Manipulation of D2 receptors with quinpirole and sulpiride affects locomotor activity before spatial behavior of rats in an active place avoidance task.

Dopamine-mediated neurotransmission is widely studied with respect to motivation, motor activity and cognitive processes. The aim of the present study was to evaluate the role of D2 receptors in the behavior of rats in the active allothetic place avoidance (AAPA) task. D2 receptor agonist quinpirole and antagonist sulpiride were administered intraperitoneally 20min prior to behavioral testing. Administration of quinpirole led to dose-dependent increase of locomotion; the spatial efficiency was spared across the dose range studied (0.05-1.0mg/kg). In contrast, sulpiride decreased locomotor activity at a dose not influencing spatial efficiency (60mg/kg); the highest dose of sulpiride (100mg/kg) caused a deficit in both locomotor and spatial behaviors. The results suggest a relatively lesser importance of D2 receptors for spatial efficiency in the AAPA task, with a predominant influence of D2 receptor ligands on motor activity.