Transcutaneous auricular vagus nerve stimulation attenuates neuroinflammation in a mouse model of traumatic brain injury

Transcutaneous auricular vagus nerve stimulation (VNS) activated the solitary tract nucleus and the dorsal motor nucleus of the vagus nerve as evidenced by a significant upregulation of the neuronal activation marker c-Fos, indicating vagus nerve activation. Transcutaneous auricular VNS treatment reduced the expression of pro-inflammatory microglial markers Tnf (1.69 ± 0.17 vs. 3.615 ± 0.86, p < 0.05) and Lcn2 (64.15 ± 14 vs. 337.7 ± 104.8, p < 0.01) in the ipsilateral injured cortex on PIDs 3 and 7, respectively. Transcutaneous auricular VNS also increased the expression of anti-inflammatory microglial marker Arg1 (55 ± 6.47 vs. 30.49 ± 3.94, p < 0.01) and astrocyte Gfap reactivity (8,582 ± 826 vs. 4,569 ± 554.3, p < 0.01) on PID 3. ( J Trauma Acute Care Surg . 2026;100: 707-713. Copyright © 2025 Wolters Kluwer Health, Inc. All rights reserved.).