About the Book
Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Pages: 73. Chapters: Seasonal affective disorder, Nocturnality, Circadian rhythm, Chronobiology, Free-running sleep, Jet lag, Melatonin, Delayed sleep phase syndrome, Roberto Refinetti, Shift work, Light therapy, Pineal gland, Photosensitive ganglion cell, Bacterial circadian rhythms, Non-24-hour sleep-wake syndrome, Polyphasic sleep, Circadian oscillator, Suprachiasmatic nucleus, Chronotype, Phase response curve, Irregular sleep-wake rhythm, Circadian rhythm sleep disorder, Melanopsin, Shift work sleep disorder, Photoperiodism, N-Acetylserotonin, Advanced sleep phase syndrome, Dark therapy, Segmented sleep, Chronotherapy, Light effects on circadian rhythm, Actigraphy, Night owl, Circasemidian rhythm, Light in school buildings, Dawn simulation, David F. Dinges, Sara Mednick, Sundowning, Sleep diary, Sleep inertia, Jurgen Aschoff, Entrainment, Diurnality, Russell G. Foster, Photoreceptor protein, Spring Fever, Ultradian, Nathaniel Kleitman, Giant retinal ganglion cells, Lark, Circaseptan, Zeitgeber, Franz Halberg, Retinohypothalamic tract, Infradian rhythm. Excerpt: Melatonin (), also known chemically as N-acetyl-5-methoxytryptamine, is a naturally occurring compound found in animals, plants and microbes. In animals, circulating levels of the hormone melatonin vary in a daily cycle, thereby allowing the entrainment of the circadian rhythms of several biological functions. Many biological effects of melatonin are produced through activation of melatonin receptors, while others are due to its role as a pervasive and powerful antioxidant, with a particular role in the protection of nuclear and mitochondrial DNA. In mammals, melatonin is secreted into the blood by the pineal gland in the brain. Known as the "hormone of darkness" it is secreted in darkness in both day-active (diurnal) and night-active (nocturnal) animals. It may also be...
