Sleep/wakefulness control using optogenetics in mice Center for Developmental Biology

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Category	Seminar
Date and Time	2011-07-11 16:00 - 17:00
Venue	Seminar Room A7F
Speaker	Akihiro Yamanaka
Affiliation	National Institute for Physiological Sciences
Title	Sleep/wakefulness control using optogenetics in mice
Poster	click here to download(PDF)
Host	Takeshi Imai
summary	Orexin/hypocretin neurons have a crucial role in the regulation of sleep and wakefulness. Although the afferent and efferent connections of these neurons have been determined, how orexin neuronal activity promotes wakefulness is incompletely understood. To further examine the role of orexin neuronal activity in sleep/wakefulness regulation, we generated transgenic mice in which orexin neurons expressed halorhodopsin, an orange light-activated chloride ion pump. Slice patch clamp recordings of orexin/halorhodopsin neurons demonstrated that photic illumination produced an outward current, hyperpolarized, and reduced the discharge rate of orexin neurons in a wavelength- and intensity-dependent manner. Acute silencing of orexin neurons in vivo by orange light illumination decreased electromyography power and increased the delta frequency in the electroencephalogram, indicative of slow wave sleep (SWS), and was time-of-day dependent. These findings suggest that activation of orexin neurons is necessary to keep animals awake during the light period.