The Allocortex includes the regions in the human brain that make up three to five layers. It forms about 10% of the cerebral cortex, called the cerebral cortex. Opposite him is the six-layered neo- or isocortex, which occupies 90% of the cerebral cortex.
The Allocortex is formed from the Archicortex and the Paleocortex. The archicortex consists of the limbic system. This is assigned to the hippocampus. To the paleocortex belongs the olfactory organ of the human organism. Thus, the Allocortex performs important functions in the emotional processing, learning and processing of odors. In addition, the mesocortex is counted as the transition between the isocortex and the archicortex with the allocortex.
In adult life, the mesocortex consists of the para-hippocompinal cortex and the cingulate gyrus. While the para-hippocomplex cortex is assigned to the allocortex, the cingulate gyrus is part of the isocortex. The Allocortex consists to a large extent of pyramidal cells. These serve to transmit recorded stimuli of a sense organ to the cortex. Tribal historically, the Allocortex belongs to the older region in the human brain.
The archicortex describes the limbic system. It includes the hippocampus, the parahippocomparis gyrus, the amygdala and the mammillary body. Although the cingulate gyrus is part of the archicortex, it is not assigned to the allocortex.
The paleocortex unites different centers of the human brain. These include the bulb and the olfactory tract, the olfactory tubercle, the septum, the prepiriform cortex and parts of the amygdaloidum, the amygdala. The paleocortex with its structures forms the olfactory bulb with the olfactory bulb. This has the shape of a butterfly feeler. The recorded stimuli are transmitted via the olfactory epithelium without switching in the thalamus directly to the cerebral cortex. The olfactory brain is called the olfactory cortex. Here the processing of the smells takes place. The Allocortex consists of three layers.
These are the Lamina molecularis, the Lamina pyramidales and the Lamina multifromis. The first layer is called stratum molecular and contains the upper dendrites of the pyramidal cells. The middle layer is formed by the stratum pyramidale and consists of the cell bodies of the pyramidal cells. The third layer contains the lower dendrites of the pyramidal cells and is called stratum oriens.
Essentially, the allocortex is formed from the hippocampus and the olfactory organ. The Paleocortex, also referred to as the olfactory cortex, evaluates all information that is collected via the olfactory epithelium and sent to it via the olfactory pathway.
Man can distinguish 5, 000 smells. In over 10 million olfactory cells, these are taken up and forwarded for processing. Smelling cells have a lifespan of a few weeks. Then they die and are replaced by new ones. This into a task that is taken over by the Allocortex. The olfactory cells are the only nerve cells in the adult nervous system that share mitotically. In mitosis, a cell nucleus divides into two daughter nuclei, which have the same genetic information.
The functions of emotional processing, learning and memory formation take place in the archicortex. In the layers of the archicortex the long-term potentiation and thus the memory consolidation takes place. Long-term potentiation transfers recorded information from short-term memory to long-term memory. These include memories, knowledge about actions or conditioning processes. The human habits as well as the unconscious processes are taken over in the archicortex. In addition, the emotion experience takes place in the limbic system and, above all, the amygdala.
Fear, lust, joy or sadness arise there. The emotions can take place at short notice or pass into long-lasting emotional phases. Positive as well as the negative emotions, moods and affect regulation finds its origin here. Thus, the Allocortex assumes an important social function as well as the regulation of emotions. The realization of a resulting emotion is defined as feeling. In this process, parts of learning and evolutionary elements such as the fear reaction flow.
Lesions in the Allocortex result in impaired odor processing as well as memory and emotion formation. The smell plays an important role in the partnership search.
The partnership attraction or sympathy is associated with the histocompatibility antigens of the human organism. Partners whose genetic structure is too similar are considered repugnant. Behind this is the evolutionary goal of preventing genetic dispositions of the offspring and producing progeny that have a strong immune system. The process of odor processing is altered in the event of lesions or impairments due to medication. In addition, a limited sense of smell affects the sense of taste.
Alexithymia is a condition known as emotional blindness. This condition includes symptoms that describe an inability or limitation in feeling. Own feelings can be perceived only insufficiently or not at all. Empathy is also not felt. A peculiarity of this disease is that the related persons suffer more from the disease than the person concerned.
Alcoholism affects the functioning of the pyramidal cells. With this, memories are lost and can no longer be replaced. If alcohol abuse leads to Korsakoff syndrome, existing memory gaps are replaced by confabulation. Memory errors are replaced by fictitious narratives.