Deep sleep maintains learning efficiency of the human brain.

Fattinger, Sara and de Beukelaar, Toon T and Ruddy, Kathy L and Volk, Carina and Heyse, Natalie C and Herbst, Joshua A and Hahnloser, Richard HR and Wenderoth, Nicole and Huber, Reto
Nature communications, 8: 15405, 2017

It is hypothesized that deep sleep is essential for restoring the brain’s capacity to learn efficiently, especially in regions heavily activated during the day. However, causal evidence in humans has been lacking due to the inability to sleep deprive one target area while keeping the natural sleep pattern intact. Here we introduce a novel approach to focally perturb deep sleep in motor cortex, and investigate the consequences on behavioural and neurophysiological markers of neuroplasticity arising from dedicated motor practice. We show that the capacity to undergo neuroplastic changes is reduced by wakefulness but restored during unperturbed sleep. This restorative process is markedly attenuated when slow waves are selectively perturbed in motor cortex, demonstrating that deep sleep is a requirement for maintaining sustainable learning efficiency.