What Is the Involvement of the Cerebellum During Sleep?

Abstract

Compared with the advances in the elucidation of the role of brainstem and hypothalamus in the control of wakefulness and sleep stages,1 the functions of the cerebellum during sleep remain relatively unexplored.2 However, the activity in the cerebellum changes concomitantly with that of the neocortex during distinct sleep stages, as shown, for example, with a simultaneous recoding of sleep EEG and regional blood flow or fMRI signals in the cerebellum in humans.2-10 Electrophysiologic studies show variation in the firing rate of Purkinje and cerebellar nuclear cells according to the neocortical sleep stage.11-15 Recent studies show hippocampal-cerebellar interactions both during non-REM (NREM) and REM sleep16 and suggest a cerebellar contribution to the generation of sleep spindles in the neocortex.15 There are several potential pathways for the coordination of neocortical or hippocampal regions with cerebellar activity during sleep (Figure). This reciprocal communication may provide a potential basis for the consolidation of motor learning and other cognitive functions.17-22 The cerebellum is affected in several disorders associated with sleep disturbances.23-25 However, the contribution of the cerebellum to the normal regulation of sleep and its role in sleep disorders are still incompletely understood. Elucidating the role of the cerebellum in the control of arousal and sleep-wake cycle has potential clinical and therapeutic implications.