REM Sleep POST-EYE Movement Activation

Correspondence: María Corsi-Cabrera, Sleep Laboratory, Facultad de Psicología, Posgrado, Universidad Nacional Autónoma de México, Av. Universidad 3004, México, D.F. 04510, México. Phone: (52-55)6-22-22-51; Fax: (52-55)6-22-23-10. [email protected] Abstract. Gamma EEG and MEG activity was studied immediately after REM sleep eye movement onset as an index of cortical activation. Two strategies were used: a descriptive approach using principal component analysis (PCA), and a statistical comparison of gamma absolute power and temporal coupling between 500-millisecond time windows before (PREEM) and after (POST-EM1, POST-EM2) eye movement onset. Longer periods of REM sleep without eye movement (T-REM) and with eye movement bursts (Ph-REM) were also compared. Findings showed that directly after eye movement (POST-EM1, POST-EM2), larger recording sites become related; EEG gamma power and local temporal coupling in the frontal and posterior association areas is higher than during T-REM and PRE-EM. During Ph-REM compared to T-REM, there is a sustained increase in gamma power and interhemispheric coupling; whereas frontal and parietal regions become uncoupled. REM sleep eye movements are accompanied by transient endogenous excitatory signals widely distributed over the brain and not confined to visual areas, that confer special properties to the system by providing conditions that allow calcium entrance to neurons and the propagation of local activity patterns to larger brain areas, thus favoring two functions attributed to REM sleep: plastic changes and the creation of new unplanned associations.