Reinstatement of heroin and cocaine self-administration behavior in the rat by intracerebral application of morphine in the ventral tegmental area

摘要: In rats trained to self-administer heroin or cocaine intravenously, non-contingent priming injections of cocaine, respectively, reinstated responding after a period extinction. similarly morphine sulphate was applied centrally sites in the ventral tegmental area (VTA), periventricular grey (PVG) and caudate nucleus following Self-administration behavior by application region VTA, but not other sites, both cocaine-trained animals. This effect blocked attenuated prior administration naltrexone, given intraperitoneally. Morphine VTA is known activate mesolimbic dopamine neurons, suggesting that activity this system may underlie effects opiates stimulants. Furthermore, fact implicated positive motivational actions drug groups, suggests reinstates drug-taking these animals activating appetitive systems brain.