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Ali MSS, Parastooei G, Raman S, Mack J, Kim YS, Chung MK. Genetic labeling of the nucleus of tractus solitarius neurons associated with electrical stimulation of the cervical or auricular vagus nerve in mice. Brain Stimul 2024; 17:987-1000. [PMID: 39173736 DOI: 10.1016/j.brs.2024.08.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 07/31/2024] [Accepted: 08/19/2024] [Indexed: 08/24/2024] Open
Abstract
INTRODUCTION Vagus nerve stimulation (VNS) is clinically useful for treating epilepsy, depression, and chronic pain. Currently, cervical VNS (cVNS) treatment is well-established, while auricular VNS (aVNS) is under development. Vagal stimulation regulates functions in diverse brain regions; therefore, it is critical to better understand how electrically-evoked vagal inputs following cVNS and aVNS engage with different brain regions. OBJECTIVE As vagus inputs are predominantly transmitted to the nucleus of tractus solitarius (NTS), we directly compared the activation of NTS neurons by cVNS or aVNS and the brain regions directly projected by the activated NTS neurons in mice. METHODS We adopted the targeted recombination in active populations method, which allows for the activity-dependent, tamoxifen-inducible expression of mCherry-a reporter protein-in neurons specifically associated with cVNS or aVNS. RESULTS cVNS and aVNS induced comparable bilateral mCherry expressions in neurons within the NTS, especially in its caudal section (cNTS). However, the numbers of mCherry-expressing neurons within different subdivisions of cNTS was distinctive. In both cVNS and aVNS, anterogradely labeled mCherry-expressing axonal terminals were similarly observed across different areas of the forebrain, midbrain, and hindbrain. These terminals were enriched in the rostral ventromedial medulla, parabrachial nucleus, periaqueductal gray, thalamic nuclei, central amygdala, and the hypothalamus. Sex difference of cVNS- and aVNS-induced labeling of NTS neurons was modest. CONCLUSION The central projections of mCherry-expressing cNTS terminals are comparable between aVNS and cVNS, suggesting that cVNS and aVNS activate distinct but largely overlapping projections into the brain through the cNTS.
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Affiliation(s)
- Md Sams Sazzad Ali
- Department of Neural and Pain Sciences, School of Dentistry, Program in Neuroscience, Center to Advance Chronic Pain Research, University of Maryland Baltimore, Baltimore, MD, 21201, USA
| | - Ghazaal Parastooei
- Department of Neural and Pain Sciences, School of Dentistry, Program in Neuroscience, Center to Advance Chronic Pain Research, University of Maryland Baltimore, Baltimore, MD, 21201, USA
| | - Swarnalakshmi Raman
- Department of Neural and Pain Sciences, School of Dentistry, Program in Neuroscience, Center to Advance Chronic Pain Research, University of Maryland Baltimore, Baltimore, MD, 21201, USA
| | - Jalen Mack
- Department of Neural and Pain Sciences, School of Dentistry, Program in Neuroscience, Center to Advance Chronic Pain Research, University of Maryland Baltimore, Baltimore, MD, 21201, USA
| | - Yu Shin Kim
- Department of Oral & Maxillofacial Surgery, School of Dentistry, Programs in Integrated Biomedical Sciences, Translational Sciences, Biomedical Engineering, Radiological Sciences, University of Texas Health Science Center at San Antonio, USA
| | - Man-Kyo Chung
- Department of Neural and Pain Sciences, School of Dentistry, Program in Neuroscience, Center to Advance Chronic Pain Research, University of Maryland Baltimore, Baltimore, MD, 21201, USA.
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Owens MM, Dalal S, Radovic A, Fernandes L, Syed H, Herndon MK, Cooper C, Singh K, Beaumont E. Vagus nerve stimulation alleviates cardiac dysfunction and inflammatory markers during heart failure in rats. Auton Neurosci 2024; 253:103162. [PMID: 38513382 PMCID: PMC11318104 DOI: 10.1016/j.autneu.2024.103162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 02/21/2024] [Accepted: 02/28/2024] [Indexed: 03/23/2024]
Abstract
Vagus nerve stimulation (VNS) is under clinical investigation as a therapy for heart failure with reduced ejection fraction (HFrEF). This study aimed to investigate its therapeutic effects on three main components of heart failure: cardiac function, cardiac remodeling and central neuroinflammation using a pressure overload (PO) rat model. Male Sprague-Dawley rats were divided into four groups: PO, PO + VNS, PO + VNS sham, and controls. All rats, except controls, underwent a PO surgery to constrict the thoracic aorta (~50 %) to induce HFrEF. Open loop VNS therapy was continuously administered to PO + VNS rats at 20 Hz, 1.0 mA for 60 days. Evaluation of cardiac function and structure via echocardiograms showed decreases in stroke volume and relative ejection fraction and increases in the internal diameter of the left ventricle during systole and diastole in PO rats (p < 0.05). However, these PO-induced adverse changes were alleviated with VNS therapy. Additionally, PO rats exhibited significant increases in myocyte cross sectional areas indicating hypertrophy, along with significant increases in myocardial fibrosis and apoptosis, all of which were reversed by VNS therapy (p < 0.05). Furthermore, VNS mitigated microglial activation in two central autonomic nuclei: the paraventricular nucleus of the hypothalamus and locus coeruleus. These findings demonstrate that when VNS therapy is initiated at an early stage of HFrEF progression (<10 % reduction in relative ejection fraction), the supplementation of vagal activity is effective in restoring multi organ homeostasis in a PO model.
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Affiliation(s)
- Misty M Owens
- Department of Biomedical Sciences, East Tennessee State University, Stanton-Gerber Hall, 178 Maple Ave., P.O. Box 70582, Mountain Home, TN, 37684, United States of America
| | - Suman Dalal
- Department of Health Sciences, East Tennessee State University, 248 Lamb Hall, PO Box 70673, Johnson City, TN, 37614, United States of America; Center of Excellence in Inflammation, Infectious Disease and Immunity, East Tennessee State University, 1276 Gilbreath Dr., Box 70300, Johnson City, TN 37614, United States of America
| | - Aleksandra Radovic
- Department of Biomedical Sciences, East Tennessee State University, Stanton-Gerber Hall, 178 Maple Ave., P.O. Box 70582, Mountain Home, TN, 37684, United States of America
| | - Luciano Fernandes
- Department of Biomedical Sciences, East Tennessee State University, Stanton-Gerber Hall, 178 Maple Ave., P.O. Box 70582, Mountain Home, TN, 37684, United States of America
| | - Hassan Syed
- Department of Biomedical Sciences, East Tennessee State University, Stanton-Gerber Hall, 178 Maple Ave., P.O. Box 70582, Mountain Home, TN, 37684, United States of America
| | - Mary-Katherine Herndon
- Department of Biomedical Sciences, East Tennessee State University, Stanton-Gerber Hall, 178 Maple Ave., P.O. Box 70582, Mountain Home, TN, 37684, United States of America
| | - Coty Cooper
- Department of Biomedical Sciences, East Tennessee State University, Stanton-Gerber Hall, 178 Maple Ave., P.O. Box 70582, Mountain Home, TN, 37684, United States of America
| | - Krishna Singh
- Department of Biomedical Sciences, East Tennessee State University, Stanton-Gerber Hall, 178 Maple Ave., P.O. Box 70582, Mountain Home, TN, 37684, United States of America; Center of Excellence in Inflammation, Infectious Disease and Immunity, East Tennessee State University, 1276 Gilbreath Dr., Box 70300, Johnson City, TN 37614, United States of America; James H. Quillen Veterans Affairs Medical Center, Lamont St & Veterans Way, Johnson City, TN 37604, United States of America
| | - Eric Beaumont
- Department of Biomedical Sciences, East Tennessee State University, Stanton-Gerber Hall, 178 Maple Ave., P.O. Box 70582, Mountain Home, TN, 37684, United States of America; Center of Excellence in Inflammation, Infectious Disease and Immunity, East Tennessee State University, 1276 Gilbreath Dr., Box 70300, Johnson City, TN 37614, United States of America.
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3
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Gullett N, Zajkowska Z, Walsh A, Harper R, Mondelli V. Heart rate variability (HRV) as a way to understand associations between the autonomic nervous system (ANS) and affective states: A critical review of the literature. Int J Psychophysiol 2023; 192:35-42. [PMID: 37543289 DOI: 10.1016/j.ijpsycho.2023.08.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 07/31/2023] [Accepted: 08/02/2023] [Indexed: 08/07/2023]
Abstract
Evidence suggests affective disorders such as depression and bipolar disorder are characterised by dysregulated autonomic nervous system (ANS) activity. These findings suggest ANS dysregulation may be involved in the pathogenesis of affective disorders. Different affective states are characterised by different ANS activity patterns (i.e., an increase or decrease in sympathetic or parasympathetic activity). To understand how ANS abnormalities are involved in the development of affective disorders, it is important to understand how affective states correlate with ANS activity before their onset. Using heart rate variability (HRV) as a tool to measure ANS activity, this review aimed to look at associations between affective states and HRV in non-clinical populations (i.e., in those without medical and psychiatric disorders). Searches on PubMed and Google Scholar were completed using the following search terms: heart rate variability, autonomic nervous system, sympathetic nervous system, parasympathetic nervous system, affective state, mood and emotion in all possible combinations. All but one of the studies examined (N = 13), demonstrated significant associations between affect and HRV. Findings suggest negative affect, encompassing both diffused longer-term experiences (i.e., mood) as well as more focused short-term experiences (i.e., emotions), may be associated with a reduction in parasympathetic activity as measured through HRV parameters known to quantify parasympathetic activity (e.g., high frequency (HF)-HRV). HRV measures typically linked to reduction in parasympathetic activity appear to be linked to negative affective states in non-clinical populations. However, given the complex and possibly non-linear relationship between HRV and parasympathetic activity, further studies need to clarify specificity of these findings. Future studies should investigate the potential utility of HRV measures as biomarkers for monitoring changes in affective states and for early detection of onset and relapse of depression in patients with affective disorders.
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Affiliation(s)
- Nancy Gullett
- King's College London, Institute of Psychiatry, Psychology and Neuroscience, Department of Psychological Medicine, London, UK.
| | - Zuzanna Zajkowska
- King's College London, Institute of Psychiatry, Psychology and Neuroscience, Department of Psychological Medicine, London, UK
| | - Annabel Walsh
- King's College London, Institute of Psychiatry, Psychology and Neuroscience, Department of Psychological Medicine, London, UK
| | - Ross Harper
- Limbic, Kemp House, 160 City Road, London EC1V 2NX, UK
| | - Valeria Mondelli
- King's College London, Institute of Psychiatry, Psychology and Neuroscience, Department of Psychological Medicine, London, UK; National Institute for Health Research Mental Health Biomedical Research Centre, South London and Maudsley NHS Foundation Trust and King's College London, London, UK
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Biniaz-Harris N, Kuvaldina M, Fallon BA. Neuropsychiatric Lyme Disease and Vagus Nerve Stimulation. Antibiotics (Basel) 2023; 12:1347. [PMID: 37760644 PMCID: PMC10525519 DOI: 10.3390/antibiotics12091347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 08/15/2023] [Accepted: 08/16/2023] [Indexed: 09/29/2023] Open
Abstract
Lyme disease, the most common tick-borne disease in the United States, is caused by infection with the spirochete Borrelia burgdorferi. While most patients with acute Lyme disease recover completely if treated with antibiotics shortly after the onset of infection, approximately 10-30% experience post-treatment symptoms and 5-10% have residual symptoms with functional impairment (post-treatment Lyme disease syndrome or PTLDS). These patients typically experience pain, cognitive problems, and/or fatigue. This narrative review provides a broad overview of Lyme disease, focusing on neuropsychiatric manifestations and persistent symptoms. While the etiology of persistent symptoms remains incompletely understood, potential explanations include persistent infection, altered neural activation, and immune dysregulation. Widely recognized is that new treatment options are needed for people who have symptoms that persist despite prior antibiotic therapy. After a brief discussion of treatment approaches, the article focuses on vagus nerve stimulation (VNS), a neuromodulation approach that is FDA-approved for depression, epilepsy, and headache syndromes and has been reported to be helpful for other diseases characterized by inflammation and neural dysregulation. Transcutaneous VNS stimulates the external branch of the vagus nerve, is minimally invasive, and is well-tolerated in other conditions with few side effects. If well-controlled double-blinded studies demonstrate that transcutaneous auricular VNS helps patients with chronic syndromes such as persistent symptoms after Lyme disease, taVNS will be a welcome addition to the treatment options for these patients.
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Affiliation(s)
- Nicholas Biniaz-Harris
- Lyme & Tick-Borne Diseases Research Center at Columbia University Irving Medical Center, 1051 Riverside Drive, New York, NY 10032, USA; (N.B.-H.); (M.K.)
| | - Mara Kuvaldina
- Lyme & Tick-Borne Diseases Research Center at Columbia University Irving Medical Center, 1051 Riverside Drive, New York, NY 10032, USA; (N.B.-H.); (M.K.)
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Brian A. Fallon
- Lyme & Tick-Borne Diseases Research Center at Columbia University Irving Medical Center, 1051 Riverside Drive, New York, NY 10032, USA; (N.B.-H.); (M.K.)
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY 10032, USA
- New York State Psychiatric Institute, 1051 Riverside Drive, New York, NY 10032, USA
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5
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Domenech P. Stimulation du nerf vague pour traiter l’épilepsie et la dépression résistante : vers une physiopathologie commune ? BULLETIN DE L'ACADÉMIE NATIONALE DE MÉDECINE 2023. [DOI: 10.1016/j.banm.2023.01.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
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D'Agostini M, Burger AM, Franssen M, Perkovic A, Claes S, von Leupoldt A, Murphy PR, Van Diest I. Short bursts of transcutaneous auricular vagus nerve stimulation enhance evoked pupil dilation as a function of stimulation parameters. Cortex 2023; 159:233-253. [PMID: 36640622 DOI: 10.1016/j.cortex.2022.11.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/28/2022] [Accepted: 11/28/2022] [Indexed: 12/23/2022]
Abstract
Transcutaneous auricular vagus nerve stimulation (taVNS) is a neurostimulatory technique hypothesised to enhance central noradrenaline. Currently, there is scarce evidence in support of a noradrenergic mechanism of taVNS and limited knowledge on its stimulation parameters (i.e., intensity and pulse width). Therefore, the present study aimed to test whether taVNS enhances pupil dilation, a noradrenergic biomarker, as a function of stimulation parameters. Forty-nine participants received sham (i.e., left ear earlobe) and taVNS (i.e., left ear cymba concha) stimulation in two separate sessions, in a counterbalanced order. We administered short bursts (5s) of seven stimulation settings varying as a function of pulse width and intensity and measured pupil size in parallel. Each stimulation setting was administered sixteen times in separate blocks. We expected short bursts of stimulation to elicit phasic noradrenergic activity as indexed by event-related pupil dilation and event-related temporal derivative. We hypothesised higher stimulation settings, quantified as the total charge per pulse (pulse width x intensity), to drive greater event-related pupil dilation and temporal derivative in the taVNS compared to sham condition. Specifically, we expected stimulation settings in the taVNS condition to be associated with a linear increase in event-related pupil dilation and temporal derivative. We found stimulation settings to linearly increase both pupil measures. In line with our hypothesis, the observed dose-dependent effect was stronger in the taVNS condition. We also found taVNS to elicit more intense and unpleasant sensations than sham stimulation. These results support the hypothesis of a noradrenergic mechanism of taVNS. However, future studies should disentangle whether stimulation elicited sensations mediate the effect of taVNS on evoked pupil dilation.
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Affiliation(s)
| | | | | | - Ana Perkovic
- Research Group Health Psychology, KU Leuven, Leuven, Belgium
| | - Stephan Claes
- The Mind Body Research Group, Department of Neuroscience, KU Leuven, Leuven, Belgium.
| | | | - Peter R Murphy
- Department of Psychology, Maynooth University, Co. Kildare, Ireland; Trinity College Institute of Neuroscience and School of Psychology, Trinity College Dublin, Ireland.
| | - Ilse Van Diest
- Research Group Health Psychology, KU Leuven, Leuven, Belgium.
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7
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Brown JC, Higgins ES, George MS. Synaptic Plasticity 101: The Story of the AMPA Receptor for the Brain Stimulation Practitioner. Neuromodulation 2022; 25:1289-1298. [PMID: 35088731 PMCID: PMC10479373 DOI: 10.1016/j.neurom.2021.09.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 08/10/2021] [Accepted: 09/08/2021] [Indexed: 02/04/2023]
Abstract
The fields of Neurobiology and Neuromodulation have never been closer. Consequently, the phrase "synaptic plasticity" has become very familiar to non-basic scientists, without actually being very familiar. We present the "Story of the AMPA receptor," an easy-to-understand "10,000 ft" narrative overview of synaptic plasticity, oriented toward the brain stimulation clinician or scientist without basic science training. Neuromodulation is unparalleled in its capacity to both modulate and probe plasticity, yet many are not comfortable with their grasp of the topic. Here, we describe the seminal discoveries that defined the canonical mechanisms of long-term potentiation (LTP), long-term depression (LTD), and homeostatic plasticity. We then provide a conceptual framework for how plasticity at the synapse is accomplished, describing the functional roles of N-methyl-d-aspartate (NMDA) receptors and calcium, their effect on calmodulin, phosphatases (ie, calcineurin), kinases (ie, calcium/calmodulin-dependent protein kinase [CaMKII]), and structural "scaffolding" proteins (ie, post-synaptic density protein [PSD-95]). Ultimately, we describe how these affect the α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor. More specifically, AMPA receptor delivery to (LTP induction), removal from (LTD), or recycling within (LTP maintenance) the synapse is determined by the status of phosphorylation and protein binding at specific sites on the tails of AMPA receptor subunits: GluA1 and GluA2. Finally, we relate these to transcranial magnetic stimulation (TMS) treatment, highlighting evidences for LTP as the basis of high-frequency TMS therapy, and briefly touch on the role of plasticity for other brain stimulation modalities. In summary, we present Synaptic Plasticity 101 as a singular introductory reference for those less familiar with the mechanisms of synaptic plasticity.
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Affiliation(s)
- Joshua C Brown
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA; Department of Neurology, Medical University of South Carolina, Charleston, SC, USA; Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, Providence, RI, USA.
| | - Edmund S Higgins
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Mark S George
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA; Ralph Johnson VA Medical Center, Charleston, SC, USA
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8
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Yesiltepe M, Cimen B, Sara Y. Effects of chronic vagal nerve stimulation in the treatment of β-amyloid-induced neuropsychiatric symptoms. Eur J Pharmacol 2022; 931:175179. [PMID: 35973478 DOI: 10.1016/j.ejphar.2022.175179] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 07/28/2022] [Accepted: 07/29/2022] [Indexed: 11/03/2022]
Abstract
Alzheimer's Disease (AD) is the leading cause of dementia and, at the time of diagnosis, half of AD patients display at least one neuropsychiatric symptom (NPS). However, there is no effective therapy for NPSs; furthermore, current treatments of NPSs accelerate cognitive decline. Due to the ineffectiveness and negative consequences of current treatments for NPSs, new approaches are strongly needed. Currently, indications for vagal nerve stimulation (VNS) include epilepsy, stroke rehabilitation and major depression but not NPSs or AD. Therefore, we investigated whether chronic VNS can treat NPSs in a rat model of AD. Here, we report the intracerebroventricular injection of amyloid-β (Aβ) results in depression-like behaviors and memory impairment in rats. Chronic VNS (0.8 mA, 500 μs, 30 Hz, 5 min/day) showed strong antidepressant and anxiolytic effects, and improved memory performance. Additionally, the anxiolytic effect of VNS was retained in the non-Aβ-treated rats. VNS also decreased aggressiveness and increased locomotor activity in both Aβ-treated and non-Aβ-treated rats. Recent studies showed VNS alters glutamatergic receptor levels, thus levels of GluA1, GluN2A, and GluN2B were determined. A significant reduction in GluN2B levels was seen in the hippocampus of VNS-treated groups which may relate to the anxiolytic effects and increased locomotor activity of VNS. In conclusion, VNS could be an effective treatment of NPSs, especially depression and anxiety, in AD patients without impairing cognition.
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Affiliation(s)
- Metin Yesiltepe
- Department of Medical Pharmacology, Hacettepe University Faculty of Medicine, Ankara, Turkey; Department of Pharmacology, Physiology & Neuroscience, New Jersey Medical School, Rutgers University, NJ, USA
| | - Bariscan Cimen
- Department of Medical Pharmacology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Yildirim Sara
- Department of Medical Pharmacology, Hacettepe University Faculty of Medicine, Ankara, Turkey.
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9
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D'Agostini M, Burger AM, Villca Ponce G, Claes S, von Leupoldt A, Van Diest I. No evidence for a modulating effect of continuous transcutaneous auricular vagus nerve stimulation on markers of noradrenergic activity. Psychophysiology 2022; 59:e13984. [PMID: 34990045 DOI: 10.1111/psyp.13984] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 11/12/2021] [Accepted: 11/15/2021] [Indexed: 01/22/2023]
Abstract
Although transcutaneous auricular vagus nerve stimulation (taVNS) is thought to increase central noradrenergic activity, findings supporting such mechanism are scarce and inconsistent. This study aimed to investigate whether taVNS modulates indirect markers of phasic and tonic noradrenergic activity. Sixty-six healthy participants performed a novelty auditory oddball task twice on separate days: once while receiving taVNS (left cymba concha), once during sham (left earlobe) stimulation. To maximize potential effects, the stimulation was delivered continuously (frequency: 25 Hz; width: 250 μs) at an intensity individually calibrated to the maximal level below pain threshold. The stimulation was administered 10 min before the oddball task and maintained throughout the session. Event-related pupil dilation (ERPD) to target stimuli and pre-stimulus baseline pupil size were assessed during the oddball task as markers of phasic and tonic noradrenergic activity, respectively. Prior to and at the end of stimulation, tonic pupil size at rest, cortisol, and salivary alpha-amylase were assessed as markers of tonic noradrenergic activity. Finally, we explored the effect of taVNS on cardiac vagal activity, respiratory rate, and salivary flow rate. Results showed a greater ERPD to both target and novelty compared to standard stimuli in the oddball task. In contrast to our hypotheses, taVNS did not impact any of the tested markers. Our findings strongly suggest that continuous stimulation of the cymba concha with the tested stimulation parameters is ineffective to increase noradrenergic activity via a vagal pathway.
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Affiliation(s)
| | | | | | - Stephan Claes
- The Mind Body Research Group, Department of Neuroscience, KU Leuven, Leuven, Belgium
| | | | - Ilse Van Diest
- Research Group Health Psychology, KU Leuven, Leuven, Belgium
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Diedrich A, Urechie V, Shiffer D, Rigo S, Minonzio M, Cairo B, Smith EC, Okamoto LE, Barbic F, Bisoglio A, Porta A, Biaggioni I, Furlan R. Transdermal auricular vagus stimulation for the treatment of postural tachycardia syndrome. Auton Neurosci 2021; 236:102886. [PMID: 34634682 PMCID: PMC8939715 DOI: 10.1016/j.autneu.2021.102886] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 08/26/2021] [Accepted: 09/16/2021] [Indexed: 01/14/2023]
Abstract
Postural Tachycardia Syndrome (POTS) is a chronic disorder characterized by symptoms of orthostatic intolerance such as fatigue, lightheadedness, dizziness, palpitations, dyspnea, chest discomfort and remarkable tachycardia upon standing. Non-invasive transdermal vagal stimulators have been applied for the treatment of epilepsy, anxiety, depression, headache, and chronic pain syndromes. Anti-inflammatory and immunomodulating effects after transdermal vagal stimulation raised interest for applications in other diseases. Patients with sympathetic overactivity, reduced cardiac vagal drive and presence of systemic inflammation like POTS may benefit from tVNS. This article will address crucial methodological aspects of tVNS and provide preliminary results of its acute and chronic use in POTS, with regards to its potential effectiveness on autonomic symptoms reduction and heart rate modulation.
