Vagus nerve stimulation: a new tool for brain research and therapy
Abstract
Biological psychiatry has a long history of using somatic therapies to treat neuropsychiatric illnesses and to understand brain function. These methods have included neurosurgery, electroconvulsive therapy, and, most recently, transcranial magnetic stimulation. Fourteen years ago researchers discovered that intermittent electrical stimulation of the vagus nerve produces inhibition of neural processes, which can alter brain electrical activity and terminate seizures in dogs. Since then, approximately 6000 people worldwide have received vagus nerve stimulation for treatment-resistant epilepsy. We review the neurobiology and anatomy of the vagus nerve and provide an overview of the vagus nerve stimulation technique. We also describe the safety and potential utility of vagus nerve stimulation as a neuroscience research tool and as a putative treatment for psychiatric conditions. Vagus nerve stimulation appears to be a promising new somatic intervention that may improve our understanding of brain function and has promise in the treatment of neuropsychiatric disorders.
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When stimulated, the vagus nerve sends signals to the NTS, and the NTS sends direct projections to the amygdala and the hypothalamus.
“When stimulated, the vagus nerve sends signals to the NTS (162) and the NTS sends direct projections to the amygdala and the hypothalamus.”
From Vagus Nerve as Modulator of the Brain–Gut Axis in Psychiatric and Inflammatory Disorders (2018) · cites this paper as [162]
Cites
Gray, J. A. (1982) · Behavioral and Brain Sciences · doi:10.1017/s0140525x00013066 · Cited by 4,477 · see citing works
JAMES, W. (1884) · Mind · doi:10.1093/mind/os-ix.34.188 · Cited by 3,446 · see citing works
Davenport, Y. B., Adland, M. L., Gold, P. W., & Goodwin, F. K. (1984) · The Lancet · doi:10.1016/s0140-6736(84)92810-1 · Cited by 2,925 · see citing works
James, W. (2005) · Williams & Wilkins eBooks · doi:10.1037/10735-001 · Cited by 2,221 · see citing works
Electrical stimulation of the subthalamic nucleus in advanced Parkinson's disease.
Limousin, P., Krack, P., Pollak, P., Benazzouz, A., Ardouin, C., Hoffmann, D., & Benabid, A. (1998) · New England Journal of Medicine · doi:10.1056/nejm199810153391603 · Cited by 2,030 · see citing works
The Neuropsychology of Anxiety
Gray, J. A., & McNaughton, N. (2003) · doi:10.1093/acprof:oso/9780198522713.001.0001 · Cited by 1,933 · see citing works
Vagus nerve stimulation therapy for partial-onset seizures
Handforth, A., DeGiorgio, C. M., Schachter, S. C., Uthman, B. M., Naritoku, D. K., Tecoma, E. S., Henry, T. R., Collins, S. D., Vaughn, B. V., Gilmartin, R. C., et al. (1998) · Neurology · doi:10.1212/wnl.51.1.48 · Cited by 1,107 · see citing works
Cingulate function in depression: a potential predictor of treatment response
Mayberg, H. S., Brannan, S. K., Mahurin, R. K., Jerabek, P. A., Brickman, J. S., Tekell, J. L., Silva, J. A., McGinnis, S., Glass, T. G., Martin, C. C., et al. (1997) · NeuroReport · doi:10.1097/00001756-199703030-00048 · Cited by 1,029 · see citing works
Sackeïm, H. A., Prudic, J., Devanand, D. P., Kiersky, J. E., Fitzsimons, L., Moody, B. J., McElhiney, M. C., Coleman, E. A., & Settembrino, J. M. (1993) · New England Journal of Medicine · doi:10.1056/nejm199303253281204 · Cited by 940 · see citing works
