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FERRÉ JOHN, ROKEM ARIEL, BUFFALO ELIZABETHA, KUTZ JNATHAN, Fairhall A. Non-Stationary Dynamic Mode Decomposition. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.08.552333. [PMID: 37609201 PMCID: PMC10441341 DOI: 10.1101/2023.08.08.552333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Many physical processes display complex high-dimensional time-varying behavior, from global weather patterns to brain activity. An outstanding challenge is to express high dimensional data in terms of a dynamical model that reveals their spatiotemporal structure. Dynamic Mode Decomposition is a means to achieve this goal, allowing the identification of key spatiotemporal modes through the diagonalization of a finite dimensional approximation of the Koopman operator. However, DMD methods apply best to time-translationally invariant or stationary data, while in many typical cases, dynamics vary across time and conditions. To capture this temporal evolution, we developed a method, Non-Stationary Dynamic Mode Decomposition (NS-DMD), that generalizes DMD by fitting global modulations of drifting spatiotemporal modes. This method accurately predicts the temporal evolution of modes in simulations and recovers previously known results from simpler methods. To demonstrate its properties, the method is applied to multi-channel recordings from an awake behaving non-human primate performing a cognitive task.
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Affiliation(s)
- JOHN FERRÉ
- Physics Department, University of Washington, Seattle, Washington 98195, USA
| | - ARIEL ROKEM
- Psychology Department and eScience Institute, University of Washington, Seattle, Washington 98195, USA
| | - ELIZABETH A. BUFFALO
- Department of Physiology and Biophysics, University of Washington School of Medicine, Washington National Primate Research Center, Seattle Washington 98195, USA
| | - J. NATHAN KUTZ
- Applied Mathematics and Electrical and Computer Engineering Department, University of Washington, Seattle, Washington 98195, USA
| | - Adrienne Fairhall
- Physiology and Biophysics Department, University of Washington, Seattle, Washington 98195, USA
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Marshall FA. Temporal-lobe Epilepsy: Harmonic and Anharmonic Periodicity in Microeletrode Voltage. ARXIV 2023:arXiv:2301.06337v1. [PMID: 36713241 PMCID: PMC9882567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Temporal-lobe epilepsy in humans is often associated with widespread, synchronized neuron firing that co-occurs with traveling waves in local field potential. These traveling waves generate stochastic oscillations in a time series of microelectrode voltage, and previous work has deemed it informative for traveling-wave analysis to study the mean periodicity. This manuscript reveals that: a) mean voltage (i.e., traveling-wave periodicity) adequately explains the observed voltage periodicity only for a select few time intervals during seizure; and b) mean voltage has a 7 Hz cosine-series representation indicative of a nonlinear system response given alpha-rhythm input. The a) result implies that residual noise should be modelled explicitly, while b) motivates a departure from the conventional plane-wave modeling regime in source-localization efforts. The 7 Hz fundamental frequency is unsurprising given the relative transparency of the brain to 14 Hz alpha rhythms in neurophysiological diseases (14 Hz being a subharmonic frequency of the 7 Hz signal).
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Affiliation(s)
- François A Marshall
- Mathematics and Statistics Boston University, 111 Cummington Mall #140C, Boston, MA 02215, United States
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Shi Z, Karmonik C, Soltes A, Tran K, Boone T, Lincoln JA, Khavari R. Altered bladder-related brain network in multiple sclerosis women with voiding dysfunction. Neurourol Urodyn 2022; 41:1612-1619. [PMID: 35842826 PMCID: PMC9399000 DOI: 10.1002/nau.25008] [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: 05/12/2022] [Revised: 06/14/2022] [Accepted: 06/30/2022] [Indexed: 11/12/2022]
Abstract
OBJECTIVES A number of neurourology imaging studies have mainly focused on investigating the brain activations during micturition in healthy and neuropathic patients. It is, however, also necessary to study brain functional connectivity (FC) within bladder-related regions to understand the brain organization during the execution of bladder function. This study aims to identify the altered brain network associated with bladder function in multiple sclerosis (MS) women with voiding dysfunction through comparisons with healthy subjects via concurrent urodynamic study (UDS)/functional magnetic resonance imaging (fMRI). MATERIALS AND METHODS Ten healthy adult women and nine adult ambulatory women with clinically stable MS for ≥6 months and symptomatic voiding phase neurogenic lower urinary tract dysfunction (NLUTD) underwent UDS/fMRI evaluation with a task of bladder filling/emptying that was repeated three to five times. We quantitatively compared their FC within 17 bladder-related brain regions during two UDS phases: "strong desire to void" and "(attempt at) voiding initiation." RESULTS At "strong desire to void," the healthy group showed significantly stronger FC in regions involved in bladder filling and suppression of voiding compared to the patient group. These regions included the bilateral anterior cingulate cortex, right supplementary motor area, and right middle frontal gyrus. During "(attempt at) voiding initiation," healthy subjects exhibited stronger FC in the right inferior frontal gyrus compared to MS patients. CONCLUSION Our study offers a new way to identify alterations in the neural mechanisms underlying NLUTD and provides potential targets for clinical interventions (such as cortical neuromodulation) aimed at restoring bladder functions in MS patients.
