The amygdala is a cluster of nuclei deep in the inner (medial) part of each temporal lobe, one in each hemisphere, just in front of the hippocampus. [1]
The 3D brain needs JavaScript. The text below still says where the amygdala is and what it does.
Slice
Opens cut by a front (coronal) slice through the amygdala. Drag to turn, pinch or scroll to zoom, tap any part to name it; .
Located medially within each temporal lobe; it is considered part of the limbic system. [1]
Paired: one in each cerebral hemisphere. The left and right amygdalae have independent memory systems but work together to store, encode and interpret emotion. [1]
Deep, not on the surface: it is a nuclear complex, a cluster of grey-matter nuclei inside the hemisphere rather than a fold of the outer cortex. [1]
OpenStax describes the hippocampus and amygdala together as medial temporal lobe structures. [2]
What it does
Has a primary role in processing memory, decision-making and emotional responses, including fear, anxiety and aggression. [1]
Plays a role in expressing fear and processing fear-inducing stimuli. Fear conditioning, in which a neutral stimulus comes to feel aversive, takes place in the right hemisphere. [1]
The right amygdala is associated with responses to fearful stimuli and with face recognition; other evidence suggests the left amygdala plays a role in the brain’s reward system. [1]
With the hippocampus and nearby cortex, it is involved in long-term memory and emotional responses. [2]
Connections
The basolateral complex connects extensively with higher-order cortex in the prefrontal, temporal and insular lobes, and with the hippocampus. [1]
The cortical and medial nuclei connect with the olfactory (smell) system and the hypothalamus. [1]
The central nucleus projects extensively to the brainstem. [1]
Its major output pathway, the stria terminalis, curves from the temporal horn of the lateral ventricle up to the region of the interventricular foramina, carrying fibres to the septal nuclei, hypothalamus and thalamus, and fibres back. [3]
Inside it
Thirteen nuclei have been identified, each with its own subdivisions. The chief ones are the basolateral complex (lateral, basal and accessory basal nuclei), the central nucleus, the cortical nucleus, the medial nucleus and the intercalated cell clusters. [1]
The primate amygdala contains about 32 different types of neuron. [1]
Other names
Plural: amygdalae or amygdalas. Latin: corpus amygdaloideum (amygdaloid body). [1]
It was first identified and named by Karl Friedrich Burdach in 1822. [1]
Size
Raw amygdala volumes are on average 10.6% larger in men, but once total brain or skull volume is accounted for there is no significant difference between men and women. [1]
On this model the left amygdala measures about 18 mm front to back, 13 mm top to bottom and 17 mm side to side (the box it fits in, not its volume); the right one is its mirror image. [4]
Centre of the left amygdala compared with the centre of the left hippocampus: 20 mm further forward; 20 mm apart in a straight line. [4]
Centre of the left amygdala compared with the centre of the hypothalamus: 26 mm further from the midline; 26 mm apart in a straight line. [4]
Facts describe anatomy and normal function only. The 3D model is the adult male BodyParts3D brain (credits and licence); real brains vary in size and shape, so its measurements describe one model, not anyone’s brain.