The dynorphin/U69-induced decrease of GABAergic synaptic transmission we describe compares well with studies performed in other brain regions. Facilitating KOR signaling also decreases GABAergic responses by 15–50% in globus pallidus (Ogura and Kita, 2000), nucleus accumbens (Hjelmstad and Fields, 2003), ventral tegmental area (Ford et al., 2007), bed nucleus stria terminalis (Li et al., 2012) and hypothalamus (Pennock and Hentges, 2011), as well as in the CeA (Kang-Park et al., 2013). Interestingly, activation of presynaptic KOR in the bed nucleus stria terminalis decrease GABA released from projecting CeA neurons (Li et al., 2012). In the CeA, data from knockout mice have identified a role for delta opioid receptors to also modulate ethanol effects (Kang-Park et al., 2007), further implicating the opioid system in ethanol actions in CeA.
