Sleep is regulated by two mechanisms:the homeostatic process and the circadian clock.Light affects sleep and alertness by entraining the circadian clock,and acutely inducing sleep/alertness,in a manner mediated by int...Sleep is regulated by two mechanisms:the homeostatic process and the circadian clock.Light affects sleep and alertness by entraining the circadian clock,and acutely inducing sleep/alertness,in a manner mediated by intrinsically photosensitive retinal ganglion cells.Because intrinsically photosensitive retinal ganglion cells are believed to be minimally sensitive to red light,which is widely used for illumination to reduce the photic disturbance to nocturnal animals during the dark phase.However,the appropriate intensity of the red light is unknown.In the present study,we recorded electroencephalograms and electromyograms of freely moving mice to investigate the effects of red light emitted by light-emitting diodes at different intensities and for different durations on the sleep–wake behavior of mice.White light was used as a control.Unexpectedly,red light exerted potent sleep-inducing effects and changed the sleep architecture in terms of the duration and number of sleep episodes,the stage transition,and the EEG power density when the intensity was 420 lx.Subsequently,we lowered the light intensity and demonstrated that red light at or below 10 lx did not affect sleep–wake behavior.White light markedly induced sleep and disrupted sleep architecture even at an intensity as low as 10 lx.Our findings highlight the importance of limiting the intensity of red light(⩽10 lx)to avoid optical influence in nocturnal behavioral experiments,particularly in the field of sleep and circadian research.展开更多
基金supported in part by grants-in-aid for scientific research from the National Natural Science Foundation of China(31530035,81420108015,81301135,31471064,31421091,81471344)the National Basic Research Program of China(2015CB856401,2011CB711000)+1 种基金a key laboratory program of the Education Commission of Shanghai Municipality(ZDSYS14005)the Shanghai Committee of Science and Technology(14JC1400900,17ZR1402000,13dz2260700).
文摘Sleep is regulated by two mechanisms:the homeostatic process and the circadian clock.Light affects sleep and alertness by entraining the circadian clock,and acutely inducing sleep/alertness,in a manner mediated by intrinsically photosensitive retinal ganglion cells.Because intrinsically photosensitive retinal ganglion cells are believed to be minimally sensitive to red light,which is widely used for illumination to reduce the photic disturbance to nocturnal animals during the dark phase.However,the appropriate intensity of the red light is unknown.In the present study,we recorded electroencephalograms and electromyograms of freely moving mice to investigate the effects of red light emitted by light-emitting diodes at different intensities and for different durations on the sleep–wake behavior of mice.White light was used as a control.Unexpectedly,red light exerted potent sleep-inducing effects and changed the sleep architecture in terms of the duration and number of sleep episodes,the stage transition,and the EEG power density when the intensity was 420 lx.Subsequently,we lowered the light intensity and demonstrated that red light at or below 10 lx did not affect sleep–wake behavior.White light markedly induced sleep and disrupted sleep architecture even at an intensity as low as 10 lx.Our findings highlight the importance of limiting the intensity of red light(⩽10 lx)to avoid optical influence in nocturnal behavioral experiments,particularly in the field of sleep and circadian research.