Mechanism Underlying the Effects of Blue Light in Humans

描述（由申请人提供）：长期以来，人们一直认为光对人类的一系列生物功能有刺激作用，包括增加激活感，如提高警觉性或执行能力。光如何刺激这些神经生物系统的机制仍有待阐明。尽管有相当多的文献研究白光的不同特性如何激活神经系统，比如重置昼夜节律起搏器或抑制促进睡眠的褪黑激素，但只有少数研究描述了白光和彩色光对唤醒机制的直接影响，而且他们的发现是模棱两可的。

DESCRIPTION (provided by applicant): Light has long been proposed to have a stimulatory effect on a range of biological functions in humans, including increased feelings of activation, such as improved alertness or ability to perform. The mechanisms underlying how light stimulates these neurobiological systems remain to be elucidated. Although a sizeable literature exists on how different properties of white light activate neurological systems, such as resetting the circadian pacemaker or inhibiting the sleep-promoting hormone melatonin, only a few studies exist describing direct effects of white and colored light on arousal mechanisms, and their findings are ambiguous. We propose to investigate the effects of different colors of light on human physiology, and in particular test the claims that specific colors of light preferentially stimulate neurobiological, physiological and endocrinological systems. Using classical photobiological techniques, we will construct action spectra for the effects of different colors of light on a range of non-image forming responses in humans. We will test the hypotheses that: 1) light-induced activation of the neurobiological sleep-wake regulatory system, as indicated by increased alertness, faster reaction time, suppression of EEG alpha activity, microsleeps and slow rolling eye movements, and suppression of pineal melatonin, is most sensitive to retinal exposure to short-wavelength blue light (460 nm) compared to equal photons of other colors of visible light; 2) light-induced activation of autonomic and hypothalamic-pituitary-adrenal axis measures of arousal, as indicated by increased heart rate variability, core body temperature, blood pressure, respiration rate, plasma cortisol levels and urinary catecholamines, is most sensitive to exposure to short wavelength blue light (460 nm) compared to equal photons of other colors; 3) phase shifts of the human circadian pacemaker, as assessed by changes in temperature, melatonin and cortisol rhythms, are most sensitive to exposure to short-wavelength blue light (460 nm) compared to equal photons of other colors. The resultant action spectra will help to identify the photoreceptor mechanism(s) by which light activates arousal and circadian resetting, these non-image forming physiological responses and enable us to distinguish between major candidate photoreceptive mechanisms, including potential novel photoreceptor systems, that might mediate such responses.