(1990) · Medical Entomology and Zoology · Cited by 919 · see citing works
Long-term treatment with vagus nerve stimulation in patients with refractory epilepsy
Morris, G. L., Mueller, W. M., & The Vagus Nerve Stimulation Study Group E–E (1999) · Neurology · doi:10.1212/wnl.53.8.1731 · Cited by 727 · see citing works
Rush, A. J., George, M. S., Sackeïm, H. A., Marangell, L. B., Husain, M. M., Giller, C. A., Nahas, Z. H., Haines, S. J., Simpson, R. K., & Goodman, R. (2000) · Biological Psychiatry · doi:10.1016/s0006-3223(99)00304-2 · Cited by 693 · see citing works
Self-citationBen‐Menachem, E., Mañon‐Espaillat, R., Ristanovic, R., Wilder, B. J., Stefan, H., Mirza, W., Tarver, W. B., Wernicke, J. F., & First International Vagus Nerve Stimulation Study Group (1994) · Epilepsia · doi:10.1111/j.1528-1157.1994.tb02482.x · Cited by 683 · see citing works
Transient Acute Depression Induced by High-Frequency Deep-Brain Stimulation
Bejjani, B.-P. W., Damier, P., Arnulf, I., Thivard, L., Bonnet, A.-M., Dormont, D., Cornu, P., Pidoux, B., Samson, Y., & Agid, Y. (1999) · New England Journal of Medicine · doi:10.1056/nejm199905133401905 · Cited by 652 · see citing works
Enhanced recognition memory following vagus nerve stimulation in human subjects
Clark, K., Naritoku, D., Smith, D. C., Browning, R., & Jensen, R. A. (1999) · Nature Neuroscience · doi:10.1038/4600 · Cited by 575 · see citing works
Locus Coeruleus Lesions Suppress the Seizure‐Attenuating Effects of Vagus Nerve Stimulation
Krahl, S. E., Clark, K. B., Smith, D. C., & Browning, R. A. (1998) · Epilepsia · doi:10.1111/j.1528-1157.1998.tb01155.x · Cited by 556 · see citing works
Transcranial Magnetic Stimulation: Applications in Neuropsychiatry
George, M. S., Lisanby, S. H., & Sackeim, H. A. (1999) · Archives of General Psychiatry · doi:10.1001/archpsyc.56.4.300 · Cited by 496 · see citing works
Self-citationCarbamazepine in manic-depressive illness: a new treatment
Ballenger, J. C., & Post, R. M. (1980) · American Journal of Psychiatry · doi:10.1176/ajp.137.7.782 · Cited by 486 · see citing works
Self-citationPenry, J. K., & Dean, J. C. (1990) · Epilepsia · doi:10.1111/j.1528-1157.1990.tb05848.x · Cited by 474 · see citing works
Inhibition of Experimental Seizures in Canines by Repetitive Vagal Stimulation
Zabara, J. (1992) · Epilepsia · doi:10.1111/j.1528-1157.1992.tb01751.x · Cited by 398 · see citing works
Schachter, S. C., & Saper, C. B. (2020) · Thieme eBooks · doi:10.1055/b-0040-177306 · Cited by 397 · see citing works
Swann, A. C. (1997) · Archives of General Psychiatry · doi:10.1001/archpsyc.1997.01830130041008 · Cited by 379 · see citing works
The neuropsychology of anxiety
Green, S. (1983) · International Journal of Psychophysiology · doi:10.1016/0167-8760(83)90031-4 · Cited by 378 · see citing works
Ben‐Menachem, E., Hamberger, A., Hedner, T., Hammond, E. J., Uthman, B. M., Slater, J. D., Treig, T., Stefan, H., Ramsay, R. E., Wernicke, J. F., et al. (1995) · Epilepsy Research · doi:10.1016/0920-1211(94)00083-9 · Cited by 377 · see citing works
Schachter, S. C., & Saper, C. B. (1998) · Epilepsia · doi:10.1111/j.1528-1157.1998.tb01151.x · Cited by 373 · see citing works
Henry, T. R., Bakay, R. A. E., Votaw, J. R., Pennell, P. B., Epstein, C. M., Faber, T. L., Grafton, S. T., & Hoffman, J. M. (1998) · Epilepsia · doi:10.1111/j.1528-1157.1998.tb01448.x · Cited by 367 · see citing works
