Brodmann area 24
Encyclopedia
Human
In the human this area is known as ventral anterior cingulate area 24, and it refers to a subdivision of the cytoarchitecturally defined cingulate cortexCingulate cortex
The cingulate cortex is a part of the brain situated in the medial aspect of the cortex. It includes the cortex of the cingulate gyrus, which lies immediately above the corpus callosum, and the continuation of this in the cingulate sulcus...
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...
(area cingularis anterior ventralis). It occupies most of the anterior cingulate gyrus in an arc around the genu
Genu
Latin for "knee", genu is a term commonly encountered in studies of anatomy. It is used to refer to several anatomical structures, including :* conditions affecting the knees, such as genu valgum and genu varum...
of 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...
. Its outer border corresponds approximately to 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...
. Cytoarchitecturally it is bounded internally by the pregenual area 33, externally by the dorsal anterior cingulate area 32, and caudally by the ventral posterior cingulate area 23 and the dorsal posterior cingulate area 31.
Francis Crick
Francis Crick
Francis Harry Compton Crick OM FRS was an English molecular biologist, biophysicist, and neuroscientist, and most noted for being one of two co-discoverers of the structure of the DNA molecule in 1953, together with James D. Watson...
, one of the discoverers of DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
, listed area 24 as the seat of free will because of its centrality in abulia and amotivational syndromes .
Guenon
In the guenonGuenon
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"...
this area is referred to as area 24 of Brodmann-1905. It includes portions of the cingulate gyrus and the frontal lobe
Frontal lobe
The frontal lobe is an area in the brain of humans and other mammals, located at the front of each cerebral hemisphere and positioned anterior to the parietal lobe and superior and anterior to the temporal lobes...
. The 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...
is thin; it lacks 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) so that the densely distributed, plump pyramidal cell
Pyramidal cell
Pyramidal neurons are a type of neuron found in areas of the brain including cerebral cortex, the hippocampus, and in the amygdala. Pyramidal neurons are the primary excitation units of the mammalian prefrontal cortex and the corticospinal tract. Pyramidal neurons were first discovered and...
s of sublayer 3b of the external pyramidal layer (III) merge with similar cells of the internal pyramidal layer (V); the multiform layer (VI) is very thin (Brodmann-1905). Note that Brodmann later divided this area into two areas, area 24 of Brodmann-1909 and area 25 of Brodmann
Brodmann area 25
Brodmann area 25 is an area in the cerebral cortex of the brain and delineated based on its cytoarchitectonic characteristics.It is also called the subgenual area, area subgenualis or subgenual cingulate....
-1909 (Brodmann-1909).
Subdivisions
The area has been subdivided further, and Vogt et al. make three division for the area in the rhesus monkey (Macaca mulatta):- 24a: "adjacent to the callosal sulcus"
- 24b: "has more clearly defined layers II, III, and Va"
- 24c: "the lower bank of the anterior cingulate sulcus"
External links and references
- For a list of Brodmann areas visit http://spot.colorado.edu/~dubin/talks/brodmann/neuronames.html
See also
- Brodmann areaBrodmann areaA Brodmann area is a region of the cerebral cortex defined based on its cytoarchitectonics, or structure and organization of cells.-History:...
- List of regions in the human brain
- Anterior cingulate cortexAnterior cingulate cortexThe anterior cingulate cortex is the frontal part of the cingulate cortex, that resembles a "collar" form around the corpus callosum, the fibrous bundle that relays neural signals between the right and left cerebral hemispheres of the brain...