Functional neuroanatomy of the basolateral amygdala: Neurons, neurotransmitters, and circuits

Abstract The basolateral nuclear complex (BNC) of the amygdala consists of lateral, basolateral, and basomedial nuclei in the rat, and homologous nuclei in the monkey (lateral, basal, and accessory basal). There are two main types of neurons in the BNC: pyramidal neurons and nonpyramidal neurons. Although these cells do not exhibit a laminar organization, their morphology, synaptology, electrophysiology, and pharmacology are remarkably similar to their counterparts in the cerebral cortex. Like the cortex, there are several distinct interneuronal subpopulations in the BNC. Collectively, the nuclei of the BNC receive information from all sensory modalities, and via projections to the central amygdalar nucleus, bed nucleus of the stria terminalis, striatum, hypothalamus, and prefrontal cortex elicit emotional behavior. The BNC also plays a critical role in the formation and extinction of emotional memories. This review summarizes the organization of the local and extrinsic connections of BNC neurons that underly these functions.