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Affiliation(s)
- André Diedrich
- Vanderbilt Autonomic Dysfunction Center, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA.
| | - Vasile Urechie
- Vanderbilt Autonomic Dysfunction Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Dana Shiffer
- Department of Biomedical Sciences, Humanitas University, Internal Medicine, Humanitas Clinical and Research Center-IRCCS, Rozzano, Italy
| | - Stefano Rigo
- Humanitas University School of Medicine, Rozzano, Italy; Virgilio Research Project, Pieve Emanuele, Milan, Italy
| | - Maura Minonzio
- Department of Biomedical Sciences, Humanitas University, Internal Medicine, Humanitas Clinical and Research Center-IRCCS, Rozzano, Italy
| | - Beatrice Cairo
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy; Department of Cardiothoracic, Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy
| | - Emily C Smith
- Vanderbilt Autonomic Dysfunction Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Luis E Okamoto
- Vanderbilt Autonomic Dysfunction Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Franca Barbic
- Department of Biomedical Sciences, Humanitas University, Internal Medicine, Humanitas Clinical and Research Center-IRCCS, Rozzano, Italy; Humanitas University, Department of Biomedical Sciences, Pieve Emanuele, Italy
| | - Andrea Bisoglio
- Humanitas University School of Medicine, Rozzano, Italy; Virgilio Research Project, Pieve Emanuele, Milan, Italy
| | - Alberto Porta
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy; Department of Cardiothoracic, Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy
| | - Italo Biaggioni
- Vanderbilt Autonomic Dysfunction Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Raffaello Furlan
- Department of Biomedical Sciences, Humanitas University, Internal Medicine, Humanitas Clinical and Research Center-IRCCS, Rozzano, Italy; Humanitas University, Department of Biomedical Sciences, Pieve Emanuele, Italy
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Dimén D, Puska G, Szendi V, Sipos E, Zelena D, Dobolyi Á. Sex-specific parenting and depression evoked by preoptic inhibitory neurons. iScience 2021; 24:103090. [PMID: 34604722 PMCID: PMC8463871 DOI: 10.1016/j.isci.2021.103090] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 07/20/2021] [Accepted: 09/01/2021] [Indexed: 01/08/2023] Open
Abstract
The role of preoptic GABAergic inhibitory neurons was addressed in parenting, anxiety and depression. Pup exposure and forced swimming resulted in similar c-Fos activation pattern in neurons expressing vesicular GABA transporter in the preoptic area with generally stronger labeling and different distributional pattern in females than in males. Chemogenetic stimulation of preoptic GABAergic cells resulted in elevated maternal motivation and caring behavior in females and mothers but aggression toward pups in males. Behavioral effects were the opposite following inhibition of preoptic GABAergic neurons suggesting their physiological relevance. In addition, increased anxiety-like and depression-like behaviors were found following chemogenetic stimulation of the same neurons in females, whereas previous pup exposure increased only anxiety-like behavior suggesting that not the pups, but overstimulation of the cells can lead to depression-like behavior. A sexually dimorphic projection pattern of preoptic GABAergic neurons was also identified, which could mediate sex-dependent parenting and associated emotional behaviors. Preoptic GABAergic neurons promote maternal behaviors in females mice Activation of preoptic GABAergic neurons induces pup-directed aggression in males Projection pattern of preoptic GABAergic neurons is sexually dimorphic Depression-like behaviors are provoked by stimulation of preoptic GABAergic neurons
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Affiliation(s)
- Diána Dimén
- MTA-ELTE Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology, Hungarian Academy of Sciences, Eötvös Loránd Research Network, Eötvös Loránd University, 1117 Budapest, Hungary
| | - Gina Puska
- MTA-ELTE Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology, Hungarian Academy of Sciences, Eötvös Loránd Research Network, Eötvös Loránd University, 1117 Budapest, Hungary.,Department of Ecology, University of Veterinary Medicine Budapest, 1078 Budapest, Hungary
| | - Vivien Szendi
- MTA-ELTE Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology, Hungarian Academy of Sciences, Eötvös Loránd Research Network, Eötvös Loránd University, 1117 Budapest, Hungary
| | - Eszter Sipos
- Department of Behavioral and Stress Studies, Institute of Experimental Medicine, 1080 Budapest, Hungary
| | - Dóra Zelena
- Department of Behavioral and Stress Studies, Institute of Experimental Medicine, 1080 Budapest, Hungary.,Centre for Neuroscience, Szentágothai Research Centre, Institute of Physiology, Medical School, University of Pécs, 7624 Pécs, Hungary
| | - Árpád Dobolyi
- MTA-ELTE Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology, Hungarian Academy of Sciences, Eötvös Loránd Research Network, Eötvös Loránd University, 1117 Budapest, Hungary
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12
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Badihian N. Ideas on a possible neural pathway in depression. Med Hypotheses 2021; 156:110688. [PMID: 34628112 DOI: 10.1016/j.mehy.2021.110688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 08/10/2021] [Accepted: 09/20/2021] [Indexed: 11/30/2022]
Abstract
Depression is the second leading cause of disability in the world. Despite developing some efficacious treatments, many patients do not respond to the treatment well due to the complexity of depression and unknown mechanisms involved in its pathogenesis. It has been reported that patients with major depressive disorder (MDD) experience autonomic dysfunctions in different aspects. Evidence suggests that modulation of the autonomic nervous system may improve depression. Von Economo neurons (VENs) are shown to be involved in the pathophysiology of some of the neurological and psychological diseases. VENs are also important for the "ego" formation, sense of empathy, intuition, and cognition. These neurons express a high level of adrenoreceptor alpha 1a, which confirms their role in the autonomic function. Here, based on some evidence, I propose the hypothesis that these neurons may play a role in depression, possibly through being involved in the autonomic function. More focused studies on VENs and their possible role in depression is suggested in future. This pathway may open a new window in the treatment of depression.
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Affiliation(s)
- Negin Badihian
- Isfahan Neurosciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran; Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran.
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13
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Helicobacter pylori Infection and Extragastric Diseases-A Focus on the Central Nervous System. Cells 2021; 10:cells10092191. [PMID: 34571840 PMCID: PMC8469861 DOI: 10.3390/cells10092191] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 08/22/2021] [Accepted: 08/23/2021] [Indexed: 02/07/2023] Open
Abstract
Helicobacter pylori (H. pylori) is most known to cause a wide spectrum of gastrointestinal impairments; however, an increasing number of studies indicates that H. pylori infection might be involved in numerous extragastric diseases such as neurological, dermatological, hematologic, ocular, cardiovascular, metabolic, hepatobiliary, or even allergic diseases. In this review, we focused on the nervous system and aimed to summarize the findings regarding H. pylori infection and its involvement in the induction/progression of neurological disorders. Neurological impairments induced by H. pylori infection are primarily due to impairments in the gut-brain axis (GBA) and to an altered gut microbiota facilitated by H. pylori colonization. Currently, regarding a potential relationship between Helicobacter infection and neurological disorders, most of the studies are mainly focused on H. pylori.
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14
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D'Agostini M, Burger AM, Franssen M, Claes N, Weymar M, von Leupoldt A, Van Diest I. Effects of transcutaneous auricular vagus nerve stimulation on reversal learning, tonic pupil size, salivary alpha-amylase, and cortisol. Psychophysiology 2021; 58:e13885. [PMID: 34245461 DOI: 10.1111/psyp.13885] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 04/26/2021] [Accepted: 05/25/2021] [Indexed: 12/11/2022]
Abstract
This study investigated whether transcutaneous auricular vagus nerve stimulation (taVNS) enhances reversal learning and augments noradrenergic biomarkers (i.e., pupil size, cortisol, and salivary alpha-amylase [sAA]). We also explored the effect of taVNS on respiratory rate and cardiac vagal activity (CVA). Seventy-one participants received stimulation of either the cymba concha (taVNS) or the earlobe (sham) of the left ear. After learning a series of cue-outcome associations, the stimulation was applied before and throughout a reversal phase in which cue-outcome associations were changed for some (reversal), but not for other (distractor) cues. Tonic pupil size, salivary cortisol, sAA, respiratory rate, and CVA were assessed at different time points. Contrary to our hypothesis, taVNS was not associated with an overall improvement in performance on the reversal task. Compared to sham, the taVNS group performed worse for distractor than reversal cues. taVNS did not increase tonic pupil size and sAA. Only post hoc analyses indicated that the cortisol decline was steeper in the sham compared to the taVNS group. Exploratory analyses showed that taVNS decreased respiratory rate but did not affect CVA. The weak and unexpected effects found in this study might relate to the lack of parameters optimization for taVNS and invite to further investigate the effect of taVNS on cortisol and respiratory rate.
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Affiliation(s)
| | - Andreas M Burger
- Research Group Health Psychology, KU Leuven, Leuven, Belgium.,Laboratory for Biological Psychology, KU Leuven, Leuven, Belgium
| | | | - Nathalie Claes
- Research Group Health Psychology, KU Leuven, Leuven, Belgium
| | - Mathias Weymar
- Department of Biological Psychology and Affective Science, Faculty of Human Sciences, University of Potsdam, Potsdam, Germany.,Faculty of Health Sciences Brandenburg, University of Potsdam, Potsdam, Germany
| | | | - Ilse Van Diest
- Research Group Health Psychology, KU Leuven, Leuven, Belgium
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15
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Mental health during the COVID-19 pandemic and beyond: The importance of the vagus nerve for biopsychosocial resilience. Neurosci Biobehav Rev 2021; 125:1-10. [PMID: 33582230 PMCID: PMC8106638 DOI: 10.1016/j.neubiorev.2021.02.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 01/27/2021] [Accepted: 02/04/2021] [Indexed: 12/22/2022]
Abstract
The COVID-19 pandemic has led to widespread increases in mental health problems, including anxiety and depression. The development of these and other psychiatric disorders may be related to changes in immune, endocrine, autonomic, cognitive, and affective processes induced by a SARS-CoV-2 infection. Interestingly, many of these same changes can be triggered by psychosocial stressors such as social isolation and rejection, which have become increasingly common due to public policies aimed at reducing the spread of SARS-CoV-2. The present review aims to shed light on these issues by describing how viral infections and stress affect mental health. First, we describe the multi-level mechanisms linking viral infection and life stress exposure with risk for psychopathology. Then, we summarize how resilience can be enhanced by targeting vagus nerve function by, for example, applying transcutaneous vagus nerve stimulation and targeting lifestyle factors, such as exercise. With these biopsychosocial insights in mind, researchers and healthcare professionals will be better equipped to reduce risk for psychopathology and increase resilience during this challenging pandemic period and beyond.
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16
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Slater C, Wang Q. Alzheimer's disease: An evolving understanding of noradrenergic involvement and the promising future of electroceutical therapies. Clin Transl Med 2021; 11:e397. [PMID: 33931975 PMCID: PMC8087948 DOI: 10.1002/ctm2.397] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 04/05/2021] [Accepted: 04/11/2021] [Indexed: 02/06/2023] Open
Abstract
Alzheimer's disease (AD) poses a significant global health concern over the next several decades. Multiple hypotheses have been put forth that attempt to explain the underlying pathophysiology of AD. Many of these are briefly reviewed here, but to-date no disease-altering therapy has been achieved. Despite this, recent work expanding on the role of noradrenergic system dysfunction in both the pathogenesis and symptomatic exacerbation of AD has shown promise. The role norepinephrine (NE) plays in AD remains complicated but pre-tangle tau has consistently been shown to arise in the locus coeruleus (LC) of patients with AD decades before symptom onset. The current research reviewed here indicates NE can facilitate neuroprotective and memory-enhancing effects through β adrenergic receptors, while α2A adrenergic receptors may exacerbate amyloid toxicity through a contribution to tau hyperphosphorylation. AD appears to involve a disruption in the balance between these two receptors and their various subtypes. There is also a poorly characterized interplay between the noradrenergic and cholinergic systems. LC deterioration leads to maladaptation in the remaining LC-NE system and subsequently inhibits cholinergic neuron function, eventually leading to the classic cholinergic disruption seen in AD. Understanding AD as a dysfunctional noradrenergic system, provides new avenues for the use of advanced neural stimulation techniques to both study and therapeutically target the earliest stages of neuropathology. Direct LC stimulation and non-invasive vagus nerve stimulation (VNS) have both demonstrated potential use as AD therapeutics. Significant work remains, though, to better understand the role of the noradrenergic system in AD and how electroceuticals can provide disease-altering treatments.
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Affiliation(s)
- Cody Slater
- Department of Biomedical EngineeringColumbia UniversityNew YorkNew YorkUSA
- Vagelos College of Physicians and SurgeonsColumbia UniversityNew YorkNew YorkUSA
| | - Qi Wang
- Department of Biomedical EngineeringColumbia UniversityNew YorkNew YorkUSA
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17
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Guo ZP, Sörös P, Zhang ZQ, Yang MH, Liao D, Liu CH. Use of Transcutaneous Auricular Vagus Nerve Stimulation as an Adjuvant Therapy for the Depressive Symptoms of COVID-19: A Literature Review. Front Psychiatry 2021; 12:765106. [PMID: 34975571 PMCID: PMC8714783 DOI: 10.3389/fpsyt.2021.765106] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 11/12/2021] [Indexed: 12/17/2022] Open
Abstract
The coronavirus disease 2019 (COVID-19) comprises more than just severe acute respiratory syndrome. It also interacts with the cardiovascular, nervous, renal, and immune systems at multiple levels, increasing morbidity in patients with underlying cardiometabolic conditions and inducing myocardial injury or dysfunction. Transcutaneous auricular vagus nerve stimulation (taVNS), which is derived from auricular acupuncture, has become a popular therapy that is increasingly accessible to the general public in modern China. Here, we begin by outlining the historical background of taVNS, and then describe important links between dysfunction in proinflammatory cytokine release and related multiorgan damage in COVID-19. Furthermore, we emphasize the important relationships between proinflammatory cytokines and depressive symptoms. Finally, we discuss how taVNS improves immune function via the cholinergic anti-inflammatory pathway and modulates brain circuits via the hypothalamic-pituitary-adrenal axis, making taVNS an important treatment for depressive symptoms on post-COVID-19 sequelae. Our review suggests that the link between anti-inflammatory processes and brain circuits could be a potential target for treating COVID-19-related multiorgan damage, as well as depressive symptoms using taVNS.
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Affiliation(s)
- Zhi-Peng Guo
- Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing, China
| | - Peter Sörös
- Research Center Neurosensory Science, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany
| | - Zhu-Qing Zhang
- Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing, China
| | - Ming-Hao Yang
- Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing, China
| | - Dan Liao
- Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing, China
| | - Chun-Hong Liu
- Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Acupuncture Neuromodulation, Beijing Institute of Traditional Chinese Medicine, Beijing, China
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18
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Vlaicu A, Bustuchina Vlaicu M. Vagus nerve stimulation for treatment-resistant depression: is this therapy distinct from other antidepressant treatments? Int J Psychiatry Clin Pract 2020; 24:349-356. [PMID: 32677482 DOI: 10.1080/13651501.2020.1779751] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
BACKGROUND The treatment-resistant depression (TRD) is a very disabling disease. OBJECTIVE The aim of this article is to provide an overview of the therapeutic activity of vagus nerve stimulation (VNS) therapy system in TRD. We summarised the progress made during the last decade in this area. METHODS We conducted a non-systematic review on the efficacy and safety of the VNS therapy for this disease. We analysed the results from acute and long-term studies that utilised this technique. Major electronic databases were searched. RESULTS The patients with TRD may show acute and long-term benefit when treated with this technique. There are promising results for VNS therapy for these patients. The level of evidence as an acute treatment option is only 3, but as chronic treatment is 2. This therapy should be offered as an added long-term treatment option for patients with chronic and recurrent difficult to treat depression. CONCLUSIONS The antidepressant effects of this procedure remain controversial. The clinical trials have produced mixed results, but VNS therapy for TRD has two distinct features that differentiate it from other antidepressant treatments: a sustained therapeutic response obtained in highly resistant depressive disorders, a favourable safety profile and guaranteed compliance.
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Affiliation(s)
- Andrei Vlaicu
- Service of Psychiatry, Hospital Andre Breton, Saint-Dizier, France
| | - Mihaela Bustuchina Vlaicu
- Neurosurgery Department, Hospital Pitié Salpêtrière, Paris, France.,INSERM, U955, The Translational Psychiatry Laboratory, Créteil, France
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19
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Pihlaja M, Failla L, Peräkylä J, Hartikainen KM. Reduced Frontal Nogo-N2 With Uncompromised Response Inhibition During Transcutaneous Vagus Nerve Stimulation-More Efficient Cognitive Control? Front Hum Neurosci 2020; 14:561780. [PMID: 33132877 PMCID: PMC7573492 DOI: 10.3389/fnhum.2020.561780] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 08/24/2020] [Indexed: 12/11/2022] Open
Abstract
We have previously shown invasive vagus nerve stimulation to improve attention and working memory and alter emotion-attention interaction in patients with refractory epilepsy, suggesting that VNS might be useful in the treatment of cognitive impairment. The current research focuses on whether non-invasive, transcutaneous vagus nerve stimulation (tVNS) has similar effects to VNS. Furthermore, we aimed to assess whether tVNS has an impact on cognitive control in general or on underlying brain physiology in a task that mimics everyday life demands where multiple executive functions are engaged while encountering intervening emotional stimuli. Event-related potentials (ERP) evoked in such a task, specifically centro-parietal P3 and frontal N2 were used as biomarkers for attention allocation and cognitive control required to carry out the task. A single-blinded, sham-controlled, within-subject study on healthy subjects (n = 25) was conducted using Executive Reaction Time Test (RT-test), a Go/NoGo task engaging multiple executive functions along with intervening threat-related distractors while EEG was recorded. tVNS at the left tragus and sham stimulation at the left ear lobe was alternately delivered throughout the task. To assess the impact of tVNS on neural activity underlying attention and cognitive control, centro-parietal P3 and frontal N2 peak amplitudes were measured in Go and NoGo conditions. Task performance was assessed with RTs and different error types reflecting cognitive control in general and distinct executive functions, such as working memory and response inhibition.No significant effects due to tVNS on performance in the Executive RT-test were observed. For N2 there was a main effect of stimulator status and a significant interaction of trial type (Go, NoGo) and stimulator status. Post hoc analysis revealed that tVNS resulted in a significant reduction of frontal N2 only in the NoGo condition. No significant effects were observed for P3 nor were there any effects of emotion. Diminished NoGo-N2 potential along with unaltered task performance during tVNS suggests fewer cognitive control resources were required to successfully withhold a prepotent response. Though caution is warranted, we suggest that tVNS may lead to more efficient neural processing with fewer resources needed for successful cognitive control, providing promise for its potential use in cognitive enhancement.
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Affiliation(s)
- Mia Pihlaja
- Behavioral Neurology Research Unit, Tampere University Hospital, Tampere, Finland.,Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Laura Failla
- Behavioral Neurology Research Unit, Tampere University Hospital, Tampere, Finland.,Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Jari Peräkylä
- Behavioral Neurology Research Unit, Tampere University Hospital, Tampere, Finland.,Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Kaisa M Hartikainen
- Behavioral Neurology Research Unit, Tampere University Hospital, Tampere, Finland.,Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
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20
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Synergistic antidepressant-like effect of capsaicin and citalopram reduces the side effects of citalopram on anxiety and working memory in rats. Psychopharmacology (Berl) 2020; 237:2173-2185. [PMID: 32388621 DOI: 10.1007/s00213-020-05528-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 04/16/2020] [Indexed: 12/20/2022]
Abstract
RATIONALE We have previously shown that in rats, capsaicin (Cap) has antidepressant-like properties when assessed using the forced swimming test (FST) and that a sub-threshold dose of amitriptyline potentiates the effects of Cap. However, synergistic antidepressant-like effects of the joint administration of Cap and the selective serotonin reuptake inhibitor citalopram (Cit) have not been reported. OBJECTIVES To assess whether combined administration of Cap and Cit has synergistic effects in the FST and to determine whether this combination prevents the side effects of Cit. METHODS Cap, Cit, and the co-administration of both substances were evaluated in a modified version of the FST (30-cm water depth) conducted in rats, as well as in the open field test (OFT), elevated plus maze (EPM), and Morris water maze (MWM). RESULTS In line with previous studies, independent administration of Cap and Cit displayed antidepressant-like properties in the FST, while the combined injection had synergistic effects. In the OFT, neither treatment caused significant increments in locomotion. In the EPM, the time spent in the closed arms was lower in groups administered either only Cap or a combination of Cap and Cit than in groups treated with Cit alone. In the MWM, both Cap and the joint treatment (Cap and Cit) improved the working memory of rats in comparison with animals treated only with Cit. CONCLUSION Combined administration of Cap and Cit produces a synergistic antidepressant-like effect in the FST and reduces the detrimental effects of Cit on anxiety and working memory.
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21
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Burger A, Van der Does W, Brosschot J, Verkuil B. From ear to eye? No effect of transcutaneous vagus nerve stimulation on human pupil dilation: A report of three studies. Biol Psychol 2020; 152:107863. [DOI: 10.1016/j.biopsycho.2020.107863] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 12/09/2019] [Accepted: 02/03/2020] [Indexed: 12/11/2022]
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22
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Colzato L, Beste C. A literature review on the neurophysiological underpinnings and cognitive effects of transcutaneous vagus nerve stimulation: challenges and future directions. J Neurophysiol 2020; 123:1739-1755. [PMID: 32208895 DOI: 10.1152/jn.00057.2020] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Brain stimulation approaches are important to gain causal mechanistic insights into the relevance of functional brain regions and/or neurophysiological systems for human cognitive functions. In recent years, transcutaneous vagus nerve stimulation (tVNS) has attracted considerable popularity. It is a noninvasive brain stimulation technique based on the stimulation of the vagus nerve. The stimulation of this nerve activates subcortical nuclei, such as the locus coeruleus and the nucleus of the solitary tract, and from there, the activation propagates to the cortex. Since tVNS is a novel stimulation technique, this literature review outlines a brief historical background of tVNS, before detailing underlying neurophysiological mechanisms of action, stimulation parameters, cognitive effects of tVNS on healthy humans, and, lastly, current challenges and future directions of tVNS research in cognitive functions. Although more research is needed, we conclude that tVNS, by increasing norepineprine (NE) and gamma-aminobutyric acid (GABA) levels, affects NE- and GABA-related cognitive performance. The review provides detailed background information how to use tVNS as a neuromodulatory tool in cognitive neuroscience and outlines important future leads of research on tVNS.
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Affiliation(s)
- Lorenza Colzato
- Cognitive Neurophysiology, Department of Child and Adolescent Psychiatry, Faculty of Medicine, TU Dresden, Dresden, Germany.,Department of Cognitive Psychology, Institute of Cognitive Neuroscience, Faculty of Psychology, Ruhr University Bochum, Bochum, Germany.,Cognitive Psychology, Faculty of Psychology, Shandong Normal University, Jinan, China
| | - Christian Beste
- Cognitive Neurophysiology, Department of Child and Adolescent Psychiatry, Faculty of Medicine, TU Dresden, Dresden, Germany.,Cognitive Psychology, Faculty of Psychology, Shandong Normal University, Jinan, China
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23
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Burger AM, D'Agostini M, Verkuil B, Van Diest I. Moving beyond belief: A narrative review of potential biomarkers for transcutaneous vagus nerve stimulation. Psychophysiology 2020; 57:e13571. [PMID: 32202671 DOI: 10.1111/psyp.13571] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 01/15/2020] [Accepted: 02/01/2020] [Indexed: 12/25/2022]
Abstract
Transcutaneous vagus nerve stimulation (tVNS) is a non-invasive neurostimulation technique that is currently being tested as a potential treatment for a myriad of neurological and psychiatric disorders. However, the working mechanisms underlying tVNS are poorly understood and it remains unclear whether stimulation activates the vagus nerve for every participant. Finding a biological marker of tVNS is imperative, as it can help guide research on clinical applications and can inform researchers on optimal stimulation sites and parameters to further optimize treatment efficacy. In this narrative review, we discuss five potential biomarkers for tVNS and review currently available evidence for these markers for both invasive and tVNS. While some of these biomarkers hold promise from a theoretical perspective, none of the potential biomarkers provide clear and definitive indications that tVNS increases the vagal activity or augments activity in the locus coeruleus-noradrenaline network. We conclude the review by providing several recommendations for how to tackle the challenges and opportunities when researching potential biomarkers for the effects of tVNS.
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Affiliation(s)
- Andreas Michael Burger
- Health Psychology Research Group, Faculty of Psychology and Educational Sciences, University of Leuven, Leuven, Belgium.,Biological Psychology Research Group, Faculty of Psychology and Educational Sciences, University of Leuven, Leuven, Belgium
| | - Martina D'Agostini
- Health Psychology Research Group, Faculty of Psychology and Educational Sciences, University of Leuven, Leuven, Belgium
| | - Bart Verkuil
- Department of Clinical Psychology, Leiden University, Leiden, the Netherlands
| | - Ilse Van Diest
- Health Psychology Research Group, Faculty of Psychology and Educational Sciences, University of Leuven, Leuven, Belgium
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24
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Vázquez-Oliver A, Brambilla-Pisoni C, Domingo-Gainza M, Maldonado R, Ivorra A, Ozaita A. Auricular transcutaneous vagus nerve stimulation improves memory persistence in naïve mice and in an intellectual disability mouse model. Brain Stimul 2020; 13:494-498. [DOI: 10.1016/j.brs.2019.12.024] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 12/10/2019] [Accepted: 12/23/2019] [Indexed: 11/16/2022] Open
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25
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Senova S, Rabu C, Beaumont S, Michel V, Palfi S, Mallet L, Domenech P. Stimulation du nerf vague dans le traitement de la dépression. Presse Med 2019; 48:1507-1519. [DOI: 10.1016/j.lpm.2019.10.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 10/08/2019] [Accepted: 10/08/2019] [Indexed: 12/12/2022] Open
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26
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Cryan JF, O'Riordan KJ, Cowan CSM, Sandhu KV, Bastiaanssen TFS, Boehme M, Codagnone MG, Cussotto S, Fulling C, Golubeva AV, Guzzetta KE, Jaggar M, Long-Smith CM, Lyte JM, Martin JA, Molinero-Perez A, Moloney G, Morelli E, Morillas E, O'Connor R, Cruz-Pereira JS, Peterson VL, Rea K, Ritz NL, Sherwin E, Spichak S, Teichman EM, van de Wouw M, Ventura-Silva AP, Wallace-Fitzsimons SE, Hyland N, Clarke G, Dinan TG. The Microbiota-Gut-Brain Axis. Physiol Rev 2019; 99:1877-2013. [DOI: 10.1152/physrev.00018.2018] [Citation(s) in RCA: 1243] [Impact Index Per Article: 248.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The importance of the gut-brain axis in maintaining homeostasis has long been appreciated. However, the past 15 yr have seen the emergence of the microbiota (the trillions of microorganisms within and on our bodies) as one of the key regulators of gut-brain function and has led to the appreciation of the importance of a distinct microbiota-gut-brain axis. This axis is gaining ever more traction in fields investigating the biological and physiological basis of psychiatric, neurodevelopmental, age-related, and neurodegenerative disorders. The microbiota and the brain communicate with each other via various routes including the immune system, tryptophan metabolism, the vagus nerve and the enteric nervous system, involving microbial metabolites such as short-chain fatty acids, branched chain amino acids, and peptidoglycans. Many factors can influence microbiota composition in early life, including infection, mode of birth delivery, use of antibiotic medications, the nature of nutritional provision, environmental stressors, and host genetics. At the other extreme of life, microbial diversity diminishes with aging. Stress, in particular, can significantly impact the microbiota-gut-brain axis at all stages of life. Much recent work has implicated the gut microbiota in many conditions including autism, anxiety, obesity, schizophrenia, Parkinson’s disease, and Alzheimer’s disease. Animal models have been paramount in linking the regulation of fundamental neural processes, such as neurogenesis and myelination, to microbiome activation of microglia. Moreover, translational human studies are ongoing and will greatly enhance the field. Future studies will focus on understanding the mechanisms underlying the microbiota-gut-brain axis and attempt to elucidate microbial-based intervention and therapeutic strategies for neuropsychiatric disorders.
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Affiliation(s)
- John F. Cryan
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Kenneth J. O'Riordan
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Caitlin S. M. Cowan
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Kiran V. Sandhu
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Thomaz F. S. Bastiaanssen
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Marcus Boehme
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Martin G. Codagnone
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Sofia Cussotto
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Christine Fulling
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Anna V. Golubeva
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Katherine E. Guzzetta
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Minal Jaggar
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Caitriona M. Long-Smith
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Joshua M. Lyte
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Jason A. Martin
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Alicia Molinero-Perez
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Gerard Moloney
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Emanuela Morelli
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Enrique Morillas
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Rory O'Connor
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Joana S. Cruz-Pereira
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Veronica L. Peterson
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Kieran Rea
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Nathaniel L. Ritz
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Eoin Sherwin
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Simon Spichak
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Emily M. Teichman
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Marcel van de Wouw
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Ana Paula Ventura-Silva
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Shauna E. Wallace-Fitzsimons
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Niall Hyland
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Gerard Clarke
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
| | - Timothy G. Dinan
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland; and Department of Physiology, University College Cork, Cork, Ireland
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Yin J, Ji F, Gharibani P, Chen JD. Vagal Nerve Stimulation for Glycemic Control in a Rodent Model of Type 2 Diabetes. Obes Surg 2019; 29:2869-2877. [PMID: 31222497 PMCID: PMC10461220 DOI: 10.1007/s11695-019-03901-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Vagal nerve stimulation (VNS) has been reported to reduce body weight and improve sympathovagal imbalance in both basic and clinical studies. Its effects on glycemic control were however unclear. The aims of this study were to investigate the effects of VNS with various parameters on blood glucose and its possible mechanisms in rats. METHODS A hyperglycemic rodent model induced by glucagon was used initially to optimize the VNS parameters; then, a type 2 diabetic rodent model induced by high-fat diet combined with streptozotocin was used to validate the VNS method. The VNS electrodes were implanted at the dorsal subdiaphragmatic vagus; three subcutaneous electrodes were implanted at the chest area for recording electrocardiogram in rats induced by glucagon. RESULTS (1) VNS with short pulse width of 0.3 ms but not 3 ms reduced blood glucose during an oral glucose tolerance test (OGTT), with a 38.4% reduction at 15 min and 26.9% at 30 min (P < 0.05, vs. sham-VNS respectively). (2) VNS at low frequency of 5 Hz but not 14 Hz or 40 Hz reduced blood glucose during the OGTT (P < 0.05, vs. sham-VNS). (3) Intermittent VNS was more potent than continuous VNS (P < 0.01). (4) No difference was found between unilateral VNS and bilateral VNS. (5) VNS enhanced vagal activity (P = 0.005). (6) The hypoglycemic effect of VNS was blocked by glucagon-like peptide-1 (GLP-1) antagonist exendin-4. CONCLUSIONS VNS at 5 Hz reduces blood glucose in diabetic rats by enhancing vagal efferent activity and the release of GLP-1.
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Affiliation(s)
- Jieyun Yin
- Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, MD, 21224, USA.
- Transtimulation Research, Inc, Oklahoma City, OK, USA.
| | - Feng Ji
- Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, MD, 21224, USA
| | - Payam Gharibani
- Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, MD, 21224, USA
| | - Jiande Dz Chen
- Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, MD, 21224, USA
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28
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Stauss HM, Daman LM, Rohlf MM, Sainju RK. Effect of vagus nerve stimulation on blood glucose concentration in epilepsy patients - Importance of stimulation parameters. Physiol Rep 2019; 7:e14169. [PMID: 31325231 PMCID: PMC6642273 DOI: 10.14814/phy2.14169] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 06/18/2019] [Accepted: 06/20/2019] [Indexed: 11/24/2022] Open
Abstract
In previous animal experiments, we demonstrated that cervical vagus nerve stimulation (VNS) inhibits pancreatic insulin secretion, thereby raises blood glucose levels, and impairs glucose tolerance through afferent signaling. However, there are no reports suggesting that similar effects occur in patients treated with chronic cervical VNS for epilepsy. In contrast to clinical VNS used for epilepsy, where the stimulation is intermittent with cycles of on and off periods, stimulation was continuous in our previous animal experiments. Thus, we hypothesized that the timing of the stimulation on/off cycles is critical to prevent impaired glucose tolerance in epilepsy patients chronically treated with cervical VNS. We conducted a retrospective analysis of medical records from patients with epilepsy. Blood glucose levels did not differ between patients treated with pharmacotherapy only (98 ± 4 mg/dL, n = 16) and patients treated with VNS plus pharmacotherapy (99 ± 3 mg/dL, n = 24, duration of VNS 4.5 ± 0.5 years). However, a multiple linear correlation analysis of patients with VNS demonstrated that during the follow‐up period of 7.9 ± 0.7 years, blood glucose levels increased in patients with long on and short off periods, whereas blood glucose did not change or even decreased in patients that were stimulated with short on and long off periods. We conclude that chronic cervical VNS in patients with epilepsy is unlikely to induce glucose intolerance or hyperglycemia with commonly used stimulation parameters. However, stimulation on times of longer than 25 sec may bear a risk for hyperglycemia, especially if the stimulation off time is shorter than 200 sec.
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Affiliation(s)
- Harald M Stauss
- Department of Biomedical Sciences, Burrell College of Osteopathic Medicine, Las Cruces, New Mexico.,Department of Health and Human Physiology, The University of Iowa, Iowa City, Iowa
| | - Lucienne M Daman
- Department of Health and Human Physiology, The University of Iowa, Iowa City, Iowa
| | - Megan M Rohlf
- Pediatric Neurology, Department of Pediatrics, The University of Iowa, Iowa City, Iowa
| | - Rup K Sainju
- Department of Neurology, The University of Iowa, Iowa City, Iowa
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29
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Klarer M, Weber-Stadlbauer U, Arnold M, Langhans W, Meyer U. Abdominal vagal deafferentation alters affective behaviors in rats. J Affect Disord 2019; 252:404-412. [PMID: 31003109 DOI: 10.1016/j.jad.2019.04.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 02/19/2019] [Accepted: 04/06/2019] [Indexed: 12/20/2022]
Abstract
BACKGROUND There is growing evidence for a role of abnormal gut-brain signaling in disorders involving altered mood and affect, including depression. Studies using vagus nerve stimulation (VNS) suggest that the disruption of vagal afferent signaling may contribute to these abnormalities. To test this hypothesis, we used a rat model of subdiaphragmatic vagal deafferentation (SDA), the most complete and selective vagal deafferentation method existing to date, to study the consequences of complete disconnection of abdominal vagal afferents on affective behaviors. METHODS SDA- and Sham-operated male rats were subjected to several tests that are commonly used in preclinical rodent models to assess the presence of anhedonic behavior, namely the novel object-induced exploration test, the novelty-suppressed eating test, and the sucrose preference test. In addition, we compared SDA and Sham rats in a social interaction test and the forced swim test to assess sociability and behavioral despair, respectively. RESULTS Compared to Sham controls, SDA rats consistently displayed signs of anhedonic behavior in all test settings used. SDA rats also showed increased immobility and reduced swimming in the forced swim test, whereas they did not differ from Sham controls with regards to social approach behavior. LIMITATIONS This study was conducted in male rats only. Hence, possible sex-specific effects of SDA on affective behaviors remained unexamined. CONCLUSIONS Our findings demonstrate that hedonic behavior and behavioral despair are subject to visceral modulation through abdominal vagal afferents. These data are compatible with preclinical models and clinical trials showing beneficial effects of VNS on depression-like and affective behaviors.
