID 6099000.
  12. ^Gerhardt von Bonin & Percival Bailey (1925)."The Neocortex of Macaca Mulatta".Journal of Anatomy.82 (Pt 4).Urbana,Illinois: TheUniversity of Illinois Press: 271.PMC 1273070.

External links

[edit]
Wikimedia Commons has media related toBrodmann areas.
  • [1] - Brodmann Areas, their functions, and the lateralization of functions across hemispheres
  • Brodmann, Mark Dubin pages on Brodmann areas.
  • Brodmann areas Brodmann areas of cortex involved in language.
  • Brodmann Illustrations BrainInfo Illustrations.
Anatomy of thecerebral cortex of thehuman brain
Frontal lobe
Superolateral
Prefrontal
Precentral
Medial/inferior
Prefrontal
Precentral
Both
Parietal lobe
Superolateral
Medial/inferior
Both
Occipital lobe
Superolateral
Medial/inferior
Temporal lobe
Superolateral
Medial/inferior
Interlobar
sulci/fissures
Superolateral
Medial/inferior
Limbic lobe
Parahippocampal gyrus
Cingulate cortex/gyrus
Hippocampal formation
Other
Insular cortex
General
Some categorizations are approximations, and someBrodmann areas span gyri.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Brodmann_area&oldid=1282962084"
Categories:
Hidden categories:

[8]ページ先頭

©2009-2025 Movatter.jp