The relationship between learning performance and dopamine in the prefrontal cortex of the rat

To clarify the relationship between dopamine (DA) release in the prefrontal cortex and learning performance, extracellular DA was measured by an in vivo microdialysis method during a discrimination learning task. Rats were trained to discriminate between lamp-on and -off states under an operant-type learning procedure. After stable discriminative behavior was established, a microdialysis experiment was conducted. Inverse relationships were seen between the relative ratio of DA after the beginning of a learning session to the basal level and the responses (total, correct and error responses) during a session. The results indicate that the degree of DA release in the prefrontal cortex is involve in the inhibitory mechanism of the response during discrimination learning performance.