Tonically discharging neurons of monkey striatum respond to preparatory and rewarding stimuli

Abstract
The behavioral relationships of 396 striatum neurons with regular, tonically elevated discharge rates were studied. While monkeys performed a delayed gonogo task, neurons predominantly located in medial putamen responded with phasic depressions (n = 30) or activations (n = 5) to task-specific stimuli. Particularly effective was an instruction light preparing for movement or no-movement reactions, and an auditory signal associated with reward delivery. Stimuli triggering arm or mouth movements were less effective. The data demonstrate that these usually poorly modulated neurons display context-dependent phasic activity in specific behavioral situations.