Heteromers of μ opioid and dopamine D1 receptors modulate opioid‐induced locomotor sensitization in a dopamine‐independent manner

Exposure to opiates induces locomotor sensitization in rodents, which has been proposed to correspond to the compulsive drug-seeking behaviour. Numerous studies have demonstrated that locomotor sensitization can occur in a dopamine transmission-independent manner; however, the underlying mechanisms are unclear.Co-immunoprecipitation, BRET and cross-antagonism assays were used to demonstrate the existence of receptor heterodimers. Function of heterodimers was evaluated by behavioural studies of locomotor sensitization.The dopamine DOur results suggest that μ receptor-D