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Affiliation(s)
- Zhaoyue Shi
- Translational Imaging Center, Houston Methodist Research Institute, Houston, Texas, USA
| | - Christof Karmonik
- Translational Imaging Center, Houston Methodist Research Institute, Houston, Texas, USA
| | - Amelia Soltes
- Department of Urology, Houston Methodist Hospital, Houston, Texas, USA
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas, USA
| | - Khue Tran
- Department of Urology, Houston Methodist Hospital, Houston, Texas, USA
| | - Timothy Boone
- Department of Urology, Houston Methodist Hospital, Houston, Texas, USA
| | - John A Lincoln
- Department of Neurology, McGovern Medical School, Houston, Texas, USA
| | - Rose Khavari
- Department of Urology, Houston Methodist Hospital, Houston, Texas, USA
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Tau deposition patterns are associated with functional connectivity in primary tauopathies. Nat Commun 2022; 13:1362. [PMID: 35292638 PMCID: PMC8924216 DOI: 10.1038/s41467-022-28896-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 02/14/2022] [Indexed: 11/08/2022] Open
Abstract
Tau pathology is the main driver of neuronal dysfunction in 4-repeat tauopathies, including cortico-basal degeneration and progressive supranuclear palsy. Tau is assumed to spread prion-like across connected neurons, but the mechanisms of tau propagation are largely elusive in 4-repeat tauopathies, characterized not only by neuronal but also by astroglial and oligodendroglial tau accumulation. Here, we assess whether connectivity is associated with 4R-tau deposition patterns by combining resting-state fMRI connectomics with both 2nd generation 18F-PI-2620 tau-PET in 46 patients with clinically diagnosed 4-repeat tauopathies and post-mortem cell-type-specific regional tau assessments from two independent progressive supranuclear palsy patient samples (n = 97 and n = 96). We find that inter-regional connectivity is associated with higher inter-regional correlation of both tau-PET and post-mortem tau levels in 4-repeat tauopathies. In regional cell-type specific post-mortem tau assessments, this association is stronger for neuronal than for astroglial or oligodendroglial tau, suggesting that connectivity is primarily associated with neuronal tau accumulation. Using tau-PET we find further that patient-level tau patterns are associated with the connectivity of subcortical tau epicenters. Together, the current study provides combined in vivo tau-PET and histopathological evidence that brain connectivity is associated with tau deposition patterns in 4-repeat tauopathies.
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Song HY, Shin DW, Jung SM, Jeong Y, Jeong B, Park CS. Feasibility study on transcutaneous auricular vagus nerve stimulation using millimeter waves. Biomed Phys Eng Express 2021; 7. [PMID: 34647906 DOI: 10.1088/2057-1976/ac2c54] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 10/01/2021] [Indexed: 11/12/2022]
Abstract
Objective. Electrical stimulation of the auricular vagus nerve is a non-invasive neuromodulation technique that has been used for various conditions, including depression, epilepsy, headaches, and cerebral ischemia. However, unwanted non-vagal nerve stimulations can occur because of diffused stimulations. The objective of this study is to develop a region-specific non-invasive vagus nerve stimulation (VNS) technique using the millimeter wave (MMW) as a stimulus for the auricular branch of the vagus nerve (ABVN).Approach. A numerical simulation was conducted to ascertain whether the MMW could excite the ABVN in the human outer-ear with a millimeter-scale spatial resolution. Additionally, MMW-induced neuronal responses in seven mice were evaluated. Transcutaneous auricular VNS (ta-VNS) was applied to the cymba conchae innervated by the AVBN using a 60-GHz continuous wave (CW). As a control, the auricle's exterior margin was stimulated and referred to as transcutaneous auricular non-vagus nerve stimulation (ta-nonVNS). During stimulation, the local field potential (LFP) in the nucleus tractus solitarii (NTS), an afferent vagal projection site, was recorded simultaneously.Main results. The ta-VNS with a stimulus level of 13 dBm showed a significant increase in the LFP power in the NTS. The mean increases in power (n = 7) in the gamma high and gamma very high bands were 8.6 ± 2.0% and 18.2 ± 5.9%, respectively. However, the ta-nonVNS with a stimulus level of 13 dBm showed a significant decrease in the LFP power in the NTS. The mean decreases in power in the beta and gamma low bands were 11.0 ± 4.4% and 10.8 ± 2.8%, respectively. These findings suggested that MMW stimulation clearly induced a different response according to the presence of ABVN.Significance. Selective auricular VNS is feasible using the MMW. This study provides the basis for the development of a new clinical treatment option using the stimulation of the ta-VNS with a square millimeter spatial resolution.
