Periarchicortex is one of two subtypes of
periallocortex,
the other being
peripaleocortex Peripaleocortex is one of two subtypes of periallocortex, the other being periarchicortex. Peripaleocortex is formed at borders between isocortex (neocortex) and paleocortex (a subtype of allocortex). It shows slow histological transition from th ...
.
It is formed at borders between
archicortex
The archicortex, or archipallium, is the phylogenetically second oldest region of the brain's cerebral cortex (the oldest is the paleocortex). In older species, such as fish, the archipallium makes up most of the cerebrum. Amphibians develop an a ...
(a subtype of
allocortex
The allocortex (from Latin allo-, meaning other, and cortex, meaning bark or crust), or heterogenetic cortex, is one of the two types of cerebral cortex in the brain, together with the neocortex. In the human brain, the allocortex is the much sm ...
) and
isocortex and shows slow
histological
Histology,
also known as microscopic anatomy or microanatomy, is the branch of biology that studies the microscopic anatomy of biological tissue (biology), tissues. Histology is the microscopic counterpart to gross anatomy, which looks at large ...
transition from the four-layered structure typical for archicortex to the six-layered structure typical for isocortex.
Cortical areas that are generally considered to belong to periarchicortex, include
presubiculum
Brodmann area 27 is a cytoarchitecturally defined cortical area that is a rostral part of the parahippocampal gyrus. It is commonly regarded as a synonym of presubiculum.
The dorsal part of the presubiculum is more commonly known as the postsu ...
,
parasubiculum
In the rodent, the parasubiculum is a retrohippocampal isocortical structure, and a major component of the subicular complex. It receives numerous subcortical and cortical inputs, and sends major projections to the superficial layers of the ento ...
,
entorhinal cortex
The entorhinal cortex (EC) is an area of the brain's allocortex, located in the medial temporal lobe, whose functions include being a widespread network hub for memory, navigation, and the perception of time.Integrating time from experience in t ...
,
perirhinal cortex
The perirhinal cortex is a brain cortex, cortical region in the medial temporal lobe that is made up of Brodmann areas Brodmann area 35, 35 and Brodmann area 36, 36. It receives highly processed sensory information from all sensory regions, and i ...
,
retrosplenial cortex
The retrosplenial cortex (RSC) is a cortical area in the brain comprising Brodmann areas 29 and 30. It is secondary association cortex, making connections with numerous other brain regions. The region's name refers to its anatomical location im ...
, periarchicortical part of
cingulate cortex
The cingulate cortex is a part of the brain situated in the medial aspect of the cerebral cortex. The cingulate cortex includes the entire cingulate gyrus, which lies immediately above the corpus callosum, and the continuation of this in the cin ...
, posterior part of
subcallosal area
The subcallosal area (parolfactory area of Broca) is a small triangular field on the medial surface of the hemisphere in front of the subcallosal gyrus, from which it is separated by the posterior parolfactory sulcus; it is continuous below with th ...
, and
subgenual area.
Periarchicortex does not contact immediately at borders with the true isocortex and does not transit directly into it. Instead, another transitional area from the isocortex side, called
proisocortex
Proisocortex or pro-isocortex is one of two subtypes of cortical areas in the areas belonging to the neocortex. The other subtype is termed the true isocortex. Proisocortical areas are transitional areas placed between areas of true isocortex and ...
, is formed at such borders.
So, at borders between "true" archicortex and true isocortex, there are two transitional areas. One such area, which is anatomically located closer to the archicortex side and histologically more resembling it, is called periarchicortex.
Another transitional area, which is anatomically located closer to the true isocortex and histologically more resembling it, is called proisocortex.
References
{{neuroanatomy-stub
Cerebral cortex