Abstract
ADHD is one of the most prevalent childhood psychiatric disorders and could be explained as a prefrontal dysfunction. Studies suggest that ADHD is related to deficits of dopamine-related functions, because methylphenidate, which is a dopamine transporter inhibitor, is the most effective medication for the treatment of ADHD. The prefrontal cortex is the cortical area where the most strong dopamine innervation is observed. Local acute injection of dopamine-related drugs to the prefrontal cortex produces modulation of task-related activity and behavioral deficits in cognitive task performances. Thus, the dysfunction of dopamine-related modulation in the prefrontal cortex could be a possible candidate of biological causes of ADHD. To prove this idea, in the future we are going to inject 6-OHDA into infant monkeys' prefrontal cortex to disturb dopamine functions chronically and compare its behavior with normal monkeys.