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Affiliation(s)
- Hi Yuen Song
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Dong Woo Shin
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Seung Moon Jung
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daejeon, Republic of Korea
| | - Yong Jeong
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daejeon, Republic of Korea.,KI for Health Science and Technology, Daejeon, 34141, Republic of Korea
| | - Bumseok Jeong
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daejeon, Republic of Korea.,KI for Health Science and Technology, Daejeon, 34141, Republic of Korea
| | - Chul Soon Park
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
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Pradier B, Wachsmuth L, Nagelmann N, Segelcke D, Kreitz S, Hess A, Pogatzki-Zahn EM, Faber C. Combined resting state-fMRI and calcium recordings show stable brain states for task-induced fMRI in mice under combined ISO/MED anesthesia. Neuroimage 2021; 245:118626. [PMID: 34637903 DOI: 10.1016/j.neuroimage.2021.118626] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 09/27/2021] [Indexed: 11/28/2022] Open
Abstract
For fMRI in animal models, the combination of low-dose anesthetic, isoflurane (ISO), and the sedative medetomidine (MED) has recently become an advocated regimen to achieve stable neuronal states and brain networks in rats that are required for reliable task-induced BOLD fMRI. However, in mice the temporal stability of neuronal states and networks in resting-state (rs)-fMRI experiments during the combined ISO/MED regimen has not been systematically investigated. Using a multimodal approach with optical calcium (Ca2+) recordings and rs-fMRI, we investigated cortical neuronal/astrocytic Ca2+activity states and brain networks at multiple time points while switching from anesthesia with 1% ISO to a combined ISO/MED regimen. We found that cortical activity states reached a steady-state 45 min following start of MED infusion as indicated by stable Ca2+ transients. Similarly, rs-networks were not statistically different between anesthesia with ISO and the combined ISO/MED regimen 45 and 100 min after start of MED. Importantly, during the transition time we identified changed rs-network signatures that likely reflect the different mode of action of the respective anesthetic; these included a dose-dependent increase in cortico-cortical functional connectivity (FC) presumably caused by reduction of ISO concentration and decreased FC in subcortical arousal nuclei due to MED infusion. Furthermore, we report detection of visual stimulation-induced BOLD fMRI during the stable ISO/MED neuronal state 45 min after induction. Based on our findings, we recommend a 45-minute waiting period after switching from ISO anesthesia to the combined ISO/MED regimen before performing rs- or task-induced fMRI experiments.
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Affiliation(s)
- Bruno Pradier
- Department of Clinical Radiology, Translational Research Imaging Center, University Hospital Münster, Münster 48149, Germany; Department of Anesthesiology Intensive Care and Pain Medicine, University Hospital Münster, Germany
| | - Lydia Wachsmuth
- Department of Clinical Radiology, Translational Research Imaging Center, University Hospital Münster, Münster 48149, Germany
| | - Nina Nagelmann
- Department of Clinical Radiology, Translational Research Imaging Center, University Hospital Münster, Münster 48149, Germany
| | - Daniel Segelcke
- Department of Anesthesiology Intensive Care and Pain Medicine, University Hospital Münster, Germany
| | - Silke Kreitz
- Institute of Experimental and Clinical Pharmacology and Toxicology, Emil Fischer Center, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Andreas Hess
- Institute of Experimental and Clinical Pharmacology and Toxicology, Emil Fischer Center, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Esther M Pogatzki-Zahn
- Department of Anesthesiology Intensive Care and Pain Medicine, University Hospital Münster, Germany
| | - Cornelius Faber
- Department of Clinical Radiology, Translational Research Imaging Center, University Hospital Münster, Münster 48149, Germany.