Rutecki, P. A. (1990) · Epilepsia · doi:10.1111/j.1528-1157.1990.tb05843.x · Cited by 341 · see citing works
Bailey, P., & Bremer, F. (1938) · Journal of Neurophysiology · doi:10.1152/jn.1938.1.5.405 · Cited by 333 · see citing works
Effects of electrode placement on the efficacy of titrated, low-dose ECT
Sackeïm, H. A., Decina, P., Kanzler, M., Kerr, B., & Malitz, S. (1987) · American Journal of Psychiatry · doi:10.1176/ajp.144.11.1449 · Cited by 300 · see citing works
Naritoku, D. K., Terry, W. J., & Helfert, R. H. (1995) · Epilepsy Research · doi:10.1016/0920-1211(95)00035-9 · Cited by 291 · see citing works
Effect of sleep deprivation on brain metabolism of depressed patients
Wu, J. C., Gillin, J. C., Buchsbaum, M. S., Hershey, T. G., Johnson, J., & Bunney, W. E. (1992) · American Journal of Psychiatry · doi:10.1176/ajp.149.4.538 · Cited by 290 · see citing works
Quantitative studies of the vagus nerve in the cat. I. The ratio of sensory to motor fibers
Foley, J. O., & DuBois, F. S. (1937) · The Journal of Comparative Neurology · doi:10.1002/cne.900670104 · Cited by 274 · see citing works
Bremner, J. D. (1997) · Archives of General Psychiatry · doi:10.1001/archpsyc.1997.01830160092012 · Cited by 273 · see citing works
The Anticonvulsant Hypothesis of the Mechanisms of Action of ECT
Sackeïm, H. A. (1999) · Journal of Ect · doi:10.1097/00124509-199903000-00003 · Cited by 254 · see citing works
Acute blood flow changes and efficacy of vagus nerve stimulation in partial epilepsy
Henry, T. R., Votaw, J. R., Pennell, P. B., Epstein, C. M., Bakay, R. A. E., Faber, T. L., Grafton, S. T., & Hoffman, J. M. (1999) · Neurology · doi:10.1212/wnl.52.6.1166 · Cited by 252 · see citing works
Studies of dosage, seizure threshold, and seizure duration in ECT
Sackeïm, H. A., Decina, P., Portnoy, S., Neeley, P., & Malitz, S. (1987) · Biological Psychiatry · doi:10.1016/0006-3223(87)90144-2 · Cited by 240 · see citing works
Sackeïm, H. A., Decina, P., Prohovnik, I., Malitz, S., & Resor, S. R. (1983) · PubMed · Cited by 211 · see citing works
Anxiety and Vagal Control of Heart Rate
Watkins, L. L., Grossman, P., Krishnan, R. R., & Sherwood, A. (1998) · Psychosomatic Medicine · doi:10.1097/00006842-199807000-00018 · Cited by 200 · see citing works
Ventricular asystole during vagus nerve stimulation for epilepsy in humans
Tatum, W. O., Moore, D. B., Stecker, M. M., Baltuch, G. H., French, J. A., Ferreira, J. A., Carney, P. M., Labar, D. R., & Vale, F. Ĺ. (1999) · Neurology · doi:10.1212/wnl.52.6.1267 · Cited by 186 · see citing works
Amar, A. P., Heck, C., Levy, M. L., Thomas, S., DeGiorgio, C. M., Oviedo, S., & Apuzzo, M. L. J. (1998) · Neurosurgery · doi:10.1097/00006123-199812000-00001 · Cited by 174 · see citing works
Asconapé, J. J., Moore, D. D., Zipes, D. P., Hartman, L. M., & Duffell, W. (1999) · Epilepsia · doi:10.1111/j.1528-1157.1999.tb02019.x · Cited by 171 · see citing works
Vagus Nerve Stimulation for the Treatment of Medically Intractable Seizures
Salinsky, M. (1996) · Archives of Neurology · doi:10.1001/archneur.1996.00550110128021 · Cited by 170 · see citing works
Fisher, R. S., & Handforth, A. (1999) · Neurology · doi:10.1212/wnl.53.4.666 · Cited by 169 · see citing works
Bockstaele, E. J. V., Peoples, J. F., & Valentino, R. J. (1999) · Biological Psychiatry · doi:10.1016/s0006-3223(99)00213-9 · Cited by 166 · see citing works
