Brodmann area 20, or BA20, is part of the temporal

cortex Cortex or cortical may refer to: Biology * Cortex (anatomy), the outermost layer of an organ ** Cerebral cortex, the outer layer of the vertebrate cerebrum, part of which is the ''forebrain'' *** Motor cortex, the regions of the cerebral cortex i ...

in the

human brain The human brain is the central organ of the human nervous system, and with the spinal cord makes up the central nervous system. The brain consists of the cerebrum, the brainstem and the cerebellum. It controls most of the activities of the ...

. The region encompasses most of the ventral temporal cortex, a region believed to play a part in high-level visual processing and recognition memory. This area is also known as inferior temporal area 20, and it refers to a subdivision of the cytoarchitecturally defined temporal region of cerebral cortex. In the human it corresponds approximately to the inferior temporal gyrus. Cytoarchitecturally it is bounded medially by the

ectorhinal area 36 Brodmann area 35, together with Brodmann area 36, comprise the perirhinal cortex. They are cytoarchitecturally defined temporal regions of the cerebral cortex. Human Brodmann area 35 This area is known as perirhinal area 35. It is a subdivision ...

(H), laterally by the

middle temporal area 21 Brodmann area 21, or BA21, is part of the temporal cortex in the human brain. The region encompasses most of the lateral temporal cortex and is also known as middle temporal area 21. In the human it corresponds approximately to the middle tempor ...

, rostrally by the

temporopolar area 38 Brodmann area 38, also BA38 or temporopolar area 38 (H), is part of the temporal cortex in the human brain. BA 38 is at the anterior end of the temporal lobe, known as the temporal pole. BA38 is a subdivision of the cytoarchitecturally defined ...

(H) and caudally by the occipitotemporal area 37 (H) (Brodmann-1909).

Guenon

Brodmann area 20 is a subdivision of the cerebral cortex of the

guenon The guenons (, ) are Old World monkeys of the genus ''Cercopithecus'' (). Not all members of this genus have the word "guenon" in their common names; also, because of changes in scientific classification, some monkeys in other genera may have co ...

defined on the basis of

cytoarchitecture Cytoarchitecture (Greek '' κύτος''= "cell" + '' ἀρχιτεκτονική''= "architecture"), also known as cytoarchitectonics, is the study of the cellular composition of the central nervous system's tissues under the microscope. Cytoarchi ...

. It is cytoarchitecturally homologous to the inferior temporal area 20 of the human (Brodmann-1909). Distinctive features (Brodmann-1905): area 20 is similar to

area 19 of Brodmann Area is the quantity that expresses the extent of a region on the plane or on a curved surface. The area of a plane region or ''plane area'' refers to the area of a shape or planar lamina, while ''surface area'' refers to the area of an open s ...

-1909 in the relative abundance of small cell types relative to the number of larger

pyramidal cell Pyramidal cells, or pyramidal neurons, are a type of multipolar neuron found in areas of the brain including the cerebral cortex, the hippocampus, and the amygdala. Pyramidal neurons are the primary excitation units of the mammalian prefrontal cor ...

s; a very dense, wide internal granular layer (IV) composed almost exclusively of

granule cell A granule is a large particle or grain. It can refer to: * Granule (cell biology), any of several submicroscopic structures, some with explicable origins, others noted only as cell type-specific features of unknown function ** Azurophilic granul ...

s, as in

area 18 of Brodmann Area is the quantity that expresses the extent of a region on the plane or on a curved surface. The area of a plane region or ''plane area'' refers to the area of a shape or planar lamina, while ''surface area'' refers to the area of an open su ...

-1909; a broad, clear internal

pyramidal layer A pyramid (from el, πυραμίς ') is a structure whose outer surfaces are triangular and converge to a single step at the top, making the shape roughly a pyramid in the geometric sense. The base of a pyramid can be trilateral, quadrilater ...

(V) with few cells; and a distinct

multiform layer The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. The cerebral cortex mostly consists of the six-layered neocortex, with just 10% consisting of ...

(VI). The major differences from areas 18 and 19 are somewhat lesser cell density; absence of a division of the external pyramidal layer (III) into sublayers 3a and 3b; layer V is more clearly distinguished from layer VI and, on average, has a greater density of pyramidal

ganglion cells {{stack, A ganglion cell is a cell found in a ganglion. Examples of ganglion cells include: * Retinal ganglion cell (RGC) found in the ganglion cell layer of the retina * Cells that reside in the adrenal medulla, where they are involved in the s ...

than in the other areas; layer VI is wider, more diffuse and has fewer cells that are concentrated in the outer part of the layer to produce a denser sublayer 6a and a less dense sublayer 6b.

External links

* For Neuroanatomy of the inferior temporal area 20 visi
BrainInfo
* For Neuroanatomy of Brodmann area 20 visi
BrainInfo
{{DEFAULTSORT:Brodmann Area 20 20 Temporal lobe

Guenon

See also

External links