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Ji N, Li Y, Wei J, Huang L, Lin WH, Li G. The Changes of Cardiovascular Neurotransmitter Levels under Low-Intensity Focused Ultrasound Stimulation of the Vagus Nerve. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-4. [PMID: 38083122 DOI: 10.1109/embc40787.2023.10340334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
BACKGROUND Our previous study has shown that stimulation of the vagus nerve with low-intensity focused ultrasound could modulate blood pressure (BP), but the underlying mechanisms remain unclear. This study investigated the changes of cardiovascular neurotransmitter levels to indirectly evaluate the responses of the autonomic nervous system and renin-angiotensin system under low-intensity focused ultrasound stimulation (FUS) of the vagus nerve. METHODS Cardiovascular neurotransmitter levels of epinephrine (EPI), norepinephrine (NE), and angiotensin II (ANGII) were measured and compared before and after the FUS in seven spontaneously hypertensive rats; and were also measured and compared between a target stimulation group (FUS, n = 6) and non-target stimulation group (Control, n = 5) after stimulation to exclude the influence of potential confounding factors. RESULTS The t-test results showed that the levels of EPI, NE, and ANGII were significantly decreased (P < 0.05) after stimulation compared to before stimulation. Additionally, the levels of NE and EPI were significantly lower (P < 0.05) in the FUS group than in the Control group after stimulation, indicating that the activities of the sympathetic nervous system and renin-angiotensin system of the vagus nerve might be inhibited by FUS of the vagus nerve. CONCLUSION These findings reveal the mechanism of BP lowing in response to FUS of the vagus nerve.Clinical Relevance-This study revealed the mechanism of BP lowering in response to focused ultrasound stimulation of the vagus nerve through analyzing the changes of cardiovascular neurotransmitter levels.
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Li D, Cao F, Han J, Wang M, Lai C, Zhang J, Xu T, Bouakaz A, Wan M, Ren P, Zhang S. The sustainable antihypertensive and target organ damage protective effect of transcranial focused ultrasound stimulation in spontaneously hypertensive rats. J Hypertens 2023; 41:852-866. [PMID: 36883470 DOI: 10.1097/hjh.0000000000003407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
Abstract
OBJECTIVE In this study, we aimed to investigate the sustainable antihypertensive effects and protection against target organ damage caused by low-intensity focused ultrasound (LIFU) stimulation and the underlying mechanism in spontaneously hypertensive rats (SHRs) model. METHODS AND RESULTS SHRs were treated with ultrasound stimulation of the ventrolateral periaqueductal gray (VlPAG) for 20 min every day for 2 months. Systolic blood pressure (SBP) was compared among normotensive Wistar-Kyoto rats, SHR control group, SHR Sham group, and SHR LIFU stimulation group. Cardiac ultrasound imaging and hematoxylin-eosin and Masson staining of the heart and kidney were performed to assess target organ damage. The c-fos immunofluorescence analysis and plasma levels of angiotensin II, aldosterone, hydrocortisone, and endothelin-1 were measured to investigate the neurohumoral and organ systems involved. We found that SBP was reduced from 172 ± 4.2 mmHg to 141 ± 2.1 mmHg after 1 month of LIFU stimulation, P < 0.01. The next month of treatment can maintain the rat's blood pressure at 146 ± 4.2 mmHg at the end of the experiment. LIFU stimulation reverses left ventricular hypertrophy and improves heart and kidney function. Furthermore, LIFU stimulation enhanced the neural activity from the VLPAG to the caudal ventrolateral medulla and reduced the plasma levels of ANGII and Aldo. CONCLUSION We concluded that LIFU stimulation has a sustainable antihypertensive effect and protects against target organ damage by activating antihypertensive neural pathways from VLPAG to the caudal ventrolateral medulla and further inhibiting the renin-angiotensin system (RAS) activity, thereby supporting a novel and noninvasive alternative therapy to treat hypertension.
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Affiliation(s)
- Dapeng Li
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University
| | - Fangyuan Cao
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University
| | - Jie Han
- Department of Cardiology, The Second Affiliated Hospital of Xi'an Jiaotong University, China
| | - Mengke Wang
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University
| | - Chunhao Lai
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University
| | - Jingjing Zhang
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University
| | - Tianqi Xu
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University
| | | | - Mingxi Wan
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University
| | - Pengyu Ren
- Institute of Medical Artificial Intelligence
- Department of Neurosurgery, The Second Affiliated Hospital of Xi'an Jiaotong University
| | - Siyuan Zhang
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University
- Sichuan Digital Economy Industry Development Research Institute, China
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Yüksel MM, Sun S, Latchoumane C, Bloch J, Courtine G, Raffin EE, Hummel FC. Low-Intensity Focused Ultrasound Neuromodulation for Stroke Recovery: A Novel Deep Brain Stimulation Approach for Neurorehabilitation? IEEE OPEN JOURNAL OF ENGINEERING IN MEDICINE AND BIOLOGY 2023; 4:300-318. [PMID: 38196977 PMCID: PMC10776095 DOI: 10.1109/ojemb.2023.3263690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 03/17/2023] [Accepted: 03/24/2023] [Indexed: 01/11/2024] Open
Abstract
Stroke as the leading cause of adult long-term disability and has a significant impact on patients, society and socio-economics. Non-invasive brain stimulation (NIBS) approaches such as transcranial magnetic stimulation (TMS) or transcranial electrical stimulation (tES) are considered as potential therapeutic options to enhance functional reorganization and augment the effects of neurorehabilitation. However, non-invasive electrical and magnetic stimulation paradigms are limited by their depth focality trade-off function that does not allow to target deep key brain structures critically important for recovery processes. Transcranial ultrasound stimulation (TUS) is an emerging approach for non-invasive deep brain neuromodulation. Using non-ionizing, ultrasonic waves with millimeter-accuracy spatial resolution, excellent steering capacity and long penetration depth, TUS has the potential to serve as a novel non-invasive deep brain stimulation method to establish unprecedented neuromodulation and novel neurorehabilitation protocols. The purpose of the present review is to provide an overview on the current knowledge about the neuromodulatory effects of TUS while discussing the potential of TUS in the field of stroke recovery, with respect to existing NIBS methods. We will address and discuss critically crucial open questions and remaining challenges that need to be addressed before establishing TUS as a new clinical neurorehabilitation approach for motor stroke recovery.
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Affiliation(s)
- Mahmut Martin Yüksel
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind InstituteÉcole Polytechnique Fédérale de LausanneGeneva1201Switzerland
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind InstituteÉcole Polytechnique Fédérale de Lausanne Valais, Clinique Romande de Réadaptation Sion1951Switzerland
| | - Shiqi Sun
- Neuro-X Institute and Brain Mind Institute, School of Life SciencesSwiss Federal Institute of Technology (EPFL)Lausanne1015Switzerland
- Department of Clinical NeuroscienceLausanne University Hospital (CHUV) and the University of Lausanne (UNIL)Lausanne1011Switzerland
- Defitech Center for Interventional Neurotherapies (NeuroRestore)EPFL/CHUV/UNILLausanne1011Switzerland
| | - Charles Latchoumane
- Neuro-X Institute and Brain Mind Institute, School of Life SciencesSwiss Federal Institute of Technology (EPFL)Lausanne1015Switzerland
- Department of Clinical NeuroscienceLausanne University Hospital (CHUV) and the University of Lausanne (UNIL)Lausanne1011Switzerland
- Defitech Center for Interventional Neurotherapies (NeuroRestore)EPFL/CHUV/UNILLausanne1011Switzerland
