1. GABA and cortical inhibition in motor and non-motor regions using combined TMS–EEG: A time analysis
- Author
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Fitzgerald, Paul B., Maller, Jerome J., Hoy, Kate, Farzan, Faranak, and Daskalakis, Zafiris J.
- Subjects
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GABA receptors , *MOTOR cortex , *TRANSCRANIAL magnetic stimulation , *ELECTROENCEPHALOGRAPHY , *PARIETAL lobe , *PREFRONTAL cortex , *EVOKED potentials (Electrophysiology) , *CONDITIONED response - Abstract
Abstract: Objective: The induction of long interval cortical inhibition (LICI) in motor cortex with paired pulse transcranial magnetic stimulation (ppTMS) is an established paradigm for the assessment of cortical inhibition, proposed to be related to GABAB receptor inhibitory neurotransmission. This study aimed to further evaluate recent methods of the assessment of LICI in non motor regions with ppTMS and electroencephalography (EEG). Methods: ppTMS was applied using a single coil to the motor and dorsolateral prefrontal cortex (DLPFC) in 14 healthy subjects, and in the parietal lobe in 5 of those subjects. Results: In the motor cortex, LICI resulted in significant suppression in mean cortical evoked activity on EEG between 75 and 250ms following delivery of the test stimulus. Maximal inhibition was seen from 50 to 250ms in DLPFC, and between 50 and 175ms in the parietal lobe. Conclusions: ppTMS may be used to produce LICI in several cortical regions with a time course similar to known GABAB activity. Significance: ppTMS induction of LICI can be recorded by combining TMS with EEG and seems to relate to GABAB activity. [Copyright &y& Elsevier]
- Published
- 2009
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