Genes, Brain and Behavior. 2020;e12641 (2020) DOI: 10.1111/gbb.12641
Anu-Katriina Pesonen1, Ilona Merikanto1,2, Risto Halonen1, Peter Ujma3,4, Tommi Makkonen5, Katri Raikkönen5, Jari Lahti5, Liisa Kuula1
1SleepWell Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
2National Institute for Health and Welfare, Helsinki, Finland
3Institute of Behavioural Sciences, Semmelweis University, Budapest, Hungary
4Epilepsy Centre, National Institute of Clinical Neurosciences, Budapest, Hungary
5Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland
Sleep spindles are thalamocortical oscillations that contribute to sleep maintenance and sleep‐related brain plasticity. The current study is an explorative study of the circadian dynamics of sleep spindles in relation to a polygenic score (PGS) for circadian preference towards morningness. The participants represent the 17‐year follow‐up of a birth cohort having both genome‐wide data and an ambulatory sleep electroencephalography measurement available ( N = 154, Mean age = 16.9, SD = 0.1 years, 57% girls). Based on a recent genome‐wide association study, we calculated a PGS for circadian preference towards morningness across the whole genome, including 354 single‐nucleotide polymorphisms. Stage 2 slow (9‐12.5 Hz, N = 186 739) and fast (12.5‐16 Hz, N = 135 504) sleep spindles were detected using an automated algorithm with individual time tags and amplitudes for each spindle. There was a significant interaction of PGS for morningness and timing of sleep spindles across the night. These growth curve models showed a curvilinear trajectory of spindle amplitudes: those with a higher PGS for morningness showed higher slow spindle amplitudes in frontal derivations, and a faster dissipation of spindle amplitude in central derivations. Overall, the findings provide new evidence on how individual sleep spindle trajectories are influenced by genetic factors associated with circadian type. The finding may lead to new hypotheses on the associations previously observed between circadian types, psychiatric problems and spindle activity.
Keywords: brain, circadian rhythm, gene, plasticity, polygenic score, polysomnography, sleep, sleep EEG, sleep spindle, sleep timing, young adult