Spontaneous and drug-induced turning behavior and thigmotactic scanning were tested either acutely (4-6 hr) or chronically (9 days) after unilateral removal of vibrissae in rats. Rats that were tested acutely scanned more with the intact vibrissae side. This asymmetry was reduced in rats that were tested chronically, indicating behavioral recovery. The indirect dopamine agonist amphetamine induced a reversed asymmetry after 9 days because the animals then scanned more with the side lacking the vibrissae. Postsynaptic doses of apomorphine administered to acutely tested rats induced more scanning with, and more turning toward, the intact vibrissae side. A negative correlation was found in the chronically tested rats between the asymmetry in spontaneous scanning and the asymmetry after apomorphine. Nonrecovered rats showed indications of a reversal after apomorphine. The results are discussed in relation to mechanisms of neural plasticity in the basal ganglia, such as receptor supersensitivity and changes in nigrostriatal afferents.