Brodmann area 23
Encyclopedia
Brodmann area 23 is a region in the brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...

 corresponding to some portion of the posterior cingulate cortex. It lies between Brodmann area 30
Brodmann area 30
Brodmann area 30, also known as agranular retrolimbic area 30, is a subdivision of the cytoarchitecturally defined retrosplenial region of the cerebral cortex. In the human it is located in the isthmus of cingulate gyrus...

 and Brodmann area 31
Brodmann area 31
Brodmann area 31, also known as dorsal posterior cingulate area 31, is a subdivision of the cytoarchitecturally defined cingulate region of the cerebral cortex. In the human it occupies portions of the posterior cingulate gyrus and medial aspect of the parietal lobe. Approximate boundaries are the...

 and is located on the medial wall of the cingulate gyrus between the callosal sulcus
Callosal sulcus
The callosal sulcus is a sulcus in the brain between the cingulate gyrus and corpus callosum, below the longitudinal cerebral fissure.-External links:* via the Neuroscience Information Framework...

 and the cingulate sulcus
Cingulate sulcus
The cingulate sulcus is a sulcus on the medial wall of the cerebral cortex. The frontal and parietal lobes are separated by the cingulate sulcus from the cingulate gyrus.-External links:* via the Neuroscience Information Framework...

.

Human

This area is also known as ventral posterior cingulate area 23. It is a subdivision of the cytoarchitecturally defined cingulate region of cerebral cortex
Cerebral cortex
The cerebral cortex is a sheet of neural tissue that is outermost to the cerebrum of the mammalian brain. It plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It is constituted of up to six horizontal layers, each of which has a different...

. In the human it occupies most of the posterior cingulate gyrus adjacent to the corpus callosum
Corpus callosum
The corpus callosum , also known as the colossal commissure, is a wide, flat bundle of neural fibers beneath the cortex in the eutherian brain at the longitudinal fissure. It connects the left and right cerebral hemispheres and facilitates interhemispheric communication...

. At the caudal extreme it is bounded approximately by the parieto-occipital sulcus. Cytoarchitecturally it is bounded dorsally by the dorsal posterior cingulate area 31, rostrally by the ventral anterior cingulate area 24, and ventrorostrally in its caudal half by the retrosplenial region
Retrosplenial region
The retrosplenial region is a brain area and part of the cingulate cortex. It is defined by Brodmann area 26, Brodmann area 29 and Brodmann area 30.-Function:...

 (Brodmann-1909).

Guenon

Brodmann area 23 is a subdivision of the cerebral cortex of the guenon
Guenon
The guenons are the genus Cercopithecus of Old World monkeys. Not all the members of this genus have the word "guenon" in their common names, and because of changes in scientific classification, some monkeys in other genera may have common names that do include the word "guenon"...

 defined on the basis of cytoarchitecture. Brodmann regarded it as topographically and cytoarchitecturally homologous to the combined ventral posterior cingulate area 23 and dorsal posterior cingulate Brodmann area 31
Brodmann area 31
Brodmann area 31, also known as dorsal posterior cingulate area 31, is a subdivision of the cytoarchitecturally defined cingulate region of the cerebral cortex. In the human it occupies portions of the posterior cingulate gyrus and medial aspect of the parietal lobe. Approximate boundaries are the...

 of the human (Brodmann-1909). Distinctive Features (Brodmann-1905): the cortex is relatively thin; smaller cells predominate; the cell density of the multiform layer (VI) is great, producing a distinct boundary with the subcortical white matter
White matter
White matter is one of the two components of the central nervous system and consists mostly of myelinated axons. White matter tissue of the freshly cut brain appears pinkish white to the naked eye because myelin is composed largely of lipid tissue veined with capillaries. Its white color is due to...

; the internal granular layer
Granular layer
The term granular layer may refer to:*the granular layer of Tomes, seen in dentin of the teeth. When dry section of the root dentin of teeth are visualized under transmitted light, a granular layer is seen adjacent to cementum.It is believed to be caused by coalescing & looping of terminal portion...

 (IV) is rather well developed; the internal pyramidal layer (V) contains a dense population of round, medium-sized ganglion cell
Ganglion cell
A retinal ganglion cell is a type of neuron located near the inner surface of the retina of the eye. It receives visual information from photoreceptors via two intermediate neuron types: bipolar cells and amacrine cells...

s concentrated at the border with layer IV; layers V and VI are narrow with a distinct mutual boundary.

Macaque

In the macaque
Macaque
The macaques constitute a genus of Old World monkeys of the subfamily Cercopithecinae. - Description :Aside from humans , the macaques are the most widespread primate genus, ranging from Japan to Afghanistan and, in the case of the barbary macaque, to North Africa...

 the researchers Bonin and Bailey describe an area they term LC which is in agreement with Brodmann area 23. The LC area
covers the posterior part of the cingulate gyrus and extends into the cingulate sulcus where, on the inferior wall, it is continuous with the frontal cortex FDL.

Subdivisions

The area has been subdivided further: In the macaque
Macaque
The macaques constitute a genus of Old World monkeys of the subfamily Cercopithecinae. - Description :Aside from humans , the macaques are the most widespread primate genus, ranging from Japan to Afghanistan and, in the case of the barbary macaque, to North Africa...

 (Macaca fascicularis) the following subdivisions have been suggested:
  • 23i (internal)
  • 23e (external)
  • 23v (ventral), the most caudalventral (inferior) portion and with most highly developed layer IV.


Another suggestion is for macaque
Macaque
The macaques constitute a genus of Old World monkeys of the subfamily Cercopithecinae. - Description :Aside from humans , the macaques are the most widespread primate genus, ranging from Japan to Afghanistan and, in the case of the barbary macaque, to North Africa...

 (Macaca mulatta)
  • 23a, adjacent to the callosal sulcus
    Callosal sulcus
    The callosal sulcus is a sulcus in the brain between the cingulate gyrus and corpus callosum, below the longitudinal cerebral fissure.-External links:* via the Neuroscience Information Framework...

     thus closest to Brodmann area 30
    Brodmann area 30
    Brodmann area 30, also known as agranular retrolimbic area 30, is a subdivision of the cytoarchitecturally defined retrosplenial region of the cerebral cortex. In the human it is located in the isthmus of cingulate gyrus...

    .
  • 23b
  • 23c


Further division of 23b is.
  • pv23b, posteroventral part for 23b, main thalamic
    Thalamus
    The thalamus is a midline paired symmetrical structure within the brains of vertebrates, including humans. It is situated between the cerebral cortex and midbrain, both in terms of location and neurological connections...

     projections from anterior nuclei.
  • d23b, dorsal part of 23b, weak connections from the anterior nuclei.

See also

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK