title: Differences in electroencephalographic non-rapid-eye movement sleep slow-wave characteristics between young and old mice.
abstract: Changes in sleep pattern are typical for the normal aging process. However, aged mice show an increase in the amount of sleep, whereas humans show a decrease when aging. Mice are considered an important model in aging studies, and this divergence warrants further investigation. Recently, insights into the network dynamics of cortical activity during sleep were obtained by investigating characteristics of individual electroencephalogram (EEG) slow waves in young and elderly humans. In this study, we investigated, for the first time, the parameters of EEG slow waves, including their incidence, amplitude, duration and slopes, in young (6 months) and older (18-24 months) C57BL/6J mice during undisturbed 24 h, and after a 6-h sleep deprivation (SD). As expected, older mice slept more but, in contrast to humans, absolute NREM sleep EEG slow-wave activity (SWA, spectral power density between 0.5-4 Hz) was higher in the older mice, as compared to the young controls. Furthermore, slow waves in the older mice were characterized by increased amplitude, steeper slopes and fewer multipeak waves, indicating increased synchronization of cortical neurons in aging, opposite to what was found in humans. Our results suggest that older mice, in contrast to elderly humans, live under a high sleep pressure.
authors.affiliation: Laboratory for Neurophysiology, Department of Molecular Cell Biology, Leiden University Medical Centre, 2333 ZC Leiden, The Netherlands.
authors.forename: Maria
authors.initials: M
authors.lastname: Panagiotou
authors.affiliation: Department of Physiology, Anatomy and Genetics, University of Oxford, OX1 3PT Oxford, UK.
authors.forename: Vladyslav V
authors.initials: VV
authors.lastname: Vyazovskiy
authors.affiliation: Laboratory for Neurophysiology, Department of Molecular Cell Biology, Leiden University Medical Centre, 2333 ZC Leiden, The Netherlands.
authors.forename: Johanna H
authors.initials: JH
authors.lastname: Meijer
authors.affiliation: Laboratory for Neurophysiology, Department of Molecular Cell Biology, Leiden University Medical Centre, 2333 ZC Leiden, The Netherlands.
authors.forename: Tom
authors.initials: T
authors.lastname: Deboer
mesh_terms: D000367:Age Factors; D000818:Animals; D004569:Electroencephalography; D055724:Electrophysiological Phenomena; D051379:Mice; D012890:Sleep / Q000502:physiology; D012894:Sleep Stages / Q000502:physiology*; D012895:Sleep, REM / Q000502:physiology