Tweaking the Human Circadian Clock with Light

• Published in: Science (American Association for the Advancement of Science) Vol. 279; no. 5349; pp. 333 - 334
• Main Authors: Oren, Dan A., Terman, Michael
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 16.01.1998; The American Association for the Advancement of Science
• Subjects: Bilirubin - physiology; Biological and medical sciences; Biology; Chronobiology; Circadian rhythm; Circadian Rhythm - physiology; Circadian rhythms; Depression (Psychology); Fundamental and applied biological sciences. Psychology; Hemoglobins - physiology; Humans; Knee; Light; Light Signal Transduction; Light sources; Melatonin - metabolism; Melatonin - physiology; Models, Biological; Neural Pathways; Photoreceptor Cells - physiology; Photoreceptors; Phototherapy; Physiological aspects; Pineal Gland - metabolism; Seasonal Affective Disorder - therapy; Sleep; Suprachiasmatic Nucleus - physiology; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Visual Pathways; Human; Biological clock; Chronobiology; Light; Environmental factor; Illumination; Biological rhythm; Circadian rhythm
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.279.5349.333

Scientists show that the endogenous clock of humans can be entrained by light application to an unexpected spot, the popliteal region--the back of the knee. Results show that popliteal illumination with a visible-spectrum light source can shift human circadian rhythms without any transduction of light through the eye.