Ricerc@Sapienza

Many preclinical studies examined cue-induced relapse to heroin and cocaine seeking in animal models, but most of these studies examined only one drug at a time. In human addicts, however, polydrug use of cocaine and heroin is common. We used a polydrug self-administration relapse model in rats to determine similarities and differences in brain areas activated during cue-induced reinstatement of heroin and cocaine seeking.

In rats trained to self-administer methamphetamine, extinction responding in the presence of drug-associated contextual and discrete cues progressively increases after withdrawal (incubation of methamphetamine craving). The conditioning factors underlying this incubation are unknown. Here, we studied incubation of methamphetamine craving under different experimental conditions to identify factors contributing to this incubation. We also determined whether the rats' response to methamphetamine priming incubates after withdrawal.