Morphine acutely regulates opioid receptor trafficking selectively in dendrites of nucleus accumbens neurons.

摘要: Morphine stimulates the internalization of μ-opioid receptors (MORs) in transfected cell models to a lesser degree than opioid peptides and other analgesic drugs, such as methadone, previous studies have reported that morphine does not produce detectable redistribution MORs neural tissue after either acute or chronic administration. Nevertheless, produces profound physiological effects, raising question whether receptor trafficking plays any role vivo actions morphine. We investigated effects opiate drugs on recombinant native nucleus accumbens, which an important mediating behavioral drugs. methadone differed their epitope-tagged bodies, introduced by viral gene transfer imaged fluorescence microscopy. A mutation cytoplasmic tail confers morphine-induced cultured cells had similar effect accumbens bodies. Surprisingly, contrast its failure affect MOR distribution detectably administration produced pronounced change visualized processes same neurons. was observed for endogenously expressed immunoelectron microscopy; increased density associated with internal membrane structures specifically dendrites. These results provide first evidence regulates neuronal processes, suggesting “compartment-selective” represents previously unanticipated type regulation contributing physiologically relevant population CNS