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Carroll AM, Pruitt DT, Riley JR, Danaphongse TT, Rennaker RL, Engineer CT, Hays SA, Kilgard MP. Vagus nerve stimulation during training fails to improve learning in healthy rats. Sci Rep 2024; 14:18955. [PMID: 39147873 PMCID: PMC11327266 DOI: 10.1038/s41598-024-69666-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 08/07/2024] [Indexed: 08/17/2024] Open
Abstract
Learning new skills requires neuroplasticity. Vagus nerve stimulation (VNS) during sensory and motor events can increase neuroplasticity in networks related to these events and might therefore serve to facilitate learning on sensory and motor tasks. We tested if VNS could broadly improve learning on a wide variety of tasks across different skill domains in healthy, female adult rats. VNS was paired with presentation of stimuli or on successful trials during training, strategies known to facilitate plasticity and improve recovery in models of neurological disorders. VNS failed to improve either rate of learning or performance for any of the tested tasks, which included skilled forelimb motor control, speech sound discrimination, and paired-associates learning. These results contrast recent findings from multiple labs which found VNS pairing during training produced learning enhancements across motor, auditory, and cognitive domains. We speculate that these contrasting results may be explained by key differences in task designs, training timelines and animal handling approaches, and that while VNS may be able to facilitate rapid and early learning processes in healthy subjects, it does not broadly enhance learning for difficult tasks.
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Affiliation(s)
- Alan M Carroll
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX, 75080-3021, USA.
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA.
| | - David T Pruitt
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
| | - Jonathan R Riley
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
| | - Tanya T Danaphongse
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
| | - Robert L Rennaker
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
- Department of Bioengineering, Erik Jonsson School of Engineering and Computer Science, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
| | - Crystal T Engineer
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
| | - Seth A Hays
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
- Department of Bioengineering, Erik Jonsson School of Engineering and Computer Science, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
| | - Michael P Kilgard
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA
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Carroll AM, Riley JR, Borland MS, Danaphongse TT, Hays SA, Kilgard MP, Engineer CT. Bursts of vagus nerve stimulation paired with auditory rehabilitation fail to improve speech sound perception in rats with hearing loss. iScience 2024; 27:109527. [PMID: 38585658 PMCID: PMC10995867 DOI: 10.1016/j.isci.2024.109527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 09/09/2023] [Accepted: 03/15/2024] [Indexed: 04/09/2024] Open
Abstract
Hearing loss can lead to long-lasting effects on the central nervous system, and current therapies, such as auditory training and rehabilitation, show mixed success in improving perception and speech comprehension. Vagus nerve stimulation (VNS) is an adjunctive therapy that can be paired with rehabilitation to facilitate behavioral recovery after neural injury. However, VNS for auditory recovery has not been tested after severe hearing loss or significant damage to peripheral receptors. This study investigated the utility of pairing VNS with passive or active auditory rehabilitation in a rat model of noise-induced hearing loss. Although auditory rehabilitation helped rats improve their frequency discrimination, learn novel speech discrimination tasks, and achieve speech-in-noise performance similar to normal hearing controls, VNS did not enhance recovery of speech sound perception. These results highlight the limitations of VNS as an adjunctive therapy for hearing loss rehabilitation and suggest that optimal benefits from neuromodulation may require restored peripheral signaling.
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Affiliation(s)
- Alan M. Carroll
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, USA
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080-3021, USA
| | - Jonathan R. Riley
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, USA
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080-3021, USA
| | - Michael S. Borland
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, USA
| | - Tanya T. Danaphongse
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, USA
| | - Seth A. Hays
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, USA
- Department of Bioengineering, Erik Jonsson School of Engineering and Computer Science, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080-3021, USA
| | - Michael P. Kilgard
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, USA
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080-3021, USA
| | - Crystal T. Engineer
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, USA
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080-3021, USA
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Raj-Koziak D, Gos E, Kutyba J, Ganc M, Jedrzejczak WW, Skarzynski PH, Skarzynski H. Effectiveness of transcutaneous vagus nerve stimulation for the treatment of tinnitus: an interventional prospective controlled study. Int J Audiol 2024; 63:250-259. [PMID: 36799648 DOI: 10.1080/14992027.2023.2177894] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 02/02/2023] [Accepted: 02/03/2023] [Indexed: 02/18/2023]
Abstract
OBJECTIVES The aim of this interventional non-randomised prospective controlled study was to assess the effectiveness of transcutaneous vagus nerve stimulation (tVNS) in human subjects with tinnitus. DESIGN The ParasymTM tVNS device was paired with an auditory stimulation. Treatment and observations were conducted over 12 weeks. Audiological evaluation was performed. Responses from a set of questionnaires and quantitative electroencephalography (qEEG) before and after treatment were collected. Voice measurements were done to assess possible side-effects of tVNS. STUDY SAMPLE The study involved 29 adults who had chronic tinnitus (15 patients who underwent tVNS paired with sounds and a control group of 14 patients who did not). RESULTS In general, subjective and objective measurements of tinnitus showed no improvement in the study group compared to the controls, although certain parameters as gauged by the questionnaires did statistically improve. The loudness and frequency of tinnitus remained the same in both groups. For the qEEG, activity in the theta band increased significantly in the study group compared to the control group. CONCLUSIONS The tVNS was not effective in reducing tinnitus symptoms in our study group. However, changes in the theta band suggest there might be cortical effects that might, with sustained treatment, lead to improvements.
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Affiliation(s)
- Danuta Raj-Koziak
- Tinnitus Department, World Hearing Center, Institute of Physiology and Pathology of Hearing, Warsaw, Poland
| | - Elżbieta Gos
- Department of Teleaudiology and Screening, World Hearing Center, Institute of Physiology and Pathology of Hearing, Warsaw, Poland
| | - Justyna Kutyba
- Department of Teleaudiology and Screening, World Hearing Center, Institute of Physiology and Pathology of Hearing, Warsaw, Poland
| | - Małgorzata Ganc
- Department of Experimental Audiology, World Hearing Center, Institute of Physiology and Pathology of Hearing, Warsaw, Poland
| | - W Wiktor Jedrzejczak
- Department of Experimental Audiology, World Hearing Center, Institute of Physiology and Pathology of Hearing, Warsaw, Poland
| | - Piotr H Skarzynski
- Department of Teleaudiology and Screening, World Hearing Center, Institute of Physiology and Pathology of Hearing, Warsaw, Poland
- Heart Failure and Cardiac Rehabilitation Department, Medical University of Warsaw, Warsaw, Poland
- Institute of Sensory Organs, Warsaw, Poland
| | - Henryk Skarzynski
- Department of Otorhinolaryngosurgery, World Hearing Center, Institute of Physiology and Pathology of Hearing, Warsaw, Poland
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Jigo M, Carmel JB, Wang Q, Rodenkirch C. Transcutaneous cervical vagus nerve stimulation improves sensory performance in humans: a randomized controlled crossover pilot study. Sci Rep 2024; 14:3975. [PMID: 38368486 PMCID: PMC10874458 DOI: 10.1038/s41598-024-54026-8] [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: 08/17/2023] [Accepted: 02/07/2024] [Indexed: 02/19/2024] Open
Abstract
Accurate senses depend on high-fidelity encoding by sensory receptors and error-free processing in the brain. Progress has been made towards restoring damaged sensory receptors. However, methods for on-demand treatment of impaired central sensory processing are scarce. Prior invasive studies demonstrated that continuous vagus nerve stimulation (VNS) in rodents can activate the locus coeruleus-norepinephrine system to rapidly improve central sensory processing. Here, we investigated whether transcutaneous VNS improves sensory performance in humans. We conducted three sham-controlled experiments, each with 12 neurotypical adults, that measured the effects of transcutaneous VNS on metrics of auditory and visual performance, and heart rate variability (HRV). Continuous stimulation was delivered to cervical (tcVNS) or auricular (taVNS) branches of the vagus nerve while participants performed psychophysics tasks or passively viewed a display. Relative to sham stimulation, tcVNS improved auditory performance by 37% (p = 0.00052) and visual performance by 23% (p = 0.038). Participants with lower performance during sham conditions experienced larger tcVNS-evoked improvements (p = 0.0040). Lastly, tcVNS increased HRV during passive viewing, corroborating vagal engagement. No evidence for an effect of taVNS was observed. These findings validate the effectiveness of tcVNS in humans and position it as a method for on-demand interventions of impairments associated with central sensory processing dysfunction.
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Affiliation(s)
| | - Jason B Carmel
- Sharper Sense, Inc., New York, NY, USA
- Department of Neurology and Orthopedics, Columbia University Medical Center, New York, NY, USA
| | - Qi Wang
- Sharper Sense, Inc., New York, NY, USA
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - Charles Rodenkirch
- Sharper Sense, Inc., New York, NY, USA.
- The Jacobs Technion-Cornell Institute at Cornell Tech, New York, NY, USA.
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Tamaoki Y, Pasapula V, Chandler C, Borland MS, Olajubutu OI, Tharakan LS, Engineer CT. Degraded inferior colliculus responses to complex sounds in prenatally exposed VPA rats. J Neurodev Disord 2024; 16:2. [PMID: 38166599 PMCID: PMC10759431 DOI: 10.1186/s11689-023-09514-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 12/07/2023] [Indexed: 01/05/2024] Open
Abstract
BACKGROUND Individuals with autism spectrum disorders (ASD) often exhibit altered sensory processing and deficits in language development. Prenatal exposure to valproic acid (VPA) increases the risk for ASD and impairs both receptive and expressive language. Like individuals with ASD, rodents prenatally exposed to VPA exhibit degraded auditory cortical processing and abnormal neural activity to sounds. Disrupted neuronal morphology has been documented in earlier processing areas of the auditory pathway in VPA-exposed rodents, but there are no studies documenting early auditory pathway physiology. Therefore, the objective of this study is to characterize inferior colliculus (IC) responses to different sounds in rats prenatally exposed to VPA compared to saline-exposed rats. METHODS In vivo extracellular multiunit recordings from the inferior colliculus were collected in response to tones, speech sounds, and noise burst trains. RESULTS Our results indicate that the overall response to speech sounds was degraded in VPA-exposed rats compared to saline-exposed controls, but responses to tones and noise burst trains were unaltered. CONCLUSIONS These results are consistent with observations in individuals with autism that neural responses to complex sounds, like speech, are often altered, and lays the foundation for future studies of potential therapeutics to improve auditory processing in the VPA rat model of ASD.
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Affiliation(s)
- Yuko Tamaoki
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA.
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA.
| | - Varun Pasapula
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
| | - Collin Chandler
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
| | - Michael S Borland
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
| | - Olayinka I Olajubutu
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
| | - Liza S Tharakan
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
| | - Crystal T Engineer
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
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Jigo M, Carmel JB, Wang Q, Rodenkirch C. Transcutaneous cervical vagus nerve stimulation improves sensory performance in humans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.08.552508. [PMID: 37609169 PMCID: PMC10441305 DOI: 10.1101/2023.08.08.552508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Accurate senses depend on high-fidelity encoding by sensory receptors and error-free processing in the brain. Progress has been made towards restoring damaged sensory receptors. However, methods for on-demand treatment of impaired central sensory processing are scarce. Prior invasive studies demonstrated that continuous vagus nerve stimulation (VNS) in rodents can activate the locus coeruleus-norepinephrine system to rapidly improve central sensory processing. Here, we investigated whether transcutaneous VNS improves sensory performance in humans. We conducted three sham-controlled experiments, each with 12 neurotypical adults, that measured the effects of transcutaneous VNS on metrics of auditory and visual performance, and heart rate variability (HRV). Continuous stimulation was delivered to cervical (tcVNS) or auricular (taVNS) branches of the vagus nerve while participants performed psychophysics tasks or passively viewed a display. Relative to sham stimulation, tcVNS improved auditory performance by 37% (p=0.00052) and visual performance by 23% (p=0.038). Participants with lower performance during sham conditions experienced larger tcVNS-evoked improvements (p=0.0040). Lastly, tcVNS increased HRV during passive viewing, corroborating vagal engagement. No evidence for an effect of taVNS was observed. These findings validate the effectiveness of tcVNS in humans and position it as a method for on-demand interventions of impairments associated with central sensory processing dysfunction.
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Affiliation(s)
| | - Jason B. Carmel
- Sharper Sense, Inc., New York, NY
- Department of Neurology and Orthopedics, Columbia University Medical Center, New York, NY
| | - Qi Wang
- Sharper Sense, Inc., New York, NY
- Department of Biomedical Engineering, Columbia University, New York, NY
| | - Charles Rodenkirch
- Sharper Sense, Inc., New York, NY
- The Jacobs Technion-Cornell Institute at Cornell Tech, New York, NY
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Aljuhani T, Coker-Bolt P, Katikaneni L, Ramakrishnan V, Brennan A, George MS, Badran BW, Jenkins D. Use of non-invasive transcutaneous auricular vagus nerve stimulation: neurodevelopmental and sensory follow-up. Front Hum Neurosci 2023; 17:1297325. [PMID: 38021221 PMCID: PMC10666166 DOI: 10.3389/fnhum.2023.1297325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 10/12/2023] [Indexed: 12/01/2023] Open
Abstract
Objective To assess the impact of non-invasive transcutaneous auricular vagal nerve stimulation (taVNS) paired with oral feeding on long-term neurodevelopmental and sensory outcomes. Method We tested 21 of 35 children who as infants were gastrostomy tube (G-tube) candidates and participated in the novel, open-label trial of taVNS paired with oral feeding. To evaluate possible effects on development at 18-months after infant taVNS, we performed the Bayley-III (n = 10) and Sensory Profile (SP-2, n = 12) assessments before the COVID pandemic, and Cognitive Adaptive Test (CAT), Clinical Linguistics and Auditory Milestone (CLAMS), Ages and Stages Questionnaire (ASQ), and Peabody Developmental Motor Scales-2 gross motor tests as possible during and after the pandemic. We compared outcomes for infants who attained full oral feeds during taVNS ('responders') or received G-tubes ('non-responders'). Results At a mean of 19-months, taVNS 'responders' showed significantly better general sensory processing on the SP-2 than 'non-responders'. There were no differences in other test scores, which were similar to published outcomes for infants who required G-tubes. Conclusion This is the first report of neurodevelopmental follow-up in infants who received taVNS-paired feeding. They had similar developmental outcomes as historical control infants failing oral feeds who received G-tubes. Our data suggests that infants who attained full oral feeds had better sensory processing.
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Affiliation(s)
- Turki Aljuhani
- Division of Health Science and Research, Medical University of South Carolina, Charleston, SC, United States
- Department of Occupational Therapy, College of Applied Medical Sciences, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Patricia Coker-Bolt
- Doctorate of Occupational Therapy Program, Hawai’i Pacific University, Honolulu, HI, United States
| | - Lakshmi Katikaneni
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC, United States
| | - Viswanathan Ramakrishnan
- Department of Public Health Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - Alyssa Brennan
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC, United States
| | - Mark S. George
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, United States
- Ralph H. Johnson VA Medical Center, Charleston, SC, Unites States
| | - Bashar W. Badran
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - Dorothea Jenkins
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC, United States
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Jenkins DD, Moss HG, Adams LE, Hunt S, Dancy M, Huffman SM, Cook D, Jensen JH, Summers P, Thompson S, George MS, Badran BW. Higher Dose Noninvasive Transcutaneous Auricular Vagus Nerve Stimulation Increases Feeding Volumes and White Matter Microstructural Complexity in Open-Label Study of Infants Slated for Gastrostomy Tube. J Pediatr 2023; 262:113563. [PMID: 37329979 PMCID: PMC11000235 DOI: 10.1016/j.jpeds.2023.113563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 06/06/2023] [Accepted: 06/12/2023] [Indexed: 06/19/2023]
Abstract
OBJECTIVE To determine whether transcutaneous auricular vagus nerve stimulation (taVNS) paired with twice daily bottle feeding increases the volume of oral feeds and white matter neuroplasticity in term-age-equivalent infants failing oral feeds and determined to need a gastrostomy tube. STUDY DESIGN In this prospective, open-label study, 21 infants received taVNS paired with 2 bottle feeds for 2 - 3 weeks (2x). We compared 1) increase oral feeding volumes with 2x taVNS and previously reported once daily taVNS (1x) to determine a dose response, 2) number of infants who attained full oral feeding volumes, and 3) diffusional kurtosis imaging and magnetic resonance spectroscopy before and after treatment by paired t tests. RESULTS All 2x taVNS treated infants significantly increased their feeding volumes compared with 10 days before treatment. Over 50% of 2x taVNS infants achieved full oral feeds but in a shorter time than 1x cohort (median 7 days [2x], 12.5 days [1x], P < .05). Infants attaining full oral feeds showed greater increase in radial kurtosis in the right corticospinal tract at the cerebellar peduncle and external capsule. Notably, 75% of infants of diabetic mothers failed full oral feeds, and their glutathione concentrations in the basal ganglia, a measure of central nervous system oxidative stress, were significantly associated with feeding outcome. CONCLUSIONS In infants with feeding difficulty, increasing the number of daily taVNS-paired feeding sessions to twice-daily significantly accelerates response time but not the overall response rate of treatment. taVNS was associated with white matter motor tract plasticity in infants able to attain full oral feeds. TRIAL REGISTRATION Clinicaltrials.gov (NCT04643808).
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Affiliation(s)
- Dorothea D Jenkins
- Department of Pediatrics at the Medical University of South Carolina, Charleston, SC; Department of Neuroscience, Medical University of South Carolina, Charleston, SC.
| | - Hunter G Moss
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC; Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC
| | - Lauren E Adams
- College of Medicine, Medical University of South Carolina, Charleston, SC
| | - Sally Hunt
- College of Medicine, Medical University of South Carolina, Charleston, SC
| | - Morgan Dancy
- Brain Stimulation Division, Department of Psychiatry, Medical University of South Carolina, Charleston, SC
| | - Sarah M Huffman
- Brain Stimulation Division, Department of Psychiatry, Medical University of South Carolina, Charleston, SC
| | - Daniel Cook
- College of Medicine, Medical University of South Carolina, Charleston, SC
| | - Jens H Jensen
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC; Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC; Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC
| | - Philipp Summers
- Brain Stimulation Division, Department of Psychiatry, Medical University of South Carolina, Charleston, SC
| | - Sean Thompson
- Department of Neurology, Emory University School of Medicine, Atlanta, GA
| | - Mark S George
- Brain Stimulation Division, Department of Psychiatry, Medical University of South Carolina, Charleston, SC; Ralph H. Johnson VA Medical Center, Charleston, SC
| | - Bashar W Badran
- Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC; Neuro-X Lab, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC
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Choudhary T, Elliott M, Euliano NR, Gurel NZ, Rivas AG, Wittbrodt MT, Vaccarino V, Shah AJ, Inan OT, Bremner JD. Effect of transcutaneous cervical vagus nerve stimulation on declarative and working memory in patients with Posttraumatic Stress Disorder (PTSD): A pilot study. J Affect Disord 2023; 339:418-425. [PMID: 37442455 DOI: 10.1016/j.jad.2023.07.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 06/10/2023] [Accepted: 07/08/2023] [Indexed: 07/15/2023]
Abstract
BACKGROUND Posttraumatic stress disorder (PTSD) is associated with changes in multiple neurophysiological systems, including verbal declarative memory deficits. Vagus Nerve Stimulation (VNS) has been shown in preliminary studies to enhance function when paired with cognitive and motor tasks. The purpose of this study was to analyze the effect of transcutaneous cervical VNS (tcVNS) on attention, declarative and working memory in PTSD patients. METHODS Fifteen PTSD patients were randomly assigned to active tcVNS (N = 8) or sham (N = 7) stimulation in a double-blinded fashion. Memory assessment tests including paragraph recall and N-back tests were performed to assess declarative and working memory function when paired with active/sham tcVNS once per month in a longitudinal study during which patients self-administered tcVNS/sham twice daily. RESULTS Active tcVNS stimulation resulted in a significant improvement in paragraph recall performance following pairing with paragraph encoding for PTSD patients at two months (p < 0.05). It resulted in a 91 % increase in paragraph recall performance within group (p = 0.03), while sham tcVNS exhibited no such trend in performance improvement. In the N-back study, positive deviations in accuracy, precision and recall measures on different day visits (7,34,64,94) of patients with respect to day 1 revealed a pattern of better performance of the active tcVNS population compared to sham VNS which did not reach statistical significance. LIMITATIONS Our sample size was small. CONCLUSIONS These preliminary results suggest that tcVNS improves attention, declarative and working memory, which may improve quality of life and productivity for patients with PTSD. Future studies are required to confirm these results.
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Affiliation(s)
- Tilendra Choudhary
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA; Department of Biomedical Informatics, Emory University School of Medicine, Atlanta, GA, USA; Atlanta VA Medical Center, Decatur, GA, USA.
| | | | | | - Nil Z Gurel
- Reality Labs, Meta Platforms Inc., Menlo Park, CA, USA
| | - Amanda G Rivas
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA
| | - Matthew T Wittbrodt
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA
| | - Viola Vaccarino
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA; Department of Medicine, Cardiology Division, Emory University School of Medicine, Atlanta, GA, USA
| | - Amit J Shah
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA; Department of Medicine, Cardiology Division, Emory University School of Medicine, Atlanta, GA, USA; Atlanta VA Medical Center, Decatur, GA, USA
| | - Omer T Inan
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA; Coulter Department of Bioengineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - J Douglas Bremner
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA; Atlanta VA Medical Center, Decatur, GA, USA; Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, USA
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McHaney JR, Schuerman WL, Leonard MK, Chandrasekaran B. Transcutaneous Auricular Vagus Nerve Stimulation Modulates Performance but Not Pupil Size During Nonnative Speech Category Learning. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2023; 66:3825-3843. [PMID: 37652065 DOI: 10.1044/2023_jslhr-22-00596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
PURPOSE Subthreshold transcutaneous auricular vagus nerve stimulation (taVNS) synchronized with behavioral training can selectively enhance nonnative speech category learning in adults. Prior work has demonstrated that behavioral performance increases when taVNS is paired with easier-to-learn Mandarin tone categories in native English listeners, relative to when taVNS is paired with harder-to-learn Mandarin tone categories or without taVNS. Mechanistically, this temporally precise plasticity has been attributed to noradrenergic modulation. However, prior work did not specifically utilize methodologies that indexed noradrenergic modulation and, therefore, was unable to explicitly test this hypothesis. Our goal for this study was to use pupillometry to gain mechanistic insights into taVNS behavioral effects. METHOD Thirty-eight participants learned to categorize Mandarin tones while pupillometry was recorded. In a double-blinded design, participants were divided into two taVNS groups that, as in the prior study, differed according to whether taVNS was paired with easier-to-learn tones or harder-to-learn tones. Learning performance and pupillary responses were measured using linear mixed-effects models. RESULTS We found that taVNS did not have any tone-specific or group behavioral or pupillary effects. However, in an exploratory analysis, we observed that taVNS did lead to faster rates of learning on trials paired with stimulation, particularly for those who were stimulated at lower amplitudes. CONCLUSIONS Our results suggest that pupillary responses may not be a reliable marker of locus coeruleus-norepinephrine system activity in humans. However, future research should systematically examine the effects of stimulation amplitude on both behavior and pupillary responses. SUPPLEMENTAL MATERIAL https://doi.org/10.23641/asha.24036666.
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Cansler R, Heidrich J, Whiting A, Tran D, Hall P, Tyler WJ. Influence of CrossFit and Deep End Fitness training on mental health and coping in athletes. Front Sports Act Living 2023; 5:1061492. [PMID: 37849685 PMCID: PMC10577405 DOI: 10.3389/fspor.2023.1061492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 09/19/2023] [Indexed: 10/19/2023] Open
Abstract
Physical exercise is known to improve mental health. Athletes can experience unique physical and emotional stressors, which can deteriorate mental health and cognitive function. Training apathy can lead to cognitive dissonance and further degrade performance by promoting maladaptive, avoidance coping strategies. Introduction of psychosocial and training variables, such as those used in CrossFit (CF) and other community-based fitness programs with strong peer support have been shown to help reduce training apathy and negative affect. Here, we explored whether addition of psychophysiological variation, experienced as "hunger for air" during underwater breath-hold exercises, could provide unique mental health benefits for athletes. We studied the influence of CF and Deep End Fitness (DEF), a community-based underwater fitness program, on several outcome measures of mental health and emotional well-being in volunteer athletes. We observed a significant reduction in stress scores of both the control CF training group and the experimental DEF group. We found that DEF produced a significant improvement in positive affect while CF training did not. Further supportive of our hypothesis that the psychological and biological stressors experienced in underwater, breath-hold training cause positive adaptive changes and benefits, DEF training uniquely increased problem-based coping. While our observations demonstrate both CF and DEF training can improve mental health in athletes, DEF produced additional, unique benefits to positive coping and attitudes of athletes. Future studies should further evaluate the broader benefits of community-based, underwater training programs on psychological and physiological health in athletes and the public.
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Affiliation(s)
- Rachel Cansler
- Department of Psychology, New York University, New York, NY, United States
- Deep End Fitness, San Diego, CA, United States
| | | | - Ali Whiting
- Deep End Fitness, San Diego, CA, United States
| | - Don Tran
- Deep End Fitness, San Diego, CA, United States
| | - Prime Hall
- Deep End Fitness, San Diego, CA, United States
| | - William J. Tyler
- Deep End Fitness, San Diego, CA, United States
- IST, LLC, Birmingham, AL, United States
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12
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Borland MS, Buell EP, Riley JR, Carroll AM, Moreno NA, Sharma P, Grasse KM, Buell JM, Kilgard MP, Engineer CT. Precise sound characteristics drive plasticity in the primary auditory cortex with VNS-sound pairing. Front Neurosci 2023; 17:1248936. [PMID: 37732302 PMCID: PMC10508341 DOI: 10.3389/fnins.2023.1248936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 08/22/2023] [Indexed: 09/22/2023] Open
Abstract
Introduction Repeatedly pairing a tone with vagus nerve stimulation (VNS) alters frequency tuning across the auditory pathway. Pairing VNS with speech sounds selectively enhances the primary auditory cortex response to the paired sounds. It is not yet known how altering the speech sounds paired with VNS alters responses. In this study, we test the hypothesis that the sounds that are presented and paired with VNS will influence the neural plasticity observed following VNS-sound pairing. Methods To explore the relationship between acoustic experience and neural plasticity, responses were recorded from primary auditory cortex (A1) after VNS was repeatedly paired with the speech sounds 'rad' and 'lad' or paired with only the speech sound 'rad' while 'lad' was an unpaired background sound. Results Pairing both sounds with VNS increased the response strength and neural discriminability of the paired sounds in the primary auditory cortex. Surprisingly, pairing only 'rad' with VNS did not alter A1 responses. Discussion These results suggest that the specific acoustic contrasts associated with VNS can powerfully shape neural activity in the auditory pathway. Methods to promote plasticity in the central auditory system represent a new therapeutic avenue to treat auditory processing disorders. Understanding how different sound contrasts and neural activity patterns shape plasticity could have important clinical implications.
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Affiliation(s)
- Michael S. Borland
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, United States
- Texas Biomedical Device Center, The University of Texas at Dallas, Richardson, TX, United States
| | - Elizabeth P. Buell
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, United States
- Texas Biomedical Device Center, The University of Texas at Dallas, Richardson, TX, United States
| | - Jonathan R. Riley
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, United States
- Texas Biomedical Device Center, The University of Texas at Dallas, Richardson, TX, United States
| | - Alan M. Carroll
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, United States
- Texas Biomedical Device Center, The University of Texas at Dallas, Richardson, TX, United States
| | - Nicole A. Moreno
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, United States
- Texas Biomedical Device Center, The University of Texas at Dallas, Richardson, TX, United States
| | - Pryanka Sharma
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, United States
- Texas Biomedical Device Center, The University of Texas at Dallas, Richardson, TX, United States
| | - Katelyn M. Grasse
- Texas Biomedical Device Center, The University of Texas at Dallas, Richardson, TX, United States
- Erik Jonsson School of Engineering and Computer Science, The University of Texas at Dallas, Richardson, TX, United States
| | - John M. Buell
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, United States
- Texas Biomedical Device Center, The University of Texas at Dallas, Richardson, TX, United States
| | - Michael P. Kilgard
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, United States
- Texas Biomedical Device Center, The University of Texas at Dallas, Richardson, TX, United States
| | - Crystal T. Engineer
- Department of Neuroscience, School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, United States
- Texas Biomedical Device Center, The University of Texas at Dallas, Richardson, TX, United States
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13
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Hays SA, Rennaker RL, Kilgard MP. How to fail with paired VNS therapy. Brain Stimul 2023; 16:1252-1258. [PMID: 37595833 DOI: 10.1016/j.brs.2023.08.009] [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: 06/23/2023] [Revised: 08/14/2023] [Accepted: 08/15/2023] [Indexed: 08/20/2023] Open
Abstract
Vagus nerve stimulation (VNS) has gained enormous traction as a promising bioelectronic therapy. In particular, the delivery of VNS paired with training to promote neural changes has demonstrated clinical success for stroke recovery and found far-reaching application in other domains, from autism to psychiatric disorders to normal learning. The success of paired VNS has been extensively documented. Here, we consider a more unusual question: why does VNS have such broad utility, and perhaps more importantly, when does VNS not work? We present a discussion of the concepts that underlie VNS therapy and an anthology of studies that describe conditions in which these concepts are violated and VNS fails. We focus specifically on the mechanisms engaged by implanted VNS, and how the parameters of stimulation, stimulation method, pharmacological manipulations, accompanying comorbidities, and specifics of concurrent training interact with these mechanisms to impact the efficacy of VNS therapy. As paired VNS therapy is increasing translated to clinical implementation, a clear understanding of the conditions in which it does, and critically, does not work is fundamental to the success of this approach.
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Affiliation(s)
- Seth A Hays
- Texas Biomedical Device Center, The University of Texas at Dallas, Richardson, TX, USA; Erik Jonsson School of Engineering and Computer Science, The University of Texas at Dallas, Richardson, TX, USA.
| | - Robert L Rennaker
- Texas Biomedical Device Center, The University of Texas at Dallas, Richardson, TX, USA; School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Michael P Kilgard
- Texas Biomedical Device Center, The University of Texas at Dallas, Richardson, TX, USA; School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA
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14
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Bremner JD, Gazi AH, Lambert TP, Nawar A, Harrison AB, Welsh JW, Vaccarino V, Walton KM, Jaquemet N, Mermin-Bunnell K, Mesfin H, Gray TA, Ross K, Saks G, Tomic N, Affadzi D, Bikson M, Shah AJ, Dunn KE, Giordano NA, Inan OT. Noninvasive Vagal Nerve Stimulation for Opioid Use Disorder. ANNALS OF DEPRESSION AND ANXIETY 2023; 10:1117. [PMID: 38074313 PMCID: PMC10699253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/31/2024]
Abstract
Background Opioid Use Disorder (OUD) is an escalating public health problem with over 100,000 drug overdose-related deaths last year most of them related to opioid overdose, yet treatment options remain limited. Non-invasive Vagal Nerve Stimulation (nVNS) can be delivered via the ear or the neck and is a non-medication alternative to treatment of opioid withdrawal and OUD with potentially widespread applications. Methods This paper reviews the neurobiology of opioid withdrawal and OUD and the emerging literature of nVNS for the application of OUD. Literature databases for Pubmed, Psychinfo, and Medline were queried for these topics for 1982-present. Results Opioid withdrawal in the context of OUD is associated with activation of peripheral sympathetic and inflammatory systems as well as alterations in central brain regions including anterior cingulate, basal ganglia, and amygdala. NVNS has the potential to reduce sympathetic and inflammatory activation and counter the effects of opioid withdrawal in initial pilot studies. Preliminary studies show that it is potentially effective at acting through sympathetic pathways to reduce the effects of opioid withdrawal, in addition to reducing pain and distress. Conclusions NVNS shows promise as a non-medication approach to OUD, both in terms of its known effect on neurobiology as well as pilot data showing a reduction in withdrawal symptoms as well as physiological manifestations of opioid withdrawal.
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Affiliation(s)
- J Douglas Bremner
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta GA
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta GA
- Atlanta Veterans Affairs Healthcare System, Decatur GA
| | - Asim H Gazi
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA
| | - Tamara P Lambert
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA
| | - Afra Nawar
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA
| | - Anna B Harrison
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA
| | - Justine W Welsh
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta GA
| | - Viola Vaccarino
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta GA
| | - Kevin M Walton
- Clinical Research Grants Branch, Division of Therapeutics and Medical Consequences, National Institute on Drug Abuse, Bethesda, MD
| | - Nora Jaquemet
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta GA
| | - Kellen Mermin-Bunnell
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta GA
| | - Hewitt Mesfin
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta GA
| | - Trinity A Gray
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta GA
| | - Keyatta Ross
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta GA
| | - Georgia Saks
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA
| | - Nikolina Tomic
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA
| | - Danner Affadzi
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta GA
| | - Marom Bikson
- Department of Biomedical Engineering, The City College of New York, New York, NY
| | - Amit J Shah
- Atlanta Veterans Affairs Healthcare System, Decatur GA
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta GA
| | - Kelly E Dunn
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore MD
| | | | - Omer T Inan
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA
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15
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Tamaoki Y, Pasapula V, Chandler C, Borland MS, Olajubutu OI, Tharakan LS, Engineer CT. Degraded inferior colliculus responses to complex sounds in prenatally exposed VPA rats. RESEARCH SQUARE 2023:rs.3.rs-3168097. [PMID: 37577524 PMCID: PMC10418539 DOI: 10.21203/rs.3.rs-3168097/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Background Individuals with autism spectrum disorders (ASD) often exhibit altered sensory processing and deficits in language development. Prenatal exposure to valproic acid (VPA) increases the risk for ASD and impairs both receptive and expressive language. Like individuals with ASD, rodents prenatally exposed to VPA exhibit degraded auditory cortical processing and abnormal neural activity to sounds. Disrupted neuronal morphology has been documented in earlier processing areas of the auditory pathway in VPA-exposed rodents, but there are no studies documenting early auditory pathway physiology. Therefore, the objective of this study is to characterize inferior colliculus (IC) responses to different sounds in rats prenatally exposed to VPA compared to saline-exposed rats. Methods Neural recordings from the inferior colliculus were collected in response to tones, speech sounds, and noise burst trains. Results Our results indicate that the overall response to speech sounds was degraded in VPA-exposed rats compared saline-exposed controls, but responses to tones and noise burst trains were unaltered. Conclusions These results are consistent with observations in individuals with autism that neural responses to complex sounds, like speech, are often altered, and lays the foundation for future studies of potential therapeutics to improve auditory processing in the VPA rat model of ASD.
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Affiliation(s)
- Yuko Tamaoki
- The University of Texas at Dallas School of Behavioral and Brain Sciences
| | - Varun Pasapula
- The University of Texas at Dallas School of Behavioral and Brain Sciences
| | - Collin Chandler
- The University of Texas at Dallas School of Behavioral and Brain Sciences
| | - Michael S Borland
- The University of Texas at Dallas School of Behavioral and Brain Sciences
| | | | - Liza S Tharakan
- The University of Texas at Dallas School of Behavioral and Brain Sciences
| | - Crystal T Engineer
- The University of Texas at Dallas School of Behavioral and Brain Sciences
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16
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Rufener KS, Wienke C, Salanje A, Haghikia A, Zaehle T. Effects of transcutaneous auricular vagus nerve stimulation paired with tones on electrophysiological markers of auditory perception. Brain Stimul 2023; 16:982-989. [PMID: 37336282 DOI: 10.1016/j.brs.2023.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 06/12/2023] [Accepted: 06/12/2023] [Indexed: 06/21/2023] Open
Abstract
BACKGROUND Transcutaneous auricular vagus nerve stimulation (taVNS) has been introduced as a non-invasive alternative to invasive vagus nerve stimulation (iVNS). While iVNS paired with tones has been highlighted as a potential effective therapy for the treatment of auditory disorders such as tinnitus, there is still scarce data available confirming the efficacy of non-invasive taVNS. Here, we assessed the effect of taVNS paired with acoustic stimuli on sensory-related electrophysiological responses. METHODS A total of 22 healthy participants were investigated with a taVNS tone-pairing paradigm using a within-subjects design. In a single session pure tones paired with either active taVNS or sham taVNS were repeatedly presented. Novel tones without electrical stimulation served as control condition. Auditory event related potentials and auditory cortex oscillations were compared before and after the tone pairing procedure between stimulation conditions. RESULTS From pre to post pairing, we observed a decrease in the N1 amplitude and in theta power to tones paired with sham taVNS while these electrophysiological measures remained stable for tones paired with active taVNS a pattern mirroring auditory sensory processing of novel, unpaired control tones. CONCLUSION Our results demonstrate the efficacy of a short-term application of non-invasive taVNS to modulate auditory processing in healthy individuals and, thereby, have potential implications for interventions in auditory processing deficits.
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Affiliation(s)
- Katharina S Rufener
- Department of Child and Adolescent Psychiatry and Psychotherapy, Otto-von-Guericke-University Magdeburg, Germany; Center for Behavioral Brain Sciences (CBBS), Otto-von-Guericke-University Magdeburg, Germany.
| | - Christian Wienke
- Department of Neurology, Otto-von-Guericke-University Magdeburg, Germany
| | - Alena Salanje
- Department of Neurology, Otto-von-Guericke-University Magdeburg, Germany
| | - Aiden Haghikia
- Department of Neurology, Otto-von-Guericke-University Magdeburg, Germany; Center for Behavioral Brain Sciences (CBBS), Otto-von-Guericke-University Magdeburg, Germany; German Center for Neurodegenerative Diseases (DZNE) Magdeburg, Germany
| | - Tino Zaehle
- Department of Neurology, Otto-von-Guericke-University Magdeburg, Germany; Center for Behavioral Brain Sciences (CBBS), Otto-von-Guericke-University Magdeburg, Germany
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17
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Cao J, Wang X, Chen J, Zhang N, Liu Z. The vagus nerve mediates the stomach-brain coherence in rats. Neuroimage 2022; 263:119628. [PMID: 36113737 PMCID: PMC10008817 DOI: 10.1016/j.neuroimage.2022.119628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Revised: 08/20/2022] [Accepted: 09/12/2022] [Indexed: 11/26/2022] Open
Abstract
Interactions between the brain and the stomach shape both cognitive and digestive functions. Recent human studies report spontaneous synchronization between brain activity and gastric slow waves in the resting state. However, this finding has not been replicated in any animal models. The neural pathways underlying this apparent stomach-brain synchrony is also unclear. Here, we performed functional magnetic resonance imaging while simultaneously recording body-surface gastric slow waves from anesthetized rats in the fasted vs. postprandial conditions and performed a bilateral cervical vagotomy to assess the role of the vagus nerve. The coherence between brain fMRI signals and gastric slow waves was found in a distributed "gastric network", including subcortical and cortical regions in the sensory, motor, and limbic systems. The stomach-brain coherence was largely reduced by the bilateral vagotomy and was different between the fasted and fed states. These findings suggest that the vagus nerve mediates the spontaneous coherence between brain activity and gastric slow waves, which is likely a signature of real-time stomach-brain interactions. However, its functional significance remains to be established.
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Affiliation(s)
- Jiayue Cao
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, USA
| | - Xiaokai Wang
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, USA
| | - Jiande Chen
- Division of Gastroenterology and Hepatology, University of Michigan, Ann Arbor, USA
| | - Nanyin Zhang
- Department of Biomedical Engineering, Huck Institutes of the life sciences, Pennsylvania State University, USA
| | - Zhongming Liu
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, USA; Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, USA.
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18
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Wilde M, Constantin L, Thorne PR, Montgomery JM, Scott EK, Cheyne JE. Auditory processing in rodent models of autism: a systematic review. J Neurodev Disord 2022; 14:48. [PMID: 36042393 PMCID: PMC9429780 DOI: 10.1186/s11689-022-09458-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 08/07/2022] [Indexed: 11/19/2022] Open
Abstract
Autism is a complex condition with many traits, including differences in auditory sensitivity. Studies in human autism are plagued by the difficulty of controlling for aetiology, whereas studies in individual rodent models cannot represent the full spectrum of human autism. This systematic review compares results in auditory studies across a wide range of established rodent models of autism to mimic the wide range of aetiologies in the human population. A search was conducted in the PubMed and Web of Science databases to find primary research articles in mouse or rat models of autism which investigate central auditory processing. A total of 88 studies were included. These used non-invasive measures of auditory function, such as auditory brainstem response recordings, cortical event-related potentials, electroencephalography, and behavioural tests, which are translatable to human studies. They also included invasive measures, such as electrophysiology and histology, which shed insight on the origins of the phenotypes found in the non-invasive studies. The most consistent results across these studies were increased latency of the N1 peak of event-related potentials, decreased power and coherence of gamma activity in the auditory cortex, and increased auditory startle responses to high sound levels. Invasive studies indicated loss of subcortical inhibitory neurons, hyperactivity in the lateral superior olive and auditory thalamus, and reduced specificity of responses in the auditory cortex. This review compares the auditory phenotypes across rodent models and highlights those that mimic findings in human studies, providing a framework and avenues for future studies to inform understanding of the auditory system in autism.
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Affiliation(s)
- Maya Wilde
- The Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Lena Constantin
- The Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Peter R Thorne
- Department of Physiology, Faculty of Medical and Health Sciences, Centre for Brain Research, University of Auckland, Auckland, New Zealand.,Section of Audiology, School of Population Health, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Johanna M Montgomery
- Department of Physiology, Faculty of Medical and Health Sciences, Centre for Brain Research, University of Auckland, Auckland, New Zealand
| | - Ethan K Scott
- The Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia.,Department of Anatomy and Physiology, School of Biomedical Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Juliette E Cheyne
- Department of Physiology, Faculty of Medical and Health Sciences, Centre for Brain Research, University of Auckland, Auckland, New Zealand.
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19
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Rodenkirch C, Carmel JB, Wang Q. Rapid Effects of Vagus Nerve Stimulation on Sensory Processing Through Activation of Neuromodulatory Systems. Front Neurosci 2022; 16:922424. [PMID: 35864985 PMCID: PMC9294458 DOI: 10.3389/fnins.2022.922424] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 06/15/2022] [Indexed: 12/13/2022] Open
Abstract
After sensory information is encoded into neural signals at the periphery, it is processed through multiple brain regions before perception occurs (i.e., sensory processing). Recent work has begun to tease apart how neuromodulatory systems influence sensory processing. Vagus nerve stimulation (VNS) is well-known as an effective and safe method of activating neuromodulatory systems. There is a growing body of studies confirming VNS has immediate effects on sensory processing across multiple sensory modalities. These immediate effects of VNS on sensory processing are distinct from the more well-documented method of inducing lasting neuroplastic changes to the sensory pathways through repeatedly delivering a brief VNS burst paired with a sensory stimulus. Immediate effects occur upon VNS onset, often disappear upon VNS offset, and the modulation is present for all sensory stimuli. Conversely, the neuroplastic effect of pairing sub-second bursts of VNS with a sensory stimulus alters sensory processing only after multiple pairing sessions, this alteration remains after cessation of pairing sessions, and the alteration selectively affects the response properties of neurons encoding the specific paired sensory stimulus. Here, we call attention to the immediate effects VNS has on sensory processing. This review discusses existing studies on this topic, provides an overview of the underlying neuromodulatory systems that likely play a role, and briefly explores the potential translational applications of using VNS to rapidly regulate sensory processing.
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Affiliation(s)
- Charles Rodenkirch
- Department of Biomedical Engineering, Columbia University, New York, NY, United States
- Jacobs Technion-Cornell Institute, Cornell Tech, New York, NY, United States
- *Correspondence: Charles Rodenkirch,
| | - Jason B. Carmel
- Department of Neurology and Orthopedics, Columbia University Medical Center, New York, NY, United States
| | - Qi Wang
- Department of Biomedical Engineering, Columbia University, New York, NY, United States
- Qi Wang,
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20
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Vagus Nerve Stimulation for Stroke Motor Recovery-What Is Next? Transl Stroke Res 2022:10.1007/s12975-022-01041-4. [PMID: 35653016 DOI: 10.1007/s12975-022-01041-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 05/24/2022] [Indexed: 10/18/2022]
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21
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Plasticity of the Central Nervous System Involving Peripheral Nerve Transfer. Neural Plast 2022; 2022:5345269. [PMID: 35342394 PMCID: PMC8956439 DOI: 10.1155/2022/5345269] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 02/09/2022] [Accepted: 02/28/2022] [Indexed: 11/22/2022] Open
Abstract
Peripheral nerve injury can lead to partial or complete loss of limb function, and nerve transfer is an effective surgical salvage for patients with these injuries. The inability of deprived cortical regions representing damaged nerves to overcome corresponding maladaptive plasticity after the reinnervation of muscle fibers and sensory receptors is thought to be correlated with lasting and unfavorable functional recovery. However, the concept of central nervous system plasticity is rarely elucidated in classical textbooks involving peripheral nerve injury, let alone peripheral nerve transfer. This article is aimed at providing a comprehensive understanding of central nervous system plasticity involving peripheral nerve injury by reviewing studies mainly in human or nonhuman primate and by highlighting the functional and structural modifications in the central nervous system after peripheral nerve transfer. Hopefully, it will help surgeons perform successful nerve transfer under the guidance of modern concepts in neuroplasticity.
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22
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Abstract
The human brain exhibits the remarkable ability to categorize speech sounds into distinct, meaningful percepts, even in challenging tasks like learning non-native speech categories in adulthood and hearing speech in noisy listening conditions. In these scenarios, there is substantial variability in perception and behavior, both across individual listeners and individual trials. While there has been extensive work characterizing stimulus-related and contextual factors that contribute to variability, recent advances in neuroscience are beginning to shed light on another potential source of variability that has not been explored in speech processing. Specifically, there are task-independent, moment-to-moment variations in neural activity in broadly-distributed cortical and subcortical networks that affect how a stimulus is perceived on a trial-by-trial basis. In this review, we discuss factors that affect speech sound learning and moment-to-moment variability in perception, particularly arousal states—neurotransmitter-dependent modulations of cortical activity. We propose that a more complete model of speech perception and learning should incorporate subcortically-mediated arousal states that alter behavior in ways that are distinct from, yet complementary to, top-down cognitive modulations. Finally, we discuss a novel neuromodulation technique, transcutaneous auricular vagus nerve stimulation (taVNS), which is particularly well-suited to investigating causal relationships between arousal mechanisms and performance in a variety of perceptual tasks. Together, these approaches provide novel testable hypotheses for explaining variability in classically challenging tasks, including non-native speech sound learning.
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Ludwig M, Wienke C, Betts MJ, Zaehle T, Hämmerer D. Current challenges in reliably targeting the noradrenergic locus coeruleus using transcutaneous auricular vagus nerve stimulation (taVNS). Auton Neurosci 2021; 236:102900. [PMID: 34781120 DOI: 10.1016/j.autneu.2021.102900] [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: 06/18/2021] [Revised: 09/03/2021] [Accepted: 10/15/2021] [Indexed: 12/11/2022]
Abstract
Transcutaneous auricular vagus nerve stimulation (taVNS), as a non-invasive brain stimulation technique may influence the locus coeruleus-norepinephrine system (LC-NE system) via modulation of the Vagus Nerve (VN) which projects to the LC. Few human studies exist examining the effects of taVNS on the LC-NE system and studies to date assessing the ability of taVNS to target the LC yield heterogeneous results. The aim of this review is to present an overview of the current challenges in assessing effects of taVNS on LC function and how translational approaches spanning animal and human research can help in this regard. A particular emphasis of the review discusses how the effects of taVNS may be influenced by changes in structure and function of the LC-NE system across the human lifespan and in disease.
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Affiliation(s)
- Mareike Ludwig
- Institute for Cognitive Neurology and Dementia Research, Faculty of Medicine, University Hospital Magdeburg, Germany; CBBS Center for Behavioral Brain Sciences, Magdeburg, Germany.
| | - Christian Wienke
- Department of Neurology, Section of Neuropsychology, Otto-v.-Guericke University, Magdeburg, Germany; CBBS Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Matthew J Betts
- Institute for Cognitive Neurology and Dementia Research, Faculty of Medicine, University Hospital Magdeburg, Germany; German Center for Neurodegenerative Diseases (DZNE), Otto-von-Guericke University Magdeburg, Magdeburg, Germany; CBBS Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Tino Zaehle
- Department of Neurology, Section of Neuropsychology, Otto-v.-Guericke University, Magdeburg, Germany; CBBS Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Dorothea Hämmerer
- Institute for Cognitive Neurology and Dementia Research, Faculty of Medicine, University Hospital Magdeburg, Germany; Institute of Cognitive Neuroscience, University College London, London, UK; Department of Psychology, University of Innsbruck; CBBS Center for Behavioral Brain Sciences, Magdeburg, Germany
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24
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Tseng CT, Gaulding SJ, Dancel CLE, Thorn CA. Local activation of α2 adrenergic receptors is required for vagus nerve stimulation induced motor cortical plasticity. Sci Rep 2021; 11:21645. [PMID: 34737352 PMCID: PMC8568982 DOI: 10.1038/s41598-021-00976-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 10/20/2021] [Indexed: 11/09/2022] Open
Abstract
Vagus nerve stimulation (VNS) paired with rehabilitation training is emerging as a potential treatment for improving recovery of motor function following stroke. In rats, VNS paired with skilled forelimb training results in significant reorganization of the somatotopic cortical motor map; however, the mechanisms underlying this form of VNS-dependent plasticity remain unclear. Recent studies have shown that VNS-driven cortical plasticity is dependent on noradrenergic innervation of the neocortex. In the central nervous system, noradrenergic α2 receptors (α2-ARs) are widely expressed in the motor cortex and have been critically implicated in synaptic communication and plasticity. In current study, we examined whether activation of cortical α2-ARs is necessary for VNS-driven motor cortical reorganization to occur. Consistent with previous studies, we found that VNS paired with motor training enlarges the map representation of task-relevant musculature in the motor cortex. Infusion of α2-AR antagonists into M1 blocked VNS-driven motor map reorganization from occurring. Our results suggest that local α2-AR activation is required for VNS-induced cortical reorganization to occur, providing insight into the mechanisms that may underlie the neuroplastic effects of VNS therapy.
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Affiliation(s)
- Ching-Tzu Tseng
- School of Behavioral and Brain Sciences, University of Texas at Dallas, 800 W. Campbell Rd, Richardson, TX, 75080, USA
| | - Solomon J Gaulding
- School of Behavioral and Brain Sciences, University of Texas at Dallas, 800 W. Campbell Rd, Richardson, TX, 75080, USA
| | - Canice Lei E Dancel
- School of Behavioral and Brain Sciences, University of Texas at Dallas, 800 W. Campbell Rd, Richardson, TX, 75080, USA
| | - Catherine A Thorn
- School of Behavioral and Brain Sciences, University of Texas at Dallas, 800 W. Campbell Rd, Richardson, TX, 75080, USA.
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25
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Rembado I, Song W, Su DK, Levari A, Shupe LE, Perlmutter S, Fetz E, Zanos S. Cortical Responses to Vagus Nerve Stimulation Are Modulated by Brain State in Nonhuman Primates. Cereb Cortex 2021; 31:5289-5307. [PMID: 34151377 PMCID: PMC8567998 DOI: 10.1093/cercor/bhab158] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 05/16/2021] [Accepted: 05/17/2021] [Indexed: 01/30/2023] Open
Abstract
Vagus nerve stimulation (VNS) has been tested as therapy for several brain disorders and as a means to modulate cortical excitability and brain plasticity. Cortical effects of VNS, manifesting as vagal-evoked potentials (VEPs), are thought to arise from activation of ascending cholinergic and noradrenergic systems. However, it is unknown whether those effects are modulated by brain state at the time of stimulation. In 2 freely behaving macaque monkeys, we delivered short trains of 5 pulses to the left cervical vagus nerve at different frequencies (5-300 Hz) while recording local field potentials (LFPs) from sites in contralateral prefrontal, sensorimotor and parietal cortical areas. Brain states were inferred from spectral components of LFPs and the presence of overt movement: active awake, resting awake, REM sleep and NREM sleep. VNS elicited VEPs in all sampled cortical areas. VEPs comprised early (<70 ms), intermediate (70-250 ms) and late (>250 ms) components. The magnitude of the intermediate and late components was largest during NREM sleep and smallest during wakefulness, whereas that of the early component was not modulated by brain state. VEPs during NREM were larger for stimuli delivered at the depolarized phase of ongoing delta oscillations. Higher pulsing frequencies generated larger VEPs. These short VNS trains did not affect brain state transitions during wakefulness or sleep. Our findings suggest that ongoing brain state modulates the evoked effects of VNS on cortical activity. This has implications for the role of ongoing cortical activity and brain state in shaping cortical responses to peripheral stimuli, for the modulation of vagal interoceptive signaling by cortical activity, and for the dose calibration of VNS therapies.
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Affiliation(s)
- Irene Rembado
- MindScope Program, Allen Institute, 615 Westlake Ave N., Seattle, WA 98103, USA
| | - Weiguo Song
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset NY 11030, USA
| | - David K Su
- Providence Regional Medical Center Cranial Joint and Spine Clinic, Everett, WA 98201, USA
| | - Ariel Levari
- Department of Physiology & Biophysics, University of Washington, Seattle, WA 98195, USA
| | - Larry E Shupe
- Department of Physiology & Biophysics, University of Washington, Seattle, WA 98195, USA
| | - Steve Perlmutter
- Department of Physiology & Biophysics, University of Washington, Seattle, WA 98195, USA
| | - Eberhard Fetz
- Department of Physiology & Biophysics, University of Washington, Seattle, WA 98195, USA
| | - Stavros Zanos
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset NY 11030, USA
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26
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Phillips I, Calloway RC, Karuzis VP, Pandža NB, O'Rourke P, Kuchinsky SE. Transcutaneous Auricular Vagus Nerve Stimulation Strengthens Semantic Representations of Foreign Language Tone Words during Initial Stages of Learning. J Cogn Neurosci 2021; 34:127-152. [PMID: 34673939 DOI: 10.1162/jocn_a_01783] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Difficulty perceiving phonological contrasts in a second language (L2) can impede initial L2 lexical learning. Such is the case for English speakers learning tonal languages, like Mandarin Chinese. Given the hypothesized role of reduced neuroplasticity in adulthood limiting L2 phonological perception, the current study examined whether transcutaneous auricular vagus nerve stimulation (taVNS), a relatively new neuromodulatory technique, can facilitate L2 lexical learning for English speakers learning Mandarin Chinese over 2 days. Using a double-blind design, one group of participants received 10 min of continuous priming taVNS before lexical training and testing each day, a second group received 500 msec of peristimulus (peristim) taVNS preceding each to-be-learned item in the same tasks, and a third group received passive sham stimulation. Results of the lexical recognition test administered at the end of each day revealed evidence of learning for all groups, but a higher likelihood of accuracy across days for the peristim group and a greater improvement in response time between days for the priming group. Analyses of N400 ERP components elicited during the same tasks indicate behavioral advantages for both taVNS groups coincided with stronger lexico-semantic encoding for target words. Comparison of these findings to pupillometry results for the same study reported in Pandža, Phillips, Karuzis, O'Rourke, and Kuchinsky (2020) suggest that positive effects of priming taVNS (but not peristim taVNS) on lexico-semantic encoding are related to sustained attentional effort.
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Affiliation(s)
- Ian Phillips
- University of Maryland Applied Research Laboratory for Intelligence & Security, College Park.,Walter Reed National Military Medical Center, Audiology and Speech Pathology Center, Bethesda, MD.,The Geneva Foundation, Bethesda, MD
| | - Regina C Calloway
- University of Maryland Applied Research Laboratory for Intelligence & Security, College Park
| | - Valerie P Karuzis
- University of Maryland Applied Research Laboratory for Intelligence & Security, College Park
| | - Nick B Pandža
- University of Maryland Applied Research Laboratory for Intelligence & Security, College Park.,University of Maryland Program in Second Language Acquisition, College Park
| | - Polly O'Rourke
- University of Maryland Applied Research Laboratory for Intelligence & Security, College Park
| | - Stefanie E Kuchinsky
- University of Maryland Applied Research Laboratory for Intelligence & Security, College Park.,Walter Reed National Military Medical Center, Audiology and Speech Pathology Center, Bethesda, MD
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27
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Keute M, Gharabaghi A. Brain plasticity and vagus nerve stimulation. Auton Neurosci 2021; 236:102876. [PMID: 34537681 DOI: 10.1016/j.autneu.2021.102876] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 07/01/2021] [Accepted: 08/29/2021] [Indexed: 01/01/2023]
Abstract
After damage to the central nervous system, caused by traumatic injury or ischemia, plasticity becomes critically important for functional recovery. When this inherent capacity to adapt is limited despite training, external stimulation may support this process. Vagus nerve stimulation (VNS) is an effective method to enhance the effect of motor rehabilitation training on functional recovery. However, the mechanisms by which VNS exerts beneficial effects on cortical plasticity are not completely understood. Experimental work suggests that VNS fosters a neurochemical milieu that facilitates synaptic plasticity and supports reinforcement mechanisms. Animal studies, furthermore, suggest that VNS delivery is time-critical and that optima in the parameter space need to be titrated for effect maximization. Human studies suggest that VNS modifies corticospinal excitability. First studies in stroke patients show positive results for invasive, and also promising findings for non-invasive VNS.
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Affiliation(s)
- Marius Keute
- Institute for Neuromodulation and Neurotechnology, Department of Neurosurgery and Neurotechnology, University of Tuebingen, Tuebingen, Germany.
| | - Alireza Gharabaghi
- Institute for Neuromodulation and Neurotechnology, Department of Neurosurgery and Neurotechnology, University of Tuebingen, Tuebingen, Germany
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28
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Morrison RA, Hays SA, Kilgard MP. Vagus Nerve Stimulation as a Potential Adjuvant to Rehabilitation for Post-stroke Motor Speech Disorders. Front Neurosci 2021; 15:715928. [PMID: 34489632 PMCID: PMC8417469 DOI: 10.3389/fnins.2021.715928] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 07/28/2021] [Indexed: 01/22/2023] Open
Abstract
Stroke often leaves lasting impairments affecting orofacial function. While speech therapy is able to enhance function after stroke, many patients see only modest improvements after treatment. This partial restoration of function after rehabilitation suggests that there is a need for further intervention. Rehabilitative strategies that augment the effects of traditional speech therapy hold promise to yield greater efficacy and reduce disability associated with motor speech disorders. Recent studies demonstrate that brief bursts of vagus nerve stimulation (VNS) can facilitate the benefits of rehabilitative interventions. VNS paired with upper limb rehabilitation enhances recovery of upper limb function in patients with chronic stroke. Animal studies reveal that these improvements are driven by VNS-dependent synaptic plasticity in motor networks. Moreover, preclinical evidence demonstrates that a similar strategy of pairing VNS can promote synaptic reorganization in orofacial networks. Building on these findings, we postulate that VNS-directed orofacial plasticity could target post-stroke motor speech disorders. Here, we outline the rationale for pairing VNS with traditional speech therapy to enhance recovery in the context of stroke of speech motor function. We also explore similar treatments that aim to enhance synaptic plasticity during speech therapy, and how VNS differs from these existing therapeutic strategies. Based on this evidence, we posit that VNS-paired speech therapy shows promise as a means of enhancing recovery after post-stroke motor speech disorders. Continued development is necessary to comprehensively establish and optimize this approach, which has the potential to increase quality of life for the many individuals suffering with these common impairments.
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Affiliation(s)
- Robert A Morrison
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, United States.,Texas Biomedical Device Center, University of Texas at Dallas, Richardson, TX, United States
| | - Seth A Hays
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, United States.,Texas Biomedical Device Center, University of Texas at Dallas, Richardson, TX, United States.,Erik Jonsson School of Engineering and Computer Science, University of Texas at Dallas, Richardson, TX, United States
| | - Michael P Kilgard
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, United States.,Texas Biomedical Device Center, University of Texas at Dallas, Richardson, TX, United States
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29
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Thompson SL, O'Leary GH, Austelle CW, Gruber E, Kahn AT, Manett AJ, Short B, Badran BW. A Review of Parameter Settings for Invasive and Non-invasive Vagus Nerve Stimulation (VNS) Applied in Neurological and Psychiatric Disorders. Front Neurosci 2021; 15:709436. [PMID: 34326720 PMCID: PMC8313807 DOI: 10.3389/fnins.2021.709436] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 06/22/2021] [Indexed: 12/12/2022] Open
Abstract
Vagus nerve stimulation (VNS) is an established form of neuromodulation with a long history of promising applications. Earliest reports of VNS in the literature date to the late 1800’s in experiments conducted by Dr. James Corning. Over the past century, both invasive and non-invasive VNS have demonstrated promise in treating a variety of disorders, including epilepsy, depression, and post-stroke motor rehabilitation. As VNS continues to rapidly grow in popularity and application, the field generally lacks a consensus on optimum stimulation parameters. Stimulation parameters have a significant impact on the efficacy of neuromodulation, and here we will describe the longitudinal evolution of VNS parameters in the following categorical progression: (1) animal models, (2) epilepsy, (3) treatment resistant depression, (4) neuroplasticity and rehabilitation, and (5) transcutaneous auricular VNS (taVNS). We additionally offer a historical perspective of the various applications and summarize the range and most commonly used parameters in over 130 implanted and non-invasive VNS studies over five applications.
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Affiliation(s)
- Sean L Thompson
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - Georgia H O'Leary
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - Christopher W Austelle
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - Elise Gruber
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - Alex T Kahn
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - Andrew J Manett
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - Baron Short
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - Bashar W Badran
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, United States
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30
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Short-Term Effects of Vagus Nerve Stimulation on Learning and Evoked Activity in Auditory Cortex. eNeuro 2021; 8:ENEURO.0522-20.2021. [PMID: 34088737 PMCID: PMC8240839 DOI: 10.1523/eneuro.0522-20.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 04/13/2021] [Accepted: 04/16/2021] [Indexed: 11/21/2022] Open
Abstract
Chronic vagus nerve stimulation (VNS) has been shown to facilitate learning, but effects of acute VNS on neural coding and behavior remain less well understood. Ferrets implanted with cuff electrodes on the vagus nerve were trained by classical conditioning on an auditory tone frequency-reward association. One tone was associated with reward while another tone was not. Tone frequencies and reward associations were changed every 2 d, requiring learning of a new relationship. When tones were paired with VNS, animals consistently learned the new association within 2 d. When VNS occurred randomly between trials, learning within 2 d was unreliable. In passively listening animals, neural activity in primary auditory cortex (A1) and pupil size were recorded before and after acute VNS-tone pairing. After pairing with a neuron’s best-frequency (BF) tone, responses by a subpopulation of neurons were reduced. VNS paired with an off-BF tone or during intertrial intervals had no effect. The BF-specific reduction in neural responses after VNS remained, even after regressing out changes explained by pupil-indexed arousal. VNS induced brief dilation in the pupil, and the size of this change predicted the magnitude of persistent changes in the neural response. This interaction suggests that fluctuations in neuromodulation associated with arousal gate the long-term VNS effects on neural activity.
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31
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Yakunina N, Nam EC. Direct and Transcutaneous Vagus Nerve Stimulation for Treatment of Tinnitus: A Scoping Review. Front Neurosci 2021; 15:680590. [PMID: 34122002 PMCID: PMC8193498 DOI: 10.3389/fnins.2021.680590] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 05/05/2021] [Indexed: 12/27/2022] Open
Abstract
Recent animal research has shown that vagus nerve stimulation (VNS) paired with sound stimuli can induce neural plasticity in the auditory cortex in a controlled manner. VNS paired with tones excluding the tinnitus frequency eliminated physiological and behavioral characteristics of tinnitus in noise-exposed rats. Several clinical trials followed and explored the effectiveness of VNS paired with sound stimuli for alleviating tinnitus in human subjects. Transcutaneous VNS (tVNS) has received increasing attention as a non-invasive alternative approach to tinnitus treatment. Several studies have also explored tVNS alone (not paired with sound stimuli) as a potential therapy for tinnitus. In this review, we discuss existing knowledge about direct and tVNS in terms of applicability, safety, and effectiveness in diminishing tinnitus symptoms in human subjects. This review includes all existing clinical and neuroimaging studies of tVNS alone or paired with acoustic stimulation in tinnitus patients and outlines the present limitations that must be overcome to maximize the potential of (t)VNS as a therapy for tinnitus.
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Affiliation(s)
- Natalia Yakunina
- Institute of Medical Science, School of Medicine, Kangwon National University, Chuncheon, South Korea
| | - Eui-Cheol Nam
- Department of Otolaryngology, School of Medicine, Kangwon National University, Chuncheon, South Korea
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32
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Darrow MJ, Mian TM, Torres M, Haider Z, Danaphongse T, Seyedahmadi A, Rennaker RL, Hays SA, Kilgard MP. The tactile experience paired with vagus nerve stimulation determines the degree of sensory recovery after chronic nerve damage. Behav Brain Res 2021; 396:112910. [PMID: 32971197 PMCID: PMC7572822 DOI: 10.1016/j.bbr.2020.112910] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 08/21/2020] [Accepted: 09/14/2020] [Indexed: 12/22/2022]
Abstract
Loss of sensory function is a common consequence of neurological injury. Recent clinical and preclinical evidence indicates vagus nerve stimulation (VNS) paired with tactile rehabilitation, consisting of delivery of a variety of mechanical stimuli to the hyposensitive skin surface, yields substantial and long-lasting recovery of somatosensory function after median and ulnar nerve transection and repair. Here, we tested the hypothesis that a specific component of the tactile rehabilitation paired with VNS is necessary for recovery of somatosensory function. In a second experiment in a separate cohort, we investigated whether VNS paired with tactile rehabilitation could improve skilled forelimb motor function. Elements of the study design, including planned sample size, assessments, and statistical comparisons, were preregistered prior to beginning data collection (https://osf.io/3tm8u/). Animals received a peripheral nerve injury (PNI) causing chronic sensory loss. Eight weeks after injury, animals were given a VNS implant followed by six weeks of tactile rehabilitation sessions consisting of repeated application of one of two distinct mechanical stimuli, a filament or a paintbrush, to the previously denervated forepaw. VNS paired with either filament indentation or brushing of the paw significantly improved recovery of forelimb withdrawal thresholds after PNI compared to tactile rehabilitation without VNS. The effect size was twice as large when VNS was paired with brushing compared to VNS paired with point indentation. An independent replication in a second cohort confirmed that VNS paired with brush restored forelimb withdrawal thresholds to normal. These rats displayed significant improvements in performance on a skilled forelimb task compared to rats that did not receive VNS. These findings support the utility of pairing VNS with tactile rehabilitation to improve recovery of somatosensory and motor function after neurological injury. Additionally, this study demonstrates that the sensory characteristics of the rehabilitation paired with VNS determine the degree of recovery.
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Affiliation(s)
- Michael J Darrow
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, United States; The University of Texas at Dallas, Erik Jonsson School of Engineering and Computer Science, Department of Bioengineering, 800 West Campbell Road, Richardson, TX 75080-3021, United States
| | - Tabarak M Mian
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, United States; The University of Texas at Dallas, School of Behavioral and Brain Sciences, 800 West Campbell Road, Richardson, TX 75080-3021, United States
| | - Miranda Torres
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, United States; The University of Texas at Dallas, School of Behavioral and Brain Sciences, 800 West Campbell Road, Richardson, TX 75080-3021, United States
| | - Zainab Haider
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, United States; The University of Texas at Dallas, School of Behavioral and Brain Sciences, 800 West Campbell Road, Richardson, TX 75080-3021, United States
| | - Tanya Danaphongse
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, United States
| | - Armin Seyedahmadi
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, United States
| | - Robert L Rennaker
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, United States; The University of Texas at Dallas, Erik Jonsson School of Engineering and Computer Science, Department of Bioengineering, 800 West Campbell Road, Richardson, TX 75080-3021, United States; The University of Texas at Dallas, School of Behavioral and Brain Sciences, 800 West Campbell Road, Richardson, TX 75080-3021, United States
| | - Seth A Hays
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, United States; The University of Texas at Dallas, Erik Jonsson School of Engineering and Computer Science, Department of Bioengineering, 800 West Campbell Road, Richardson, TX 75080-3021, United States; The University of Texas at Dallas, School of Behavioral and Brain Sciences, 800 West Campbell Road, Richardson, TX 75080-3021, United States.
| | - Michael P Kilgard
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, United States; The University of Texas at Dallas, Erik Jonsson School of Engineering and Computer Science, Department of Bioengineering, 800 West Campbell Road, Richardson, TX 75080-3021, United States; The University of Texas at Dallas, School of Behavioral and Brain Sciences, 800 West Campbell Road, Richardson, TX 75080-3021, United States
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33
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Gurel NZ, Jiao Y, Wittbrodt MT, Ko YA, Hankus A, Driggers EG, Ladd SL, Shallenberger L, Murrah N, Huang M, Haffar A, Alkhalaf M, Levantsevych O, Nye JA, Vaccarino V, Shah AJ, Inan OT, Bremner JD, Pearce BD. Effect of transcutaneous cervical vagus nerve stimulation on the pituitary adenylate cyclase-activating polypeptide (PACAP) response to stress: A randomized, sham controlled, double blind pilot study. COMPREHENSIVE PSYCHONEUROENDOCRINOLOGY 2020; 4:100012. [PMID: 35755625 PMCID: PMC9216713 DOI: 10.1016/j.cpnec.2020.100012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 09/17/2020] [Accepted: 10/15/2020] [Indexed: 12/24/2022] Open
Abstract
Pituitary adenylate cyclase-activating peptide (PACAP) is a neuropeptide that plays a key role in the neurobiology of the stress response, and prior studies suggest that its function is dysregulated in post-traumatic stress disorder (PTSD). Transcutaneous cervical vagus nerve stimulation (tcVNS) acts through PACAP and other neurobiological systems to modulate stress responses and/or symptoms of PTSD. In this pilot study, we examined the effects of tcVNS on PACAP in a three day chronic stress laboratory paradigm involving serial traumatic and mental stress exposures in healthy individuals with a history of exposure to psychological trauma (n = 18) and patients with PTSD (n = 12). Methods A total of 30 subjects with a history of exposure to psychological trauma experience were recruited (12 with PTSD diagnosis) for a three-day randomized double-blinded study of tcVNS or sham stimulation. Subjects underwent a protocol that included both personalized trauma recall and non-personalized mental stressors (public speaking, mental arithmetic) paired to tcVNS or sham stimulation over three days. Blood was collected at baseline and multiple time points after exposure to stressors. Linear mixed-effects models were used to assess changes in PACAP over time (in response to stressors) and its relation to active tcVNS or sham stimulation. Results PACAP blood levels increased over the course of three days for both active tcVNS and sham groups. This increase was statistically-significant in the sham group at the end of the second (Cohen’s drm = 0.35, p = 0.04), and third days (drm = 0.41, p = 0.04), but not in the active tcVNS group (drm = 0.21, drm = 0.18, and p > 0.20). Conclusion These pilot findings suggest tcVNS may attenuate this neurobiological stress-response. Larger studies are needed to investigate gender and interaction effects. We examined the effects of tcVNS on PACAP in a three day chronic stress paradigm involving traumatic and mental stress. PACAP levels increased over the course of three days for both groups, the elevation of PACAP was larger in the sham group. These findings suggest that tcVNS may be a potential intervention for stress-related psychiatric disorders.
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Affiliation(s)
- Nil Z. Gurel
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Yunshen Jiao
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Matthew T. Wittbrodt
- Department of Psychiatry and Behavioral Sciences, Emory School of Medicine, Atlanta, GA, USA
| | - Yi-An Ko
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Allison Hankus
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Emily G. Driggers
- Department of Psychiatry and Behavioral Sciences, Emory School of Medicine, Atlanta, GA, USA
| | - Stacy L. Ladd
- Department of Psychiatry and Behavioral Sciences, Emory School of Medicine, Atlanta, GA, USA
- Department of Radiology, Emory School of Medicine, Atlanta, GA, USA
| | - Lucy Shallenberger
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Nancy Murrah
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Minxuan Huang
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Ammer Haffar
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Mhmtjamil Alkhalaf
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Oleksiy Levantsevych
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Jonathon A. Nye
- Department of Radiology, Emory School of Medicine, Atlanta, GA, USA
| | - Viola Vaccarino
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA
- Department of Medicine, Division of Cardiology, Emory School of Medicine, Atlanta, GA, USA
| | - Amit J. Shah
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA
- Department of Medicine, Division of Cardiology, Emory School of Medicine, Atlanta, GA, USA
- Atlanta VA Medical Center, Decatur, GA, USA
| | - Omer T. Inan
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA
- Coulter Department of Bioengineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - J. Douglas Bremner
- Department of Psychiatry and Behavioral Sciences, Emory School of Medicine, Atlanta, GA, USA
- Department of Radiology, Emory School of Medicine, Atlanta, GA, USA
- Atlanta VA Medical Center, Decatur, GA, USA
| | - Bradley D. Pearce
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA
- Corresponding author.
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Noise Induced Hearing Loss and Tinnitus-New Research Developments and Remaining Gaps in Disease Assessment, Treatment, and Prevention. Brain Sci 2020; 10:brainsci10100732. [PMID: 33066210 PMCID: PMC7602100 DOI: 10.3390/brainsci10100732] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 10/09/2020] [Accepted: 10/10/2020] [Indexed: 01/10/2023] Open
Abstract
Long-term noise exposure often results in noise induced hearing loss (NIHL). Tinnitus, the generation of phantom sounds, can also result from noise exposure, although understanding of its underlying mechanisms are limited. Recent studies, however, are shedding light on the neural processes involved in NIHL and tinnitus, leading to potential new and innovative treatments. This review focuses on the assessment of NIHL, available treatments, and development of new pharmacologic and non-pharmacologic treatments based on recent studies of central auditory plasticity and adaptive changes in hearing. We discuss the mechanisms and maladaptive plasticity of NIHL, neuronal aspects of tinnitus triggers, and mechanisms such as tinnitus-associated neural changes at the cochlear nucleus underlying the generation of tinnitus after noise-induced deafferentation. We include observations from recent studies, including our own studies on associated risks and emerging treatments for tinnitus. Increasing knowledge of neural plasticity and adaptive changes in the central auditory system suggest that NIHL is preventable and transient abnormalities may be reversable, although ongoing research in assessment and early detection of hearing difficulties is still urgently needed. Since no treatment can yet reverse noise-related damage completely, preventative strategies and increased awareness of hearing health are essential.
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De Ridder D, Langguth B, Vanneste S. Vagus nerve stimulation for tinnitus: A review and perspective. PROGRESS IN BRAIN RESEARCH 2020; 262:451-467. [PMID: 33931191 DOI: 10.1016/bs.pbr.2020.08.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Vagus nerve stimulation is a promising new tool in the treatment of chronic tinnitus. Current protocols involve pairing sounds, which exclude the tinnitus frequency, with simultaneous vagus nerve stimulation (VNS). This is based on extensive preclinical animal studies that demonstrate that pairing non-tinnitus sounds with VNS results in a tonotopic map plasticity. It is thought that by expanding the non-tinnitus sound representation, it is possible to overturn the expanded tonotopic map associated with the tinnitus frequency in these animal models. These findings have been translated into a clinical approach, where a clinically significant, but moderate improvement, in tinnitus distress and a modest benefit in tinnitus loudness perception has been shown. Yet, pairing tinnitus matched sound to VNS may produce tinnitus improvement by Pavlovian conditioning, in which the distressful tinnitus sound becomes associated with a relaxing "rest and digest" response from activation of the vagus nerve. If this hypothesis is correct, beneficial effects should be achieved with paired sounds that resemble the tinnitus sounds as much as possible. In conclusion, although the potential to use VNS to drive neural plasticity to reduce or eliminate the neural drivers of ongoing tinnitus is exciting, much work is needed to more completely understand the neural basis of tinnitus and to develop tailored therapies to address the suffering caused by this heterogeneous condition. Whether pairing of the vagus stimulation with non-tinnitus or tinnitus-matched sounds is essential is still to be determined.