| | - Jocelyne Bloch
- Neuro-X Institute and Brain Mind Institute, School of Life SciencesSwiss Federal Institute of Technology (EPFL)Lausanne1015Switzerland
- Department of Clinical NeuroscienceLausanne University Hospital (CHUV) and the University of Lausanne (UNIL)Lausanne1015Switzerland
- Defitech Center for Interventional Neurotherapies (NeuroRestore)EPFL/CHUV/UNILLausanne1015Switzerland
- Department of NeurosurgeryLausanne University HospitalLausanne1011Switzerland
| | - Gregoire Courtine
- Department of Clinical NeuroscienceLausanne University Hospital (CHUV) and the University of Lausanne (UNIL)Lausanne1015Switzerland
- Defitech Center for Interventional Neurotherapies (NeuroRestore)EPFL/CHUV/UNILLausanne1015Switzerland
- Department of NeurosurgeryLausanne University HospitalLausanne1011Switzerland
| | - Estelle Emeline Raffin
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind InstituteÉcole Polytechnique Fédérale de LausanneGeneva1201Switzerland
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind InstituteÉcole Polytechnique Fédérale de Lausanne Valais, Clinique Romande de Réadaptation Sion1951Switzerland
| | - Friedhelm Christoph Hummel
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind InstituteÉcole Polytechnique Fédérale de LausanneGeneva1202Switzerland
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind InstituteÉcole Polytechnique Fédérale de Lausanne Valais, Clinique Romande de Réadaptation Sion1951Switzerland
- Clinical NeuroscienceUniversity of Geneva Medical SchoolGeneva1211Switzerland
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Recent updates in autonomic research: a focus on new technologies with high-resolution procedures to study sympathetic nerve activity, plasma proteomic profiling in POTS, and non-invasive neuromodulation with focused ultrasound. Clin Auton Res 2023; 33:11-14. [PMID: 36662319 DOI: 10.1007/s10286-023-00924-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 01/10/2023] [Indexed: 01/21/2023]
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Nagai M, Dote K, Kato M, Sasaki S, Oda N, Förster CY. Afterload reduction after non-invasive vagus nerve stimulation in acute heart failure. Front Hum Neurosci 2023; 17:1149449. [PMID: 37033910 PMCID: PMC10076847 DOI: 10.3389/fnhum.2023.1149449] [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: 01/21/2023] [Accepted: 03/08/2023] [Indexed: 04/11/2023] Open
Abstract
Introduction While central blood pressure (BP) has been recognized as a major indicator of left ventricular (LV) afterload, the reduction of central pressure decreases LV afterload and may prevent heart failure (HF) decompensation. Non-invasive transcutaneous vagus nerve stimulation (tVNS) was shown to improve cardiac function in HF patients. In this study, the relationship between active tVNS and reduction of central BP was investigated in patients with acute HF (AHF). Methods The 22 patients hospitalized for AHF after initial stabilization (median 80 yrs, males 60%) were randomly assigned to active or sham group. For 1 h daily over 5 days, low-level transcutaneous electrical stimulation (LLTS) (20 Hz, 1 mA) was performed after attaching an ear clip to the tragus (active group) or the earlobe (sham control group). Before and after stimulation, central aortic systolic pressure (CASP), brachial systolic BP (SBP), diastolic BP (DBP) as well as heart rate (HR) were noninvasively measured. Results No significant differences in baseline characteristics were observed between the active and sham groups. In the active group, CASP, SBP, DBP, and HR each decreased significantly after stimulation (all p < 0.05), whereas in the sham group, CASP, SBP, DBP, and HR each increased significantly after stimulation (all p < 0.05). All the changes in CASP, SBP, DBP and HR before and after stimulation were also significantly different between active and sham groups (all p < 0.01). There were no device-related side effects. Conclusion In this study, the left tragus tVNS resulted in an acute afterload reduction in the elderly AHF patients. Non-invasive LLTS may be useful and safe for reducing afterload in AHF. Clinical trial registration ClinicalTrials.gov, identifier UMIN000044121.
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Affiliation(s)
- Michiaki Nagai
- Department of Cardiology, Hiroshima City Asa Hospital, Hiroshima, Japan
- *Correspondence: Michiaki Nagai,
| | - Keigo Dote
- Department of Cardiology, Hiroshima City Asa Hospital, Hiroshima, Japan
| | - Masaya Kato
- Department of Cardiology, Hiroshima City Asa Hospital, Hiroshima, Japan
| | - Shota Sasaki
- Department of Cardiology, Hiroshima City Asa Hospital, Hiroshima, Japan
| | - Noboru Oda
- Department of Cardiology, Hiroshima City Asa Hospital, Hiroshima, Japan
| | - Carola Y. Förster
- Department of Anaesthesiology, Intensive Care, Emergency and Pain Medicine, University Hospital Würzburg, Würzburg, Germany
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Ji N, Li Y, Wei J, Chen F, Xu L, Li G, Lin WH. Autonomic modulation by low-intensity focused ultrasound stimulation of the vagus nerve. J Neural Eng 2022; 19. [PMID: 36541473 DOI: 10.1088/1741-2552/aca8cd] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 12/05/2022] [Indexed: 12/12/2022]
Abstract
Objective.Our previous study has shown that low-intensity focused ultrasound stimulation (FUS) of the vagus nerve could modulate blood pressure (BP), but its underlying mechanisms remain unclear. We hypothesized that low-intensity FUS of the vagus nerve would regulate autonomic function and thus BP.Approach.17 anesthetized spontaneously hypertensive rats were treated with low-intensity FUS of the left vagus nerve for 15 min each trial. Continuous BP, heart rate, respiration rate (RR), and core body temperature were simultaneously recorded to evaluate the effects on BP and other physiological parameters. Heart rate variability (HRV), systolic BP variability, and baroreflex sensitivity were computed to evaluate the autonomic modulation function. A Control-sham group without stimulation and another Control-FUS group with non-target stimulation were also examined to exclude the influence of potential confounding factors on autonomic modulation.Main results.A prolonged significant decrease in BP, pulse pressure, RR, the normalized low-frequency power of HRV, and the low-to-high frequency power ratio of HRV were found after the low-intensity FUS of the left vagus nerve in comparison with the baseline and those of the control groups, demonstrating that activities of the sympathetic nervous system were inhibited. The prolonged significant increase of the normalized high-frequency power of HRV suggested the activation of parasympathetic activity.Significance.Low-intensity FUS of the left vagus nerve effectively improved the autonomic function by activating parasympathetic efferent and inhibiting sympathetic efferent, which contributes to BP reduction. The findings shed light on the hypotensive mechanism underlying FUS.
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Affiliation(s)
- Ning Ji
- College of Medicine and Biological Information Engineering, Northeastern University, Shenyang 110819, People's Republic of China.,CAS Key Lab of Human-Machine Intelligence-Synergy Systems and Research Center for Neural Engineering, Shenzhen Institutes of Advanced Technology (SIAT), Chinese Academy of Sciences (CAS), Shenzhen 518055, People's Republic of China
| | - Yuanheng Li
- CAS Key Lab of Human-Machine Intelligence-Synergy Systems and Research Center for Neural Engineering, Shenzhen Institutes of Advanced Technology (SIAT), Chinese Academy of Sciences (CAS), Shenzhen 518055, People's Republic of China
| | - Jingjing Wei
- CAS Key Lab of Human-Machine Intelligence-Synergy Systems and Research Center for Neural Engineering, Shenzhen Institutes of Advanced Technology (SIAT), Chinese Academy of Sciences (CAS), Shenzhen 518055, People's Republic of China.,Department of Human Anatomy, Zhuhai Campus of Zunyi Medical University, Zhuhai 519041, People's Republic of China
| | - Fei Chen
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, People's Republic of China
| | - Lisheng Xu
- College of Medicine and Biological Information Engineering, Northeastern University, Shenyang 110819, People's Republic of China
| | - Guanglin Li
- CAS Key Lab of Human-Machine Intelligence-Synergy Systems and Research Center for Neural Engineering, Shenzhen Institutes of Advanced Technology (SIAT), Chinese Academy of Sciences (CAS), Shenzhen 518055, People's Republic of China
| | - Wan-Hua Lin
- CAS Key Lab of Human-Machine Intelligence-Synergy Systems and Research Center for Neural Engineering, Shenzhen Institutes of Advanced Technology (SIAT), Chinese Academy of Sciences (CAS), Shenzhen 518055, People's Republic of China
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Powell K, White TG, Nash C, Rebeiz T, Woo HH, Narayan RK, Li C. The Potential Role of Neuromodulation in Subarachnoid Hemorrhage. Neuromodulation 2022; 25:1215-1226. [PMID: 35088724 DOI: 10.1016/j.neurom.2021.12.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 11/15/2021] [Accepted: 11/17/2021] [Indexed: 12/20/2022]
Abstract
OBJECTIVES Aneurysmal subarachnoid hemorrhage (SAH) continues to be a difficult cerebrovascular disease with limited pharmacologic treatment options. Cerebral vasospasm (CV) and delayed cerebral ischemia (DCI) are leading causes of morbidity and mortality after SAH. Despite the advances in the understanding of its pathophysiology and tremendous efforts to date, nimodipine is currently the sole Food and Drug Administration-approved treatment for patients with SAH, with benefits that are marginal at best. The neuromodulation therapies are promising, especially those that target CV and DCI to improve functional outcomes. The aim of this review is therefore to summarize the available evidence for each type of neuromodulation for CV and DCI, with a special focus on its pathophysiological mechanisms, in addition to their clinical utility and drawbacks, which we hope will lead to future translational therapy options after SAH. MATERIALS AND METHODS We conducted a comprehensive review of preclinical and clinical studies demonstrating the use of neuromodulation for SAH. The literature search was performed using PubMed, Embase, and ClinicalTrials.gov. A total of 21 articles published from 1992 to 2021 and eight clinical trials were chosen. RESULTS The studies reviewed provide a compelling demonstration that neuromodulation is a potentially useful strategy to target multiple mechanisms of DCI and thus to potentially improve functional outcomes from SAH. There are several types of neuromodulation that have been tested to treat CV and DCI, including the trigeminal/vagus/facial nerve stimulation, sphenopalatine ganglion and spinal cord stimulation, transcranial direct electrical stimulation, transcutaneous electrical neurostimulation, and electroacupuncture. Most of them are in the preclinical or early phases of clinical application; however, they show promising results. CONCLUSIONS DCI has a complex pathogenesis, making the unique anatomical distribution and pleiotropic capabilities of various types of neuromodulation a promising field of study. We may be at the cusp of a breakthrough in the use of these techniques for the treatment of this stubbornly difficult disease.
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Affiliation(s)
- Keren Powell
- Translational Brain Research Laboratory, The Feinstein Institutes for Medical Research, Manhasset, NY, USA
| | - Timothy G White
- Translational Brain Research Laboratory, The Feinstein Institutes for Medical Research, Manhasset, NY, USA; Department of Neurosurgery, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA
| | - Christine Nash
- Translational Brain Research Laboratory, The Feinstein Institutes for Medical Research, Manhasset, NY, USA
| | - Tania Rebeiz
- Department of Neurosurgery, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA
| | - Henry H Woo
- Department of Neurosurgery, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA
| | - Raj K Narayan
- Translational Brain Research Laboratory, The Feinstein Institutes for Medical Research, Manhasset, NY, USA; Department of Neurosurgery, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA
| | - Chunyan Li
- Translational Brain Research Laboratory, The Feinstein Institutes for Medical Research, Manhasset, NY, USA; Department of Neurosurgery, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA.
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Filkin V, Kuznetsov I, Antonova O, Tarotin I, Nemov A, Aristovich K. Can ionic concentration changes due to mechanical deformation be responsible for the neurostimulation caused by focused ultrasound? A simulation study. Physiol Meas 2021; 42. [PMID: 34530410 DOI: 10.1088/1361-6579/ac2790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 09/16/2021] [Indexed: 11/12/2022]
Abstract
Objective.Ultrasound stimulation is an emerging neuromodulation technique, for which the exact mechanism of action is still unknown. Despite the number of hypotheses such as mechanosensitive ion channels and intermembrane cavitation, they fail to explain all of the observed experimental effects. Here we are investigating the ionic concentration change as a prime mechanism for the neurostimulation by the ultrasound.Approach.We derive the direct analytical relationship between the mechanical deformations in the tissue and the electric boundary conditions for the cable theory equations and solve them for two types of neuronal axon models: Hodgkin-Huxley and C-fibre. We detect the activation thresholds for a variety of ultrasound stimulation cases including continuous and pulsed ultrasound and estimate the mechanical deformations required for reaching the thresholds and generating action potentials (APs).Main results.We note that the proposed mechanism strongly depends on the mechanical properties of the neural tissues, which at the moment cannot be located in literature with the required certainty. We conclude that given certain common linear assumptions, this mechanism alone cannot cause significant effects and be responsible for neurostimulation. However, we also conclude that if the lower estimation of mechanical properties of neural tissues in literature is true, or if the normal cavitation occurs during the ultrasound stimulation, the proposed mechanism can be a prime cause for the generation of APs.Significance.The approach allows prediction and modelling of most observed experimental effects, including the probabilistic ones, without the need for any extra physical effects or additional parameters.
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Affiliation(s)
- Vladimir Filkin
- Higher School of Mechanics and Control, Peter the Great St. Petersburg Polytechnic University, Russia
| | - Igor Kuznetsov
- Higher School of Mechanics and Control, Peter the Great St. Petersburg Polytechnic University, Russia
| | - Olga Antonova
- Higher School of Mechanics and Control, Peter the Great St. Petersburg Polytechnic University, Russia
| | - Ilya Tarotin
- Department of Medical Physics and Biomedical Engineering, University College London, United Kingdom
| | - Alexander Nemov
- Higher School of Mechanics and Control, Peter the Great St. Petersburg Polytechnic University, Russia
| | - Kirill Aristovich
- Department of Medical Physics and Biomedical Engineering, University College London, United Kingdom
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Ji N, Lin WH, Li Y, Chen F, Xu L, Li G. A Pilot Study of Thermal Effect of Low-intensity Focused Ultrasound on Blood Pressure Modulation. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021; 2021:5690-5693. [PMID: 34892413 DOI: 10.1109/embc46164.2021.9630455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Our recent study showed that low-intensity focused ultrasound stimulation (FUS) of the vagus nerve is capable of lowering blood pressure (BP). However, it remains unknown that what is the underlying mechanisms of BP modulation with FUS. In our preliminary experiments, we noticed that there was temperature elevation accompanied the FUS. Thus, to verify whether the thermal effect of ultrasound contributes in the BP-lowering effect, this study compared the BP response under the FUS (with thermal effect and mechanical effect) and the alternative heating source treatment (AHST) (with thermal effect only) of left vagus nerve. Six Sprague Dawley rats were randomly divided into two groups (FUS, n=3 and AHST, n=3). In vivo temperature measurements were conducted to evaluate the heating performance of the FUS and the AHST. Blood pressure (BP) waveform was continuously recorded from the right common artery and was used for analyzing systolic BP (SBP), diastolic BP (DBP), mean BP (MBP), and heart rate (HR). The results showed that the SBP, DBP, MBP and HR decreased during the 15-min FUS. However, most of the SBP, DBP, MBP and HR increased during the 15-min AHST, which had the approximate temperature elevation of the FUS. Thus, the thermal effect of ultrasound probably does not contribute in the BP-lowering effect induced by low-intensity FUS of the vagus nerve.
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