The possible role of Dopamine D3 receptor antagonism on motor activity in rats

Although the pathophysiology of RLS still is unclear, the efficacy of levodopa and dopamine D2/D3-receptor agonists on the sensory and motor symptoms of RLS implicate an involvement of the dopaminergic system. We investigated whether symptoms frequently seen in RLS can be observed in rodents, following the chronic (5weeks) daily administration of a selective dopamine D3 (SB-277011–1, SB27) or mixed D2/D3 (sulpiride, SUL) receptor antagonist with polysomnographic and motor activity assessments, performed at baseline and at the end of the treatment phase. Animals treated with SB27 showed an increase in sleep laten…