Chronic Methamphetamine Self-Administration Dysregulates Oxytocin Plasma Levels and Oxytocin Receptor Fibre Density in the Nucleus Accumbens Core and Subthalamic Nucleus of the Rat

摘要: Abstract The neuropeptide oxytocin attenuates reward and abuse for the psychostimulant methamphetamine (METH). Recent findings have implicated nucleus accumbens (NAc) core subthalamic (STh) in modulation of acute METH relapse to METH-seeking behaviour. Surprisingly, receptor (OTR) is only modestly involved both regions attenuation METH-primed reinstatement. Coupled with limited investigation role OTR psychostimulant-induced behaviours, we primarily investigated whether there are cellular changes NAc STh, as well plasma levels, after chronic i.v. self-administration (IVSA) extinction drug-taking. An additional aim was examine central corticotrophin-releasing factor (CRF) corticosterone levels were also apparent because interaction stress-regulatory mechanisms. Male Sprague-Dawley rats trained lever press (0.1 mg/kg/infusion) under a fixed-ratio 1 schedule or received yoked saline infusions during 2-h sessions 20 days. cohort underwent behavioural 15 days IVSA. Subsequent last day IVSA extinction, blood collected enzyme immunoassay, immunofluorescence conducted on STh coronal sections. Rats that self-administered had higher decreased OTR-immunoreactive (-IR) fibres than controls. In animals remained elevated, OTR-IR fibre density increased trend towards normalisation evident core. CRF-IR brain did not change across treatment groups. These demonstrate systems, centrally within peripherally through measures, dysregulated abuse.