RT Journal Article
SR Electronic
T1 Theta-Burst Transcranial Magnetic Stimulation Alters Cortical Inhibition
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 1193
OP 1203
DO 10.1523/JNEUROSCI.1379-10.2011
VO 31
IS 4
A1 Alia Benali
A1 Jörn Trippe
A1 Elke Weiler
A1 Annika Mix
A1 Elisabeth Petrasch-Parwez
A1 Wolfgang Girzalsky
A1 Ulf T. Eysel
A1 Ralf Erdmann
A1 Klaus Funke
YR 2011
UL http://www.jneurosci.org/content/31/4/1193.abstract
AB Human cortical excitability can be modified by repetitive transcranial magnetic stimulation (rTMS), but the cellular mechanisms are largely unknown. Here, we show that the pattern of delivery of theta-burst stimulation (TBS) (continuous versus intermittent) differently modifies electric activity and protein expression in the rat neocortex. Intermittent TBS (iTBS), but not continuous TBS (cTBS), enhanced spontaneous neuronal firing and EEG gamma band power. Sensory evoked cortical inhibition increased only after iTBS, although both TBS protocols increased the first sensory response arising from the resting cortical state. Changes in the cortical expression of the calcium-binding proteins parvalbumin (PV) and calbindin D-28k (CB) indicate that changes in spontaneous and evoked cortical activity following rTMS are in part related to altered activity of inhibitory systems. By reducing PV expression in the fast-spiking interneurons, iTBS primarily affected the inhibitory control of pyramidal cell output activity, while cTBS, by reducing CB expression, more likely affected the dendritic integration of synaptic inputs controlled by other classes of inhibitory interneurons. Calretinin, the third major calcium-binding protein expressed by another class of interneurons was not affected at all. We conclude that different patterns of TBS modulate the activity of inhibitory cell classes differently, probably depending on the synaptic connectivity and the preferred discharge pattern of these inhibitory neurons.