Front. Mol. Neurosci., 20 January 2010 | http://dx.doi.org/10.3389/neuro.02.031.2009
Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA, USA
How does the brain regulate the sleep–wake cycle? What are the temporal codes of sleep- and wake-promoting neural circuits? How do these circuits interact with each other across the light/ dark cycle? Over the past few decades, many studies from a variety of disciplines have made substantial progress in answering these fundamental questions. For example, neurobiologists and basal forebrain. Sleep-promoting circuits have been found in the preoptic area and hypothalamus. One of the greatest challenges in recent years has been to selectively record and manipulate these sleep–wake centers in vivo with high spatial and temporal resolution. Recent developments in microbial opsin-based neuromodulation tools, collectively referred to as “optogenetics,” have provided a novel method to demonstrate causal links between neural activity and specifi c behaviors. Here, we propose to use optogenetics as a fundamental tool to probe the necessity, suffi ciency, and connectivity of defi ned neural circuits in the regulation of sleep and wakefulness.