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Affiliation(s)
- Melanie Klarer
- Physiology and Behavior Laboratory, ETH Zurich, Schwerzenbach, Switzerland; Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, Zurich, Switzerland.
| | - Ulrike Weber-Stadlbauer
- Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, Zurich, Switzerland
| | - Myrtha Arnold
- Physiology and Behavior Laboratory, ETH Zurich, Schwerzenbach, Switzerland
| | - Wolfgang Langhans
- Physiology and Behavior Laboratory, ETH Zurich, Schwerzenbach, Switzerland
| | - Urs Meyer
- Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, Zurich, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Switzerland
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30
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Characterization of plasma cytokine response to intraperitoneally administered LPS & subdiaphragmatic branch vagus nerve stimulation in rat model. PLoS One 2019; 14:e0214317. [PMID: 30921373 PMCID: PMC6438475 DOI: 10.1371/journal.pone.0214317] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Accepted: 03/11/2019] [Indexed: 01/17/2023] Open
Abstract
Vagus nerve stimulation (VNS) has been on the forefront of inflammatory disorder research and has yielded many promising results. Questions remain, however, about the biological mechanisms of such treatments and the inconsistencies in the methods used in research efforts. Here, we aimed to clarify the inflammatory response to intraperitoneal (IP) injections of lipopolysaccharide (LPS) in rats, while analyzing corresponding effects of electrical stimulation to subdiaphragmatic branches (anterior gastric, accessory celiac, and hepatic) of the left vagus nerve. We accomplished an in-depth characterization of the time-varying cytokine cascade response in the serum of 58 rats to an acute IP LPS challenge over a 330-minute period by utilizing curve-fitting and starting point-alignment methods. We then explored the post-LPS neuromodulation effects of electrically stimulating individually cuffed subdiaphragmatic branches. Through our analysis, we found there to be a consistent order of IP LPS cytokine response (IL-10, TNF-α, GM-CSF, IL-17F, IL-6, IL-22, INF-γ). Apart from IL-10, the IP cytokine cascade was more variable in starting time and occurred later than in previously recorded intravenous (IV) challenges. We also found distinct regulatory effects on multiple cytokine levels by each of the three subdiaphragmatic stimulation subsets. While the time-variability of IP LPS use in rats complicates its utility, we have shown it to be a practical, arguably more physiologically relevant method than IV in rats when our methods are used. More importantly, we have shown that selective subdiaphragmatic neurostimulation can be utilized to selectively induce specific effects on inflammation in the body.
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31
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Keute M, Boehrer L, Ruhnau P, Heinze HJ, Zaehle T. Transcutaneous Vagus Nerve Stimulation (tVNS) and the Dynamics of Visual Bistable Perception. Front Neurosci 2019; 13:227. [PMID: 30906250 PMCID: PMC6418039 DOI: 10.3389/fnins.2019.00227] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 02/26/2019] [Indexed: 12/20/2022] Open
Abstract
Transcutaneous vagus nerve stimulation (tVNS) is widely used for clinical applications, but its mechanism of action is poorly understood. One candidate pathway that might mediate the effects of tVNS is an increase in GABAergic neurotransmission. In this study, we investigated the effect of tVNS on visual bistable perception, which is highly coupled to GABA. Participants were 34 healthy young subjects. We used a static (Necker cube) and a dynamic (structure from motion) bistable perception task. Each subject underwent tVNS as well as sham (placebo) stimulation for ∼45 min. We analyze effects of tVNS on percept durations by means of Bayesian multilevel regression. We find no evidence for a modulation of bistable perception dynamics through tVNS in either task, but the analyses do not ultimately confirm the null hypothesis either. We discuss different possible implications of our finding and propose that GABAergic effects of tVNS should be further investigated using more direct measures of GABA concentration, and, more generally, that a better understanding of the mechanisms of action of vagus nerve stimulation is needed. Finally, we discuss limitations of our study design, data analysis, and conclusions.
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Affiliation(s)
- Marius Keute
- Department of Neurology, Otto von Guericke University Magdeburg, Magdeburg, Germany
| | - Lisa Boehrer
- Department of Neurology, Otto von Guericke University Magdeburg, Magdeburg, Germany
| | - Philipp Ruhnau
- Department of Neurology, Otto von Guericke University Magdeburg, Magdeburg, Germany
| | - Hans-Jochen Heinze
- Department of Neurology, Otto von Guericke University Magdeburg, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany.,Department of Behavioral Neurology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Tino Zaehle
- Department of Neurology, Otto von Guericke University Magdeburg, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany
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32
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Abstract
Glucose is the long-established, obligatory fuel for brain that fulfills many critical functions, including ATP production, oxidative stress management, and synthesis of neurotransmitters, neuromodulators, and structural components. Neuronal glucose oxidation exceeds that in astrocytes, but both rates increase in direct proportion to excitatory neurotransmission; signaling and metabolism are closely coupled at the local level. Exact details of neuron-astrocyte glutamate-glutamine cycling remain to be established, and the specific roles of glucose and lactate in the cellular energetics of these processes are debated. Glycolysis is preferentially upregulated during brain activation even though oxygen availability is sufficient (aerobic glycolysis). Three major pathways, glycolysis, pentose phosphate shunt, and glycogen turnover, contribute to utilization of glucose in excess of oxygen, and adrenergic regulation of aerobic glycolysis draws attention to astrocytic metabolism, particularly glycogen turnover, which has a high impact on the oxygen-carbohydrate mismatch. Aerobic glycolysis is proposed to be predominant in young children and specific brain regions, but re-evaluation of data is necessary. Shuttling of glucose- and glycogen-derived lactate from astrocytes to neurons during activation, neurotransmission, and memory consolidation are controversial topics for which alternative mechanisms are proposed. Nutritional therapy and vagus nerve stimulation are translational bridges from metabolism to clinical treatment of diverse brain disorders.
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Affiliation(s)
- Gerald A Dienel
- Department of Neurology, University of Arkansas for Medical Sciences , Little Rock, Arkansas ; and Department of Cell Biology and Physiology, University of New Mexico , Albuquerque, New Mexico
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33
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Abstract
The microbiome in the gut is a diverse environment, housing the majority of our bacterial microbes. This microecosystem has a symbiotic relationship with the surrounding multicellular organism, and a balance and diversity of specific phyla of bacteria support general health. When gut bacteria diversity diminishes, there are systemic consequences, such as gastrointestinal and psychological distress. This pathway of communication is known as the microbiome-gut-brain axis. Interventions such as probiotic supplementation that influence microbiome also improve both gut and brain disorders. Recent evidence suggests that aerobic exercise improves the diversity and abundance of genera from the Firmcutes phylum, which may be the link between the positive effects of exercise on the gut and brain. The purpose of this review is to explain the complex communication pathway of the microbiome-gut-brain axis and further examine the role of exercise on influencing this communication highway.
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Affiliation(s)
- Alyssa Dalton
- Department of Health, Exercise, and Sports Sciences, University of New Mexico, Albuquerque, NM, USA
| | - Christine Mermier
- Department of Health, Exercise, and Sports Sciences, University of New Mexico, Albuquerque, NM, USA
| | - Micah Zuhl
- Department of Health, Exercise, and Sports Sciences, University of New Mexico, Albuquerque, NM, USA,CONTACT Micah Zuhl Department of Health, Exercise, and Sports Sciences, University of New Mexico, Albuquerque, NM, USA
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34
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Kucia K, Merk W, Zapalowicz K, Medrala T. Vagus Nerve Stimulation For Treatment Resistant Depression: Case Series Of Six Patients - Retrospective Efficacy And Safety Observation After One Year Follow Up. Neuropsychiatr Dis Treat 2019; 15:3247-3254. [PMID: 31819452 PMCID: PMC6883943 DOI: 10.2147/ndt.s217816] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 08/15/2019] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVE One year observation and evaluation of the VNS (vagus nerve stimulation) efficacy and safety for patients with treatment resistant depression in Polish conditions. METHODS An open label, uncontrolled and one center retrospective study of VNS therapy was implemented with stable pharmacotherapy in 6 patients with treatment resistant depression (TRD). For the first 3 months, only VNS parameters were altered but the pharmacological treatment was unchanged and in the following 9 months, medication and VNS dosing parameters were altered according to the clinical state of the patients. RESULTS The baseline 24-item Hamilton Depression Rating Scale (HAMD-24) score averaged 24. Both response (>50% reduction in baseline scores) and remission rates after 3 months of treatment were only 40%. After 1 year of VNS therapy, the response rates increased to 86%. Most frequent side-effects were voice alteration (86% at 3 months of stimulation) and headaches (40%). CONCLUSION VNS treatment was safe and effective in TRD patients and its efficacy increased with time. Efficacy ratings are similar to the previously reported studies using a congenial protocol.
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Affiliation(s)
- Krzysztof Kucia
- Department of Psychiatry and Psychotherapy, School of Medicine in Katowice, Medical University of Silesia, GCM, Katowice 40-635, Poland
| | - Wojciech Merk
- Department of Psychiatry and Psychotherapy, School of Medicine in Katowice, Medical University of Silesia, GCM, Katowice 40-635, Poland
| | | | - Tomasz Medrala
- Department of Psychiatry and Psychotherapy, School of Medicine in Katowice, Medical University of Silesia, GCM, Katowice 40-635, Poland
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35
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Exercise and gut microbiota: clinical implications for the feasibility of Tai Chi. JOURNAL OF INTEGRATIVE MEDICINE-JIM 2018; 15:270-281. [PMID: 28659231 DOI: 10.1016/s2095-4964(17)60342-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Recent studies have shown exercise is associated with changes in the gut microbiota in humans as well as in experimental animals. Tai Chi is an exercise that integrates a martial art, deep breathing and mediation, and has various beneficial effects for health. This review summarizes current knowledge and recent literature on the association between exercise and gut microbiota, and explores the feasibility of Tai Chi for improving gut microbiota composition and function. PubMed/MEDLINE was used to search the English literature for the keywords exercise and gut microbiota. Fourteen relevant studies were identified. In humans, exercise increases the gut microbial diversity. However, the evidence for this association is weak, as previous studies were small-scale, non-controlled studies of short duration or cross-sectional design. In animals, exercise alters the composition of gut microbiota, with some studies suggesting exercise increases the Bacteroidetes/Firmicutes ratio. However, these results are controversial, partly because host genetics and physical fitness also influence gut microbiota. Furthermore, the intensity of exercise may play a key role in how exercise affects gut microbiota. Tai Chi is a moderate-intensity exercise that improves immune function and inflammation of the gut. Tai Chi may also affect gut microbiota through vagal modulation and mediating the hypothalamic-pituitary-adrenal axis. However, no studies have investigated the association between Tai Chi and gut microbiota. Well designed studies exploring the effects of Tai Chi on gut microbiota are needed.
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36
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Capsaicin produces antidepressant-like effects in the forced swimming test and enhances the response of a sub-effective dose of amitriptyline in rats. Physiol Behav 2018; 195:158-166. [DOI: 10.1016/j.physbeh.2018.08.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Revised: 08/19/2018] [Accepted: 08/19/2018] [Indexed: 12/14/2022]
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37
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Burger AM, Van Diest I, van der Does W, Hysaj M, Thayer JF, Brosschot JF, Verkuil B. Transcutaneous vagus nerve stimulation and extinction of prepared fear: A conceptual non-replication. Sci Rep 2018; 8:11471. [PMID: 30065275 PMCID: PMC6068181 DOI: 10.1038/s41598-018-29561-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 07/10/2018] [Indexed: 12/17/2022] Open
Abstract
Transcutaneous stimulation of the auricular branch of the vagus nerve (tVNS) may accelerate fear extinction in healthy humans. Here, we aimed to investigate this hypothesis in healthy young participants in a prepared learning paradigm, using spider pictures as conditioned stimuli. After a fear conditioning phase, participants were randomly allocated to receive tVNS (final N = 42) or sham stimulation (final N = 43) during an extinction phase. Conditioned fear was assessed using US expectancy ratings, skin conductance and fear potentiated startle responses. After successful fear acquisition, participants in both groups showed a reduction of fear over the course of the extinction phase. There were no between-group differences in extinction rates for physiological indices of fear. Contrary to previous findings, participants in the tVNS condition also did not show accelerated declarative extinction learning. Participants in the tVNS condition did have lower initial US expectancy ratings for the CS− trials than those who received sham stimulation, which may indicate an enhanced processing of safety cues due to tVNS. In conclusion, the expected accelerated extinction due to tVNS was not observed. The results from this study call for more research on the optimal tVNS stimulation intensity settings.
