Surprise, fear, anguish, affection, affection, joy, excitement… All these words denote different emotions that we all feel on a daily basis
These are reactions that we have to stimuli that can come both from the outside (for example seeing a spider, a baby or being told about your long-awaited promotion) and from within the person themselves (a thought or memory that makes you suffer or feel happy). These reactions, at the brain level, depend on a series of circuits that are capable of organizing and connecting perception and emotion, the main system in charge of this being the limbic system, and within this system the amygdala is one of the main nuclei.
In this article We are going to focus on this structure, the amygdala, in order to visualize what it is and some of its main functions
The amygdala is a subcortical structure located in the inner part of the medial temporal lobe This element has connections with the vast majority of the brain, being a nucleus of special relevance that can affect the entire nervous system and the functionality of the organism.
It is a key element for survival, because Its main function is to integrate emotions with the response patterns corresponding to these, provoking a response at a physiological level or the preparation of a behavioral response. Likewise, it is responsible for coordinating the areas that notice the somatic expression of emotion and the cerebral cortex in charge of conscious feeling, thus playing a highly relevant role in the assessment of the emotional meaning of experiences.
The amygdala is, therefore, the main core of emotion control and feelings in the brain, also controlling responses of satisfaction or fear. Its connections not only produce an emotional reaction but due to its connection with the frontal lobe it also allows the inhibition of behaviors.
Now, the amygdala is not a simple “piece” of the human brain, with a predictable and well-known pattern of functioning. In fact, none of the brain structures are like this, but in the case of the amygdala this is even more evident, taking into account that It is related to many other areas of the central nervous system It is a complex structure, being an almond-shaped structure located in the limbic system of the brain. It is made up of different parts, which is why it is sometimes also called the amygdaloid complex.
Parts of the tonsillar complex
As we have said, the amygdala is not a uniform structure, but rather it is divisible into various sub-elements Among them the following stand out:
1. Corticomedial nucleus
This part of the amygdaloid complex has a great involvement in the capture of pheromones, participating to a large extent in the control of both male and female sexual behavior. It also participates in hormonal control and the satiety response during eating.
2. Basolateral nuclei
Its main participation is in the control of intake through the feeling of satiety Likewise, its involvement in the realization and learning of learned emotional responses, such as fear reactions to different stimuli, is essential.
3. Central core
This nucleus is the one that has the greatest participation in the expression of the emotional response affecting both at a physiological level, producing the sensations and physical reactions that provoke emotions and having a great participation in the autonomic nervous system, and at a behavioral level by allowing the performance of behaviors that respond to the sensations that produce perceptions.
Likewise, this nucleus also affects the genesis and maintenance of feelings, which differ from emotions because they are patterns of thought and psychophysiological reactivity maintained over time and less specific to a specific situation.
Functions of the tonsillar complex
As mentioned, the amygdala is a complex structure and vital for survival, participating and being linked to a large number of psychological and physiological phenomena Let’s see some of them below:
1. Integration of emotions and autonomic responses
The amygdala manages with great precision the emission or inhibition of emotional responses both at a conscious and unconscious level, its function being the most studied and one of the most relevant. It allows us to associate sensations of gratification or aversion to the experiences we live. It participates in both positive emotions such as reactions of joy or happiness and other emotions of a more adaptive nature, as we will see in the next point.
2. Fear management and fight/flight reaction
In this regard, one of the main functions of the amygdala and The fact that fear management is a key part of survival At a phylogenetic level, this nucleus has allowed the survival of our species, since it is what allows us to react after perceiving a potentially threatening stimulus to physical integrity, stimulating or inhibiting the fight/flight response. In fact, injuries to the amygdala can cause extremely aggressive reactions and the loss of fear, with all the repercussions that the absence of this feeling can entail.
3. Emotional learning
Associative and conditioned learning are also greatly influenced by the action of the amygdala This structure allows the choice of strategies to apply in the presence of stimuli, as well as detecting situations in which said strategies are also applicable. This is due to the link between emotion and cognition, as well as the maintenance of motivation by linking one’s own objectives to specific feelings.
In addition to the learning process, The amygdala also affects the structuring of memories This is due to the association of memories with emotional states, which allow a greater connection and fixation of the material to be remembered, allowing its consolidation.
In fact, even when the hippocampus fails and does not allow certain memories to be stored, the amygdala allows a certain emotional memory of a situation to be preserved, which is why it is possible, for example, to be very afraid of dogs (emotional memory). without remembering why this occurred (due to the stress suffered in a traumatic event with a dog, that “narrative” memory of what occurred has not been preserved).
5. Regulation of sexual behavior
Sexual behavior is also influenced by the action of the amygdala In addition to allowing the association of different stimuli with pleasure, the emotional bond between individuals and its association with the maintenance of intimate relationships are due, among other structures, to the amygdaloid complex.
6. Aggression
The amygdala is also linked to aggression The studies carried out to date indicate that a malfunction of this can cause the loss of aggressive and self-defense reactions, while hyperstimulation of the amygdaloid complex causes extremely aggressive and violent reactions.
7. Satiety response
Another aspect in which the amygdala has a certain influence is in the control of intake, contributing greatly to the maintenance of body homeostasis through its influence on the perception of satiation.
