Prior Cocaine Experience Impairs Normal Phasic Dopamine Signals of Reward Value in Accumbens Shell.

ABSTRACT: Dopamine signals have repeatedly been linked to associative learning and motivational processes. However, there is considerably less agreement on a role for dopamine in reward processing, and therefore whether neuroplastic changes in dopamine function following chronic exposure to drugs of abuse such as cocaine may impair appropriate valuation of rewarding stimuli. To quantify this, we voltammetrically measured real-time dopamine release in the nucleus accumbens (NAc) core or shell while rats received unsignaled deliveries of either a small (1 pellet) or large (2 pellets) reward. In drug-naive controls, core dopamine signals did not discriminate between reward size at any point, while in the shell dopamine encoded magnitude differences only in a slower postpeak period. Despite this lack of

SUBMITTER: Saddoris MP 

PROVIDER: S-EPMC5240185 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature