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Wu YL, Christodoulou AG, Beumer JH, Rigatti LH, Fisher R, Ross M, Watkins S, Cortes DRE, Ruck C, Manzoor S, Wyman SK, Stapleton MC, Goetzman E, Bharathi S, Wipf P, Wang H, Tan T, Christner SM, Guo J, Lo CWY, Epperly MW, Greenberger JS. Mitigation of Fetal Radiation Injury from Mid-Gestation Total-body Irradiation by Maternal Administration of Mitochondrial-Targeted GS-Nitroxide JP4-039. Radiat Res 2024; 202:565-579. [PMID: 39074819 DOI: 10.1667/rade-24-00095.1] [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: 03/28/2024] [Accepted: 06/11/2024] [Indexed: 07/31/2024]
Abstract
Victims of a radiation terrorist event will include pregnant women and unborn fetuses. Mitochondrial dysfunction and oxidative stress are key pathogenic factors of fetal radiation injury. The goal of this preclinical study is to investigate the efficacy of mitigating fetal radiation injury by maternal administration of the mitochondrial-targeted gramicidin S (GS)-nitroxide radiation mitigator JP4-039. Pregnant female C57BL/6NTac mice received 3 Gy total-body irradiation (TBI) at mid-gestation embryonic day 13.5 (E13.5). Using novel time-and-motion-resolved 4D in utero magnetic resonance imaging (4D-uMRI), we found TBI caused extensive injury to the fetal brain that included cerebral hemorrhage, loss of cerebral tissue, and hydrocephalus with excessive accumulation of cerebrospinal fluid (CSF). Histopathology of the fetal mouse brain showed broken cerebral vessels and elevated apoptosis. Further use of novel 4D Oxy-wavelet MRI capable of probing in vivo mitochondrial function in intact brain revealed a significant reduction of mitochondrial function in the fetal brain after 3 Gy TBI. This was validated by ex vivo Oroboros mitochondrial respirometry. One day after TBI (E14.5) maternal administration of JP4-039, which passes through the placenta, significantly reduced fetal brain radiation injury and improved fetal brain mitochondrial respiration. Treatment also preserved cerebral brain tissue integrity and reduced cerebral hemorrhage and cell death. JP4-039 administration following irradiation resulted in increased survival of pups. These findings indicate that JP4-039 can be deployed as a safe and effective mitigator of fetal radiation injury from mid-gestational in utero ionizing radiation exposure.
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Affiliation(s)
- Yijen L Wu
- Department of Pediatrics, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15201
- Rangos Research Center Animal Imaging Core, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania 15224
| | - Anthony G Christodoulou
- Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095
| | - Jan H Beumer
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
- Cancer Therapeutics Program, UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania 15232
| | - Lora H Rigatti
- Division of Laboratory Animal Resources (DLAR), University of Pittsburgh, Pittsburgh, Pennsylvania 15213
| | - Renee Fisher
- Department of Radiation Oncology, School of Medicine, UPMC Hillman Cancer Center, Pittsburgh, PA 15232
| | - Mark Ross
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Simon Watkins
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Devin R E Cortes
- Department of Pediatrics, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15201
- Rangos Research Center Animal Imaging Core, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania 15224
- Department of Biomedical Engineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
| | - Cody Ruck
- Department of Pediatrics, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15201
- Rangos Research Center Animal Imaging Core, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania 15224
| | - Shanim Manzoor
- Department of Pediatrics, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15201
- Rangos Research Center Animal Imaging Core, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania 15224
| | - Samuel K Wyman
- Department of Pediatrics, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15201
- Rangos Research Center Animal Imaging Core, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania 15224
| | - Margaret C Stapleton
- Department of Pediatrics, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15201
| | - Eric Goetzman
- Department of Pediatrics, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15201
| | - Sivakama Bharathi
- Department of Pediatrics, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15201
| | - Peter Wipf
- Department of Biomedical Engineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
- Department of Chemistry, Kenneth P. Dietrich School of Arts & Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Hong Wang
- Department of Biostatistics, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Tuantuan Tan
- Department of Pediatrics, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15201
| | - Susan M Christner
- Cancer Therapeutics Program, UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania 15232
| | - Jianxia Guo
- Cancer Therapeutics Program, UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania 15232
| | - Cecilia W Y Lo
- Department of Pediatrics, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15201
| | - Michael W Epperly
- Department of Radiation Oncology, School of Medicine, UPMC Hillman Cancer Center, Pittsburgh, PA 15232
| | - Joel S Greenberger
- Department of Radiation Oncology, School of Medicine, UPMC Hillman Cancer Center, Pittsburgh, PA 15232
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Wu YL, Christodoulou AG, Beumer JH, Rigatti LH, Fisher R, Ross M, Watkins S, Cortes DRE, Ruck C, Manzoor S, Wyman SK, Stapleton MC, Goetzman E, Bharathi S, Wipf P, Tan T, Eiseman JL, Christner SM, Guo J, Lo CWY, Epperly MW, Greenberger JS. Mitigation of Fetal Irradiation Injury from Mid-Gestation Total Body Radiation with Mitochondrial-Targeted GS-Nitroxide JP4-039. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.13.580105. [PMID: 38405696 PMCID: PMC10888932 DOI: 10.1101/2024.02.13.580105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Victims of a radiation terrorist event will include pregnant women and unborn fetuses. Mitochondrial dysfunction and oxidative stress are key pathogenic factors of fetal irradiation injury. The goal of this preclinical study is to investigate the efficacy of mitigating fetal irradiation injury by maternal administration of the mitochondrial-targeted gramicidin S (GS)- nitroxide radiation mitigator, JP4-039. Pregnant female C57BL/6NTac mice received 3 Gy total body ionizing irradiation (TBI) at mid-gestation embryonic day 13.5 (E13.5). Using novel time- and-motion-resolved 4D in utero magnetic resonance imaging (4D-uMRI), we found TBI caused extensive injury to the fetal brain that included cerebral hemorrhage, loss of cerebral tissue, and hydrocephalus with excessive accumulation of cerebrospinal fluid (CSF). Histopathology of the fetal mouse brain showed broken cerebral vessels and elevated apoptosis. Further use of novel 4D Oxy-wavelet MRI capable of probing in vivo mitochondrial function in intact brain revealed significant reduction of mitochondrial function in the fetal brain after 3Gy TBI. This was validated by ex vivo Oroboros mitochondrial respirometry. Maternal administration JP4-039 one day after TBI (E14.5), which can pass through the placental barrier, significantly reduced fetal brain radiation injury and improved fetal brain mitochondrial respiration. This also preserved cerebral brain tissue integrity and reduced cerebral hemorrhage and cell death. As JP4-039 administration did not change litter sizes or fetus viability, together these findings indicate JP4-039 can be deployed as a safe and effective mitigator of fetal radiation injury from mid-gestational in utero ionizing radiation exposure. One Sentence Summary Mitochondrial-targeted gramicidin S (GS)-nitroxide JP4-039 is safe and effective radiation mitigator for mid-gestational fetal irradiation injury.
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Eby AL, Remedios LW, Kim ME, Li M, Gao Y, Gore JC, Schilling KG, Landman BA. Identification of functional white matter networks in BOLD fMRI. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2024; 12926:129260T. [PMID: 39220214 PMCID: PMC11364407 DOI: 10.1117/12.3006231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
White matter signals in resting state blood oxygen level dependent functional magnetic resonance (BOLD-fMRI) have been largely discounted, yet there is growing evidence that these signals are indicative of brain activity. Understanding how these white matter signals capture function can provide insight into brain physiology. Moreover, functional signals could potentially be used as early markers for neurological changes, such as in Alzheimer's Disease. To investigate white matter brain networks, we leveraged the OASIS-3 dataset to extract white matter signals from resting state BOLD-FMRI data on 711 subjects. The imaging was longitudinal with a total of 2,026 images. Hierarchical clustering was performed to investigate clusters of voxel-level correlations on the timeseries data. The stability of clusters was measured with the average Dice coefficients on two different cross fold validations. The first validated the stability between scans, and the second validated the stability between populations. Functional clusters at hierarchical levels 4, 9, 13, 18, and 24 had local maximum stability, suggesting better clustered white matter. In comparison with JHU-DTI-SS Type-I Atlas defined regions, clusters at lower hierarchical levels identified well-defined anatomical lobes. At higher hierarchical levels, functional clusters mapped motor and memory functional regions, identifying 50.00%, 20.00%, 27.27%, and 35.14% of the frontal, occipital, parietal, and temporal lobe regions respectively.
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Affiliation(s)
| | | | | | - Muwei Li
- Vanderbilt University, Nashville, TN
- Vanderbilt University Medical Center, Nashville, TN
| | - Yurui Gao
- Vanderbilt University, Nashville, TN
- Vanderbilt University Medical Center, Nashville, TN
| | - John C Gore
- Vanderbilt University, Nashville, TN
- Vanderbilt University Medical Center, Nashville, TN
| | | | - Bennett A Landman
- Vanderbilt University, Nashville, TN
- Vanderbilt University Medical Center, Nashville, TN
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Eby AL, Remedios LW, Kim ME, Li M, Gao Y, Gore JC, Schilling KG, Landman BA. Identification of functional white matter networks in BOLD fMRI. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.08.556881. [PMID: 38328148 PMCID: PMC10849525 DOI: 10.1101/2023.09.08.556881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
White matter signals in resting state blood oxygen level dependent functional magnetic resonance (BOLD-fMRI) have been largely discounted, yet there is growing evidence that these signals are indicative of brain activity. Understanding how these white matter signals capture function can provide insight into brain physiology. Moreover, functional signals could potentially be used as early markers for neurological changes, such as in Alzheimer's Disease. To investigate white matter brain networks, we leveraged the OASIS-3 dataset to extract white matter signals from resting state BOLD-FMRI data on 711 subjects. The imaging was longitudinal with a total of 2,026 images. Hierarchical clustering was performed to investigate clusters of voxel-level correlations on the timeseries data. The stability of clusters was measured with the average Dice coefficients on two different cross fold validations. The first validated the stability between scans, and the second validated the stability between subject populations. Functional clusters at hierarchical levels 4, 9, 13, 18, and 24 had local maximum stability, suggesting better clustered white matter. In comparison with JHU-DTI-SS Type-I Atlas defined regions, clusters at lower hierarchical levels identified well defined anatomical lobes. At higher hierarchical levels, functional clusters mapped motor and memory functional regions, identifying 50.00%, 20.00%, 27.27%, and 35.14% of the frontal, occipital, parietal, and temporal lobe regions respectively.
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Padawer-Curry JA, Bowen RM, Jarang A, Wang X, Lee JM, Bauer AQ. Wide-Field Optical Imaging in Mouse Models of Ischemic Stroke. Methods Mol Biol 2023; 2616:113-151. [PMID: 36715932 DOI: 10.1007/978-1-0716-2926-0_11] [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] [Indexed: 01/31/2023]
Abstract
Functional neuroimaging is a powerful tool for evaluating how local and global brain circuits evolve after focal ischemia and how these changes relate to functional recovery. For example, acutely after stroke, changes in functional brain organization relate to initial deficit and are predictive of recovery potential. During recovery, the reemergence and restoration of connections lost due to stroke correlate with recovery of function. Thus, information gleaned from functional neuroimaging can be used as a proxy for behavior and inform on the efficacy of interventional strategies designed to affect plasticity mechanisms after injury. And because these findings are consistently observed across species, bridge measurements can be made in animal models to enrich findings in human stroke populations. In mice, genetic engineering techniques have provided several new opportunities for extending optical neuroimaging methods to more direct measures of neuronal activity. These developments are especially useful in the context of stroke where neurovascular coupling can be altered, potentially limiting imaging measures based on hemodynamic activity alone. This chapter is designed to give an overview of functional wide-field optical imaging (WFOI) for applications in rodent models of stroke, primarily in the mouse. The goal is to provide a protocol for laboratories that want to incorporate an affordable functional neuroimaging assay into their current research thrusts, but perhaps lack the background knowledge or equipment for developing a new arm of research in their lab. Within, we offer a comprehensive guide developing and applying WFOI technology with the hope of facilitating accessibility of neuroimaging technology to other researchers in the stroke field.
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Affiliation(s)
- Jonah A Padawer-Curry
- Department of Radiology, Washington University in St. Louis, St. Louis, MO, USA
- Imaging Science PhD Program, Washington University in St. Louis, St. Louis, MO, USA
| | - Ryan M Bowen
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
- Department of Neurology, Washington University in St. Louis, St. Louis, MO, USA
| | - Anmol Jarang
- Department of Radiology, Washington University in St. Louis, St. Louis, MO, USA
| | - Xiaodan Wang
- Department of Radiology, Washington University in St. Louis, St. Louis, MO, USA
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Jin-Moo Lee
- Department of Radiology, Washington University in St. Louis, St. Louis, MO, USA
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
- Department of Neurology, Washington University in St. Louis, St. Louis, MO, USA
| | - Adam Q Bauer
- Department of Radiology, Washington University in St. Louis, St. Louis, MO, USA.
- Imaging Science PhD Program, Washington University in St. Louis, St. Louis, MO, USA.
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA.
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Orije JEMJ, Van der Linden A. A brain for all seasons: An in vivo MRI perspective on songbirds. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2022; 337:967-984. [PMID: 35989548 PMCID: PMC9804379 DOI: 10.1002/jez.2650] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 07/08/2022] [Accepted: 08/03/2022] [Indexed: 01/05/2023]
Abstract
Seasonality in songbirds includes not only reproduction but also seasonal changes in singing behavior and its neural substrate, the song control system (SCS). Prior research mainly focused on the role of sex steroids on this seasonal SCS neuroplasticity in males. In this review, we summarize the advances made in the field of seasonal neuroplasticity by applying in vivo magnetic resonance imaging (MRI) in male and female starlings, analyzing the entire brain, monitoring birds longitudinally and determining the neuronal correlates of seasonal variations in plasma hormone levels and song behavior. The first MRI studies in songbirds used manganese enhanced MRI to visualize the SCS in a living bird and validated previously described brain volume changes related to different seasons and testosterone. MRI studies with testosterone implantation established how the consequential boost in singing was correlated to structural changes in the SCS, indicating activity-induced neuroplasticity as song proficiency increased. Next, diffusion tensor MRI explored seasonal neuroplasticity in the entire brain, focusing on networks beyond the SCS, revealing that other sensory systems and even the cerebellum, which is important for the integration of sensory perception and song behavior, experience neuroplasticity starting in the photosensitive period. Functional MRI showed that olfactory, and auditory processing was modulated by the seasons. The convergence of seasonal variations in so many sensory and sensorimotor systems resembles multisensory neuroplasticity during the critical period early in life. This sheds new light on seasonal songbirds as a model for unlocking the brain by recreating seasonally the permissive circumstances for heightened neuroplasticity.
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Affiliation(s)
- Jasmien Ellen Maria Jozef Orije
- Department of Biomedical SciencesBio‐Imaging Lab, University of AntwerpAntwerpenBelgium,NEURO Research Centre of Excellence, University of AntwerpAntwerpenBelgium
| | - Annemie Van der Linden
- Department of Biomedical SciencesBio‐Imaging Lab, University of AntwerpAntwerpenBelgium,NEURO Research Centre of Excellence, University of AntwerpAntwerpenBelgium
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Review of the Research Progress of Human Brain Oxygen Extraction Fraction by Magnetic Resonance Imaging. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:4554271. [PMID: 36304964 PMCID: PMC9596244 DOI: 10.1155/2022/4554271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 09/02/2022] [Accepted: 09/15/2022] [Indexed: 11/17/2022]
Abstract
In recent years, the incidence of cerebrovascular diseases (CVD) is increasing, which seriously endangers human health. The study on hemodynamics of cerebrovascular disease can help us to understand, prevent, and treat the disease. As one of the important parameters of human cerebral hemodynamics and tissue metabolism, OEF (oxygen extraction fraction) is of great value in central nervous system diseases. The use of BOLD (blood oxygen level dependent) effect offers the possibility to study cerebral hemodynamic and metabolic characteristics by MRI (magnetic resonance imaging) measurements. Therefore, this paper reviews the hemodynamic parameters of brain tissue, discusses the principles and methods of quantitative BOLD-based MRI measurements of OEF, and discusses the advantages and disadvantages of each method.
