Hippocampus: functions and structure of the memory organ

seahorse it is one of the most important parts of the brain.

It is located in what is called the limbic system, and is closely related to both mental processes related to memory and those related to the production and regulation of emotional states, as well as to intervention. in navigation. imagine movement through a particular space.

The anatomy of the hippocampus

The etymology of the term “hippocampus”, a word invented by the anatomist
Giulio Cesare Aranzio, Refers to the resemblance between this brain structure and a hippocampus. This is a small, curved, elongated organ located inside the temporal lobe and goes from the hypothalamus to the amygdala. Therefore, each brain has two hippocampi: one in each hemisphere of the brain.

In addition, the hippocampus is associated with a part of the cerebral cortex called the archicortex, which is one of the most ancestral regions of the human brain; that is, it appeared several million years ago in our evolutionary line. This is why the hippocampus is so well connected to other parts of the limbic system, that it seems to provide answers to some of the most basic needs of our most distant mammalian ancestors. In turn, this fact already allows us to understand that mental processes related to emotions are related to the functions of the hippocampus. Let’s see what they are.

The functions of the hippocampus

The main function of the hippocampus is to intervene in the generation and retrieval of memories in conjunction with many areas distributed throughout the cortex and with other areas of the limbic system.

Consequently, it has a very important role in the consolidation of the learning achieved, because on the one hand it allows certain information to pass into long-term memory and on the other hand it links this type of content to certain positive or positive values. negative, depending on whether the memories were associated with pleasant or painful experiences (physiologically or psychologically).

Fill mental processes related to emotion those that determine whether the value of an experience stored as memory is positive or negative. What we experience as emotions has a functional part that has to do with how we learn to behave by following learned rules that work in our favor: avoiding repeating mistakes and reliving pleasurable sensations.

The hippocampus and memory

You might think about it
the hippocampus is the part of the brain where long-term memories are stored. However, the reality is more complex than this idea.

The relationship between the hippocampus and long-term memories is not so straightforward:
this body acts as a mediator, or repertoire, of memoriesThe appearance and disappearance are associated, so we know how memory works, with the activation and deactivation of neural networks distributed over many areas of the brain. In other words, the hippocampus does not “contain” memories, but acts as an activation node that activates different memories distributed by different parts of the brain.

In addition, the hippocampus is more tied to some types of memory than others. More precisely,
plays a role in declarative memory managementThat is, the content can be expressed verbally; however, nondeclarative memory, which is involved in memorizing movement patterns and motor skills (such as dancing or cycling), is instead regulated by structures such as the basal ganglia and the cerebellum.

It is known that injury to this area of ​​the brain generally produces anterograde and retrograde amnesia in the production and evocation of memories related to declarative memory, but non-declarative memory is generally preserved. A person with a severely damaged hippocampus may continue to learn, for example, manual skills (although they may not remember learning this process).

The seahorse in space navigation

From what is known about the hippocampus,
this brain structure also seems to intervene in the way we perceive spaceThat is, the way we keep in mind a three-dimensional space through which we move, taking into account its volumes and references.

In fact, in the hippocampus, a type of neuron called site cells has been discovered, which you can learn more about in this article.

The hippocampus under disease

The region of the hippocampal formation is one of the first areas in which diseases such as dementia or Alzheimer’s disease. This is why people who begin to experience this disease see how their abilities to form new memories or to remember more or less recent autobiographical information are diminished.

However, even if the hippocampus is severely damaged,
Usually, the oldest and most relevant memories in a person’s life take a long time to fadeThis could mean that over time the oldest and most relevant memories become more and more “independent” from the hippocampus.

Bibliographical references:

  • López-Pousa S., Vilalta Franch J., Llinàs Reglà J. (2002). Handbook of Dementia, 2nd edition. Prous Science, Barcelona.
  • Martínez Lage JM, Láinez Andrés JM (2000). Alzheimer’s: theory and practice. Medical class editions, Madrid.

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