Are clock genes involved in altered circadian rhythms during space flight?
Abstract
Hormone secretion in mammals often displays circadian rhythms. These rhythms usually relay on internal "biological clocks", which adjusts to geophysical parameters like the light/dark cycle, temperature cycle, or gravity force, all functioning as time cues. In humans, synchronized external and internal rhythms are important for good performance. This study focuses on the effect of altered gravity on the rhythmic secretory pattern of prolactin (PRL), a hormone of the hypothalamic-pituitary system. Several studies have shown that space flight disturbs PRL secretion. Further, we will investigate the response of clock gene expression in the suprachiasmatic nucleus (SCN), the central circadian pacemaker implicated in the neural network for timed PRL secretion, under various gravitational fields. The results of this study will demonstrate the vulnerability of mammalian endocrine systems to changes in gravity and may help in the design of counter actions for stabilizing circadian rhythms during long-term manned space flight.
- Publication:
-
ESA Special Publication
- Pub Date:
- August 2005
- Bibcode:
- 2005ESASP.585E...7E