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Author (up) Kozaki, T.; Hidaka, Y.; Takakura, J.-Y.; Kusano, Y.
Title Salivary melatonin suppression under 100-Hz flickering blue light and non-flickering blue light conditions Type Journal Article
Year 2020 Publication Neuroscience Letters Abbreviated Journal Neurosci Lett
Volume 722 Issue Pages 134857
Keywords Human Health; Flickering light; Intrinsically photosensitive retinal ganglion cell; Light; Light emitting diode; Melatonin
Abstract Bright light at night has been known to suppress melatonin secretion. Photoreceptors, known as intrinsically photosensitive retinal ganglion cells (ipRGCs), project dark/bright information into the superchiasmatic nucleus, which regulates the circadian system. Electroretinograms of ipRGCs show fluctuation that is synchronized with light ON-OFF stimulation. This finding suggests that the flickering condition of light may have an impact on our circadian system. In this study, we evaluate light-induced melatonin suppression under flickering and non-flickering light conditions. Fifteen male subjects between the ages of 20 and 23 years (mean +/- SD, 21.9 +/- 1.9) were exposed to three light conditions (dim, 100-Hz flickering and non-flickering light) from 1:00 a.m. to 2:30 a.m. Saliva samples were taken just before 1:00 and at 1:15, 1:30, 2:00, and 2:30 a.m. Repeated-measure t-test with Bonferroni correction showed a significant decrease in melatonin levels under both 100-Hz and non-flickering light conditions compared to dim light conditions after 2:00 a.m. Moreover, at 2:30 a.m., the rate of change in melatonin level under 100 Hz of flickering light was significantly lower than that under non-flickering light. Our present findings suggest that 100-Hz flickering light may suppress melatonin secretion more than non-flickering light.
Address Department of Health and Nutrition Sciences, Nishikyushu University, 4490-9 Osaki, Kanzaki, Japan
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3940 ISBN Medium
Area Expedition Conference
Notes PMID:32097701 Approved no
Call Number GFZ @ kyba @ Serial 2855
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