Activation of fast sleep spindles at the premotor cortex and parietal areas contributes to motor learning: a study using sLORETA.
OBJECTIVE
The present study examined whether slow and/or fast sleep spindles are related to visuomotor learning, by examining the densities of current sleep spindle activities.


METHODS
Participants completed a visuomotor task before and after sleep on the learning night. This task was not performed on the non-learning night. Standard polysomnographic recordings were made. After the amplitudes of slow and fast spindles were calculated, sLORETA was used to localize the source of slow and fast spindles and to investigate the relationship between spindle activity and motor learning.


RESULTS
Fast spindle amplitude was significantly larger on the learning than on the non-learning nights, particularly at the left frontal area. sLORETA revealed that fast spindle activities in the left frontal and left parietal areas were enhanced when a new visuomotor skill was learned. There were no significant learning-dependent changes in slow spindle activity.


CONCLUSIONS
Fast spindle activity increases in cortical areas that are involved in learning a new visuomotor skill. The thalamocortical network that underlies the generation of fast spindles may contribute to the synaptic plasticity that occurs during sleep.


CONCLUSIONS
Activity of fast sleep spindles is a possible biomarker of memory deficits.
Faculty of Sport Sciences, Waseda University, Tokorozawa, Saitama 359-1192, Japan.
Masako
M
Tamaki
Tatsuya
T
Matsuoka
Hiroshi
H
Nittono
Tadao
T
Hori
D000328:Adult; D001931:Brain Mapping / Q000379:methods; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000033:anatomy & histology / Q000502:physiology*; D006801:Humans; D007858:Learning / Q000502:physiology*; D015225:Magnetoencephalography / Q000379:methods*; D008297:Male; D009044:Motor Cortex / Q000502:physiology; D009068:Movement / Q000502:physiology; D009415:Nerve Net / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology; D009483:Neuropsychological Tests; D010296:Parietal Lobe / Q000033:anatomy & histology / Q000502:physiology*; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology; D012890:Sleep / Q000502:physiology*; D013788:Thalamus / Q000502:physiology; D013997:Time Factors; D055815:Young Adult