Brodmann area 24
Brodmann area 24 is part of the anterior cingulate in the human brain. In the human this area is known as ventral anterior cingulate area 24, it refers to a subdivision of the cytoarchitecturally defined cingulate cortex region of cerebral cortex, it occupies most of the anterior cingulate gyrus in an arc around the genu of the corpus callosum. Its outer border corresponds to the cingulate sulcus. Cytoarchitecturally it is bounded internally by the pregenual area 33, externally by the dorsal anterior cingulate area 32, caudally by the ventral posterior cingulate area 23 and the dorsal posterior cingulate area 31. Francis Crick, one of the co-discoverers of the structure of DNA, listed area 24 as the seat of free will because of its centrality in abulia and amotivational syndromes. In the guenon this area is referred to as area 24 of Brodmann-1905, it includes portions of the frontal lobe. The cortex is thin. Note that Brodmann divided this area into two areas, area 24 of Brodmann-1909 and area 25 of Brodmann-1909.
The area has been subdivided further, Vogt et al. make three division for the area in the rhesus monkey: 24a: "adjacent to the callosal sulcus" 24b: "has more defined layers II, III, Va" 24c: "the lower bank of the anterior cingulate sulcus" Brodmann area List of regions in the human brain Anterior cingulate cortex List of Brodmann areas
Cytoarchitecture known as cytoarchitectonics, is the study of the cellular composition of the central nervous system's tissues under the microscope. Cytoarchitectonics is one of the ways to parse the brain, by obtaining sections of the brain using a microtome and staining them with chemical agents which reveal where different neurons are located; the study of the parcellation of nerve fibers into layers forms the subject of myeloarchitectonics, an approach complementary to cytoarchitectonics. Defining cerebral cytoarchitecture began with the advent of histology—the science of slicing and staining brain slices for examination, it is credited to the Viennese psychiatrist Theodor Meynert, who in 1867 noticed regional variations in the histological structure of different parts of the gray matter in the cerebral hemispheres. Paul Flechsig was the first to present the cytoarchitecture of human brain into 40 areas. Alfred Walter Campbell present the cytoarchitecture of the human brain into 14 areas.
Sir Grafton Elliot Smith, a New South Wales native working in Cairo, identified 50 areas. Korbinian Brodmann worked on the brains of diverse mammalian species and developed a division of the cerebral cortex into 52 discrete areas. Brodmann used numbers to categorize the different architectural areas and he believed that each of these regions served a unique functional purpose. Constantin von Economo and Georg N. Koskinas, two neurologists in Vienna, produced a landmark work in brain research by defining 107 cortical areas on the basis of cytoarchitectonic criteria, they used letters to categorize the architecture, e.g. "F" for areas of the frontal lobe. The Nissl staining technique is used for determining the cytoarchitectonics of neuroanatomical structures, using common agents such as thionin, cresyl violet, or neutral red; these dyes intensely stain "Nissl bodies", which are abundant in neurons and reveal specific patterns of cytoarchitecture in the brain. Other common staining techniques used by histologists in other tissues leave brain tissue appearing homogeneous and do not reveal the level of organization apparent in a Nissl stain.
