Impact d’une sieste sur plasticité cérébrale induite par stimulation magnétique transcrânienne
In humans, various repetitive transcranial magnetic stimulation (rTMS) protocols can be used to modulate motor cortical plasticity. These techniques have shed light on the role of sleep in neural plasticity regulation. Recent work has demonstrated that when a night of sleep follows one session of rTMS over the hand motor cortex (M1), the capacity to induce subsequent plasticity by another rTMS session in M1 is enhanced. The present study investigated whether such metaplasticity could also benefit from a day nap. Fourteen healthy participants received two sessions of intermittent theta burst stimulation (iTBS) known for its excitatory effects on cortical excitability over M1 spaced by either a 90-minute nap or an equivalent amount of wake. Motor cortical excitability was measured in terms of amplitude of motor evoked potentials (MEP), which were assessed before iTBS and after the stimulation. Results show that the first iTBS session did not induce significant change in MEP amplitude. The second iTBS session induced variable plastic changes regardless of whether participants slept or stayed awake. The effects of iTBS on motor cortical excitability were highly variable within and between individuals. The possible causes of such variability are discussed.
Theta burst stimulation (TBS) Plasticity Sleep Nap Transcranial magnetic stimulation (TMS) Metaplasticity Variability Human