Figure 2

Main connections of the CeA involved in pain processes. The CeA received highly processed polymodal information from the cerebral cortex and the thalamus essentially through inputs from the lateral (L) and basolateral (BL) nuclei, and more direct nociceptive information from the parabrachial nucleus. Intercalated cell masses (ITC) provide an inhibitory input driven by L and BL. Most of these afferents contact neurons in the capsular (CeLC) and lateral (CeL) subdivisions of the central nucleus which control the activity of neurons in the medial subdivision (CeM). Efferents arise mainly from the CeM and target the other components of the central extended amygdala, thalamic nuclei and the integrative, modulator and effector centers in the hypothalamus and the brainstem. Most of these structures send a reciprocal projection to the central nucleus.