Anatomy of the limbic system

The limbic system consists of several parts within the telencephalon, also known as the cerebrum; the diencephalon, which includes the thalamus and hypothalamus; and the midbrain.

The term “limbic” means “border” in latin, so this system’s name originated from its location at the border between the telencephalon and diencephalon.

One way to remember the limbic system is to think of the word HOME; Homeostasis, Olfaction, Memory, Emotion.

This is because limbic system structures are involved in olfaction, or smell, in the regulation of emotions, like anger and fear, and other behaviors, like aggression and sexual behaviour.

Memory formation and the recollection of those memories are supported by the limbic system, and It can even influence responses of the autonomic nervous system, like cardiovascular or gastrointestinal functions.

To easily recall some of the functions, you can remember the famous 5 F’s, which are: Feeding, Fleeing, Fighting, Feeling and...Fornicating, the last one being, really, just a fancy word for Sex.

Structures that are included in the limbic system include the: hypothalamus, olfactory cortex, hippocampal formation, amygdala, subcallosal area, cingulate gyrus, parahippocampal gyrus, mammillary bodies and the basal forebrain.

Let’s take a closer look at each of them, starting with the hippocampal formation, which is crucial for converting short-term memory into long-term memory, shipping those memories into other cortical regions for long-term storage and assisting in retrieval of memories when needed.

It is also involved in spatial orientation, which is the ability to identify the position of our body relative to the objects around us.

The hippocampal formation consists of the hippocampus, the dentate gyrus, subiculum and entorhinal cortex.