Proisocortex or pro-isocortex is one of two subtypes of
cortical areas in the areas belonging to the
neocortex
The neocortex, also called the neopallium, isocortex, or the six-layered cortex, is a set of layers of the mammalian cerebral cortex involved in higher-order brain functions such as sensory perception, cognition, generation of motor commands, ...
. The other subtype is termed the true isocortex. Proisocortical areas are transitional areas placed between areas of true isocortex and areas of periallocortex (which themselves are transitional between "true"
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 proisocortex). The histological structure of proisocortex is also transitional between true isocortex and either
peripaleocortex or
periarchicortex, depending on with which subtype of periallocortex the given proisocortical area borders.
Proisocortex is found in the
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 ...
(part of the
limbic system
The limbic system, also known as the paleomammalian cortex, is a set of brain structures located on both sides of the thalamus, immediately beneath the medial temporal lobe of the cerebrum primarily in the forebrain.Schacter, Daniel L. 2012. ''P ...
), in
Brodmann's areas
24,
25,
30 and
32, the
insula and
parahippocampal gyrus
The parahippocampal gyrus (or hippocampal gyrus') is a grey matter cortical region, a gyrus of the brain that surrounds the hippocampus and is part of the limbic system. The region plays an important role in memory encoding and retrieval. It ha ...
.
The transitional cortical areas from isocortical side (i.e. proisocortex) and from allocortical side (i.e. periarchicortex and peripaleocortex) together are called
mesocortex
The paralimbic cortex is an area of three-layered cortex that includes the following regions: the piriform cortex, entorhinal cortex, the parahippocampal cortex on the medial surface of the temporal lobe, and the cingulate cortex just above the c ...
. The mesocortex is essentially the same as
paralimbic cortex, as all mesocortical transitional areas are found exclusively in paralimbic region, and vice versa - all the paralimbic cortex is mesocortical in its nature (embryonic and phylogenetic origins) and in its histology. But the term "mesocortex" represents a different concept from the term "paralimbic cortex". The mesocortex is distinguished from other cortical areas based on
cytoarchitectonics
Cytoarchitecture (from Greek κύτος 'cell' and ἀρχιτεκτονική 'architecture'), also known as cytoarchitectonics, is the study of the cellular composition of the central nervous system's tissues under the microscope. Cytoarchite ...
and histology, while the paralimbic cortex is an anatomical designation, meaning cortical areas near subcortical limbic structures.
References
External links
Proisocortex BrainInfo.
Cerebral cortex
{{Cortex types