The neocortex participates in the most complex brain functions
The neocortex is the most complex sector of the cerebral cortex . Also known as neocortex , isocortex or neopallium , it is the part that, in terms of the process of evolution , appeared closest in time.
Contribution in complex actions
The most advanced functions of the brain require the intervention of the neocortex. From sensory perception to the production of motor commands, through the control of space and conscious thought, many complex actions are carried out with input from the neocortex.
In the genus Homo the neocortex reaches its most extended development. That is why species in this group, such as Homo sapiens , show superior cognitive function.
Made up of six layers, the neocortex represents approximately 90% of the total mass of the cerebral cortex. There are about 14 billion neurons in it, according to estimates by neurologists.
Gray matter is the main component of the neocortex structure . The thickness of said structure varies between 2 and 4 millimeters thick, depending on the area.
It characterizes us
It can be said that the reasoning capacity that human beings have is possible thanks to the characteristics of our neocortex. The different types of perceptions are associated and integrated in this area, which is key to analyzing information , reflecting and making decisions based on these processes.
Language and calculation skills, for example, depend on the neocortex. Long-term memory also has a close link with the functioning of this sector of our brain.
Its structure has a relative uniformity. According to the Spanish scientist named Rafael Lorente de No , it is possible to identify a series of vertically aligned columns that contain processing cells. This organization can be observed by means of Nissl staining not only in our species, but also in other primates. These are small patches whose diameter is around half a millimeter and their depth is two millimeters.
Layers of the neocortex
In a previous paragraph we talked about the six layers that make up the neocortex. The description of this structure was made by the German neurologist named Korbinian Brodmann , who also recognized fifty-two different regions when studying their cytoarchitecture. His statements, which became public in 1909, arose from his work in the laboratory of the neurologist and physicist Oskar Vogt , also German.
The first layer, which is called the external plexiform , is located on the surface and connects to the innermost meninge, the pia mater . It has a low number of dispersed neurons, and almost its entire composition is made up of glial cells and extensions of pyramidal neurons. The second is called external granular ; It has many stellate neurons and some small pyramidal neurons.
The study of the neocortex has more than a century
We reach layer number three, which is known as the external pyramidal layer. It has pyramidal neurons of two sizes, small and medium, as well as others that are not pyramidal and have their intracortical axons in a vertical orientation . The fourth is the internal granular , whose cells include pyramidal and stellate. The previous three are part of the supragranular group, while the next two are infragranular .
The internal pyramidal layer is the fifth layer, where there are large pyramidal neurons from which axons arise that leave the neocortex to reach the basal ganglia and other structures. In this layer there are also the so-called Betz cells , which are related to voluntary motor control. Finally, the multiform layer has a majority of small multiform and pyramidal neurons and is responsible for sending fibers to the thalamus, connecting it with the neocortex with great precision.