ABSTRACT
Much of our understanding of the neural mechanisms underlying the effects of abused drugs has, for practical and ethical reasons associated with the invasive nature of the procedures involved, been limited to studies using laboratory animals. Although such studies have provided considerable information about neural systems in general, they are limited because they can only provide inferential evidence about the abuse potential of a drug in humans. In recent years, however, the development of positron emission tomography (PET) has provided a noninvasive approach to imaging biochemical processes in the brain. PET permits in vivo studies of the effects of psychoactive drugs on neural activity in humans. A specific application of PET scanning, the measurement of global or regional cerebral metabolic rate(s) for glucose, has been used in most PET studies on the acute effects of abused drugs.
