This article is part of a series on Noninvasive Brain stimulation, edited by Dr Edwards.

Review

Transcranial magnetic stimulation, synaptic plasticity and network oscillations

Patricio T Huerta and Bruce T Volpe

Weill Medical College at Cornell University, Department of Neurology and Neuroscience, Burke Cornell Medical Research Institute, 785 Mamaroneck Ave, White Plains, NY 10605, USA

author email corresponding author email

Journal of NeuroEngineering and Rehabilitation 2009, 6:7doi:10.1186/1743-0003-6-7

Published:	2 March 2009

Abstract

Transcranial magnetic stimulation (TMS) has quickly progressed from a technical curiosity to a bona-fide tool for neurological research. The impetus has been due to the promising results obtained when using TMS to uncover neural processes in normal human subjects, as well as in the treatment of intractable neurological conditions, such as stroke, chronic depression and epilepsy. The basic principle of TMS is that most neuronal axons that fall within the volume of magnetic stimulation become electrically excited, trigger action potentials and release neurotransmitter into the postsynaptic neurons. What happens afterwards remains elusive, especially in the case of repeated stimulation. Here we discuss the likelihood that certain TMS protocols produce long-term changes in cortical synapses akin to long-term potentiation and long-term depression of synaptic transmission. Beyond the synaptic effects, TMS might have consequences on other neuronal processes, such as genetic and protein regulation, and circuit-level patterns, such as network oscillations. Furthermore, TMS might have non-neuronal effects, such as changes in blood flow, which are still poorly understood.