Striatal plasticity and motor learning-importance of circadian rhythms, sleep stages and dreaming

In this brief comment, we emphasize the importance of circadian rhythms, sleep stages and especially REM sleep for motor and procedural learning which needs to be taken into account when studying striatal plasticity. Mode and timing of application could also play a crucial role for long-term dopaminergic therapies and behavioural and other changes. We further propose a model where the brain, during REM sleep/dreaming, by random recombinations of small pieces of past experiences, tries to anticipate situations not yet experienced and to prepare it-self, in an 'off' situation, for adequate new motor procedural responses.