Striatal dopaminergic changes depend on the attractive or aversive value of stimulus

Using a conditioned aversion paradigm we reported previously that dopaminergic (DA) responses were opposite in the core part of the nucleus accumbens depending on the affective value of the stimulus. The opposite responses were more marked in the left hemisphere. Anatomo-functional similarities between the core part of the nucleus accumbens and the dorsal striatum have been described. In the present study we tested the hypothesis that DA responses in the left ventromedial part of dorsal striatum (VMS) depend on the affective value of the stimulus. Responses of DA neurons were studied using in vivo voltammetry coupled with computer-assisted numerical analysis. A rapid and marked DA increase and a delayed DA decrease were observed in rats presented to the appetitive and the aversive olfactory stimulus, respectively.