Limbic system

The limbic system is a complex set of structures that is located on both sides of the thalamus , just below the brain. It includes structures such as the hypothalamus , hippocampus , tonsils, and many other nearby areas. It is considered as the main person in charge of our emotional life, and has a lot to do with the formation of our memories , in addition to participating especially when it comes to behaviors that we need to develop for our survival, such as feeding, reproduction and fighting responses or flight.

Limbic system characteristics

The main characteristics of the limbic system are the following:

• It is a network of neurons that are distributed throughout the brain and that are mixed with many different structures.
• It is related to emotional responses, learning, and memory .
• The personality , the memories and our way of being, depends largely on the limbic system.
• Also involved in the creation of memory to long term .
• Regulate visceral activity and emotional response based on sensory information.
• It is responsible for regulating the character of individuals.
• It also acts on the peripheral nervous system .
• The word limbic has an etymological root in the Latin word limbus, which means ” edge ” or ” limit “.
• It is the oldest part of the brain seen from an evolutionary point of view.

History of the limbic system

The first time the term was used was in 1878 by the doctor Paul Broca who used it to refer to an area located at the lower edge of the pineal area. In 1890, Henry Turner named the parts of the limbic system the nasal brain and later, in 1937, James Papez included more structures and even introduced the term limbic brain.

The concept of the limbic system was eventually expanded by scientists such as Goldar , Heimer, and Nauta . In the area of psychology during the twentieth century, the system has been considered as the subconscious and the thinking of the human being.

Location

The limbic system can be found deep within the brain, below the cerebral cortex, and above the brain stem .

Parties

The parts of the limbic system are as follows:

• Hypothalamus : it is an area located in the diencephalon and is closely related to the regulation of our emotions and the endocrine system .
• Hippocampus : actively participates in the processes of the mind that are related to memory , experience and the formation of memories . It is located on the inside of the temporal lobes near the thalamus and tonsils. The hippocampus is a site in the brain where new neurons are created from adult stem cells, a process known as neurogenesis .
• Amygdala : they are located on the sides of the hippocampus , this means that we have one in each of the hemispheres of the brain. It intervenes in the emotional responses that are learned when we face a certain situation and participate in the learning of emotions.
• Orbitofrontal cortex: it  is a valve that allows the exit of emotions to the different areas of the frontal lobe . It intervenes in reducing the impulses considered as irrational that manage to reach the limbic system. Participate in taking actions to achieve medium or long-term goals.

Features

The limbic system is responsible for creating autonomous responses and emotions . It is involved in creating responses to threatening situations by increasing heart rate , respiration, and blood pressure. Participates in creating fear response through stimulation of the hypothalamus and amygdala.

Another of its functions is the participation in the creation of emotional memory , in the acquisition, maintenance and elimination of phobias and to facilitate survival, it also regulates the behaviors to eat and the appetite, and the olfactory system of the human body.

Limbic system diseases

Some of the diseases that can occur in the limbic system are the following:

• Dementia : it is related to the appearance of neurodegenerative diseases such as Alzheimer’s and Pick’s disease . When the system, especially the hippocampus, is atrophied or damaged, senile plaques begin to develop and the body’s ability to control movements is impaired.
• Anxiety : they arise as a result of difficulties in regulating the activity that occurs in the tonsils .
• Epilepsy : it is a direct consequence of the affectation to the limbic system. The most common type that occurs in adults is temporal lobe epilepsy and arises when there is sclerosis in the hippocampus.
• Affective disorders : bipolarity and depression are characteristic diseases of the damage produced in the limbic system, emotional integration and learning problems, as well as problems controlling emotions.