The limbic system

What is the limbic system?

The limbic system is a set of structures on the inside edge of the cerebrum. It is your brain’s ‘emotion centre’.

The limbic system is responsible for emotions, motivation, pleasure, sexual arousal and memory (especially that associated with smell and emotions).

How will a tumour of the limbic system affect me?

It is a highly complex and interconnected system so it is difficult to predict how a tumour in this area will affect your functions.

Inappropriate emotional reactions to situations, for instance overreaction or loss of fear and hyper sexuality could be a symptom if a certain part of the limbic system is affected.

The inability to form new memories is another possible symptom.

The limbic system in detail

Some of the structures that make up the limbic system and their main functions are listed below.

• The amygdala is responsible for helping to store memoriesof emotional events. It plays a role in conditioning your emotional responses to events, such as fear. It also triggers motivation for reward. Problems affecting the amygdala have been known to cause inappropriate emotional reactions to situations, for instance overreaction or loss of fear, and hypersexuality.
• The cingulated gyrus regulates response to pain and anger, including heart rate.
• The hippocampus is essential for the formation and storage of long-term memories. People with this area affected may have the inability to form new memories (anterograde amnesia).
• The mamillary bodies are important in memory processing. They are highly susceptible to alcohol damage.
• The hypothalamus regulates the autonomic nervous system. This is the system that controls unconscious physical responses in your body including heart rate, blood pressure, sexual arousal, thirst, hunger, and sleep.
• The thalamus is a hugely important structure as it relays information to the cerebral cortex from many other parts of the brain and body.