Brodmann area

A Brodmann area is a region of the cortex defined based on its cytoarchitecture, or organization of cells.

Brodmann areas were originally defined and numbered by Korbinian Brodmann based on the organization of neurons he observed in the cortex using the Nissl stain. Brodmann published his maps of cortical areas in humans, monkeys, and other species in 1909, along with many other findings and observations regarding the general cell types and laminar organization of the mammalian cortex. (The same Brodmann area number in different species does not necessarily indicate homologous areas.) Although the Brodmann areas have been discussed, debated, refined, and renamed exhaustively for nearly a century, they 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's areas 1, 2 and 3 are the primary somatosensory cortex; area 4 is the primary motor cortex; area 17 is the primary visual cortex; and areas 41 and 42 correspond closely to primary auditory cortex. Higher order functions of the association cortical areas are also consistently localized to the same Brodmann areas by neurophysiological, functional imaging, and other methods (e.g., the consistent localization of Broca's speech and language area to the left Brodmann areas 44 and 45).

Some of the original Brodmann areas have been subdivided further, e.g., "23a" and "23b". [Cite journal
author = Brent A. Vogt, Deepak N. Pandya, Douglas L. Rosene
title = Cingulate cortex of the rhesus monkey: I. Cytoarchitecture and thalamic afferents
journal = The Journal of Comparative Neurology
volume = 262
issue = 2
pages = 256–270
month = August
year = 1987
doi = 10.1002/cne.902620207]

Brodmann areas for human & non-human primates

* Areas 1, 2 & 3 - Primary Somatosensory Cortex (frequently referred to as Areas 3, 1, 2 by convention)
* Area 4 - Primary Motor Cortex
* Area 5 - Somatosensory Association Cortex
* Area 6 - Pre-Motor and Supplementary Motor Cortex (Secondary Motor Cortex)
* Area 7 - Somatosensory Association Cortex
* Area 8 - Includes Frontal eye fields
* Area 9 - Dorsolateral prefrontal cortex
* Area 10 - Anterior prefrontal cortex (most rostral part of superior and middle frontal gyri)
* Area 11 - Orbitofrontal area (orbital and rectus gyri, plus part of the rostral part of the superior frontal gyrus)
* Area 12 - Orbitofrontal area (used to be part of BA11, refers to the area between the superior frontal gyrus and the inferior rostral sulcus)
* Area 13 and Area 14^* - Insular cortex
* Area 15^* - Anterior Temporal Lobe
* Area 17 - Primary visual cortex (V1)
* Area 18 - Secondary visual cortex (V2)
* Area 19 - Associative visual cortex (V3)
* Area 20 - Inferior temporal gyrus
* Area 21 - Middle temporal gyrus
* Area 22 - Superior temporal gyrus, of which the caudal part participates to Wernicke's area
* Area 23 - Ventral Posterior cingulate cortex
* Area 24 - Ventral Anterior cingulate cortex
* Area 25 - Subgenual cortex
* Area 26 - Ectosplenial area
* Area 27 - Piriform cortex
* Area 28 - Posterior Entorhinal Cortex
* Area 29 - Retrosplenial cingular cortex
* Area 30 - Part of cingular cortex
* Area 31 - Dorsal Posterior cingular cortex
* Area 32 - Dorsal anterior cingulate cortex
* Area 33 - Part of anterior cingulate cortex
* Area 34 - Anterior Entorhinal Cortex (on the Parahippocampal gyrus)
* Area 35 - Perirhinal cortex (on the Parahippocampal gyrus)
* Area 36 - Parahippocampal cortex (on the Parahippocampal gyrus)
* Area 37 - Fusiform gyrus
* Area 38 - Temporopolar area (most rostral part of the superior and middle temporal gyri)
* Area 39 - Angular gyrus, part of Wernicke's area
* Area 40 - Supramarginal gyrus part of Wernicke's area
* Areas 41 & 42 - Primary and Auditory Association Cortex
* Area 43 - Subcentral area (between insula and post/precentral gyrus)
* Area 44 - pars opercularis, part of Broca's area
* Area 45 - pars triangularis Broca's area
* Area 46 - Dorsolateral prefrontal cortex
* Area 47 - Inferior prefrontal gyrus
* Area 48 - Retrosubicular area (a small part of the medial surface of the temporal lobe)
* Area 52 - Parainsular area (at the junction of the temporal lobe and the insula)

(*) Area only found in non-human primates.

Criticism

When von Bonin and Bailey were to construct a brain map for the macaque 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" [Cite book
author = Gerhardt von Bonin & Percival Bailey
title = The Neocortex of Macaca Mulatta
publisher = The University of Illinois Press
location = Urbana, Illinois
year = 1925] They instead used the cytoarchitechtonic scheme of Constantin von Economo and Georg N. Koskinas published in 1925 [Cite book
author = Constantin von Economo & Georg N. Koskinas
title = Die Cytoarchitektonik der Hirnrinde des erwachsenen Menschen
publisher = Julius Springer
year = 1925
location = Vienna and Berlin] which had the "only acceptable detailed description of the human cortex".

See also

* Brain
* Cortical area
* List of regions in the human brain

References

External links

* [http://www.trincoll.edu/~dlloyd/brodmann.html brodmann x func] — Functional categorization of Brodmann areas.
* [http://spot.colorado.edu/~dubin/talks/brodmann/brodmann.html Brodmann] , Mark Dubin pages on Brodmann areas.
* [http://braininfo.rprc.washington.edu/scripts/indexotheratlas.aspx?othersiteID= Brodmann areas of cortex involved in language]