A considerable reduction of the run performance (tread-mill test) and a smaller impairment of the swimming capacity occurs in adult rats injected intraperitoneally in the neonatal period with three doses of 50 mg/kg b.w. or 6-hydroxydopamine. In other rats treated i. p. with disulfiram (200 mg/kg) the run performance was significantly reduced. These data, together with histological observations, show the important role of central and peripheral noradrenergic, and not only dopaminergic, mediation in the control of motor behaviour.