The control of sleep and wakefulness by mesolimbic dopamine systems.

The mesolimbic dopamine pathway between the ventral tegmental area (VTA) and the nucleus accumbens (NAc) plays a central role in motivational behaviors. Recent findings indicate that the VTA and NAc are also involved in sleep/wake regulation - the topic of this review. First, we present an overview of the growing evidence from rodent studies revealing a wake-regulatory role of VTA dopamine neurons. We also discuss brain areas and their neurotransmitters or neuromodulators that may regulate the activity of wake-promoting VTA dopamine neurons. This is followed by a summary of current knowledge of the role of the NAc in regulating slow-wave sleep and a discussion of where and how this control of sleep physiology might be regulated by upstream neurotransmitters and neuromodulators, including dopamine and the classic somnogen adenosine.