Meeting Abstract
Sleep deprivation has been linked with various abnormal behaviours and negative effects on health in humans. Chronically elevated stress levels have been linked with serious health implications. The objective of the current study is to examine the physiological effects of sleep deprivation in a vertebrate organism, zebrafish (Danio rerio). Specifically, the physiological and biochemical response of sleep deprivation, as a result of prolonged light exposure, will be studied in. Previous research has demonstrated that fish do experience a “sleep-like” state defined as continuous intervals of immobility for ≥ 6 seconds. Preliminary behavioural analysis of sleep-like states in D. rerio (n=2) using an integrative tracking software (Ethovision XT, Noldus) has demonstrated that D. rerio exposed to control light exposure cycles (14 hr light/10 hr dark) spend 33.37% of their time in a sleep-like state during dark hours. Whereas fish exposed to an increase in light exposure (24 hr light/0 hr dark) demonstrated a 2.8 fold reduction in time spent in a sleep-like state. As such, the physiological effects of acute (24 hr light/0 hr dark) and chronic (4 weeks: 24 hr light/0 hr dark) sleep deprivation will be analyzed in D. rerio by analyzing mRNA expression levels of key genes that control the synthesis and release of glucocorticoids via the hypothalamic-pituitary axis and whole body cortisol and glucose levels. As corticosteroid production via the hypothalamic-pituitary axis is one of the most evolutionary conserved organismal responses to stress we propose that responses observed in D. rerio may provide insight into the stress effects of sleep deprivation in mammals.
