Differential reactivity of dopaminergic neurons in the nucleus accumbens in response to different behavioral situations. An in vivo voltammetric study in free moving rats.

The reactivity of dopaminergic (DA) terminals in the nucleus accumbens was investigated in male rats submitted to tail-pinch or various social interactions. The DA activity was assessed by measurement of the presynaptic metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) by using differential pulse voltammetry in free moving preparations. Tail-pinch lasting 5 min or 10 min was followed by increases in DA activity of 25% and 35%, respectively. Three types of social interaction were used: interaction with an aggressive male congener, interaction with a non-aggressive male congener or interaction with a female congener. The greatest increase in dopaminergic activity (40%) was observed after the aggressive interaction. The reactivity of the DA neurons within the nucleus accumbens is, therefore, dependent on the characteristics of the behavioral situation.