A role for dopamine D1-like receptors in acute food deprivation-induced reinstatement of heroin seeking in rats.

Dopamine has a critical role in drug reinforcement and the reinstatement of drug seeking due to priming or exposure to drug-associated cues. In contrast, the role of dopamine in stress-induced reinstatement is not clear. We have previously demonstrated that acute food deprivation, a clinically relevant stressor, reinstates heroin seeking in rats via a leptin-dependent mechanism. Recent reports have suggested a modulating role for leptin on dopamine transmission and drug-related behaviours. Thus, here we investigated the role of dopamine in acute food deprivation-induced reinstatement of heroin seeking. Rats were trained to self-administer heroin (0.05 mg/kg per infusion) for 10 d. Following training, heroin seeking was extinguished and rats were tested for 48-h food deprivation-induced reinstatement while pretreated with the dopamine D1-, D2-, or D3-like receptor antagonists: SCH 23390 (0.0, 5.0 or 10.0 microg/kg), raclopride (0.0, 50.0 or 100.0 microg/kg) or NGB 2904 (0.0, 0.1 or 5.0 mg/kg), respectively. The dopamine D1-like receptor antagonist, SCH 23390, but neither of the other antagonists, showed a dose-dependent attenuation of food deprivation-induced reinstatement. Our results suggest that acute food deprivation-induced reinstatement may be mediated, at least in part, by activation of the dopamine D1-like receptor.