Visuomotor adaptation increases the number of spindles associated with slow oscillations during NREM sleep

SOLANO A, RIQUELME L, PEREZ-CHADA D, DELLA MAGGIORE V

San Diego

Congreso; Annual meeting of the Society for Neuroscience; 2018

Society for Neuroscience

It has been suggested that during nocturnal consolidation of hippocampal memories, slow oscillations(SO) facilitate the emergence of sleep spindles, which in turn recruit hippocampal ripples (Staresina etal, 2015). Convergent experimental evidence from human and non-human animals suggests in factthat long-term hippocampal memory measured overnight is associated with an increase in the level ofcoupling between sleep spindles and slow oscillations (~1Hz) during Non-Rapid Eye Movement(NREM) sleep. Little is known, however, about the presence and relevance of this SO-spindle couplingin non-hippocampal motor memories. To address this issue, we carried out a study in whichpolisomnographic recordings were obtained from 10 healthy right-handed participants during a night ofsleep after performing a visuomotor adaptation task with the right hand. Participants came to the sleeplab three times (familiarization, experimental and control sessions), each separated by one week, andperformed the task before and after a full night of sleep. During the experimental session subjectslearned to adapt to a 45 deg rotation; during the control session, subjects performed the same taskwithout the perturbation. Sleep recordings were staged according to standard criteria. Spindles andSlow Oscillations were identified using standard detection algorithms in artifact-free NREM sleepsegments (Mölle et al, 2011). SO (0.5-1.25Hz) and Spindle (10-16Hz) density and the couplingbetween Spindles and SO was computed. No differences were found in the sleep architecture acrossexperimental conditions. There were no significant differences in the frequency and duration ofspindles across conditions. Yet, we found a significant increase in the density of Spindles in theexperimental compared to the control session (Session: F(1,8)=3.539, p=.097; Channel:F(10,80)=5.068, p=.001; Session*Chan: F(10,80)=2.164, p=.028). This increment detected in thefrontal (FC1) and central (C3, C4) electrodes was associated with the occurrence of SO (RM-ANOVA.Session: F(1,8)=2.410, p=0.159; Channel: F(10,80)=6.673, p=0.001; Session*Chan interaction:F(10,80)=2.310, p=0.019). Our results suggest that the SO-Spindle interaction may not be privative ofhippocampal memories, but may reflect a non-specific process underlying consolidation in differentmemory systems.