<qa>  What is the gamma-aminobutyric acid A receptor-mediatedSICI is measured by delivering a subthreshold conditioning pulse prior to the suprathreshold test pulse at short interstimulus intervals ISI of 1-5 milliseconds ms resulting in a lower motor evoked potential MEP response to the test pulse. SICI is regarded as a gamma-aminobutyric acid A GABA-A receptor-mediated inhibition that involves activation of the cortical inhibitory interneurons. ICF is measured using a paradigm similar to SICI but with a longer ISI of 8-30 ms resulting in increase in MEP response. Glutamate is probably involved in producing ICF through cortical facilitation. 