Facilitation of late somatosensory evoked potentials by electrical train stimuli.
Somatosensory evoked potentials (SSEP) may reflect synaptic events and could be suitable to characterise the short-time plasticity of synaptic potentials (SP). For this purpose, the left superficial radial nerve was stimulated in 7 subjects with single or trains of 3 stimuli (C4' against Fz, time interval 500 ms, 1 Hz or 0.4 Hz). The within train interstimulus intervals (ISI) were varied from 2 ms to 10 ms. N20, N1 and N2 displayed a significant gain in amplitude following train stimuli compared with single stimuli. Short ISIs of 2-4 ms led to higher amplitudes of N20, N1 and N2 compared with longer ISIs of 7-10 ms. In general, larger amplitude values were observed with 0.4 Hz stimulus repetition compared with 1.0 Hz. This data reflects synaptic facilitation and refractoriness/habituation. Our results could be helpful to non-invasevely investigate synaptic decay dynamics by late SSEP in diseases of the central nervous system such as migraine or epilepsy.
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Zakharova
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Kornhuber
D000328:Adult; D001921:Brain / Q000502:physiology*; D004558:Electric Stimulation; D004569:Electroencephalography; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D006185:Habituation, Psychophysiologic / Q000502:physiology*; D006801:Humans; D008297:Male; D009473:Neuronal Plasticity / Q000502:physiology*; D055815:Young Adult