An educational overview of vagus nerve anatomy and taVNS research.
The vagus nerve (cranial nerve X) is the longest and most complex of the cranial nerves. It runs from the brainstem through the neck and thorax to the abdomen, connecting the brain to most major organs including the heart, lungs, digestive tract, and spleen. It is a key component of the parasympathetic nervous system, playing a significant role in regulating heart rate, digestion, respiration, inflammation, and immune response.
A small branch known as the auricular branch of the vagus nerve (ABVN) or Arnold's nerve supplies sensory innervation to specific regions of the outer ear. This provides an accessible pathway for non-invasive vagus nerve stimulation. The ABVN primarily innervates the cymba concha and parts of the ear canal.
Butt MF, et al. The anatomical basis for transcutaneous auricular vagus nerve stimulation. J Anat. 2020;236(4):588-611. pubmed.ncbi.nlm.nih.gov/31960460
Peuker ET, Filler TJ. The nerve supply of the human auricle. Clin Anat. 2002;15(1):35-37. pubmed.ncbi.nlm.nih.gov/11835540
Transcutaneous auricular Vagus Nerve Stimulation (taVNS) is a non-invasive technique that delivers mild electrical stimulation to the auricular branch of the vagus nerve through the skin of the outer ear. taVNS is distinct from surgically implanted VNS, offering a non-invasive alternative.
Published research has explored taVNS in areas including autonomic nervous system regulation, heart rate variability, neuroplasticity, inflammatory response modulation, pain processing, and cognitive function. The field continues to grow with new studies being published regularly.
Badran BW, et al. Neurophysiologic effects of transcutaneous auricular vagus nerve stimulation. Brain Stimul. 2018;11(3):492-500. pubmed.ncbi.nlm.nih.gov/29361411
Yap JY, et al. Critical review of transcutaneous vagus nerve stimulation. Front Neurosci. 2020;14:284. pubmed.ncbi.nlm.nih.gov/32351348
Clancy JA, et al. Non-invasive vagus nerve stimulation in healthy humans reduces sympathetic nerve activity. Brain Stimul. 2014;7(6):871-877. pubmed.ncbi.nlm.nih.gov/25164907
Antonenko D, et al. Transcutaneous auricular vagus nerve stimulation modulates heart rate variability. Neurobiol Stress. 2021;15:100386. pubmed.ncbi.nlm.nih.gov/34584916
Tracey KJ. The inflammatory reflex. Nature. 2002;420(6917):853-859. pubmed.ncbi.nlm.nih.gov/12490958
Koopman FA, et al. Vagus nerve stimulation inhibits cytokine production. Proc Natl Acad Sci USA. 2016;113(29):8284-8289. pubmed.ncbi.nlm.nih.gov/27382171
Redgrave J, et al. Safety and tolerability of transcutaneous vagus nerve stimulation. Brain Stimul. 2018;11(6):1225-1238. pubmed.ncbi.nlm.nih.gov/30104163
For broader searches: PubMed — taVNS publications | ClinicalTrials.gov — taVNS studies