Table 2.
Neuroinflammation modulation by VNS in animal model.
| Authors | Year | Models | VNS setting | Physiology/function studied |
|---|---|---|---|---|
| Mihaylova et al. | 2012 | Rat | 2 mA, 2 Hz, pulse width 0.3 ms, 10 min, repeated every 45 min, total 4.5 h | Anti-inflammatory effect of VNS on cerebral microcirculatory integrity |
| Meneses et al. | 2016 | Rat | 0.75 mA, 5 Hz, pulse width 2 ms, 30 s | Anti-inflammatory effects of VNS |
| Farrand et al. | 2017 | Rat | 0.8 mA, 30 Hz, 100 μs, 500 ms, 15 biphasic pulses every 30 s, 30 min twice, 4 h apart, 10 days | Therapeutic potential of VNS in a rat PD model |
| Nizamutdinov et al. | 2018 | Rat | Amplitude n/a, 5 Hz, pulse width 1 ms, 30 s on, 4 min and 30 s off, for 2 or 4 weeks | Pain threshold restoration by VNS in a GWI rat model |
| Jiang et al. | 2018 | Rat | Percutaneous auricular VNS: 0.8 mA, 30 Hz, 500 ms train of 15 biphasic pulses every 30 s, 30 min, every 2 days for 8 days, acupuncture needles inserted into the left cavum concha | SN dopaminergic neurodegeneration, the associated neuroinflammation and immune responses in PD animals |
| Chen et al. | 2018 | Mice | 0.5 mA, 5 Hz, 30 s every 5 min for 1 h | Effects on CMI by VNS in animals of CMI when exposed to colitis and the anti-inflammatory mechanisms |
| Huffman et al. | 2019 | Mice | Percutaneous cervical VNS: amplitude to reach 10% reduction in HR, 20 Hz, pulse width 300 ms, biphasic, charge-balanced pulses, 30 min, echo-guided needle electrode insertion at carotid sheath | Change of microglial activation and cognitive dysfunction following LPS endotoxinemia by VNS |
| Cai et al. | 2019 | Rat | Percutaneous auricular VNS: 0.5 mA, 20 Hz, 30 s train, 4 times, 5 min apart, acupuncture needles implanted on the left cavum concha | Changes of surgery-induced cognitive dysfunction in an aged rat model of POCD by VNS |
| Farrand et al. | 2020 | Rat | 0.75 A, pulse width 250 μs, with (1) low VNS: 10 Hz, 30 min on, 23.5 h off (2) standard VNS: 20 Hz, 30 s on, 5 min off, 24 h/day (3) burst VNS: 300 Hz (10 pulses per burst), 19 s inter-burst interval, 24 h/day | Different VNS paradigms in a PD animal model |
| Guo et al. | 2020 | Rat | Transauricular VNS (taVNS): 2 mA, 15 Hz, 30 min, 28 days, self-adsorption conductive magnet fixed in bilateral cavity of the auricular concha | Anti-inflammatory effect of VNS in rats with depression and chronic somatic pain comorbidity |
| Zhang et al. | 2020 | Rat | 1 V, 5 Hz, 2 ms, 30 s on, 5 min off, for 20 min | Changes of neuroinflammation and CIPN by VNS via CAP |
| Venkatasamy et al. | 2021 | Mice | Amplitude n.p., 5 Hz, pulse width 1 ms, 30 s on, 4 min 30 s off, continuous for 2 weeks | Chronic cognitive deficit and hippocampal astrocytosis in a rat model of GWI |
| Wang J. Y. et al. | 2021 | Rat | Percutaneous auricular VNS: EA apparatus at the auricular concha, 2 mA, 2 and 15 Hz, switched every s, 30 min/days, 21 days | Changes of hippocampal neuroinflammation and role of α7nAChR by taVNS |
| Liu et al. | 2022 | Rat | Transcutaneous cervical VNS on skin covering right vagal nerve, 3 parameters tested: (1) voltage: 1 V, 11.4 V, or 24.4 V, 25 Hz, 2 min (2) duration: 11.4 V, 25 Hz, 2 or 3 rounds of 2 min, 5 min apart, or single 6 min (3) chronic daily VNS: 11.4 V, 25 Hz, 2 rounds of 2 min, 5 min apart, 4 weeks vs. single VNS | Optimal nVNS paradigm for migraine |
| Namgung et al. | 2022 | Rat | Acute VNS: 10 mA, 5 Hz, pulse width 5 ms, 5 min Chronic VNS: 10 mA, 5 Hz, pulse width 5 ms, 5 min, 7 days | Regulation of pro-inflammatory cytokines in the hippocampus in a rat model of continuous stress |
| Tang et al. | 2022 | Rat | 0.5 mA, 20 Hz, pulse width 0.5 ms, 30 s on and 5 min off, total 1h | Neuroprotective effects of VNS through α7nAChR-mediated inhibition of pyroptosis |
| Iannucci et al. | 2022 | Mice | Amplitude n/a, 5 Hz, 1 ms pulse width, 30 s on, 4 min 30 s off, total 2–4 weeks | Improvement of cognitive impairment and hippocampal dysfunction by VNS in a model of GWI |
| Chen et al. | 2022 | Rat | 1.0 mA, 0.5 ms, 30 Hz, 10 min/day, 14 days | Efficacy and therapeutic mechanism of VNS in SCI |
| Caravaca et al. | 2022 | Mice | 1 mA, 250 μs biphasic pulse, 50 s interphase delay, 10 Hz, 5 min | Resolution of inflammation by VNS |
α7nAChR, α7 nicotinic acetylcholine receptor; CAP, cholinergic anti-inflammatory pathway; CIPN, chemotherapy-induced peripheral neuropathy; CMI, cerebral cortical microinfarct; EA, electroacupuncture; GWI, Gulf War Illness; LPS, lipopolysaccharide; n/a: not applicable; PD, Parkinson's disease; POCD, Post-operative cognition decline; SCI, spinal cord injury; SN, substantia nigra; VNS, vagus nerve stimulation.