Welcome to 2 minute neuroscience, where I simplistically explain neuroscience topics
in 2 minutes or less.
In this installment I will discuss the amygdala.
The amygdala is a collection of nuclei found in the temporal lobe.
There are two amygdalae, one in each cerebral hemisphere.
The term amygdala means “almond,” referring to one of the most prominent nuclei of the
amygdala that has an almond-like shape.
The major nuclei of the amygdala include the lateral nucleus, basal nucleus, accessory
basal nucleus, central nucleus, medial nucleus, and cortical nucleus.
Each of these nuclei can also be partitioned into subnuclei.
One common scheme for anatomically organizing the amygdala is to divide it into a basolateral
region (made up of the lateral, basal, and accessory basal nuclei), and a cortico-medial
region (made up of the cortical, medial, and central nuclei) . There are, however, other
common ways of anatomically dividing the amygdala as well.
The amygdala has traditionally been considered part of the limbic system, a group of structures
linked to the processing of emotions.
The amygdala has historically best been known for its role in processing fearful emotions.
When a threatening stimulus is present in the environment, it is thought that the amygdala
is also involved in identifying it as a threat and initiating a fight-or-flight response
More recent evidence, however, indicates that the amygdala is active during the processing
of positive stimuli as well.
Thus, it is now thought the amygdala’s role is more complex than that of a “threat detector.”
It may be involved with assigning positive or negative value to stimuli and with the
consolidation of memories that have a strong positive or negative emotional component.
It is also still being explored in a variety of other behaviors ranging from addiction
to social interaction.
Thus, its functions are diverse and still not fully understood.