Purinergic modulation of extracellular glutamate levels in the nucleus accumbens in vivo.

In the present study, the P2 receptor-mediated modulation of the extracellular glutamate concentration was investigated by microdialysis in the nucleus accumbens (NAc) of freely moving rats. Because of the known interference of dopaminergic and glutamatergic mechanisms in this area the experiments were performed with animals intra-accumbally treated with 6-hydroxydopamine (6-OHDA) to deplete dopamine pools. Perfusion of the NAc with the prototypic P2 receptor agonist 2-methylthioadenosine 5'-triphosphate (2-MeSATP, 0.

Basal and feeding-evoked dopamine release in the rat nucleus accumbens is depressed by leptin.

The involvement of the satiety-controlling hormone leptin in the modulation of the reward-associated dopamine release was investigated by monitoring the extracellular dopamine concentration in microdialysates from the nucleus accumbens of rats during feeding after infusion of leptin or artificial cerebrospinal fluid into the lateral ventricle of rats. Leptin suppressed the basal as well as the feeding-evoked extracellular dopamine concentration and reduced the amount and duration of food intake compared to the pair-feed vehicle-treated controls. These results suggest that leptin is involved in the dopaminergic modulation of feeding-induced rewarding functions.