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Affiliation(s)
- Andreas M Burger
- Institute of Psychology, Leiden University, Wassenaarseweg 52, 2333, AK, Leiden, The Netherlands. .,Faculty of Psychology, Katholieke Universiteit Leuven, Tiensestraat 102, 3000, Leuven, Belgium.
| | - Ilse Van Diest
- Faculty of Psychology, Katholieke Universiteit Leuven, Tiensestraat 102, 3000, Leuven, Belgium
| | - Willem van der Does
- Institute of Psychology, Leiden University, Wassenaarseweg 52, 2333, AK, Leiden, The Netherlands
| | - Marsida Hysaj
- Institute of Psychology, Leiden University, Wassenaarseweg 52, 2333, AK, Leiden, The Netherlands
| | - Julian F Thayer
- Department of Psychology, The Ohio State University, 1835 Neil Avenue Mall, Columbus, OH, 43210, United States
| | - Jos F Brosschot
- Institute of Psychology, Leiden University, Wassenaarseweg 52, 2333, AK, Leiden, The Netherlands
| | - Bart Verkuil
- Institute of Psychology, Leiden University, Wassenaarseweg 52, 2333, AK, Leiden, The Netherlands
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Mercante B, Ginatempo F, Manca A, Melis F, Enrico P, Deriu F. Anatomo-Physiologic Basis for Auricular Stimulation. Med Acupunct 2018; 30:141-150. [PMID: 29937968 DOI: 10.1089/acu.2017.1254] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Introduction: Stimulation of cranial nerves modulates central nervous system (CNS) activity via the extensive connections of their brainstem nuclei to higher-order structures. Clinical experience with vagus-nerve stimulation (VNS) demonstrates that it produces robust therapeutic effects, however, posing concerns related to its invasiveness and side-effects. Discussion: Trigeminal nerve stimulation (TNS) has been recently proposed as a valid alternative to VNS. The ear presents afferent vagus and trigeminal-nerve distribution; its innervation is the theoretical basis of different reflex therapies, including auriculotherapy. An increasing number of studies have shown that several therapeutic effects induced by invasive VNS and TNS, can be reproduced by noninvasive auricular-nerve stimulation. However, the sites and neurobiologic mechanisms by which VNS and TNS produce their therapeutic effects are not clear yet. Conclusions: Accumulating evidence suggests that VNS and TNS share multiple levels and mechanisms of action in the CNS.
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Affiliation(s)
- Beniamina Mercante
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43/b, 07100 Sassari Italy
| | - Francesca Ginatempo
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43/b, 07100 Sassari Italy
| | - Andrea Manca
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43/b, 07100 Sassari Italy
| | - Francesco Melis
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43/b, 07100 Sassari Italy
| | - Paolo Enrico
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43/b, 07100 Sassari Italy
| | - Franca Deriu
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43/b, 07100 Sassari Italy
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Somann JP, Albors GO, Neihouser KV, Lu KH, Liu Z, Ward MP, Durkes A, Robinson JP, Powley TL, Irazoqui PP. Chronic cuffing of cervical vagus nerve inhibits efferent fiber integrity in rat model. J Neural Eng 2017; 15:036018. [PMID: 29219123 DOI: 10.1088/1741-2552/aaa039] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Numerous studies of vagal nerve stimulation (VNS) have been published showing it to be a potential treatment for chronic inflammation and other related diseases and disorders. Studies in recent years have shown that electrical stimulation of the vagal efferent fibers can artificially modulate cytokine levels and reduce systematic inflammation. Most VNS research in the treatment of inflammation have been acute studies on rodent subjects. Our study tested VNS on freely moving animals by stimulating and recording from the cervical vagus with nerve cuff electrodes over an extended period of time. APPROACH We used methods of electrical stimulation, retrograde tracing (using Fluorogold) and post necropsy histological analysis of nerve tissue, flow cytometry to measure plasma cytokine levels, and MRI scanning of gastric emptying. This novel combination of methods allowed examination of physiological aspects of VNS previously unexplored. MAIN RESULTS Through our study of 53 rat subjects, we found that chronically cuffing the left cervical vagus nerve suppressed efferent Fluorogold transport in 43 of 44 animals (36 showed complete suppression). Measured cytokine levels and gastric emptying rates concurrently showed nominal differences between chronically cuffed rats and those tested with similar acute methods. Meanwhile, results of electrophysiological and histological tests of the cuffed nerves revealed them to be otherwise healthy, consistent with previous literature. SIGNIFICANCE We hypothesize that due to these unforeseen and unexplored physiological consequences of the chronically cuffed vagus nerve in a rat, that inflammatory modulation and other vagal effects by VNS may become unreliable in chronic studies. Given our findings, we submit that it would benefit the VNS community to re-examine methods used in previous literature to verify the efficacy of the rat model for chronic VNS studies.
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Affiliation(s)
- Jesse P Somann
- Department of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana, United States of America. Center for Implantable Devices (CID), Purdue University, West Lafayette, Indiana, United States of America
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Mercante B, Enrico P, Floris G, Quartu M, Boi M, Serra MP, Follesa P, Deriu F. Trigeminal nerve stimulation induces Fos immunoreactivity in selected brain regions, increases hippocampal cell proliferation and reduces seizure severity in rats. Neuroscience 2017; 361:69-80. [DOI: 10.1016/j.neuroscience.2017.08.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 07/06/2017] [Accepted: 08/03/2017] [Indexed: 12/11/2022]
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Burger A, Verkuil B, Fenlon H, Thijs L, Cools L, Miller H, Vervliet B, Van Diest I. Mixed evidence for the potential of non-invasive transcutaneous vagal nerve stimulation to improve the extinction and retention of fear. Behav Res Ther 2017; 97:64-74. [DOI: 10.1016/j.brat.2017.07.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 07/07/2017] [Accepted: 07/07/2017] [Indexed: 12/22/2022]
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Tyler R, Cacace A, Stocking C, Tarver B, Engineer N, Martin J, Deshpande A, Stecker N, Pereira M, Kilgard M, Burress C, Pierce D, Rennaker R, Vanneste S. Vagus Nerve Stimulation Paired with Tones for the Treatment of Tinnitus: A Prospective Randomized Double-blind Controlled Pilot Study in Humans. Sci Rep 2017; 7:11960. [PMID: 28931943 PMCID: PMC5607328 DOI: 10.1038/s41598-017-12178-w] [Citation(s) in RCA: 105] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 09/05/2017] [Indexed: 12/19/2022] Open
Abstract
The aim of the pilot study was to evaluate the effect of Vagus Nerve Stimulation (VNS) paired with sounds in chronic tinnitus patients. All participants were implanted and randomized to a paired VNS (n = 16) or control (n = 14) group. After 6 weeks of home therapy, all participants received paired VNS. The device was used on 96% of days with good compliance. After 6 weeks, the paired VNS group improved on the Tinnitus Handicap Inventory (THI) (p = 0.0012) compared to controls (p = 0.1561). The between-group difference was 10.3% (p = 0.3393). Fifty percent of the participants in the paired VNS group showed clinically meaningful improvements compared to 28% in controls. At one year, 50% of participants had a clinically meaningful response. The therapy had greater benefits for participants with tonal and non-blast induced tinnitus at the end of 6 (24.3% vs. 2%, p = 0.05) and 12 weeks (34% vs. 2%, p = 0.004) compared to controls with 80% and 70% responding at 6 months and 1 year, respectively. Adverse effects were mild and well-tolerated and the therapy had a similar safety profile to VNS for epilepsy. VNS paired with tones may be effective for a subgroup of tinnitus patients and provides impetus for a larger pivotal study.
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Affiliation(s)
- Richard Tyler
- University of Iowa Department of Otolaryngology-Head and Neck Surgery and Communication Sciences and Disorders, The University of Iowa, Iowa City, IA, USA.
| | - Anthony Cacace
- Department of Communication Sciences & Disorders, Wayne State University, Detroit, MI, USA
| | - Christina Stocking
- Department of Communicative Disorders and Sciences, University at Buffalo, Buffalo, NY, USA
| | - Brent Tarver
- MicroTransponder, Inc., 2802 Flintrock Trace, Suite 226, Austin, TX, USA
| | - Navzer Engineer
- MicroTransponder, Inc., 2802 Flintrock Trace, Suite 226, Austin, TX, USA
| | - Jeffrey Martin
- Callier Center for Communication Disorders, School for Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Aniruddha Deshpande
- Department of Speech-Language-Hearing Sciences, Hofstra University, Hempstead, NY, USA
| | - Nancy Stecker
- Department of Communicative Disorders and Sciences, University at Buffalo, Buffalo, NY, USA
| | - Melissa Pereira
- Department of Communicative Disorders and Sciences, University at Buffalo, Buffalo, NY, USA
| | - Michael Kilgard
- Texas Biomedical Device Center, University of Texas at Dallas, Richardson, TX, USA
| | - Chester Burress
- MicroTransponder, Inc., 2802 Flintrock Trace, Suite 226, Austin, TX, USA
| | - David Pierce
- MicroTransponder, Inc., 2802 Flintrock Trace, Suite 226, Austin, TX, USA
| | - Robert Rennaker
- Texas Biomedical Device Center, University of Texas at Dallas, Richardson, TX, USA
| | - Sven Vanneste
- Lab for Clinical and Integrative Neuroscience, School for Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
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Abstract
Major depressive disorder (MDD) is prevalent. Although standards antidepressants are more effective than placebo, up to 35% of patients do not respond to 4 or more conventional treatments and are considered to have treatment-resistant depression (TRD). Considerable effort has been devoted to trying to find effective treatments for TRD. This review focuses on vagus nerve stimulation (VNS), approved for TRD in 2005 by the Food and Drugs Administration. Stimulation is carried by bipolar electrodes on the left cervical vagus nerve, which are attached to an implanted stimulator generator. The vagus bundle contains about 80% of afferent fibers terminating in the medulla, from which there are projections to many areas of brain, including the limbic forebrain. Various types of brain imaging studies reveal widespread functional effects in brain after either acute or chronic VNS. Although more randomized control trials of VNS need to be carried out before a definitive conclusion can be reached about its efficacy, the results of open studies, carried out over period of 1 to 2 years, show much more efficacy when compared with results from treatment as usual studies. There is an increase in clinical response to VNS between 3 and 12 months, which is quite different from that seen with standard antidepressant treatment of MDD. Preclinically, VNS affects many of the same brain areas, neurotransmitters (serotonin, norepinephrine) and signal transduction mechanisms (brain-derived neurotrophic factor-tropomyosin receptor kinase B) as those found with traditional antidepressants. Nevertheless, the mechanisms by which VNS benefits patients nonresponsive to conventional antidepressants is unclear, with further research needed to clarify this.
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Affiliation(s)
- Flavia R Carreno
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
- Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
| | - Alan Frazer
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- South Texas Veterans Health Care System, San Antonio, TX, USA
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Sun L, Peräkylä J, Holm K, Haapasalo J, Lehtimäki K, Ogawa KH, Peltola J, Hartikainen KM. Vagus nerve stimulation improves working memory performance. J Clin Exp Neuropsychol 2017; 39:954-964. [PMID: 28492363 DOI: 10.1080/13803395.2017.1285869] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Vagus nerve stimulation (VNS) is used for treating refractory epilepsy and major depression. While the impact of this treatment on seizures has been established, its impact on human cognition remains equivocal. The goal of this study is to elucidate the immediate effects of vagus nerve stimulation on attention, cognition, and emotional reactivity in patients with epilepsy. Twenty patients (12 male and 8 female; 45 ± 13 years old) treated with VNS due to refractory epilepsy participated in the study. Subjects performed a computer-based test of executive functions embedded with emotional distractors while their brain activity was recorded with electroencephalography. Subjects' cognitive performance, early visual event-related potential N1, and frontal alpha asymmetry were studied when cyclic vagus nerve stimulation was on and when it was off. We found that vagus nerve stimulation improved working memory performance as seen in reduced errors on a subtask that relied on working memory, odds ratio (OR) = 0.63 (95% confidence interval, CI [0.47, 0.85]) and increased N1 amplitude, F(1, 15) = 10.17, p = .006. In addition, vagus nerve stimulation resulted in longer reaction time, F(1, 16) = 8.23, p = .019, and greater frontal alpha asymmetry, F(1, 16) = 11.79, p = .003, in response to threat-related distractors. This is the first study to show immediate improvement in working memory performance in humans with clinically relevant vagus nerve stimulation. Furthermore, vagus nerve stimulation had immediate effects on emotional reactivity evidenced in behavior and brain physiology.
