This enables future work to characterize E/I profile of spindles, investigate their interaction with SOs, test their role as windows of phase-dependent synaptic plasticity & causal relevance for systems memory consolidation to build effective therapies in psychiatry & neurology.

Our findings suggests spindles exerts asymmetrical “pulsed inhibition” on corticospinal excitability, complementing previous reports of phasic modulation of MEPs by the sleep SO as well as asymmetrical “pulsed facilitation” by the sensorimotor mu-alpha rhythm during wakefulness.

We provide the first in-human demonstration of the feasibility of real-time sleep spindle phase-triggered TMS in humans and of a phasic modulation of corticospinal excitability by the sleep spindle.