Relative Timing Between Kappa Opioid Receptor Activation and Cocaine Determines the Impact on Reward and Dopamine Release.

ABSTRACT: Negative affective states can increase the rewarding value of drugs of abuse and promote drug taking. Chronic cocaine exposure increases levels of the neuropeptide dynorphin, an endogenous ligand at kappa opioid receptors (KOR) that suppresses dopamine release in the nucleus accumbens (NAc) and elicits negative affective states upon drug withdrawal. However, there is evidence that the effects of KOR activation on affective state are biphasic: immediate aversive effects are followed by delayed increases in reward. The impact of KOR-induced affective states on reward-related effects of cocaine over time is not known. We hypothesize that the initial aversive effects of KOR activation increase, whereas the delayed rewarding effects decrease, the net effects of cocaine on reward and dopamine re

SUBMITTER: Chartoff EH 

PROVIDER: S-EPMC4748424 | biostudies-literature | 2016 Mar

REPOSITORIES: biostudies-literature