TITLE
Inducing LTD-Like Effect in the Human Motor Cortex with Low Frequency and Very Short Duration Paired Associative Stimulation: An Exploratory Study.
AUTHORS
Srivanitchapoom P; Park JE; Thirugnanasambandam N; Panyakaew P; Ramos VF; Pandey S; Wu T; Hallett M. Institution Srivanitchapoom, Prachaya. Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA; Division of Neurology, Department of Medicine, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand. Park, Jung E. Human Motor Control Section, National Institute o f Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA. Thirugnanasambandam, Nivethida. Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA. Panyakaew, Pattamon. Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA; Department of Medicine, Faculty of Medicine, Chulalongkorn Center of Excellence on Parkinson’s Disease and Related Disorders, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok 10330, Thailand. Ramos, Vesper Fe Marie. Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA. Pandey, Sanjay. Govind Ballabh Pant Hospital, New Delhi 110002, Ind ia. Wu, Tianxia. Clinical Neurosciences Program, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA. Hallett, Mark. Human Motor Control Section, National Institute o f Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
SOURCE
Neural Plasticity. 2016:3920298, 2016.
ABSTRACT
Paired associative stimulation (PAS) is an established technique to investigate synaptic plasticity in the human motor cortex (M1). Classically, to induce long-term depression- (LTD-) or long-term potentiation-like effects in the human M1, studies have used low frequency and long duration trains of PAS. In the present study, we explored an LTD-like effect using very short duration and low frequency of PAS10ms protocols in human M1.
METHODS
Six protocols of low frequency PAS1 0ms (ranging from 0.2Hz to 1Hz) were investigated with very short durations of 1 and 2 minutes stimulation. Six healthy volunteers were included in each protocol. We obtained motor-evoked potentials from right abductor pollicis brevis muscle before and after applying PAS10ms up to 30 minutes. After we found PAS10ms protocol which induced an LTD-like effect, we tested that protocol on additional 5 subjects.
RESULTS
One-way repeated-measures ANOVA showed that only the group of 1-minute stimulation of 0.2 5Hz induced an LTD-like effect. When adding the additional subjects, the effect remained and lasted for 30 minutes.
CONCLUSION
Low frequency and very short duration of PAS10ms potentially induced an LTD-like effect in human M1. With further verification, this method might be useful for research relating to synaptic plasticity by reducing the duration of study and minimizing subject discomfort.
Publication Type Journal Article.
Research Support, N.I.H., Intramural.
