This brain system is involved in memory and emotions.
In addition, it is a system very involved in survival functions and metabolic functions. In this article we will know what the limbic system consists of, and why it is also called “emotional brain”. In addition, we will explain what their structures are, where they are located and what function(s) each of them has.
Limbic system: what does it consist of?
The limbic system, also known as “emotional brain”, is a system formed by several brain structuresthat connect with each other, and that is located in the temporal zone of the brain. It is a brain system especially related to emotions. Specifically, it is responsible for coordinating autonomic and endocrine responses with emotional states.
In addition, it also participates in the storage of information. Among its outstanding structures are the hippocampus and the amygdala.
The first person to talk about the limbic system wasPaul Broca, referring to it as “the great limbic lobe.” Broca placed this system near the pineal gland. Its name comes precisely from there, because such a system made “limbo” or edge with this gland, in addition to other structures.
Years later, in 1949, physiologist MacLean conceptualized the limbic system as we know it today. In addition, he gave it its current name and added structures to it.
Structures and functions
Thus, the limbic system is formed by various structures that connect between them.
We are going to see what structures these are and what function(s) each one of them has next.
1. Hypothalamus
It is a small structure made up of a large number of nuclei and fibers . It deals with the autonomic nervous system and the endocrine system; specifically, it is in charge of coordinating both systems. Another of its functions is to enable the survival of the species, thanks to its participation in processes of fight, flight, feeding and reproduction.
The hypothalamus sits below another structure, the thalamus; specifically, it is located at the base of the brain, on both sides of the ventral portion of the third ventricle.
On the other hand, within it we find the mammillary bodies, responsible for receiving impulses from other structures also from the limbic system: the amygdala and the hippocampus. Once these impulses are received, the mammillary bodies forward them to the thalamus.
2. Hippocampal formation
The hippocampal formation as part of the limbic system is located in the medial temporal lobe . Its main function is to promote long-term memory and learning processes. It is made up of the following structures: the hippocampus, the trigone/fornix, and the limbic cortex. Let’s get to know each of these substructures of the limbic system:
2.1. Hippocampus
The hippocampus, a structure located in the forebrain , plays a very important role in regulating basic survival processes. In addition, it is one of the oldest regions of the human brain.
The hippocampus also has a relevant role in memory processes; Specifically, one of the memories that it “regulates” is remote memory (memories of the distant past). This makes it a key structure to know who we are and where we come from, that is, for our identity.
Another memory that it takes care of is the most emotional memory; The hippocampus filters those experiences that we have lived with intensity and that have “marked” us on an emotional level. The hippocampus, together with the hypothalamus, as parts of the limbic system, allow us to remember certain experiences and also remember what we feel with them (that is, the emotion associated with them).
2.2. trigone/fornix
The trigone or fornix consists of a bundle of axons that connects the hippocampus with other regions of the brain . Its connection with the mammillary bodies of the hippocampus is of great importance. This structure has a fundamental function in the transmission of information between various structures of the limbic system.
23. limbic cortex
This structure of the hippocampal formation is located in the medial temporal lobe of the brain. Its functions are related to memory processes; Specifically, it is responsible for consolidating and recovering declarative memories (episodic and semantic).
Episodic memories are related to autobiographical experiences, and semantic ones, with the learning of words and the world around us.
On the other hand, the limbic cortex connects different structures within the limbic system, just like the previous structure (trigonus/fornix).
3. Tonsil
The amygdala is another key structure of the limbic system, located in the medial temporal lobe . Specifically, it is located in the lateral ventricle of the temporal lobe (inside the rostral temporal lobe). It is considered the main “center of emotions”.
The amygdala has the following functions: assessing the emotional meaning of experiences and coordinating the somatic expression of emotion with conscious feeling. In addition, it is closely related to the experience of fear, with the survival instinct and with the basic emotions of the human being. The amygdala is made up of various nuclei, which are:
3.1. medial nucleus of the amygdala
This nucleus projects to the Medial Preoptic Area and the Ventromedial Nucleus of the hypothalamus. It is involved in processes related to hunger.
3.2. Basolateral nuclei of the amygdala
On the other hand, these nuclei are involved in satiety processes and in learned emotional responses.
3.3. central nucleus of the amygdala
Finally, the central nucleus of the amygdala controls the expression of the components of the emotional response (behavioral, autonomic and endocrine). It is related to emotional experience, to feeling.
the emotional brain
As we have already mentioned, the limbic system is also sometimes called the “emotional brain”. This is explained by its great implication in diverse emotional processes . However, more and more studies show that talking about “emotional brain” to refer to the limbic system is, if not, simplistic.
beyond the emotions
We say simplistic because in reality, the limbic system is involved in many other processes, such as memory, learning, and even metabolic functions (thermal regulation, reproductive functions, and vegetative functions).
On the other hand, the limbic system is also very involved in processes related to the survival of the species, such as: the regulation of fear, anger, hatred, sadness and passion (although the latter are also emotions).
References
- Carlson, N. (2014). Physiology of behavior. Madrid: Pearson.
- Kolb , B. & Whishaw , I. (2006). Human neuropsychology. Madrid: Pan American Medical Publishing House.
- Rosenweig, M.; Breedlove, S.; Watson, N. (2005) Psychobiology. An introduction to Behavioral, Cognitive and Clinical Neuroscience. Barcelona: Ariel.
To the classic question “what do you do?” I always answer “basically I am a psychologist”. In fact, my academic training has revolved around the psychology of development, education and community, a field of study influenced my volunteer activities, as well as my first work experiences in personal services.