Abstract
Dopamine (DA) neurons originate midbrain and innervate to the striatum, hypothalamus, pituitary, limbic, and neocortex. The DA system is involved with not only motor control but also learning, memory, and reward/motivation. From the viewpoint of the dopamine hypothesis of schizophrenia, the DA networks through the prefrontal cortex and the limbic system have been a widespread concern. Recent technological developments in positron emission tomography in particular, have increased knowledge on psychiatric and psychological understanding of the mind through in vivo experiments in humans. A recent proposal to measure DA release in situ with an apparent binding potential of DA receptors as an index is a promising tool for understanding the DA systems in psycopsychiatrical entity.