Nissl staining reveals details ranging from the macroscopic, such as the laminar pattern of the cerebral cortex or the interlocking nuclear patterns of the diencephalon and brainstem, to the microscopic, such as the distinctions between individual neurons and glia in any subregion of the central nervous system. Many other neuroanatomic and cytoarchitectonic techniques are available to supplement Nissl cytoarchitectonics, including immunohistochemistry and in situ hybridization, which allow one to label any gene or protein expressed in any group of cells in the brain. However, Nissl cytoarchitecture remains a reliable and familiar starting or reference point for neuroscientists wishing to examine or communicate their findings in a recognized anatomical framework and/or in reference to neuroanatomical atlases which use the same technique. Otfrid Foerster
Brodmann area 40
Brodmann area 40 is part of the parietal cortex in the human brain. The inferior part of BA40 is in the area of the supramarginal gyrus, which lies at the posterior end of the lateral fissure, in the inferior lateral part of the parietal lobe, it is bounded by the intraparietal sulcus, the inferior postcentral sulcus, the posterior subcentral sulcus and the lateral sulcus. It is bounded caudally by the angular area 39, rostrally and dorsally by the caudal postcentral area 2, ventrally by the subcentral area 43 and the superior temporal area 22. Cytoarchitectonically defined subregions of rostral BA40/the supramarginal gyrus are PF, PFcm, PFm, PFop, PFt. Area PF is the homologue to macaque area PF, part of the mirror neuron system, active in humans during imitation; the supramarginal gyrus part of Brodmann area 40 is the region in the inferior parietal lobe, involved in reading both as regards meaning and phonology. Parietal operculum Brodmann area List of regions in the human brain
Brodmann area 13
Brodmann area 13 is a subdivision of the cerebral cortex as defined on the guenon monkey and on the basis of cytoarchitecture. Brodmann area 13 is found in humans as part of the insula; this structure lies between the medial layers of the brain. Thus it is sometimes misidentified as not being a Brodmann area. Located in the anterior part of the insular cortex, Brodmann area 13 shares with other parts of the insular cortex a wide molecular layer and wide multiform layer; the external granular layer is dense. The external lamina pyramidalis externa has a central stripe of less cellular density that separates two sublayers, IIIa and IIIb; the internal granular layer is sufficiently wide and dense to separate sublayer IIIb from layer V. The boundary between layers V and VI is defined by larger ganglion cells, more pyramidal in shape, in layer V giving way to smaller, more spindle-shaped cells that become denser and more homogeneous deeper in layer VI; the spindle cells are arrayed horizontally as in the claustrum, which Brodmann considered a extension of layer VI beyond the extreme capsule.
Brodmann areas List of regions in the human brain BrainInfo - Brodmann Area 13 Brodmannarea.info
Brodmann area 52
Brodmann area 52 or parainsular area, is a subdivision of the cytoarchitecturally defined temporal region of the cerebral cortex in the brain. It is located in the bank of the lateral sulcus on the dorsal surface of the temporal lobe, its medial boundary corresponds to the junction between the temporal lobe and the insula. Cytoarchitecturally it is bounded laterally by the anterior transverse temporal area 42. Brodmann area
Brodmann area 22
Brodmann area 22 is one of Brodmann's area's – cytoarchitecturally defined regions of the brain. It is part of the superior temporal gyrus included in the language processing region known as Wernicke's area. Brodmann area 22 is the cytoarchitecturally defined posterior superior temporal gyrus on the left side of the brain. In the left hemisphere this area helps with understanding of individual words. On the right side of the brain it helps to discriminate pitch and sound intensity, both of which are necessary to perceive melody and prosody; this part of the brain is part of Wernicke's area. The other main region included in Wernicke's area is the supramarginal gyrus, it is bounded rostrally by Brodmann area 38, medially by Brodmann area 42, ventrocaudally by Brodmann area 21, dorsocaudally by Brodmann area 40, Brodmann area 39. These cortical regions surround the lower left posterior Sylvian fissure. Brodmann area 22 is a subdivision of the cerebral cortex of the guenon defined on the basis of cytoarchitecture.
It is cytoarchitecturally homologous to the superior temporal area 22 of the human. Distinctive features: compared to Brodmann area 21-1909 the cortical thickness of area 22 is greater. Brodmann area List of regions in the human brain For Neuroanatomy of the superior temporal area 22 visit BrainInfo For Neuroanatomy of Brodmann area 22 visit BrainInfo
Brodmann area 12
Brodmann area 12 is a subdivision of the cerebral cortex of the guenon defined on the basis of cytoarchitecture. It occupies the most rostral portion of the frontal lobe. Brodmann-1909 did not regard it as homologous, either topographically or cytoarchitecturally, to rostral area 12 of the human. Distinctive features: a quite distinct internal granular layer separates slender pyramidal cells of the external pyramidal layer and the internal pyramidal layer, it is indirectly connected to the global palladius as well as the substantia nigra, due to efferents to the striatum. Glutaminergic input is turned into GABAergic input there, which allows the frontal lobes to exhibit some control over basal ganglia activity. Brodmann area List of regions in the human brain For Neuroanatomy of this area see BrainInfo