Effect of Repetitive Transcranial Magnetic Stimulation (rTMS) Over the Brain on the Neurotransmitter Binding

Effect of Repetitive Transcranial Magnetic Stimulation (rTMS) Over the Brain on the Neurotransmitter Binding

Effect of rTMS Over Primary Motor Cortex on Gamma-aminobutyric Acid A (GABAA)-[18F]Flumazenil Binding: A Positron Emission Tomography (PET) Study

The purpose of this study is to determine whether repetitive transcranial magnetic stimulation (rTMS) over the brain can modulate the binding of neurotransmitter (GABA in this study) to its receptor using the special PET study.

Repetitive transcranial magnetic stimulation (rTMS) can modulate the excitability of cortex but exact mechanism is not well determined in human-beings. Changes in some neurotransmitters' status in brain after rTMS have been suggested as a possible mechanism, but role of GABA is not clear. Twelve healthy people will be recruited. They will receive the rTMS over the primary motor cortex of the dominant hand. Individual subject will receive three sessions of rTMS with wash-out period (more than 3 days) between the rTMS sessions. Three rTMS sessions are high frequency (10Hz), low frequency (1Hz) and sham rTMS. The order of rTMS sessions will be randomly decided. After completing each rTMS session, [18F]flumazenil-PET will be checked. The purpose of this study is to investigate 1)whether rTMS over the primary motor cortex can modulate the [18F]flumazenil binding potential and 2)whether the modulation of [18F]flumazenil binding potential by rTMS can be different according to the applied frequency of rTMS.

Neuronal plasticity, Neurotransmitter agents, Receptors, neurotransmitter, Transcranial magnetic stimulation, Stroke, gamma-Aminobutyric Acid

<high frequency rTMS parameters> Intensity: 120% of resting motor threshold; Location: Motor hotspot in primary motor cortex for the dominant hand; Frequency: 10Hz; Number of total stimuli: 750; Coil orientation: tangential to scalp

<low frequency rTMS parameters> Intensity: 120% of resting motor threshold; Location: Motor hotspot in primary motor cortex for the dominant hand; Frequency: 1Hz; Number of total stimuli: 1200; Coil orientation: tangential to the scalp

<Sham rTMS parameters> Intensity: 120% of resting motor threshold; Location: Motor hotspot in primary motor cortex for the dominant hand; Frequency: 1Hz; Number of total stimuli: 1200; Coil orientation: perpendicular to scalp

Immediately after rTMS session , PET image will be acquired. By using these images, [18F]flumazenil binding potential will be calculated in selected anatomical region up to 3 months

Inclusion Criteria: Healthy people 18-50 yrs old Right handedness Written informed consent Exclusion Criteria: Previous medical diseases such as seizure, stroke, diabetes, hypertension. Taking any drugs Smoker Pregnancy Contraindication of PET or MRI Stroke or any tumor in MRI Metals objects in the head or eyes Cardiac pacemaker or cochlear implant

Department of Rehabilitation Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea

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