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

SOLANO, AGUSTIN; RIQUELME, LUIS; PEREZ CHADA, DANIEL; DELLA MAGGIORE, VALERIA

San Diego

Congreso; Neuroscience 2018 - SfN Annual Meeting; 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 et al, 2015). Convergent experimental evidence from human and non-human animals suggests in fact that long-term hippocampal memory measured overnight is associated with an increase in the level of coupling 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 coupling in non-hippocampal motor memories. To address this issue, we carried out a study in which polisomnographic recordings were obtained from 10 healthy right-handed participants during a night of sleep after performing a visuomotor adaptation task with the right hand. Participants came to the sleep lab three times (familiarization, experimental and control sessions), each separated by one week, and performed the task before and after a full night of sleep. During the experimental session subjects learned to adapt to a 45 deg rotation; during the control session, subjects performed the same task without the perturbation. Sleep recordings were staged according to standard criteria. Spindles and Slow Oscillations were identified using standard detection algorithms in artifact-free NREM sleep segments (Mölle et al, 2011). SO (0.5-1.25Hz) and Spindle (10-16Hz) density and the coupling between Spindles and SO was computed. No differences were found in the sleep architecture across experimental conditions. There were no significant differences in the frequency and duration of spindles across conditions. Yet, we found a significant increase in the density of Spindles in the experimental 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 the frontal (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 of hippocampal memories, but may reflect a non-specific process underlying consolidation in different memory systems.