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Yu W, Wu X, Chen Y, Liang Z, Jiang J, Misrani A, Su Y, Peng Y, Chen J, Tang B, Sun M, Long C, Shen J, Yang L. Pelvic Pain Alters Functional Connectivity Between Anterior Cingulate Cortex and Hippocampus in Both Humans and a Rat Model. Front Syst Neurosci 2021; 15:642349. [PMID: 34149369 PMCID: PMC8210850 DOI: 10.3389/fnsys.2021.642349] [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: 12/22/2020] [Accepted: 04/26/2021] [Indexed: 01/06/2023] Open
Abstract
The anterior cingulate cortex (ACC) and hippocampus (HIPP) are two key brain regions associated with pain and pain-related affective processing. However, whether and how pelvic pain alters the neural activity and connectivity of the ACC and HIPP under baseline and during social pain, and the underlying cellular and molecular mechanisms, remain unclear. Using functional magnetic resonance imaging (fMRI) combined with electrophysiology and biochemistry, we show that pelvic pain, particularly, primary dysmenorrhea (PDM), causes an increase in the functional connectivity between ACC and HIPP in resting-state fMRI, and a smaller reduction in connectivity during social exclusion in PDM females with periovulatory phase. Similarly, model rats demonstrate significantly increased ACC-HIPP synchronization in the gamma band, associating with reduced modulation by ACC-theta on HIPP-gamma and increased levels of receptor proteins and excitation. This study brings together human fMRI and animal research and enables improved therapeutic strategies for ameliorating pain and pain-related affective processing.
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Affiliation(s)
- Wenjun Yu
- Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou, China.,Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.,College of Education, Jinggangshan University, Ji'an, China
| | - Xiaoyan Wu
- Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.,School of Psychology, South China Normal University, Guangzhou, China
| | - Yunan Chen
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Zhiying Liang
- Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jinxiang Jiang
- Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou, China
| | - Afzal Misrani
- Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou, China
| | - Yun Su
- Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yigang Peng
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Jian Chen
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Binliang Tang
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Mengyao Sun
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Cheng Long
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Jun Shen
- Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Li Yang
- Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou, China
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Shi Z, Tran K, Karmonik C, Boone T, Khavari R. High spatial correlation in brain connectivity between micturition and resting states within bladder-related networks using 7 T MRI in multiple sclerosis women with voiding dysfunction. World J Urol 2021; 39:3525-3531. [PMID: 33512570 PMCID: PMC8344374 DOI: 10.1007/s00345-021-03599-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 01/08/2021] [Indexed: 12/30/2022] Open
Abstract
Background Several studies have reported brain activations and functional connectivity (FC) during micturition using functional magnetic resonance imaging (fMRI) and concurrent urodynamics (UDS) testing. However, due to the invasive nature of UDS procedure, non-invasive resting-state fMRI is being explored as a potential alternative. The purpose of this study is to evaluate the feasibility of utilizing resting states as a non-invasive alternative for investigating the bladder-related networks in the brain. Methods We quantitatively compared FC in brain regions belonging to the bladder-related network during the following states: ‘strong desire to void’, ‘voiding initiation (or attempt at voiding initiation)’, and ‘voiding (or continued attempt of voiding)’ with FC during rest in nine multiple sclerosis women with voiding dysfunction using fMRI data acquired at 7 T and 3 T. Results The inter-subject correlation analysis showed that voiding (or continued attempt of voiding) is achieved through similar network connections in all subjects. The task-based bladder-related network closely resembles the resting-state intrinsic network only during voiding (or continued attempt of voiding) process but not at other states. Conclusion Resting states fMRI can be potentially utilized to accurately reflect the voiding (or continued attempt of voiding) network. Concurrent UDS testing is still necessary for studying the effects of strong desire to void and initiation of voiding (or attempt at initiation of voiding). Supplementary Information The online version contains supplementary material available at 10.1007/s00345-021-03599-4.
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Affiliation(s)
- Zhaoyue Shi
- Translational Imaging Center, Houston Methodist Research Institute, Houston, TX, USA
| | - Khue Tran
- Department of Urology, Houston Methodist Hospital, Houston, TX, USA
| | - Christof Karmonik
- Translational Imaging Center, Houston Methodist Research Institute, Houston, TX, USA
| | - Timothy Boone
- Department of Urology, Houston Methodist Hospital, Houston, TX, USA
| | - Rose Khavari
- Department of Urology, Houston Methodist Hospital, Houston, TX, USA.
