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2010
07
15
Structure of Neocortex (大脳新皮質の構造)
Cerebrum has a role of decision-making.
In this page, I explain the structure of Brain Cortex.
Brain Cortex, especially Neocortex has six-layered structure.
In contrast, Limbic Cortex has three.
(And more precisely, In Neocortex, Association Area is clearly divided into six layers, but Sensorial Area or Motor Area the boundaries are fuzzy. )
By this structure, these regions can different functions at the same time.
Furthermore, Neocortex are composed of column-shaped assemblies of neurons.(0.5 mm width and 2 or 3 mm height)
Each Assembly’s neurons have functionally common property.
This assembly is called "Column" and it is fundmental unit.
And to extend the area, Neocortex has wrinkles or sulci.
If that helps, in the early 20th century,
Brodmann (German analyst) classified Neocortex into 52 parts by examining the layered structure, kind of neurons, alignment, and density.
So the classification is called “Brodmann’s Brain Map”
▲Outer surface
▲Inner surface
PR
2010/07/15 (Thu.) Trackback() Comment(0) Brain
2010
06
15
Brain’s Neuroanatomy 1
The human brain broadly divided into limbic cortex, cerebral neocortex.
Limbic cortex is mainly responsible for the output of instinctive affectivity (appetite, sleep drive, etc), motivation, control of autonomic nervous system (heart movement, breathing, etc), and memory.
Cerebral neocortex gets engaged in intellectual activities, sensation.
Now I explain about the relationship between the two areas.
Here is one example.
When one man exhibits a affectivity such as “I want to do something” , it is motivated by cingulate gyrus.
And then Cerebral neocortex considers “What should we do”.
After that, it asks to hippocampus in limbic cortex “Before, how did I do such situation?”
Hippocampus refers in a library in the brain and answer the question.
Then amygdala in limbic cortex decides the value.
Cerebral neocortex makes the program, and executes it.
The brain cerebration consists of such a process.
2010/06/15 (Tue.) Trackback() Comment(0) Brain