The spectral sensitivity of human circadian phase resetting and melatonin suppression to light changes dynamically with light duration

作者：Melissa A. St. Hilaire, María Lovísa Ámundadóttir, Shadab A. Rahman, Shantha M. W. Rajaratnam, Melanie Rüger, George C. Brainard, Charles Andrew Czeisler, Marilyne Andersen, Joshua J. Gooley, Steven W. Lockley · 发表于：Proceedings of the National Academy of Sciences · 年份：2022 · DOI：10.1073/pnas.2205301119 · 被引用次数：73 · 研究领域：Circadian rhythm and melatonin、Impact of Light on Environment and Health、Photoreceptor and optogenetics research

Human circadian, neuroendocrine, and neurobehavioral responses to light are mediated primarily by melanopsin-containing intrinsically-photosensitive retinal ganglion cells (ipRGCs) but they also receive input from visual photoreceptors. Relative photoreceptor contributions are irradiance- and duration-dependent but results for long-duration light exposures are limited. We constructed irradiance-response curves and action spectra for melatonin suppression and circadian resetting responses in participants exposed to 6.5-h monochromatic 420, 460, 480, 507, 555, or 620 nm light exposures initiated near the onset of nocturnal melatonin secretion. Melatonin suppression and phase resetting action spectra were best fit by a single-opsin template with lambda max at 481 and 483 nm, respectively. Linear combinations of melanopsin (ipRGC), short-wavelength (S) cone, and combined long- and medium-wavelength (L+M) cone functions were also fit and compared. For melatonin suppression, lambda max was 441 nm in the first quarter of the 6.5-h exposure with a second peak at 550 nm, suggesting strong initial S and L+M cone contribution. This contribution decayed over time; lambda max was 485 nm in the final quarter of light exposure, consistent with a predominant melanopsin contribution. Similarly, for circadian resetting, lambda max ranged from 445 nm (all three functions) to 487 nm (L+M-cone and melanopsin functions only), suggesting significant S-cone contribution, consistent with recent model...