Photoperiodism, Melatonin and the Pineal

Photoperiodism, melatonin and the pineal Ciba Foundation Symposium 117 Chairman: R.V. Short 1985 Melatonin was isolated from the mammalian pineal in 1985, but only relatively recently, as the Chairman points out, has evidence accumulated for its role as the Hormone of Darkness, the Hourglass of Time'. The rhythmic melatonin signal from the pineal appears to provide information about photoperiod in many species that show seasonal cycles in reproduction, moulting and other processes. But how do animals respond to the pineal melatonin signal? What determines photoperiodism in birds, which do not seem to use this signal to regulate breeding? What is the significance of retinal melatonin? Does melatonin have a function in humans? These are amongst the issues considered at the symposium recorded in this book. In addition to the morphology and photoneural control of the pineal, the contributors describe the effects of melatonin and of manipulating photoperiod in several laboratory and economically important species - hormones, seasonal cycles, circadian rhythms and influences during development and sexual maturation have been studied.In humans, the possible significance of melatonin in puberty, malignant disease and affective disorders is considered, as are results suggesting that melatonin can entrain fatigue (or alertness), with discussion of the therapeutic potential of this hormone in certain disturbances of biological rhythm, including jet lag. This book should be of interest to physiologists, neuropharmacologists, endocrinologists, behavioural biologists, psychologists and clinical investigators with a special interest in the pineal. Other Ciba Foundation Symposia published by Pitman: No 102: Origins and development of adaptation Chairman: B.C. Clarke 1984 ISBN 0 272 79749 9 No 104: Photoperiodic regulation of insect and molluscan hormones Chairman: W. Mordue 1984 ISBN 0 272 79751 0 No 113: Retinoids, differentiation and disease Chairman: M.B. Sporn 1985 ISBN 0 272 79813 4