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Affiliation(s)
- Lihua Sun
- a Behavioral Neurology Research Unit , Tampere University Hospital , Tampere , Finland
| | - Jari Peräkylä
- a Behavioral Neurology Research Unit , Tampere University Hospital , Tampere , Finland.,b Faculty of Medicine and Life Sciences , University of Tampere , Tampere , Finland
| | - Katri Holm
- a Behavioral Neurology Research Unit , Tampere University Hospital , Tampere , Finland.,b Faculty of Medicine and Life Sciences , University of Tampere , Tampere , Finland
| | - Joonas Haapasalo
- c Department of Neuroscience and Rehabilitation , Tampere University Hospital , Tampere , Finland
| | - Kai Lehtimäki
- c Department of Neuroscience and Rehabilitation , Tampere University Hospital , Tampere , Finland
| | - Keith H Ogawa
- d John Magaddino Neuroscience Laboratory , Saint Mary's College of California , Moraga , CA , USA
| | - Jukka Peltola
- b Faculty of Medicine and Life Sciences , University of Tampere , Tampere , Finland.,c Department of Neuroscience and Rehabilitation , Tampere University Hospital , Tampere , Finland
| | - Kaisa M Hartikainen
- a Behavioral Neurology Research Unit , Tampere University Hospital , Tampere , Finland.,b Faculty of Medicine and Life Sciences , University of Tampere , Tampere , Finland
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Salloum NC, Walker MC, Gangwani S, Conway CR. Emergence of mania in two middle-aged patients with a history of unipolar treatment-refractory depression receiving vagus nerve stimulation. Bipolar Disord 2017; 19:60-64. [PMID: 28098427 DOI: 10.1111/bdi.12463] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 12/13/2016] [Indexed: 12/01/2022]
Abstract
OBJECTIVES We report on two patients who experienced emergence of full manic symptoms while receiving vagal nerve stimulation (VNS). METHODS Two patients, both with a well-documented and verified history of longstanding unipolar depression, were initiated on VNS for treatment of their severe major depressive episodes. RESULTS The two patients had emergence of full manic symptoms after 8 and 9 months of VNS, respectively. Manic symptoms were adequately managed with standard treatments (mood stabilizer and electroconvulsive therapy) and VNS was continued in the two subjects for up to 5 years without any further occurrences of manic/hypomanic episodes. CONCLUSIONS These cases suggest that some patients with treatment-resistant depression may have a previously unrecognized bipolar disorder, triggered only by VNS. This report also provides evidence that VNS-induced manic switches, however serious and troubling to patients, can be managed safely, and that VNS maintenance can be continued for an extended period of time without manic relapses. Although the mechanism of action of VNS is not known, emerging evidence supports central nervous system dopaminergic and possibly cholinergic system involvement.
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Affiliation(s)
- Naji C Salloum
- Department of Psychiatry, Washington University, St. Louis, MO, USA
| | - Marie C Walker
- Department of Psychiatry, Washington University, St. Louis, MO, USA
| | - Sunil Gangwani
- Department of Psychiatry, Washington University, St. Louis, MO, USA
| | - Charles R Conway
- Department of Psychiatry, Washington University, St. Louis, MO, USA
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47
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Won E, Kim YK. Stress, the Autonomic Nervous System, and the Immune-kynurenine Pathway in the Etiology of Depression. Curr Neuropharmacol 2017; 14:665-73. [PMID: 27640517 PMCID: PMC5050399 DOI: 10.2174/1570159x14666151208113006] [Citation(s) in RCA: 155] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 10/17/2015] [Accepted: 11/01/2015] [Indexed: 12/27/2022] Open
Abstract
The autonomic nervous system is one of the major neural pathways activated by stress. In situations that are often associated with chronic stress, such as major depressive disorder, the sympathetic nervous system can be continuously activated without the normal counteraction of the parasympathetic nervous system. As a result, the immune system can be activated with increased levels of pro-inflammatory cytokines. These inflammatory conditions have been repeatedly observed in depression. In the search for the mechanism by which the immune system might contribute to depression, the enhanced activity of indoleamine 2,3-dioxygenase by pro-inflammatory cytokines has been suggested to play an important role. Indoleamine 2,3-dioxygenase is the first enzyme in the kynurenine pathway that converts tryptophan to kynurenine. Elevated activity of this enzyme can cause imbalances in downstream kynurenine metabolites. This imbalance can induce neurotoxic changes in the brain and create a vulnerable glial-neuronal network, which may render the brain susceptible to depression. This review focuses on the interaction between stress, the autonomic nervous system and the immune system which can cause imbalances in the kynurenine pathway, which may ultimately lead to major depressive disorder.
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Affiliation(s)
| | - Yong-Ku Kim
- Department of Psychiatry, Korea University Ansan Hospital, College of Medicine, 123 Jeokgeum-ro, Danwon-gu, Ansan 425-021, Republic of Korea
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Nicholson WC, Kempf MC, Moneyham L, Vance DE. The potential role of vagus-nerve stimulation in the treatment of HIV-associated depression: a review of literature. Neuropsychiatr Dis Treat 2017; 13:1677-1689. [PMID: 28721049 PMCID: PMC5499939 DOI: 10.2147/ndt.s136065] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Depression is the most common comorbidity and neuropsychiatric complication in HIV. Estimates suggest that the prevalence rate for depression among HIV-infected individuals is three times that of the general population. The association between HIV and clinical depression is complex; however, chronic activation of inflammatory mechanisms, which disrupt central nervous system (CNS) function, may contribute to this association. Disruptions in CNS function can result in cognitive disorders, social withdrawal, fatigue, apathy, psychomotor impairment, and sleep disturbances, which are common manifestations in depression and HIV alike. Interestingly, the parasympathetic system-associated vagus nerve (VN) has primary homeostatic properties that restore CNS function following a stress or inflammatory response. Unfortunately, about 30% of adults with HIV are resistant to standard psychotherapeutic and psychopharmacological treatments for depression, thus suggesting the need for alternative treatment approaches. VN stimulation (VNS) and its benefits as a treatment for depression have been well documented, but remain unexplored in the HIV population. Historically, VNS has been delivered using a surgically implanted device; however, transcutanous VNS (tVNS) with nonsurgical auricular technology is now available. Although it currently lacks Food and Drug Administration approval in the US, evidence suggests several advantages of tVNS, including a reduced side-effect profile when compared to standard treatments and comparable results to implantable VNS in treating depression. Therefore, tVNS could offer an alternative for managing depression in HIV via regulating CNS function; moreover, tVNS may be useful for treatment of other symptoms common in HIV. From this, implications for nursing research and practice are provided.
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Affiliation(s)
| | | | - Linda Moneyham
- School of Nursing, University of Alabama at Birmingham, Birmingham, AL, USA
| | - David E Vance
- School of Nursing, University of Alabama at Birmingham, Birmingham, AL, USA
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49
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Non-neuronal cardiac cholinergic system influences CNS via the vagus nerve to acquire a stress-refractory propensity. Clin Sci (Lond) 2016; 130:1913-28. [PMID: 27528769 DOI: 10.1042/cs20160277] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 08/15/2016] [Indexed: 12/31/2022]
Abstract
We previously developed cardiac ventricle-specific choline acetyltransferase (ChAT) gene-overexpressing transgenic mice (ChAT tgm), i.e. an in vivo model of the cardiac non-neuronal acetylcholine (NNA) system or non-neuronal cardiac cholinergic system (NNCCS). By using this murine model, we determined that this system was responsible for characteristics of resistance to ischaemia, or hypoxia, via the modulation of cellular energy metabolism and angiogenesis. In line with our previous study, neuronal ChAT-immunoreactivity in the ChAT tgm brains was not altered from that in the wild-type (WT) mice brains; in contrast, the ChAT tgm hearts were the organs with the highest expression of the ChAT transgene. ChAT tgm showed specific traits in a central nervous system (CNS) phenotype, including decreased response to restraint stress, less depressive-like and anxiety-like behaviours and anti-convulsive effects, all of which may benefit the heart. These phenotypes, induced by the activation of cardiac NNCCS, were dependent on the vagus nerve, because vagus nerve stimulation (VS) in WT mice also evoked phenotypes similar to those of ChAT tgm, which display higher vagus nerve discharge frequency; in contrast, lateral vagotomy attenuated these traits in ChAT tgm to levels observed in WT mice. Furthermore, ChAT tgm induced several biomarkers of VS responsible for anti-convulsive and anti-depressive-like effects. These results suggest that the augmentation of the NNCCS transduces an effective and beneficial signal to the afferent pathway, which mimics VS. Therefore, the present study supports our hypothesis that activation of the NNCCS modifies CNS to a more stress-resistant state through vagus nerve activity.
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Wostyn S, Staljanssens W, De Taeye L, Strobbe G, Gadeyne S, Van Roost D, Raedt R, Vonck K, van Mierlo P. EEG Derived Brain Activity Reflects Treatment Response from Vagus Nerve Stimulation in Patients with Epilepsy. Int J Neural Syst 2016; 27:1650048. [PMID: 27712133 DOI: 10.1142/s0129065716500489] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The mechanism of action of vagus nerve stimulation (VNS) is yet to be elucidated. To that end, the effects of VNS on the brain of epileptic patients were studied. Both when VNS was switched "On" and "Off", the brain activity of responders (R, seizure frequency reduction of over 50%) was compared to the brain activity of nonresponders (NR, seizure frequency reduction of less than 50%). Using EEG recordings, a significant increase in P300 amplitude for R and a significant decrease in P300 amplitude for NR were found. We found biomarkers for checking the efficacy of VNS with accuracy up to 94%. The results show that P300 features recorded in nonmidline electrodes are better P300 biomarkers for VNS efficacy than P300 features recorded in midline electrodes. Using source localization and connectivity analyses, the activity of the limbic system, insula and orbitofrontal cortex was found to be dependent on VNS switched "On" versus "Off" or patient group (R versus NR). The results suggest an important role for these areas in the mechanism of action of VNS, although a larger patient study should be done to confirm the findings.
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Affiliation(s)
- Simon Wostyn
- * MEDISIP, Department of Electronics and Information Systems, Ghent University, Ghent, Belgium.,† iMinds Medical IT Department, Ghent University, Ghent, Belgium
| | - Willeke Staljanssens
- * MEDISIP, Department of Electronics and Information Systems, Ghent University, Ghent, Belgium.,† iMinds Medical IT Department, Ghent University, Ghent, Belgium
| | - Leen De Taeye
- ‡ LCEN3, Department of Neurology, Ghent University, Ghent, Belgium
| | - Gregor Strobbe
- * MEDISIP, Department of Electronics and Information Systems, Ghent University, Ghent, Belgium
| | - Stefanie Gadeyne
- ‡ LCEN3, Department of Neurology, Ghent University, Ghent, Belgium
| | - Dirk Van Roost
- § Department of Neurosurgery, Ghent University Hospital, Ghent, Belgium
| | - Robrecht Raedt
- ‡ LCEN3, Department of Neurology, Ghent University, Ghent, Belgium
| | - Kristl Vonck
- ‡ LCEN3, Department of Neurology, Ghent University, Ghent, Belgium
| | - Pieter van Mierlo
- * MEDISIP, Department of Electronics and Information Systems, Ghent University, Ghent, Belgium.,† iMinds Medical IT Department, Ghent University, Ghent, Belgium.,¶ Functional Brain Mapping lab, University of Geneva, Geneva, Switzerland
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