Peripheral control of hypersynchronous discharge in epilepsy
Zabara, J. (1985) · Electroencephalography and Clinical Neurophysiology · doi:10.1016/0013-4694(85)90626-1 · Cited by 163 · see citing works
Regulation of Limbic Motor Seizures by GABA and Glutamate Transmission in Nucleus Tractus Solitarius
Walker, B. R., Easton, A. E., & Gale, K. (1999) · Epilepsia · doi:10.1111/j.1528-1157.1999.tb00818.x · Cited by 161 · see citing works
Transcranial magnetic stimulation in neuropsychiatry
George, M. S., & Belmaker, R. H. (2000) · Cited by 153 · see citing works
Self-citationŌkuma, T., Kishimoto, A., Inoue., M. D. K., Hisashi, M., Atsushi, O., Matsushita, T., Nakao, T., & Ogura, C. (1973) · Psychiatry and Clinical Neurosciences · doi:10.1111/j.1440-1819.1973.tb02661.x · Cited by 146 · see citing works
Use of ECT for the Inpatient Treatment of Recurrent Major Depression
Olfson, M., Marcus, S. C., Sackeïm, H. A., Thompson, J., & Pincus, H. A. (1998) · American Journal of Psychiatry · doi:10.1176/ajp.155.1.22 · Cited by 134 · see citing works
Lamotrigine in Rapid-Cycling Bipolar Disorder
Fatemi, S. H., RAPPORT, D. J., Calabrese, J. R., & THURAS, P. D. (1997) · The Journal of Clinical Psychiatry · doi:10.4088/jcp.v58n1202 · Cited by 120 · see citing works
Mechanisms of Action of Anticonvulsants in Affective Disorders
Post, R. M., Weiss, S. R. B., & Chuang, D. (1992) · Journal of Clinical Psychopharmacology · doi:10.1097/00004714-199202001-00005 · Cited by 119 · see citing works
Increased limbic blood flow and total sleep deprivation in major depression with melancholia
Ebert, D., Feistel, H., Barocka, A., & Kaschka, W. P. (1994) · Psychiatry Research Neuroimaging · doi:10.1016/0925-4927(94)90004-3 · Cited by 108 · see citing works
Cingulate function in depression.
Larisch, R., Klimke, A., Vosberg, H., Gaebel, W., & Mueller-Gaertner, H. W. (1997) · PubMed · Cited by 94 · see citing works
Anxiety disorders and the use and abuse of drugs.
Calabrese, J. R., & Delucchi, G. A. (1989) · PubMed · Cited by 56 · see citing works
Depression, Cardiac Death, and the Central Nervous System
Glassman, A. H. (1998) · Neuropsychobiology · doi:10.1159/000026482 · Cited by 21 · see citing works
Hu, T.-W., & Rush, A. J. (1995) · Social Psychiatry and Psychiatric Epidemiology · doi:10.1007/bf00789058 · Cited by 16 · see citing works
Self-citation
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Vagus Nerve as Modulator of the Brain–Gut Axis in Psychiatric and Inflammatory Disorders
Breit, S., Kupferberg, A., Rogler, G., & Hasler, G. (2018) · Frontiers in Psychiatry · doi:10.3389/fpsyt.2018.00044 · Cited by 1,189 · see citing works
Deep Brain Stimulation to Reward Circuitry Alleviates Anhedonia in Refractory Major Depression
Schlaepfer, T. E., Cohen, M. X., Frick, C., Kosel, M., Brodesser, D., Axmacher, N., Joe, A. Y., Kreft, M., Lenartz, D., & Sturm, V. (2008) · Neuropsychopharmacology · doi:10.1038/sj.npp.1301408 · Cited by 1,027 · see citing works
The cholinergic anti-inflammatory pathway: a missing link in neuroimmunomodulation
Pavlov, V. A., Wang, H., Czura, C. J., Friedman, S. G., & Tracey, K. J. (2003) · Molecular Medicine · doi:10.1007/bf03402177 · Cited by 772 · see citing works
The bowel and beyond: The enteric nervous system in neurological disorders
Rao, M., & Gershon, M. D. (2016) · Nature Reviews Gastroenterology & Hepatology · doi:10.1038/nrgastro.2016.107 · Cited by 629 · see citing works