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Affiliation(s)
- Dirk De Ridder
- Department of Surgical Sciences, Section of Neurosurgery, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand.
| | - Berthold Langguth
- Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany
| | - Sven Vanneste
- Lab for Clinical and Integrative Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, United States; Global Brain Health Institute & Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
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Bremner JD, Gurel NZ, Wittbrodt MT, Shandhi MH, Rapaport MH, Nye JA, Pearce BD, Vaccarino V, Shah AJ, Park J, Bikson M, Inan OT. Application of Noninvasive Vagal Nerve Stimulation to Stress-Related Psychiatric Disorders. J Pers Med 2020; 10:E119. [PMID: 32916852 PMCID: PMC7563188 DOI: 10.3390/jpm10030119] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 09/02/2020] [Accepted: 09/03/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Vagal Nerve Stimulation (VNS) has been shown to be efficacious for the treatment of depression, but to date, VNS devices have required surgical implantation, which has limited widespread implementation. METHODS New noninvasive VNS (nVNS) devices have been developed which allow external stimulation of the vagus nerve, and their effects on physiology in patients with stress-related psychiatric disorders can be measured with brain imaging, blood biomarkers, and wearable sensing devices. Advantages in terms of cost and convenience may lead to more widespread implementation in psychiatry, as well as facilitate research of the physiology of the vagus nerve in humans. nVNS has effects on autonomic tone, cardiovascular function, inflammatory responses, and central brain areas involved in modulation of emotion, all of which make it particularly applicable to patients with stress-related psychiatric disorders, including posttraumatic stress disorder (PTSD) and depression, since dysregulation of these circuits and systems underlies the symptomatology of these disorders. RESULTS This paper reviewed the physiology of the vagus nerve and its relevance to modulating the stress response in the context of application of nVNS to stress-related psychiatric disorders. CONCLUSIONS nVNS has a favorable effect on stress physiology that is measurable using brain imaging, blood biomarkers of inflammation, and wearable sensing devices, and shows promise in the prevention and treatment of stress-related psychiatric disorders.
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Affiliation(s)
- James Douglas Bremner
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA 30322, USA; (M.T.W.); (M.H.R.)
- Department of Radiology, Emory University School of Medicine, Atlanta, GA 30322, USA;
- Atlanta VA Medical Center, Decatur, GA 30033, USA; (A.J.S.); (J.P.)
| | - Nil Z. Gurel
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA; (N.Z.G.); (M.H.S.); (O.T.I.)
| | - Matthew T. Wittbrodt
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA 30322, USA; (M.T.W.); (M.H.R.)
| | - Mobashir H. Shandhi
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA; (N.Z.G.); (M.H.S.); (O.T.I.)
| | - Mark H. Rapaport
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA 30322, USA; (M.T.W.); (M.H.R.)
| | - Jonathon A. Nye
- Department of Radiology, Emory University School of Medicine, Atlanta, GA 30322, USA;
| | - Bradley D. Pearce
- Department of Epidemiology, Rollins School of Public Health, Atlanta, GA 30322, USA; (B.D.P.); (V.V.)
| | - Viola Vaccarino
- Department of Epidemiology, Rollins School of Public Health, Atlanta, GA 30322, USA; (B.D.P.); (V.V.)
- Department of Medicine, Cardiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Amit J. Shah
- Atlanta VA Medical Center, Decatur, GA 30033, USA; (A.J.S.); (J.P.)
- Department of Epidemiology, Rollins School of Public Health, Atlanta, GA 30322, USA; (B.D.P.); (V.V.)
- Department of Medicine, Cardiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Jeanie Park
- Atlanta VA Medical Center, Decatur, GA 30033, USA; (A.J.S.); (J.P.)
- Department of Medicine, Renal Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Marom Bikson
- Department of Biomedical Engineering, City University of New York, New York, NY 10010, USA;
| | - Omer T. Inan
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA; (N.Z.G.); (M.H.S.); (O.T.I.)
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
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Adcock KS, Chandler C, Buell EP, Solorzano BR, Loerwald KW, Borland MS, Engineer CT. Vagus nerve stimulation paired with tones restores auditory processing in a rat model of Rett syndrome. Brain Stimul 2020; 13:1494-1503. [PMID: 32800964 DOI: 10.1016/j.brs.2020.08.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 07/26/2020] [Accepted: 08/07/2020] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Rett syndrome is a rare neurological disorder associated with a mutation in the X-linked gene MECP2. This disorder mainly affects females, who typically have seemingly normal early development followed by a regression of acquired skills. The rodent Mecp2 model exhibits many of the classic neural abnormalities and behavioral deficits observed in individuals with Rett syndrome. Similar to individuals with Rett syndrome, both auditory discrimination ability and auditory cortical responses are impaired in heterozygous Mecp2 rats. The development of therapies that can enhance plasticity in auditory networks and improve auditory processing has the potential to impact the lives of individuals with Rett syndrome. Evidence suggests that precisely timed vagus nerve stimulation (VNS) paired with sound presentation can drive robust neuroplasticity in auditory networks and enhance the benefits of auditory therapy. OBJECTIVE The aim of this study was to investigate the ability of VNS paired with tones to restore auditory processing in Mecp2 transgenic rats. METHODS Seventeen female heterozygous Mecp2 rats and 8 female wild-type (WT) littermates were used in this study. The rats were exposed to multiple tone frequencies paired with VNS 300 times per day for 20 days. Auditory cortex responses were then examined following VNS-tone pairing therapy or no therapy. RESULTS Our results indicate that Mecp2 mutation alters auditory cortex responses to sounds compared to WT controls. VNS-tone pairing in Mecp2 rats improves the cortical response strength to both tones and speech sounds compared to untreated Mecp2 rats. Additionally, VNS-tone pairing increased the information contained in the neural response that can be used to discriminate between different consonant sounds. CONCLUSION These results demonstrate that VNS-sound pairing may represent a strategy to enhance auditory function in individuals with Rett syndrome.
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Affiliation(s)
- Katherine S Adcock
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA; The University of Texas at Dallas, School of Behavioral and Brain Sciences, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
| | - Collin Chandler
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA; The University of Texas at Dallas, Erik Jonsson School of Engineering and Computer Science, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
| | - Elizabeth P Buell
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA; The University of Texas at Dallas, School of Behavioral and Brain Sciences, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
| | - Bleyda R Solorzano
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
| | - Kristofer W Loerwald
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
| | - Michael S Borland
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA; The University of Texas at Dallas, School of Behavioral and Brain Sciences, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA
| | - Crystal T Engineer
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA; The University of Texas at Dallas, School of Behavioral and Brain Sciences, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA; The University of Texas at Dallas, Erik Jonsson School of Engineering and Computer Science, 800 West Campbell Road BSB11, Richardson, TX, 75080, USA.
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Llanos F, McHaney JR, Schuerman WL, Yi HG, Leonard MK, Chandrasekaran B. Non-invasive peripheral nerve stimulation selectively enhances speech category learning in adults. NPJ SCIENCE OF LEARNING 2020; 5:12. [PMID: 32802406 PMCID: PMC7410845 DOI: 10.1038/s41539-020-0070-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 06/05/2020] [Indexed: 05/30/2023]
Abstract
Adults struggle to learn non-native speech contrasts even after years of exposure. While laboratory-based training approaches yield learning, the optimal training conditions for maximizing speech learning in adulthood are currently unknown. Vagus nerve stimulation has been shown to prime adult sensory-perceptual systems towards plasticity in animal models. Precise temporal pairing with auditory stimuli can enhance auditory cortical representations with a high degree of specificity. Here, we examined whether sub-perceptual threshold transcutaneous vagus nerve stimulation (tVNS), paired with non-native speech sounds, enhances speech category learning in adults. Twenty-four native English-speakers were trained to identify non-native Mandarin tone categories. Across two groups, tVNS was paired with the tone categories that were easier- or harder-to-learn. A control group received no stimulation but followed an identical thresholding procedure as the intervention groups. We found that tVNS robustly enhanced speech category learning and retention of correct stimulus-response associations, but only when stimulation was paired with the easier-to-learn categories. This effect emerged rapidly, generalized to new exemplars, and was qualitatively different from the normal individual variability observed in hundreds of learners who have performed in the same task without stimulation. Electroencephalography recorded before and after training indicated no evidence of tVNS-induced changes in the sensory representation of auditory stimuli. These results suggest that paired-tVNS induces a temporally precise neuromodulatory signal that selectively enhances the perception and memory consolidation of perceptually salient categories.
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Affiliation(s)
- Fernando Llanos
- Department of Communication Science and Disorders, University of Pittsburgh, Pittsburgh, PA 15260 USA
| | - Jacie R. McHaney
- Department of Communication Science and Disorders, University of Pittsburgh, Pittsburgh, PA 15260 USA
| | - William L. Schuerman
- Neurological Surgery, University of California, San Francisco, San Francisco, CA 94143 USA
| | - Han G. Yi
- Neurological Surgery, University of California, San Francisco, San Francisco, CA 94143 USA
| | - Matthew K. Leonard
- Neurological Surgery, University of California, San Francisco, San Francisco, CA 94143 USA
| | - Bharath Chandrasekaran
- Department of Communication Science and Disorders, University of Pittsburgh, Pittsburgh, PA 15260 USA
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Adair D, Truong D, Esmaeilpour Z, Gebodh N, Borges H, Ho L, Bremner JD, Badran BW, Napadow V, Clark VP, Bikson M. Electrical stimulation of cranial nerves in cognition and disease. Brain Stimul 2020; 13:717-750. [PMID: 32289703 PMCID: PMC7196013 DOI: 10.1016/j.brs.2020.02.019] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 02/13/2020] [Accepted: 02/17/2020] [Indexed: 02/06/2023] Open
Abstract
The cranial nerves are the pathways through which environmental information (sensation) is directly communicated to the brain, leading to perception, and giving rise to higher cognition. Because cranial nerves determine and modulate brain function, invasive and non-invasive cranial nerve electrical stimulation methods have applications in the clinical, behavioral, and cognitive domains. Among other neuromodulation approaches such as peripheral, transcranial and deep brain stimulation, cranial nerve stimulation is unique in allowing axon pathway-specific engagement of brain circuits, including thalamo-cortical networks. In this review we amalgamate relevant knowledge of 1) cranial nerve anatomy and biophysics; 2) evidence of the modulatory effects of cranial nerves on cognition; 3) clinical and behavioral outcomes of cranial nerve stimulation; and 4) biomarkers of nerve target engagement including physiology, electroencephalography, neuroimaging, and behavioral metrics. Existing non-invasive stimulation methods cannot feasibly activate the axons of only individual cranial nerves. Even with invasive stimulation methods, selective targeting of one nerve fiber type requires nuance since each nerve is composed of functionally distinct axon-types that differentially branch and can anastomose onto other nerves. None-the-less, precisely controlling stimulation parameters can aid in affecting distinct sets of axons, thus supporting specific actions on cognition and behavior. To this end, a rubric for reproducible dose-response stimulation parameters is defined here. Given that afferent cranial nerve axons project directly to the brain, targeting structures (e.g. thalamus, cortex) that are critical nodes in higher order brain networks, potent effects on cognition are plausible. We propose an intervention design framework based on driving cranial nerve pathways in targeted brain circuits, which are in turn linked to specific higher cognitive processes. State-of-the-art current flow models that are used to explain and design cranial-nerve-activating stimulation technology require multi-scale detail that includes: gross anatomy; skull foramina and superficial tissue layers; and precise nerve morphology. Detailed simulations also predict that some non-invasive electrical or magnetic stimulation approaches that do not intend to modulate cranial nerves per se, such as transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS), may also modulate activity of specific cranial nerves. Much prior cranial nerve stimulation work was conceptually limited to the production of sensory perception, with individual titration of intensity based on the level of perception and tolerability. However, disregarding sensory emulation allows consideration of temporal stimulation patterns (axon recruitment) that modulate the tone of cortical networks independent of sensory cortices, without necessarily titrating perception. For example, leveraging the role of the thalamus as a gatekeeper for information to the cerebral cortex, preventing or enhancing the passage of specific information depending on the behavioral state. We show that properly parameterized computational models at multiple scales are needed to rationally optimize neuromodulation that target sets of cranial nerves, determining which and how specific brain circuitries are modulated, which can in turn influence cognition in a designed manner.
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Affiliation(s)
- Devin Adair
- Department of Biomedical Engineering, City College of New York, New York, NY, USA
| | - Dennis Truong
- Department of Biomedical Engineering, City College of New York, New York, NY, USA
| | - Zeinab Esmaeilpour
- Department of Biomedical Engineering, City College of New York, New York, NY, USA.
| | - Nigel Gebodh
- Department of Biomedical Engineering, City College of New York, New York, NY, USA
| | - Helen Borges
- Department of Biomedical Engineering, City College of New York, New York, NY, USA
| | - Libby Ho
- Department of Biomedical Engineering, City College of New York, New York, NY, USA
| | - J Douglas Bremner
- Department of Psychiatry & Behavioral Sciences and Radiology, Emory University School of Medicine, Atlanta, GA, USA; Atlanta VA Medical Center, Decatur, GA, USA
| | - Bashar W Badran
- Department of Psychiatry & Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Vitaly Napadow
- Martinos Center for Biomedical Imaging, Department of Radiology, MGH, Harvard medical school, Boston, MA, USA
| | - Vincent P Clark
- Psychology Clinical Neuroscience Center, Dept. Psychology, MSC03-2220, University of New Mexico, Albuquerque, NM, 87131, USA; Department of Psychology, University of New Mexico, Albuquerque, NM, 87131, USA; The Mind Research Network of the Lovelace Biomedical Research Institute, 1101 Yale Blvd. NE, Albuquerque, NM, 87106, USA
| | - Marom Bikson
- Department of Biomedical Engineering, City College of New York, New York, NY, USA.
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Souza RR, Robertson NM, Mathew E, Tabet MN, Bucksot JE, Pruitt DT, Rennaker RL, Hays SA, McIntyre CK, Kilgard MP. Efficient parameters of vagus nerve stimulation to enhance extinction learning in an extinction-resistant rat model of PTSD. Prog Neuropsychopharmacol Biol Psychiatry 2020; 99:109848. [PMID: 31863872 DOI: 10.1016/j.pnpbp.2019.109848] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 12/11/2019] [Accepted: 12/16/2019] [Indexed: 12/20/2022]
Abstract
Vagus nerve stimulation (VNS) has shown promise as an adjuvant treatment for posttraumatic stress disorder (PTSD), as it enhances fear extinction and reduces anxiety symptoms in multiple rat models of this condition. Yet, identification of the optimal stimulation paradigm is needed to facilitate clinical translation of this potential therapy. Using an extinction-resistant rat model of PTSD, we tested whether varying VNS intensity and duration could maximize extinction learning while minimizing the total amount of stimulation. We confirmed that sham rats failed to extinguish after a week of extinction training. Delivery of the standard LONG VNS trains (30 s) at 0.4 mA enhanced extinction and reduced anxiety but did not prevent fear return. Increasing the intensity of LONG VNS trains to 0.8 mA prevented fear return and attenuated anxiety symptoms. Interestingly, delivering 1, 4 or 16 SHORT VNS bursts (0.5 s) at 0.8 mA during each cue presentation in extinction training also enhanced extinction. LONG VNS trains or multiple SHORT VNS bursts at 0.8 mA attenuated fear renewal and reinstatement, promoted extinction generalization and reduced generalized anxiety. Delivering 16 SHORT VNS bursts also facilitated extinction in fewer trials. This study provides the first evidence that brief bursts of VNS can enhance extinction training, reduce relapse and support symptom remission using much less VNS than previous protocols. These findings suggest that VNS parameters can be adjusted in order to minimize total charge delivery and maximize therapeutic effectiveness.
