Prodynorphin neurons are abundant in the CeA (Marchant et al., 2007), and KOR immunoreactivity is localized in the CeA and medial amygdala, with no specific staining in the lateral, basolateral and cortical amygdaloid nuclei (Mansour et al., 1996). Within the CeA, KOR-like immunoreactive fibers are localized predominantly in the medial division, identifying this area as a prime target for electrophysiological recordings. The synaptic network in CeA is mostly GABAergic and projection neurons also are GABAergic (Sah et al., 2003), thus we focused on inhibitory transmission in the medial division of the CeA in this study.
