Ultrastructural relationship between the AMPA-GluR2 receptor subunit and the mu-opioid receptor in the mouse central nucleus of the amygdala

► Non-calcium-permeable AMPA receptors are enriched in intracellular and surface sites in dendrites of central nucleus of the amygdala neurons. ► Dendrites in the central amygdala that express non-calcium-permeable AMPA receptors receive excitatory-type synapses from unlabeled axon terminals. ► Non-calcium-permeable AMPA receptors and mu-opioid receptors are primarily co-expressed in central amygdala dendrites receiving excitatory synapses. ► Given the critical role of non-calcium-permeable AMPA receptor function in neural and behavioral adaptability, their dendritic association with μOR provides a neuronal substrate for opioid-mediated plasticity involving the central nucleus of the amygdala.