Fig. 3

Chronic daily nVNS exerts comparable efficacy to acute treatment. A Schematic diagram of chronic daily noninvasive transcutaneous VNS paradigm. A Bar indicates 2 × 2-minute stimulation (B-C) Representative intra-cortical microelectrode recordings and whisker–box plots show the effects of noninvasive femoral nerve stimulation (nFNS) or noninvasive transcutaneous VNS (2 × 2-minute, 11.4 V) on electrical threshold (B) and KCl (1 M)-evoked CSD frequency (C) in rats. Whisker–box plots show that chronic daily nVNS significantly elevates electrical threshold and inhibits KCl-evoked CSD frequency in rats (whisker: full range; line: median; cross: mean; ^*P=0.0184 for electrical threshold, ^*P=0.0039 for CSD frequency, compared to daily nFNS group, n=6 for nFNS and n=8 for nVNS, unpaired-t-test with Welch’s correction), which is comparable to acute treatment (Fig. 2)