THE RELATIONSHIP BETWEEN LEARNING-PERFORMANCE AND DOPAMINE IN THE PREFRONTAL CORTEX OF THE RAT

To clarify the relationship between dopamine (DA) release in the prefr ontal cortex and learning performance, extracellular DA was measured b y an in vivo microdialysis method during a discrimination learning tas k. Rats were trained to discriminate between lamp-on and -off states u nder an operant-type learning procedure. After stable discriminative b ehavior was established, a microdialysis experiment was conducted. Inv erse relationships were seen between the relative ratio of DA after th e beginning of a learning session to the basal level and the responses (total, correct and error responses) during a session. The results in dicate that the degree of DB release in the prefrontal cortex is invol ve in the inhibitory mechanism of the response during discrimination l earning performance.