Sackeim, H. (2001) · Neuropsychopharmacology · doi:10.1016/s0893-133x(01)00271-8 · Cited by 568 · see citing works
Self-citationNemeroff, C. B., Mayberg, H. S., Krahl, S. E., McNamara, J., Frazer, A., Henry, T. R., George, M. S., Charney, D. S., & Brannan, S. K. (2006) · Neuropsychopharmacology · doi:10.1038/sj.npp.1301082 · Cited by 496 · see citing works
Self-citationFollesa, P., Biggio, F., Gorini, G., Caria, S., Talani, G., Dazzi, L., Puligheddu, M., Marrosu, F., & Biggio, G. (2007) · Brain Research · doi:10.1016/j.brainres.2007.08.045 · Cited by 352 · see citing works
Harshaw, C. (2015) · Psychological Bulletin · doi:10.1037/a0038101 · Cited by 302 · see citing works
Spinal Cord Stimulation Restores Locomotion in Animal Models of Parkinson's Disease
Fuentes, R., Petersson, P., Siesser, W. B., Caron, M. G., & Nicolelis, M. A. L. (2009) · Science · doi:10.1126/science.1164901 · Cited by 298 · see citing works
Nerves, Reflexes, and the Enteric Nervous System: Pathogenesis of the Irritable Bowel Syndrome
Gershon, M. D. (2005) · Journal of Clinical Gastroenterology · doi:10.1097/01.mcg.0000156403.37240.30 · Cited by 271 · see citing works
A review of functional neuroimaging studies of vagus nerve stimulation (VNS)
Chae, J.-H., Nahas, Z., Lomarev, M., Denslow, S., Lorberbaum, J. P., Bohning, D. E., & George, M. S. (2003) · Journal of Psychiatric Research · doi:10.1016/s0022-3956(03)00074-8 · Cited by 255 · see citing works
Self-citationA pilot study of vagus nerve stimulation (VNS) for treatment-resistant anxiety disorders
George, M. S., Ward, H. E., Ninan, P. T., Pollack, M., Nahas, Z., Anderson, B., Kose, S., Howland, R. H., Goodman, W. K., & Ballenger, J. C. (2008) · Brain Stimulation · doi:10.1016/j.brs.2008.02.001 · Cited by 251 · see citing works
Self-citationCholinergic antiinflammatory pathway inhibition of tumor necrosis factor during ischemia reperfusion
Bernik, T. R., Friedman, S. G., Ochani, M., DiRaimo, R., Susarla, S., Czura, C. J., & Tracey, K. J. (2002) · Journal of Vascular Surgery · doi:10.1067/mva.2002.129643 · Cited by 228 · see citing works
Vagus nerve stimulation for depression: efficacy and safety in a European study
Schlaepfer, T. E., Frick, C., Zobel, A., Maier, W., Heuser, I., Bajbouj, M., O'Keane, V., Corcoran, C., Adolfsson, R., Trimble, M., et al. (2008) · Psychological Medicine · doi:10.1017/s0033291707001924 · Cited by 205 · see citing works
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Iseger, T. A., van Bueren, N. E. R., Kenemans, J. L., Gevirtz, R., & Arns, M. (2020) · Brain Stimulation · doi:10.1016/j.brs.2019.10.006 · Cited by 142 · see citing works
Noble, L. J., Gonzalez, I. J., Meruva, V. B., Callahan, K. A., Belfort, B. D., Ramanathan, K. R., Meyers, E., Kilgard, M. P., Rennaker, R. L., & McIntyre, C. K. (2017) · Translational Psychiatry · doi:10.1038/tp.2017.191 · Cited by 121 · see citing works
Zobel, A., Joe, A., Freymann, N., Clusmann, H., Schramm, J., Reinhardt, M., Biersack, H.-J., Maier, W., & Broich, K. (2005) · Psychiatry Research: Neuroimaging · doi:10.1016/j.pscychresns.2005.02.010 · Cited by 117 · see citing works
Marin, M.-F., Camprodon, J. A., Dougherty, D. D., & Milad, M. R. (2014) · Depression and Anxiety · doi:10.1002/da.22252 · Cited by 106 · see citing works
Human vagus nerve branching in the cervical region.
