Project description:Animals deficient for the alpha subunit of the large conductance calcium dependent potassium channel (BK) were sleep deprived for 4 hours and compared to wildtype littermates as well as animals (wildtype littermate and BK deficient) left undisturbed for the same time.
Project description:Animals deficient for the alpha subunit of the large conductance calcium dependent potassium channel (BK) were sleep deprived for 4 hours and compared to wildtype littermates as well as animals (wildtype littermate and BK deficient) left undisturbed for the same time.
Project description:Study objectivesAlthough blood pressure during sleep and the difference in blood pressure between sleep and wakefulness carry prognostic information, little is known on their central neural mechanisms. Hypothalamic neurons releasing hypocretin (orexin) peptides control wake-sleep behavior and autonomic functions and are lost in narcolepsy-cataplexy. We investigated whether chronic lack of hypocretin signaling alters blood pressure during sleep.DesignComparison of blood pressure as a function of the wake-sleep behavior between 2 different hypocretin-deficient mouse models and control mice with the same genetic background.SettingN/A.SubjectsHypocretin-ataxin3 transgenic mice with genetic ablation of hypocretin neurons (TG, n = 12); hypocretin gene knock-out mice (KO, n = 8); congenic wild-type controls (WT, n = 10).InterventionsInstrumentation with electrodes for sleep recordings and a telemetric blood pressure transducer.Measurements and resultsBlood pressure was significantly higher in either TG or KO than in WT during non-rapid eye movement sleep (NREMS; 4 ± 2 and 7 ± 2 mm Hg, respectively) and rapid eye movement sleep (REMS; 11 ± 2 and 12 ± 3 mm Hg, respectively), whereas it did not differ significantly between groups during wakefulness. Accordingly, the decrease in blood pressure between either NREMS or REMS and wakefulness was significantly blunted in TG and KO with respect to WT.ConclusionsChronic lack of hypocretin signaling may entail consequences on blood pressure that are potentially adverse and that vary widely among wake-sleep states.
Project description:Dividing attention across two tasks performed simultaneously usually results in impaired performance on one or both tasks. Most studies have found no difference in the dual-task cost of dividing attention in rested and sleep-deprived states. We hypothesized that, for a divided attention task that is highly cognitively-demanding, performance would show greater impairment during exposure to sleep deprivation. A group of 30 healthy males aged 21-30 years was exposed to 40 h of continuous wakefulness in a laboratory setting. Every 2 h, subjects completed a divided attention task comprising 3 blocks in which an auditory Go/No-Go task was 1) performed alone (single task); 2) performed simultaneously with a visual Go/No-Go task (dual task); and 3) performed simultaneously with both a visual Go/No-Go task and a visually-guided motor tracking task (triple task). Performance on all tasks showed substantial deterioration during exposure to sleep deprivation. A significant interaction was observed between task load and time since wake on auditory Go/No-Go task performance, with greater impairment in response times and accuracy during extended wakefulness. Our results suggest that the ability to divide attention between multiple tasks is impaired during exposure to sleep deprivation. These findings have potential implications for occupations that require multi-tasking combined with long work hours and exposure to sleep loss.
