Mu opioid receptor expression by nucleus accumbens inhibitory interneurons promotes affiliative social behavior.

Mu opioid receptors in the nucleus accumbens regulate motivated behavior, including pursuit of natural rewards like social interaction as well as exogenous opioids. We used a suite of genetic and viral strategies to conditionally delete mu opioid receptor expression from all major neuron types in the nucleus accumbens. We pinpoint inhibitory interneurons as an essential site of mu opioid receptor expression for typical social behavior, independent from exogenous opioid sensitivity.