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Oscillations as a window into neuronal mechanisms underlying dorsal anterior cingulate cortex function. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2020; 158:311-335. [PMID: 33785150 DOI: 10.1016/bs.irn.2020.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The function of dorsal Anterior Cingulate Cortex (dACC) remains poorly understood. While many methods, spanning bottom-up and top-down approaches, have been deployed, the view they offer is often conflicting. Integrating bottom-up and top-down approaches requires an intermediary with sufficient explanatory power, theoretical development, and empirical support. Oscillations in the local field potential (LFP) provide such a link. LFP oscillations arise from empirically well-characterized neuronal circuit motifs. Synchronizing the firing of individual units has appealing properties to bind disparate brain regions and propagate information, including gating, routing, and coding. Moreover, the LFP, rather than single unit activity, more closely relates to macro-scale recordings, such as the electroencephalogram and functional magnetic resonance imaging. Thus, LFP oscillations are a critical link that allow for the inference of neuronal micro-circuitry underlying macroscopic brain recordings.
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Li Y, Lee J, Long X, Qiao Y, Ma T, He Q, Cao P, Zhang X, Zheng H. A Magnetic Resonance-Guided Focused Ultrasound Neuromodulation System With a Whole Brain Coil Array for Nonhuman Primates at 3 T. IEEE TRANSACTIONS ON MEDICAL IMAGING 2020; 39:4401-4412. [PMID: 32833632 DOI: 10.1109/tmi.2020.3019087] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The phased-array radio frequency (RF) coil plays a vital role in magnetic resonance-guided focused ultrasound (MRgFUS) neuromodulation studies, where accurate brain functional stimulations and neural circuit observations are required. Although various designs of phased-array coils have been reported, few are suitable for ultrasound stimulations. In this study, an MRgFUS neuromodulation system comprised of a whole brain coverage non-human primate (NHP) RF coil and an MRI-compatible ultrasound device was developed. When compared to a single loop coil, the NHP coil provided up to a 50% increase in the signal-to-noise ratio (SNR) in the brain and acquired better anatomical image-quality. The NHP coil also demonstrated the ability to achieve higher spatial resolution and reduce distortion in echo-planer imaging (EPI). Ultrasound beam characteristics and transcranial magnetic resonance acoustic radiation force (MR-ARF) were measured for simulated positions, and calculated B0 maps were employed to establish MRI-compatibility. The differences between focused off and on ultrasound techniques were measured using SNR, g-factors, and temporal SNR (tSNR) analyses and all deviations were under 2.3%. The EPI images quality and stable tSNR demonstrated the suitability of the MRgFUS neuromodulation system to conduct functional MRI studies. Last, the time course of the blood oxygen level dependent (BOLD) signal of posterior cingulate cortex in a focused ultrasound neuromodulation study was detected and repeated with MR thermometry.
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Lu H, Jaime S, Yang Y. Origins of the Resting-State Functional MRI Signal: Potential Limitations of the "Neurocentric" Model. Front Neurosci 2019; 13:1136. [PMID: 31708731 PMCID: PMC6819315 DOI: 10.3389/fnins.2019.01136] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Accepted: 10/08/2019] [Indexed: 02/06/2023] Open
Abstract
Resting-state functional connectivity (rsFC) is emerging as a research tool for systems and clinical neuroscience. The mechanism underlying resting-state functional MRI (rsfMRI) signal, however, remains incompletely understood. A widely held assumption is that the spontaneous fluctuations in blood oxygenation level-dependent (BOLD) signal reflect ongoing neuronal processes (herein called “neurocentric” model). In support of this model, evidence from human and animal studies collectively reveals that the spatial synchrony of spontaneously occurring electrophysiological signal recapitulates BOLD rsFC networks. Two recent experiments from independent labs designed to specifically examine neuronal origins of rsFC, however, suggest that spontaneously occurring neuronal events, as assessed by multiunit activity or local field potential (LFP), although statistically significant, explain only a small portion (∼10%) of variance in resting-state BOLD fluctuations. These two studies, although each with its own limitations, suggest that the spontaneous fluctuations in rsfMRI, may have complex cellular origins, and the “neurocentric” model may not apply to all brain regions.
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Affiliation(s)
- Hanbing Lu
- Neuroimaging Research Branch, National Institute on Drug Abuse (NIDA) Intramural Research Program, National Institutes of Health, Bethesda, MD, United States
| | - Saul Jaime
- Division of Pharmacology & Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX, United States.,Waggoner Center for Alcohol & Addiction Research, The University of Texas at Austin, Austin, TX, United States
| | - Yihong Yang
- Neuroimaging Research Branch, National Institute on Drug Abuse (NIDA) Intramural Research Program, National Institutes of Health, Bethesda, MD, United States
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