Sleep

Brain-specific loss of the sirtuin 1 (SIRT1) gene has surprisingly little effect on sleep architecture or circadian rhythms in mice, according to a study published in Scientific Reports. The study also provides the first preclinical test of nicotinamide mononucleotide (NMN) as a direct sleep aid — and finds no benefit. What they found Researchers generated […]

Non-REM sleep spindles and REM alpha bursts work together to level the strength of newly acquired episodic memories, according to a study published in the Journal of Sleep Research. Spindle density predicted improvement for memories that had been weakened by interference, while REM alpha burst power predicted forgetting across the board. What they found Twenty-four […]

A new patient-reported outcome tool called FINI — the Functional Impacts of Narcolepsy Instrument — has been developed to capture the real-world burden of narcolepsy beyond excessive daytime sleepiness. The tool, introduced by Gert Jan Lammers and colleagues in Sleep, covers tiredness, cognitive functioning, cataplexy, social activities, daily tasks, and responsibilities. Most existing narcolepsy scales […]

A single night of sleep deprivation increases levels of the synaptic density marker SV2A in the thalamus, hippocampus, and parietal cortex, according to a randomized PET imaging study published in PLoS Biology. The findings provide direct in vivo support for the synaptic homeostasis hypothesis in humans. What they found Forty healthy adults (mean age 27.5 […]

Use of benzodiazepines and Z-drugs is associated with a 29% higher odds of developing Alzheimer’s disease, according to a systematic review and meta-analysis published in Drugs. However, the association varies by drug class, duration of action, and how the diagnosis is defined, and the authors caution that residual confounding and reverse causation limit causal interpretation. […]

Women have higher density of sleep spindles and greater power in both sigma and delta frequency bands during sleep compared with men, according to a systematic review and meta-analysis published in the Journal of Sleep Research. The finding holds for healthy adults but could not be confirmed in people with insomnia, where data remain too […]

Fragmented sleep after learning is linked to poorer memory and weaker neural reactivation of recently encoded information, according to a new study published as a preprint on bioRxiv. The effect holds across younger and older adults, but the neural signature differs with age. What they found Researchers used actigraphy to track sleep across a 24-hour […]

Performance gains attributed to sophisticated machine learning models for wearable sleep staging may actually reflect dataset characteristics and evaluation choices, according to a study published in Sleep Advances. A simple baseline that estimates wake probability from raw activity data alone can explain much of the variance in performance across architectures. What they found Researchers tested […]

Artificial light at night not only keeps reef fish awake, it also inflicts DNA damage on their brain neurons, researchers at Bar-Ilan University and Harvard University report in Current Biology. The study, led by Shachaf Ben-Ezra, is the first to directly link light-pollution-driven sleep disruption to neuronal genomic instability in a wild vertebrate, raising questions […]

Nightmare disorder has long been considered a REM parasomnia, but new research from King’s College London reveals that its signature may lie in the NREM sleep microarchitecture instead. In a study of 26 adults with nightmare disorder and 32 controls, published in NPJ Biological Timing and Sleep, Istvan Papp and colleagues found that people with […]