Responses of monkey dopamine neurons during learning of behavioral reactions.

摘要: 1. Previous studies have shown that dopamine (DA) neurons respond to stimuli of behavioral significance, such as primary reward and conditioned predicting eliciting reactions. The present study investigated how these responses develop vary when the significance changes during different stages learning. Impulses from DA were recorded with movable microelectrodes areas A8, A9, A10 in two awake monkeys successive acquisition tasks. distinguished other by their long duration (1.8-5.0 ms) low spontaneous frequency (0.5-7.0 imp/s). 2. In first task, animals learned reach a small box front them it opened visibly audibly. Before conditioning, activated few times empty reacted saccadic eye movements. Neuronal disappeared on repeated stimulus presentation. Thus neuronal related novelty an unexpected orienting behavior. 3. Subsequently, contained morsel apple one out six trials. Animals ocular saccades nearly every opening reached was present. One-third 49 phasically door opening. response stronger food responded simultaneously sight associated reward. 4. When trial, regularly target-directed arm movements, majority 76 same lacked light not task performance illuminated at position alternate sessions, thus demonstrating specificity for stimuli. 5. second employed operant conditioning reaction time situation which resting key toward lever illuminated. unconditioned light. During lasting 2-3 days, one-half 25 drop liquid delivered reinforcing reaching movement. contrast, regular intervals (2.5-3.5 s) but performed.(ABSTRACT TRUNCATED AT 400 WORDS)