Anxiolytic effects of oxytocin in cue-induced cocaine seeking behavior in rats.

Rationale: Oxytocin (OT) is a neuropeptide previously related to reward, learning, memory, and stress, events associated with cocaine addiction. OT has shown anxiolytic properties in different animal models of anxiety. Moreover, previous data have demonstrated an increase in mRNA OT levels within the nucleus accumbens (NAc) following acute and chronic cocaine exposure in rats.

Metabotropic glutamate receptor 5 within nucleus accumbens shell modulates environment-elicited cocaine conditioning expression.

The metabotropic glutamate receptors 5 (mGluRs5) within the Nucleus Accumbens (NAc) have been implicated in the modulation of psychostimulant reward. We hypothesized that blockade of mGluR5 within the NAc shell would impair cocaine conditioning in rats. For this study, animals were implanted with cannulae within the NAc shell, and separate groups were exposed to a multimodal environment within activity chambers that signaled cocaine (cocaine-paired) or saline (controls, cocaine-unpaired) injections.

NMDA antagonist AP-5 increase environmentally induced cocaine-conditioned locomotion within the nucleus accumbens.

An environment previously associated with cocaine use can elicit cravings, even in the absence of the drug, which may be due to the formation of strong associations between the environment and the drug. These associations can result from motor learning and reinforcing effects of cocaine, and may be mediated in part by ionotropic glutamate receptors in the nucleus accumbens (N.Acc.