A prominent group of neurons forming an almond shaped structure at the level of the temporal cortex in primates, and form part of the limbic system. In the rat, the amygdala is ventrolateral, close to both the temporal and perirhinal cortices. It is divided schematically into four groups: cortical & basal (main olfactory), medial (accessory olfactory), central (autonomic), basolateral & lateral (frontotemporal & temporal cortices). The precise role of this region remains incompletely understood. It seems that one of its roles is to mark perceptions with an affective label that provides an appropriate significance in the environment of the species. In the framework of pain, it triggers an aversive reaction and fear that causes the organism to avoid dangerous stimuli. It also plays a role in the development of memories with an emotional component.