The amygdala (Latin, corpus amygdaloideum) is an almond-shape set of neurons located deep in the brain's medial temporal lobe.
Shown to play a key role in the processsing of emotions, the amygdala forms part of the limbic system.
In humans and other animals, this subcortical brain structure is linked to both fear responses and pleasure.
Its size is positively correlated with aggressive behavior across species.
In humans, it is the most sexually-dimorphic brain structure, and shrinks by more than 30% in males upon castration.
Conditions such as anxiety, autism, depression, post-traumatic stress disorder, and phobias are suspected of being linked to abnormal functioning of the amygdala, owing to damage, developmental problems, or neurotransmitter imbalance.