Topic: Mu-opioid Receptor

In the dentate gyrus (DG), granule cells (GCs) and local interneurons transform dense cortical neuron ensemble theta/gamma band activity into sparse DG output to generate contextual representations. GABAB receptor-mediated inhibition contributes to sparse DG activity, but it is unclear how it contributes to frequency-dependent synaptic integration and spike output. We recorded perforant-path excitatory postsynaptic potentials from GCs in ventral horizontal slices from adult male and female mice and found GABAB-receptor dependent inhibition of action potential firing during gamma frequency trai

The ventral tegmental area (VTA) is a major site of opioid reward processing. Mu-opioid receptor (MOR) agonism inhibits GABAergic VTA interneurons, thereby disinhibiting dopamine release from nucleus accumbens-projecting VTA neurons. This GABA disinhibition circuit canonically drives opioid-induced reward and opioid-seeking in the VTA. However, we recently discovered MOR-expressing VTA neurons that release glutamate. In opposition to the classic GABA disinhibition model, MOR agonism on glutamatergic VTA neurons decreases activity in VTA dopamine neurons. Here, we investigated the role of GABA-