サルを使った注意欠陥/多動性障害(ADHD)モデルの必要性

抄録

ADHD is one of the most prevalent childhood psychiatric disorders. Although ADHD is not caused by a single cause, many studies suggest that ADHD can be explained as prefrontal dysfunctions. Since the prefrontal cortex participates in working memory, attentional control, inhibition of inappropriate behavior, and regulation of emotion and motivation, the fact that many children exhibiting ADHD show disinhibition of behavioral responses and difficulty in sustained attention suggests strong contribution of the prefrontal cortex to ADHD. Studies also suggest that ADHD is related to deficits of dopamine-related functions, because methylphenidate, which is a dopamine transporter inhibitor, is the most effective drug for the treatment of ADHD and because genetic studies suggest the relations between ADHD and dopamine functions. The prefrontal cortex is the cortical area where the most strong dopamine innervation is observed. In addition, local 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 possible candidates of biological causes of ADHD. To prove this notion, it is now necessary to make a primate model of ADHD by artificially disturbing dopamine functions in the prefrontal cortex clonically and examine its behavior and neural activities. [Jpn J Physiol 55 Suppl:S56 (2005)]