Hammer, N., Glätzner, J., Feja, C., Kühne, C., Meixensberger, J., Planitzer, U., Schleifenbaum, S., Tillmann, B. N., & Winkler, D. (2015) · PLOS ONE · doi:10.1371/journal.pone.0118006 · Cited by 88 · see citing works
Cook (2014) · doi:10.1016/j.nec.2013.10.002 · Cited by 69 · see citing works
Smith, N. B., Doran, J. M., Sippel, L. M., & Harpaz-Rotem, I. (2017) · Neuroscience Letters · doi:10.1016/j.neulet.2017.01.006 · Cited by 46 · see citing works
Tissue/Organ Adaptable Bioelectronic Silk‐Based Implants
Zhu, Z., Yan, Z., Ni, S., Yang, H., Xie, Y., Wang, X., Zou, D., Tao, C., Jiang, W., Jiang, J., et al. (2024) · Advanced Materials · doi:10.1002/adma.202405892 · Cited by 27 · see citing works
Acute and prophylactic effects of anticonvulsants in bipolar depression
Post, R. M., Speer, A. M., Obrocea, G. V., & Leverich, G. S. (2002) · Clinical Neuroscience Research · doi:10.1016/s1566-2772(02)00047-6 · Cited by 20 · see citing works
Neuromodulation for obsessive-compulsive disorder
Aronson, J. P., Katnani, H. A., & Eskandar, E. N. (2014) · Neurosurgery Clinics of North America · doi:10.1016/j.nec.2013.08.003 · Cited by 18 · see citing works
Vagus nerve stimulation: Introduction and technical aspects
Pisapia, J., & Baltuch, G. (2015) · Neuromodulation in Psychiatry · doi:10.1002/9781118801086.ch17 · Cited by 11 · see citing works
- Authors
- George, M. S., Sackeim, H. A., Rush, A. J., Marangell, L. B., Nahas, Z., Husain, M. M., Lisanby, S., Burt, T., Goldman, J., & Ballenger, J. C.
- Affiliations
- Medical University of South Carolina (US)
- The University of Texas Southwestern Medical Center (US)
- Baylor College of Medicine (US)
- New York State Psychiatric Institute (US)
- Corresponding author
- George, Mark S.
- Venue
- Biological Psychiatry
- Publisher
- Elsevier BV
- Published
- 2000-02
- Volume
- 47
- Issue
- 4
- Pages
- 287-295
- ISSN
- 0006-3223 (ISSN-L)
- OpenAlex
- W2017887406
- Cited by
- 461
- References
- 56
- Citations by year
- 2026: 12 · 2025: 21 · 2024: 23 · 2023: 16 · 2022: 19 · 2021: 12 · 2020: 20 · 2019: 19 · 2018: 15 · 2017: 18 · 2016: 14 · 2015: 27 · 2014: 17 · 2013: 31 · 2012: 11
- FWCI
- 2.25
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- Biological Psychiatry (publishedVersion)
- PubMed (publishedVersion)
- Topics
- Life Sciences › Neuroscience › Neurology › Vagus Nerve Stimulation Research
- Health Sciences › Medicine › Neurology › Neurological disorders and treatments
- Life Sciences › Neuroscience › Cellular and Molecular Neuroscience › Neuroscience and Neural Engineering
- Keywords
- vagus nerve stimulation, vagus nerve anatomy, drug-resistant epilepsy, neuropsychiatric disorders, somatic therapy, brain electrical activity, neuromodulation
- MeSH terms
- Brain, Major Depressive Disorder, Depressive Disorder, Major, Electroconvulsive Therapy, Electric Stimulation Therapy, Epilepsy, Humans, Locus Coeruleus, Neural Pathways, Vagus Nerve, Treatment Outcome
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