The European journal of neuroscience
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Randomized Controlled Trial Comparative Study
Differences between the effects of three plasticity inducing protocols on the organization of the human motor cortex.
Several experimental protocols induce lasting changes in the excitability of motor cortex. Some involve direct cortical stimulation, others activate the somatosensory system and some combine motor and sensory stimulation. The effects usually are measured as changes in amplitude of the motor-evoked-potential (MEP) or short-interval intracortical inhibition (SICI) elicited by a single or paired pulses of transcranial magnetic stimulation (TMS). ⋯ Motor practice had a dual effect and increased MEPs as well as affecting sensorimotor organization. The implication is that different protocols target different sets of cortical circuits. We speculate that protocols that involve repeated activation of motor cortical output lead to lasting changes in efficacy of synaptic connections in output circuits, whereas protocols that emphasize sensory inputs affect the strength of sensory inputs to motor circuits.