Synchronization of Circadian Rhythms of House Sparrows by Oral Melatonin: Effects of Changing Period
| Autor: | Eberhard Gwinner, S. Heigl |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Male
0301 basic medicine endocrine system medicine.medical_specialty Physiology Period (gene) medicine.medical_treatment Melatonin rhythm Pinealectomy Motor Activity Biology Pineal Gland Birds Melatonin 03 medical and health sciences 0302 clinical medicine Rhythm Physiology (medical) Internal medicine medicine Zeitgeber Animals Circadian rhythm Feeding Behavior Circadian Rhythm 030104 developmental biology Endocrinology Light effects on circadian rhythm hormones hormone substitutes and hormone antagonists 030217 neurology & neurosurgery medicine.drug |
| Zdroj: | Journal of Biological Rhythms. 10:225-233 |
| ISSN: | 1552-4531 0748-7304 |
| Popis: | House sparrows (Passer domesticus) whose circadian rhythms of locomotor activity and feeding had been abolished by pinealectomy were held in constant dim light and periodically exposed to melatonin in the drinking water. By alternating 8 h of melatonin water with variable phases of tap water, rhythms with periods (T) ranging from 21 to 27 h were produced. When melatonin was administered in rhythms with periods of 23,24, and 25 h, feeding and locomotion behavior of most birds were rhythmic and synchronized with the exogenous melatonin rhythm. The rest phase coincided approximately with the phase of melatonin availability. Under melatonin cycles < 23 h and > 25 h, fewer birds had synchronized rhythms. Nonsynchronized birds were either arrhythmic or they expressed free-running rhythms. Under melatonin rhythms with periods between 23 and 26 h, the phase-angle difference between defined phases of the behavioral rhythms and the melatonin rhythm became more positive with increasing T. These data are consistent with the hypothesis (a) that periodic exogenous melatonin can substitute, at least to a certain degree, for the endogenous plasma melatonin rhythm normally resulting from the periodic melatonin secretion by the pineal gland, and (b) that this melatonin rhythm acts on another oscillator, possibly the SCN, as part of the overall circadian pacemaking system. |
| Databáze: | OpenAIRE |
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