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Affiliation(s)
- Rimenez R Souza
- Texas Biomedical Device Center, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, United States of America; School of Behavioral Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, United States of America.
| | - Nicole M Robertson
- Texas Biomedical Device Center, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, United States of America
| | - Ezek Mathew
- Texas Biomedical Device Center, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, United States of America; School of Behavioral Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, United States of America
| | - Michel N Tabet
- Texas Biomedical Device Center, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, United States of America; School of Behavioral Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, United States of America
| | - Jesse E Bucksot
- Texas Biomedical Device Center, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, United States of America; Erik Jonsson School of Engineering and Computer Science, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, United States of America
| | - David T Pruitt
- Texas Biomedical Device Center, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, United States of America; School of Behavioral Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, United States of America; Erik Jonsson School of Engineering and Computer Science, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, United States of America
| | - Robert L Rennaker
- Texas Biomedical Device Center, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, United States of America; School of Behavioral Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, United States of America; Erik Jonsson School of Engineering and Computer Science, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, United States of America
| | - Seth A Hays
- Texas Biomedical Device Center, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, United States of America; Erik Jonsson School of Engineering and Computer Science, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, United States of America
| | - Christa K McIntyre
- Texas Biomedical Device Center, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, United States of America; School of Behavioral Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, United States of America
| | - Michael P Kilgard
- Texas Biomedical Device Center, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, United States of America; School of Behavioral Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, United States of America
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Badran BW, Jenkins DD, Cook D, Thompson S, Dancy M, DeVries WH, Mappin G, Summers P, Bikson M, George MS. Transcutaneous Auricular Vagus Nerve Stimulation-Paired Rehabilitation for Oromotor Feeding Problems in Newborns: An Open-Label Pilot Study. Front Hum Neurosci 2020; 14:77. [PMID: 32256328 PMCID: PMC7093597 DOI: 10.3389/fnhum.2020.00077] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 02/20/2020] [Indexed: 01/12/2023] Open
Abstract
Neonates born premature or who suffer brain injury at birth often have oral feeding dysfunction and do not meet oral intake requirements needed for discharge. Low oral intake volumes result in extended stays in the hospital (>2 months) and can lead to surgical implant and explant of a gastrostomy tube (G-tube). Prior work suggests pairing vagus nerve stimulation (VNS) with motor activity accelerates functional improvements after stroke, and transcutaneous auricular VNS (taVNS) has emerged as promising noninvasive form of VNS. Pairing taVNS with bottle-feeding rehabilitation may improve oromotor coordination and lead to improved oral intake volumes, ultimately avoiding the need for G-tube placement. We investigated whether taVNS paired with oromotor rehabilitation is tolerable and safe and facilitates motor learning in infants who have failed oral feeding. We enrolled 14 infants [11 premature and 3 hypoxic-ischemic encephalopathy (HIE)] who were slated for G-tube placement in a prospective, open-label study of taVNS-paired rehabilitation to increase feeding volumes. Once-daily taVNS was delivered to the left tragus during bottle feeding for 2 weeks, with optional extension. The primary outcome was attainment of oral feeding volumes and weight gain adequate for discharge without G-tube while also monitoring discomfort and heart rate (HR) as safety outcomes. We observed no adverse events related to stimulation, and stimulation-induced HR reductions were transient and safe and likely confirmed vagal engagement. Eight of 14 participants (57%) achieved adequate feeding volumes for discharge without G-tube (mean treatment length: 16 ± 6 days). We observed significant increases in feeding volume trajectories in responders compared with pre-stimulation (p < 0.05). taVNS-paired feeding rehabilitation appears safe and may improve oral feeding in infants with oromotor dyscoordination, increasing the rate of discharge without G-tube, warranting larger controlled trials.
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Affiliation(s)
- Bashar W. Badran
- Department of Psychiatry, Medical University of South Carolina, Charleston, SC, United States
| | - Dorothea D. Jenkins
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC, United States
| | - Daniel Cook
- Department of Psychiatry, Medical University of South Carolina, Charleston, SC, United States
| | - Sean Thompson
- Department of Psychiatry, Medical University of South Carolina, Charleston, SC, United States
| | - Morgan Dancy
- Department of Psychiatry, Medical University of South Carolina, Charleston, SC, United States
| | - William H. DeVries
- Department of Psychiatry, Medical University of South Carolina, Charleston, SC, United States
| | - Georgia Mappin
- Department of Psychiatry, Medical University of South Carolina, Charleston, SC, United States
| | - Philipp Summers
- Department of Psychiatry, Medical University of South Carolina, Charleston, SC, United States
| | - Marom Bikson
- Department of Biomedical Engineering, City College of New York, New York, NY, United States
| | - Mark S. George
- Department of Psychiatry, Medical University of South Carolina, Charleston, SC, United States
- Ralph H. Johnson VA Medical Center, Charleston, SC, United States
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Cook DN, Thompson S, Stomberg-Firestein S, Bikson M, George MS, Jenkins DD, Badran BW. Design and validation of a closed-loop, motor-activated auricular vagus nerve stimulation (MAAVNS) system for neurorehabilitation. Brain Stimul 2020; 13:800-803. [PMID: 32289710 DOI: 10.1016/j.brs.2020.02.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Revised: 02/18/2020] [Accepted: 02/24/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Studies have found that pairing vagus nerve stimulation (VNS) with motor activity accelerates cortical reorganization. This synchronous pairing may enhance motor recovery. OBJECTIVE To develop and validate a motor-activated auricular vagus nerve stimulation (MAAVNS) system as a potential neurorehabilitation tool. METHODS We created MAAVNS and validated its function as part of an ongoing clinical trial investigating whether taVNS-paired rehabilitation enhances oromotor learning. We compared 3 different MAAVNS EMG electrode configurations in 3 neonates. The active lead was placed over the buccinator muscle. Reference lead placements were orbital, temporal or frontal. RESULTS The frontal reference lead produced the highest sensitivity (0.87 ± 0.07 (n = 8)) and specificity (0.64 ± 0.13 (n = 8)). Oral sucking reliably triggers MAAVNS stimulation with high confidence. CONCLUSION EMG electrodes placed on target orofacial muscles can effectively trigger taVNS stimuli in infants in a closed loop fashion.
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Affiliation(s)
- Daniel N Cook
- Brain Stimulation Laboratory, Department of Psychiatry, Medical University of South Carolina, USA
| | - Sean Thompson
- Brain Stimulation Laboratory, Department of Psychiatry, Medical University of South Carolina, USA
| | - Sasha Stomberg-Firestein
- Brain Stimulation Laboratory, Department of Psychiatry, Medical University of South Carolina, USA
| | - Marom Bikson
- Department of Biomedical Engineering, City College of New York, USA
| | - Mark S George
- Brain Stimulation Laboratory, Department of Psychiatry, Medical University of South Carolina, USA; Ralph H. Johnson VA Medical Center, Charleston, SC, USA
| | | | - Bashar W Badran
- Brain Stimulation Laboratory, Department of Psychiatry, Medical University of South Carolina, USA.
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Gurel NZ, Huang M, Wittbrodt MT, Jung H, Ladd SL, Shandhi MMH, Ko YA, Shallenberger L, Nye JA, Pearce B, Vaccarino V, Shah AJ, Bremner JD, Inan OT. Quantifying acute physiological biomarkers of transcutaneous cervical vagal nerve stimulation in the context of psychological stress. Brain Stimul 2020; 13:47-59. [PMID: 31439323 PMCID: PMC8252146 DOI: 10.1016/j.brs.2019.08.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 07/24/2019] [Accepted: 08/04/2019] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Stress is associated with activation of the sympathetic nervous system, and can lead to lasting alterations in autonomic function and in extreme cases symptoms of posttraumatic stress disorder (PTSD). Vagal nerve stimulation (VNS) is a potentially useful tool as a modulator of autonomic nervous system function, however currently available implantable devices are limited by cost and inconvenience. OBJECTIVE The purpose of this study was to assess the effects of transcutaneous cervical VNS (tcVNS) on autonomic responses to stress. METHODS Using a double-blind approach, we investigated the effects of active or sham tcVNS on peripheral cardiovascular and autonomic responses to stress using wearable sensing devices in 24 healthy human participants with a history of exposure to psychological trauma. Participants were exposed to acute stressors over a three-day period, including personalized scripts of traumatic events, public speech, and mental arithmetic tasks. RESULTS tcVNS relative to sham applied immediately after traumatic stress resulted in a decrease in sympathetic function and modulated parasympathetic/sympathetic autonomic tone as measured by increased pre-ejection period (PEP) of the heart (a marker of cardiac sympathetic function) of 4.2 ms (95% CI 1.6-6.8 ms, p < 0.01), decreased peripheral sympathetic function as measured by increased photoplethysmogram (PPG) amplitude (decreased vasoconstriction) by 47.9% (1.4-94.5%, p < 0.05), a 9% decrease in respiratory rate (-14.3 to -3.7%, p < 0.01). Similar effects were seen when tcVNS was applied after other stressors and in the absence of a stressor. CONCLUSION Wearable sensing modalities are feasible to use in experiments in human participants, and tcVNS modulates cardiovascular and peripheral autonomic responses to stress.
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Affiliation(s)
- Nil Z Gurel
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
| | - Minxuan Huang
- Department of Epidemiology, Rollins School of Public Health, Atlanta, GA, USA
| | - Matthew T Wittbrodt
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA
| | - Hewon Jung
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Stacy L Ladd
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA; Department of Radiology, Emory University School of Medicine, Atlanta, GA, USA
| | - Md Mobashir H Shandhi
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Yi-An Ko
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Atlanta, GA, USA
| | - Lucy Shallenberger
- Department of Epidemiology, Rollins School of Public Health, Atlanta, GA, USA
| | - Jonathon A Nye
- Department of Radiology, Emory University School of Medicine, Atlanta, GA, USA
| | - Bradley Pearce
- Department of Epidemiology, Rollins School of Public Health, Atlanta, GA, USA
| | - Viola Vaccarino
- Department of Epidemiology, Rollins School of Public Health, Atlanta, GA, USA; Department of Internal Medicine, Emory University School of Medicine, Atlanta, GA, USA
| | - Amit J Shah
- Department of Epidemiology, Rollins School of Public Health, Atlanta, GA, USA; Department of Internal Medicine, Emory University School of Medicine, Atlanta, GA, USA; Atlanta VA Medical Center, Decatur, GA, USA
| | - J Douglas Bremner
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA; Department of Radiology, Emory University School of Medicine, Atlanta, GA, USA; Atlanta VA Medical Center, Decatur, GA, USA
| | - Omer T Inan
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA; Coulter Department of Bioengineering, Georgia Institute of Technology, Atlanta, GA, USA
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44
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Borland MS, Vrana WA, Moreno NA, Fogarty EA, Buell EP, Vanneste S, Kilgard MP, Engineer CT. Pairing vagus nerve stimulation with tones drives plasticity across the auditory pathway. J Neurophysiol 2019; 122:659-671. [PMID: 31215351 DOI: 10.1152/jn.00832.2018] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Previous studies have demonstrated that pairing vagus nerve stimulation (VNS) with sounds can enhance the primary auditory cortex (A1) response to the paired sound. The neural response to sounds following VNS-sound pairing in other subcortical and cortical auditory fields has not been documented. We predicted that VNS-tone pairing would increase neural responses to the paired tone frequency across the auditory pathway. In this study, we paired VNS with the presentation of a 9-kHz tone 300 times a day for 20 days. We recorded neural responses to tones from 2,950 sites in the inferior colliculus (IC), A1, anterior auditory field (AAF), and posterior auditory field (PAF) 24 h after the last pairing session in anesthetized rats. We found that VNS-tone pairing increased the percentage of IC, A1, AAF, and PAF that responds to the paired tone frequency. Across all tested auditory fields, the response strength to tones was strengthened in VNS-tone paired rats compared with control rats. VNS-tone pairing reduced spontaneous activity, frequency selectivity, and response threshold across the auditory pathway. This is the first study to document both cortical and subcortical plasticity following VNS-sound pairing. Our findings suggest that VNS paired with sound presentation is an effective method to enhance auditory processing.NEW & NOTEWORTHY Previous studies have reported primary auditory cortex plasticity following vagus nerve stimulation (VNS) paired with a sound. This study extends previous findings by documenting that fields across the auditory pathway are altered by VNS-tone pairing. VNS-tone pairing increases the percentage of each field that responds to the paired tone frequency. This is the first study to document both cortical and subcortical plasticity following VNS-sound pairing.
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Affiliation(s)
- Michael S Borland
- The University of Texas at Dallas, Texas Biomedical Device Center, Richardson, Texas.,The University of Texas at Dallas, School of Behavioral and Brain Sciences, Richardson, Texas
| | - Will A Vrana
- The University of Texas at Dallas, School of Behavioral and Brain Sciences, Richardson, Texas
| | - Nicole A Moreno
- The University of Texas at Dallas, Texas Biomedical Device Center, Richardson, Texas.,The University of Texas at Dallas, School of Behavioral and Brain Sciences, Richardson, Texas
| | - Elizabeth A Fogarty
- The University of Texas at Dallas, School of Behavioral and Brain Sciences, Richardson, Texas
| | - Elizabeth P Buell
- The University of Texas at Dallas, Texas Biomedical Device Center, Richardson, Texas.,The University of Texas at Dallas, School of Behavioral and Brain Sciences, Richardson, Texas
| | - Sven Vanneste
- The University of Texas at Dallas, Texas Biomedical Device Center, Richardson, Texas.,The University of Texas at Dallas, School of Behavioral and Brain Sciences, Richardson, Texas
| | - Michael P Kilgard
- The University of Texas at Dallas, Texas Biomedical Device Center, Richardson, Texas.,The University of Texas at Dallas, School of Behavioral and Brain Sciences, Richardson, Texas
| | - Crystal T Engineer
- The University of Texas at Dallas, Texas Biomedical Device Center, Richardson, Texas.,The University of Texas at Dallas, School of Behavioral and Brain Sciences, Richardson, Texas
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45
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Hulsey DR, Shedd CM, Sarker SF, Kilgard MP, Hays SA. Norepinephrine and serotonin are required for vagus nerve stimulation directed cortical plasticity. Exp Neurol 2019; 320:112975. [PMID: 31181199 DOI: 10.1016/j.expneurol.2019.112975] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 05/31/2019] [Accepted: 06/06/2019] [Indexed: 11/18/2022]
Abstract
Vagus nerve stimulation (VNS) paired with forelimb training drives robust, specific reorganization of movement representations in the motor cortex. This effect is hypothesized to be mediated by VNS-dependent engagement of neuromodulatory networks. VNS influences activity in the locus coeruleus (LC) and dorsal raphe nucleus (DRN), but the involvement of these neuromodulatory networks in VNS-directed plasticity is unknown. We tested the hypothesis that cortical norepinephrine and serotonin are required for VNS-dependent enhancement of motor cortex plasticity. Rats were trained on a lever pressing task emphasizing proximal forelimb use. Once proficient, all rats received a surgically implanted vagus nerve cuff and cortical injections of either immunotoxins to deplete serotonin or norepinephrine, or vehicle control. Following surgical recovery, rats received half second bursts of 0.8 mA or sham VNS after successful trials. After five days of pairing intracortical microstimulation (ICMS) was performed in the motor cortex contralateral to the trained limb. VNS paired with training more than doubled cortical representations of proximal forelimb movements. Depletion of either cortical norepinephrine or serotonin prevented this effect. The requirement of multiple neuromodulators is consistent with earlier studies showing that these neuromodulators regulate synaptic plasticity in a complimentary fashion.
