Amygdala

An almond shaped neural structure of various nuclei located in the anterior medial temporal lobe, primarily involved in learned, emotional conditioning and memory (e.g. fear).

Reference:
Bear, M.F., Connors, B.W. & Paradiso, M.A. (2001). Neuroscience: Exploring the Brain. (2nd Edition). Baltimore, MD: Lippincott Williams & Wilkins.