Effects of Stimulus Frequency, Intensity, and Sex on the Autonomic Response to Transcutaneous Vagus Nerve Stimulation
This study aimed to determine how transcutaneous vagus nerve stimulation (tVNS) alters autonomic nervous activity by comparing the effects of different tVNS frequencies and current intensities. We also investigated the sex-dependent autonomic response to tVNS. Thirty-five healthy adult participants...
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MDPI AG
2022-08-01
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| Series: | Brain Sciences |
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| Online Access: | https://www.mdpi.com/2076-3425/12/8/1038 |
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| author | Hirotake Yokota Mutsuaki Edama Ryo Hirabayashi Chie Sekine Naofumi Otsuru Kei Saito Sho Kojima Shota Miyaguchi Hideaki Onishi |
| author_facet | Hirotake Yokota Mutsuaki Edama Ryo Hirabayashi Chie Sekine Naofumi Otsuru Kei Saito Sho Kojima Shota Miyaguchi Hideaki Onishi |
| author_sort | Hirotake Yokota |
| collection | DOAJ |
| description | This study aimed to determine how transcutaneous vagus nerve stimulation (tVNS) alters autonomic nervous activity by comparing the effects of different tVNS frequencies and current intensities. We also investigated the sex-dependent autonomic response to tVNS. Thirty-five healthy adult participants were stimulated using a tVNS stimulator at the left cymba conchae while sitting on a reclining chair; tVNS-induced waveform changes were then recorded for different stimulus frequencies (Experiment 1: 3.0 mA at 100 Hz, 25 Hz, 10 Hz, 1 Hz, and 0 Hz (no stimulation)) and current intensities (Experiment 2: 100 Hz at 3.0 mA, 1.0 mA, 0.2 mA (below sensory threshold), and 0 mA (no stimulation)) using an electrocardiogram. Pulse widths were set at 250 µs in both experiment 1 and 2. Changes in heart rate (HR), root-mean-square of the difference between two successive R waves (RMSSD), and the ratio between low-frequency (LF) (0.04–0.15 Hz) and high-frequency (HF) (0.15–0.40 Hz) bands (LF/HF) in spectral analysis, which indicates sympathetic and parasympathetic activity, respectively, in heart rate variability (HRV), were recorded for analysis. Although stimulation at all frequencies significantly reduced HR (<i>p</i> = 0.001), stimulation at 100 Hz had the most pronounced effect (<i>p</i> = 0.001) in Experiment 1 and was revealed to be required to deliver at 3.0 mA in Experiment 2 (<i>p</i> = 0.003). Additionally, participants with higher baseline sympathetic activity experienced higher parasympathetic response during stimulation, and sex differences may exist in the autonomic responses by the application of tVNS. Therefore, our findings suggest that optimal autonomic changes induced by tVNS to the left cymba conchae vary depending on stimulating parameters and sex. |
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| institution | Directory Open Access Journal |
| issn | 2076-3425 |
| language | English |
| last_indexed | 2024-03-09T11:48:42Z |
| publishDate | 2022-08-01 |
| publisher | MDPI AG |
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| spelling | doaj.art-b0456ac3748d495e826a6fa3f181da372023-11-30T23:18:10ZengMDPI AGBrain Sciences2076-34252022-08-01128103810.3390/brainsci12081038Effects of Stimulus Frequency, Intensity, and Sex on the Autonomic Response to Transcutaneous Vagus Nerve StimulationHirotake Yokota0Mutsuaki Edama1Ryo Hirabayashi2Chie Sekine3Naofumi Otsuru4Kei Saito5Sho Kojima6Shota Miyaguchi7Hideaki Onishi8Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata 950-3198, JapanInstitute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata 950-3198, JapanInstitute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata 950-3198, JapanInstitute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata 950-3198, JapanInstitute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata 950-3198, JapanInstitute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata 950-3198, JapanInstitute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata 950-3198, JapanInstitute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata 950-3198, JapanInstitute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata 950-3198, JapanThis study aimed to determine how transcutaneous vagus nerve stimulation (tVNS) alters autonomic nervous activity by comparing the effects of different tVNS frequencies and current intensities. We also investigated the sex-dependent autonomic response to tVNS. Thirty-five healthy adult participants were stimulated using a tVNS stimulator at the left cymba conchae while sitting on a reclining chair; tVNS-induced waveform changes were then recorded for different stimulus frequencies (Experiment 1: 3.0 mA at 100 Hz, 25 Hz, 10 Hz, 1 Hz, and 0 Hz (no stimulation)) and current intensities (Experiment 2: 100 Hz at 3.0 mA, 1.0 mA, 0.2 mA (below sensory threshold), and 0 mA (no stimulation)) using an electrocardiogram. Pulse widths were set at 250 µs in both experiment 1 and 2. Changes in heart rate (HR), root-mean-square of the difference between two successive R waves (RMSSD), and the ratio between low-frequency (LF) (0.04–0.15 Hz) and high-frequency (HF) (0.15–0.40 Hz) bands (LF/HF) in spectral analysis, which indicates sympathetic and parasympathetic activity, respectively, in heart rate variability (HRV), were recorded for analysis. Although stimulation at all frequencies significantly reduced HR (<i>p</i> = 0.001), stimulation at 100 Hz had the most pronounced effect (<i>p</i> = 0.001) in Experiment 1 and was revealed to be required to deliver at 3.0 mA in Experiment 2 (<i>p</i> = 0.003). Additionally, participants with higher baseline sympathetic activity experienced higher parasympathetic response during stimulation, and sex differences may exist in the autonomic responses by the application of tVNS. Therefore, our findings suggest that optimal autonomic changes induced by tVNS to the left cymba conchae vary depending on stimulating parameters and sex.https://www.mdpi.com/2076-3425/12/8/1038transcutaneous vagus nerve stimulation (tVNS)heart rate variabilitystimulus frequencystimulus intensitysex differencesparasympathetic nervous activity |
| spellingShingle | Hirotake Yokota Mutsuaki Edama Ryo Hirabayashi Chie Sekine Naofumi Otsuru Kei Saito Sho Kojima Shota Miyaguchi Hideaki Onishi Effects of Stimulus Frequency, Intensity, and Sex on the Autonomic Response to Transcutaneous Vagus Nerve Stimulation Brain Sciences transcutaneous vagus nerve stimulation (tVNS) heart rate variability stimulus frequency stimulus intensity sex differences parasympathetic nervous activity |
| title | Effects of Stimulus Frequency, Intensity, and Sex on the Autonomic Response to Transcutaneous Vagus Nerve Stimulation |
| title_full | Effects of Stimulus Frequency, Intensity, and Sex on the Autonomic Response to Transcutaneous Vagus Nerve Stimulation |
| title_fullStr | Effects of Stimulus Frequency, Intensity, and Sex on the Autonomic Response to Transcutaneous Vagus Nerve Stimulation |
| title_full_unstemmed | Effects of Stimulus Frequency, Intensity, and Sex on the Autonomic Response to Transcutaneous Vagus Nerve Stimulation |
| title_short | Effects of Stimulus Frequency, Intensity, and Sex on the Autonomic Response to Transcutaneous Vagus Nerve Stimulation |
| title_sort | effects of stimulus frequency intensity and sex on the autonomic response to transcutaneous vagus nerve stimulation |
| topic | transcutaneous vagus nerve stimulation (tVNS) heart rate variability stimulus frequency stimulus intensity sex differences parasympathetic nervous activity |
| url | https://www.mdpi.com/2076-3425/12/8/1038 |
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