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Affiliation(s)
- Daniel R Hulsey
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, United States of America.
| | - Christine M Shedd
- The University of Texas at Dallas, School of Behavioral Brain Sciences, 800 West Campbell Road, GR41, Richardson, TX 75080-3021, United States of America
| | - Sadmaan F Sarker
- The University of Texas at Dallas, Erik Jonsson School of Engineering and Computer Science, 800 West Campbell Road, Richardson, TX 75080-3021, United States of America
| | - Michael P Kilgard
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, United States of America; The University of Texas at Dallas, School of Behavioral Brain Sciences, 800 West Campbell Road, GR41, Richardson, TX 75080-3021, United States of America
| | - Seth A Hays
- The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, United States of America; The University of Texas at Dallas, Erik Jonsson School of Engineering and Computer Science, 800 West Campbell Road, Richardson, TX 75080-3021, United States of America
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46
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Yaghouby F, Shafer B, Vasudevan S. A rodent model for long-term vagus nerve stimulation experiments. ACTA ACUST UNITED AC 2019. [DOI: 10.2217/bem-2019-0016] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Aim: Investigations into the benefits of vagus nerve stimulation (VNS) using rodents have led to promising findings for treating clinical disorders. However, the majority of research has been limited to acute timelines. We developed a rodent model for longitudinal assessment of VNS and validated it with a long-term experiment incorporating continuous physiological monitoring. While the primary aim was not to investigate the effects of VNS on the cardiovascular system, we analyzed cardiovascular parameters to demonstrate the model's capabilities in a long-term stimulation-and-recording setup. Materials & methods: Rats were implanted with a cuff electrode around the cervical vagus nerve and electrocardiogram monitoring devices were implanted in the peritoneal cavity. We also designed a connector mount for seamless access to the cuff electrode for VNS in awake-behaving rats. Results & conclusion: Results signified easy-to-interface VNS system, electrode robustness and discernible physiological signals in a long-term setup. Analysis of the cardiovascular parameters revealed some transient effects during VNS. Our proposed model enables long-term VNS experiments along with physiological monitoring in unanesthetized rats.
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Affiliation(s)
- Farid Yaghouby
- US Food & Drug Administration, Center for Devices & Radiological Health (CDRH), Office of Science & Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD 20993, USA
| | - Benjamin Shafer
- US Food & Drug Administration, Center for Devices & Radiological Health (CDRH), Office of Science & Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD 20993, USA
| | - Srikanth Vasudevan
- US Food & Drug Administration, Center for Devices & Radiological Health (CDRH), Office of Science & Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD 20993, USA
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47
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Buell EP, Borland MS, Loerwald KW, Chandler C, Hays SA, Engineer CT, Kilgard MP. Vagus Nerve Stimulation Rate and Duration Determine whether Sensory Pairing Produces Neural Plasticity. Neuroscience 2019; 406:290-299. [PMID: 30904665 DOI: 10.1016/j.neuroscience.2019.03.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 02/27/2019] [Accepted: 03/08/2019] [Indexed: 01/28/2023]
Abstract
Repeatedly pairing a brief train of vagus nerve stimulation (VNS) with an auditory stimulus drives reorganization of primary auditory cortex (A1), and the magnitude of this VNS-dependent plasticity is dependent on the stimulation parameters, including intensity and pulse rate. However, there is currently little data to guide the selection of VNS train durations, an easily adjusted parameter that could influence the effect of VNS-based therapies. Here, we tested the effect of varying the duration of the VNS train on the extent of VNS-dependent cortical plasticity. Rats were exposed to a 9 kHz tone 300 times per day for 20 days. Coincident with tone presentation, groups received trains of 4, 16, or 64 pulses of VNS delivered at 30 Hz, corresponding to train durations of 0.125 s, 0.5 s, and 2.0 s, respectively. High-density microelectrode mapping of A1 revealed that 0.5 s duration VNS trains significantly increased the number of neurons in A1 that responded to tones near the paired tone frequency. Trains lasting 0.125 or 2.0 s failed to alter A1 responses, indicating that both shorter and longer stimulation durations are less effective at enhancing plasticity. A second set of experiments evaluating the effect of delivering 4 or 64 pulses in a fixed 0.5 s VNS train duration paired with tone presentation reveal that both slower and faster stimulation rates are less effective at enhancing plasticity. We incorporated these results with previous findings describing the effect of stimulation parameters on VNS-dependent plasticity and activation of neuromodulatory networks to generate a model of synaptic activation by VNS.
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Affiliation(s)
- Elizabeth P Buell
- Texas Biomedical Device Center, Richardson, TX 75080, USA; The University of Texas at Dallas, School of Behavioral Brain Sciences, 800 West Campbell Road, GR 41, Richardson, TX 75080-3021, USA.
| | - Michael S Borland
- Texas Biomedical Device Center, Richardson, TX 75080, USA; The University of Texas at Dallas, School of Behavioral Brain Sciences, 800 West Campbell Road, GR 41, Richardson, TX 75080-3021, USA
| | - Kristofer W Loerwald
- Texas Biomedical Device Center, Richardson, TX 75080, USA; The University of Texas at Dallas, School of Behavioral Brain Sciences, 800 West Campbell Road, GR 41, Richardson, TX 75080-3021, USA
| | - Collin Chandler
- The University of Texas at Dallas, School of Behavioral Brain Sciences, 800 West Campbell Road, GR 41, Richardson, TX 75080-3021, USA
| | - Seth A Hays
- Texas Biomedical Device Center, Richardson, TX 75080, USA; The University of Texas at Dallas, School of Behavioral Brain Sciences, 800 West Campbell Road, GR 41, Richardson, TX 75080-3021, USA; The University of Texas at Dallas, Erik Jonsson School of Engineering and Computer Science, BSB 11; Richardson, TX 75080, USA
| | - Crystal T Engineer
- Texas Biomedical Device Center, Richardson, TX 75080, USA; The University of Texas at Dallas, School of Behavioral Brain Sciences, 800 West Campbell Road, GR 41, Richardson, TX 75080-3021, USA
| | - Michael P Kilgard
- Texas Biomedical Device Center, Richardson, TX 75080, USA; The University of Texas at Dallas, School of Behavioral Brain Sciences, 800 West Campbell Road, GR 41, Richardson, TX 75080-3021, USA
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48
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Morrison RA, Hulsey DR, Adcock KS, Rennaker RL, Kilgard MP, Hays SA. Vagus nerve stimulation intensity influences motor cortex plasticity. Brain Stimul 2018; 12:256-262. [PMID: 30409712 DOI: 10.1016/j.brs.2018.10.017] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 10/29/2018] [Accepted: 10/31/2018] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Vagus nerve stimulation (VNS) paired with forelimb motor training enhances reorganization of movement representations in the motor cortex. Previous studies have shown an inverted-U relationship between VNS intensity and plasticity in other brain areas, such that moderate intensity VNS yields greater cortical plasticity than low or high intensity VNS. However, the relationship between VNS intensity and plasticity in the motor cortex is unknown. OBJECTIVE In this study we sought to test the hypothesis that VNS intensity exhibits an inverted-U relationship with the degree of motor cortex plasticity in rats. METHODS Rats were taught to perform a lever pressing task emphasizing use of the proximal forelimb musculature. Once proficient, rats underwent five additional days of behavioral training in which low intensity VNS (0.4 mA), moderate intensity VNS (0.8 mA), high intensity VNS (1.6 mA), or sham stimulation was paired with forelimb movement. 24 h after the completion of behavioral training, intracortical microstimulation (ICMS) was used to document movement representations in the motor cortex. RESULTS VNS delivered at 0.8 mA caused a significant increase in motor cortex proximal forelimb representation compared to training alone. VNS delivered at 0.4 mA and 1.6 mA failed to cause a significant expansion of proximal forelimb representation. CONCLUSION Moderate intensity 0.8 mA VNS optimally enhances motor cortex plasticity while low intensity 0.4 mA and high intensity 1.6 mA VNS fail to enhance plasticity. Plasticity in the motor cortex exhibits an inverted-U function of VNS intensity similar to previous findings in auditory cortex.
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Affiliation(s)
- Robert A Morrison
- The University of Texas at Dallas, School of Behavioral Brain Sciences, Richardson, TX, USA; The University of Texas at Dallas, Texas Biomedical Device Center, Richardson, TX, USA.
| | - Daniel R Hulsey
- The University of Texas at Dallas, Texas Biomedical Device Center, Richardson, TX, USA
| | - Katherine S Adcock
- The University of Texas at Dallas, School of Behavioral Brain Sciences, Richardson, TX, USA; The University of Texas at Dallas, Texas Biomedical Device Center, Richardson, TX, USA
| | - Robert L Rennaker
- The University of Texas at Dallas, School of Behavioral Brain Sciences, Richardson, TX, USA; The University of Texas at Dallas, Texas Biomedical Device Center, Richardson, TX, USA; The University of Texas at Dallas, Erik Jonsson School of Engineering and Computer Science, Richardson, TX, USA
| | - Michael P Kilgard
- The University of Texas at Dallas, School of Behavioral Brain Sciences, Richardson, TX, USA; The University of Texas at Dallas, Texas Biomedical Device Center, Richardson, TX, USA; The University of Texas at Dallas, Erik Jonsson School of Engineering and Computer Science, Richardson, TX, USA
| | - Seth A Hays
- The University of Texas at Dallas, School of Behavioral Brain Sciences, Richardson, TX, USA; The University of Texas at Dallas, Texas Biomedical Device Center, Richardson, TX, USA; The University of Texas at Dallas, Erik Jonsson School of Engineering and Computer Science, Richardson, TX, USA
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49
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Buell EP, Loerwald KW, Engineer CT, Borland MS, Buell JM, Kelly CA, Khan II, Hays SA, Kilgard MP. Cortical map plasticity as a function of vagus nerve stimulation rate. Brain Stimul 2018; 11:1218-1224. [PMID: 30037658 PMCID: PMC6487479 DOI: 10.1016/j.brs.2018.07.045] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 06/04/2018] [Accepted: 07/16/2018] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Repeatedly pairing a brief train of vagus nerve stimulation (VNS) with an external event can reorganize the sensory or motor cortex. A 30 Hz train of sixteen VNS pulses paired with a tone significantly increases the number of neurons in primary auditory cortex (A1) that respond to tones near the paired tone frequency. The effective range of VNS pulse rates for driving cortical map plasticity has not been defined. OBJECTIVE/HYPOTHESIS This project investigated the effects of VNS rate on cortical plasticity. We expected that VNS pulse rate would affect the degree of plasticity caused by VNS-tone pairing. METHODS Rats received sixteen pulses of VNS delivered at a low (7.5 Hz), moderate (30 Hz), or high (120 Hz) rate paired with 9 kHz tones 300 times per day over a 20 day period. RESULTS More A1 neurons responded to the paired tone frequency in rats from the moderate rate VNS group compared to naïve controls. The response strength was also increased in these rats. In contrast, rats that received high or low rate VNS failed to exhibit a significant increase in the number of neurons tuned to sounds near 9 kHz. CONCLUSION Our results demonstrate that the degree of cortical plasticity caused by VNS-tone pairing is an inverted-U function of VNS pulse rate. The apparent high temporal precision of VNS-tone pairing helps identify optimal VNS parameters to achieve the beneficial effects from restoration of sensory or motor function.
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Affiliation(s)
- E P Buell
- Texas Biomedical Device Center, Richardson, TX, 75080, USA; The University of Texas at Dallas, School of Behavioral Brain Sciences, 800 West Campbell Road, GR 41, Richardson, TX, 75080-3021, USA.
| | - K W Loerwald
- Texas Biomedical Device Center, Richardson, TX, 75080, USA; The University of Texas at Dallas, School of Behavioral Brain Sciences, 800 West Campbell Road, GR 41, Richardson, TX, 75080-3021, USA
| | - C T Engineer
- Texas Biomedical Device Center, Richardson, TX, 75080, USA; The University of Texas at Dallas, School of Behavioral Brain Sciences, 800 West Campbell Road, GR 41, Richardson, TX, 75080-3021, USA
| | - M S Borland
- Texas Biomedical Device Center, Richardson, TX, 75080, USA; The University of Texas at Dallas, School of Behavioral Brain Sciences, 800 West Campbell Road, GR 41, Richardson, TX, 75080-3021, USA
| | - J M Buell
- Texas Biomedical Device Center, Richardson, TX, 75080, USA
| | - C A Kelly
- The University of Texas at Dallas, School of Behavioral Brain Sciences, 800 West Campbell Road, GR 41, Richardson, TX, 75080-3021, USA
| | - I I Khan
- The University of Texas at Dallas, School of Behavioral Brain Sciences, 800 West Campbell Road, GR 41, Richardson, TX, 75080-3021, USA
| | - S A Hays
- Texas Biomedical Device Center, Richardson, TX, 75080, USA; The University of Texas at Dallas, Erik Jonsson School of Engineering and Computer Science, BSB 11, Richardson, TX, 75080, USA
| | - M P Kilgard
- Texas Biomedical Device Center, Richardson, TX, 75080, USA; The University of Texas at Dallas, School of Behavioral Brain Sciences, 800 West Campbell Road, GR 41, Richardson, TX, 75080-3021, USA
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50
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Loerwald KW, Buell EP, Borland MS, Rennaker RL, Hays SA, Kilgard MP. Varying Stimulation Parameters to Improve Cortical Plasticity Generated by VNS-tone Pairing. Neuroscience 2018; 388:239-247. [PMID: 30063940 DOI: 10.1016/j.neuroscience.2018.07.038] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 07/11/2018] [Accepted: 07/20/2018] [Indexed: 12/20/2022]
Abstract
Pairing vagus nerve stimulation (VNS) with movements or sounds can direct robust plasticity in motor or auditory cortex, respectively. The degree of map plasticity is influenced by the intensity and pulse width of VNS, number of VNS-event pairings, and the interval between each pairing. It is likely that these parameters interact, influencing optimal implementation of VNS pairing protocols. We varied VNS intensity, number of stimulations, and inter-stimulation interval (ISI) to test for interactions among these parameters. Rats were implanted with a vagus nerve stimulating cuff and randomly assigned to one of three treatment groups to receive 20 days of VNS paired with a 9-kHz tone: (1) Fast VNS: 50 daily pairings of 400-µA VNS with a 30-s ISI; (2) Dispersed VNS: 50 daily pairings of 400-µA VNS with a 180-s ISI; and (3) Standard VNS: 300 daily pairings of 800-µA VNS with a 30-s ISI. Following 20 days of VNS-tone pairing, multi-unit recordings were conducted in primary auditory cortex (A1) and receptive field properties were analyzed. Increasing ISI (Dispersed VNS) did not lead to an enhancement of cortical plasticity. Reducing the current intensity and number of stimulations (Fast VNS) resulted in robust cortical plasticity, using 6 times fewer VNS pairings than the Standard protocol. These findings reveal an interaction between current intensity, stimulation number, and ISI and identify a novel VNS paradigm that is substantially more efficient than the previous standard paradigm.
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Affiliation(s)
| | - Elizabeth P Buell
- The University of Texas at Dallas, School of Behavioral Brain Sciences, 800 West Campbell Road, GR 41, Richardson, TX 75080-3021, United States
| | - Michael S Borland
- The University of Texas at Dallas, School of Behavioral Brain Sciences, 800 West Campbell Road, GR 41, Richardson, TX 75080-3021, United States
| | - Robert L Rennaker
- Texas Biomedical Device Center, Richardson, TX 75080, United States; The University of Texas at Dallas, School of Behavioral Brain Sciences, 800 West Campbell Road, GR 41, Richardson, TX 75080-3021, United States; The University of Texas at Dallas, Erik Jonsson School of Engineering and Computer Science, BSB 11, Richardson, TX 75080, United States
| | - Seth A Hays
- Texas Biomedical Device Center, Richardson, TX 75080, United States; The University of Texas at Dallas, Erik Jonsson School of Engineering and Computer Science, BSB 11, Richardson, TX 75080, United States.
| | - Michael P Kilgard
- Texas Biomedical Device Center, Richardson, TX 75080, United States; The University of Texas at Dallas, School of Behavioral Brain Sciences, 800 West Campbell Road, GR 41, Richardson, TX 75080-3021, United States
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