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Hokama Y, Nishimura M, Usugi R, Fujiwara K, Katagiri C, Takagi H, Ishiuchi S. Recovery from the damage of cranial radiation modulated by memantine, an NMDA receptor antagonist, combined with hyperbaric oxygen therapy. Neuro Oncol 2022; 25:108-122. [PMID: 35762568 PMCID: PMC9825311 DOI: 10.1093/neuonc/noac162] [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: 02/08/2022] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Radiotherapy is an important treatment option for central nervous system malignancies. However, cranial radiation induces hippocampal dysfunction and white matter injury; this leads to cognitive dysfunction, and results in a reduced quality of life in patients. Excitatory glutamate signaling through N-methyl-d-aspartate receptors (NMDARs) plays a central role both in hippocampal neurogenesis and in the myelination of oligodendrocytes in the cerebrum. METHODS We provide a method for quantifying neurogenesis in human subjects in live brain during cancer therapy. Neuroimaging using originally created behavioral tasks was employed to examine human hippocampal memory pathway in patients with brain disorders. RESULTS Treatment with memantine, a non-competitive NMDAR antagonist, reversed impairment in hippocampal pattern separation networks as detected by functional magnetic resonance imaging. Hyperbaric preconditioning of the patients just before radiotherapy with memantine mostly reversed white matter injury as detected by whole brain analysis with Tract-Based Spatial Statics. Neuromodulation combined with the administration of hyperbaric oxygen therapy and memantine during radiotherapy facilitated the restoration of hippocampal function and white matter integrity, and improved higher cognitive function in patients receiving cranial radiation. CONCLUSIONS The method described herein, for diagnosis of hippocampal dysfunction, and therapeutic intervention can be utilized to restore some of the cognitive decline experienced by patients who have received cranial radiation. The underlying mechanism of restoration is the production of new neurons, which enhances functionality in pattern separation networks in the hippocampi, resulting in an increase in cognitive score, and restoration of microstructural integrity of white matter tracts revealed by Tract-Based Spatial Statics Analysis.
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Affiliation(s)
- Yohei Hokama
- Department of Neurosurgery, Graduate School of Medicine, University of The Ryukyus, 207 Uehara, Nishihara-machi, Okinawa 903-0215, Japan
| | - Masahiko Nishimura
- Department of Neurosurgery, Graduate School of Medicine, University of The Ryukyus, 207 Uehara, Nishihara-machi, Okinawa 903-0215, Japan
| | - Ryoichi Usugi
- Department of Neurosurgery, Graduate School of Medicine, University of The Ryukyus, 207 Uehara, Nishihara-machi, Okinawa 903-0215, Japan
| | - Kyoko Fujiwara
- Department of Neurosurgery, Graduate School of Medicine, University of The Ryukyus, 207 Uehara, Nishihara-machi, Okinawa 903-0215, Japan
| | - Chiaki Katagiri
- Department of Neurosurgery, Graduate School of Medicine, University of The Ryukyus, 207 Uehara, Nishihara-machi, Okinawa 903-0215, Japan
| | - Hiroshi Takagi
- Department of Neurosurgery, Graduate School of Medicine, University of The Ryukyus, 207 Uehara, Nishihara-machi, Okinawa 903-0215, Japan
| | - Shogo Ishiuchi
- Corresponding Author: Dr. Shogo Ishiuchi, Department of Neurosurgery, Graduate School of Medicine, University of The Ryukyus, 207 Uehara, Nishihara-machi, Okinawa 903-0215, Japan ()
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Nunez-Elizalde AO, Krumin M, Reddy CB, Montaldo G, Urban A, Harris KD, Carandini M. Neural correlates of blood flow measured by ultrasound. Neuron 2022; 110:1631-1640.e4. [PMID: 35278361 PMCID: PMC9235295 DOI: 10.1016/j.neuron.2022.02.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 01/06/2022] [Accepted: 02/15/2022] [Indexed: 12/17/2022]
Abstract
Functional ultrasound imaging (fUSI) is an appealing method for measuring blood flow and thus infer brain activity, but it relies on the physiology of neurovascular coupling and requires extensive signal processing. To establish to what degree fUSI trial-by-trial signals reflect neural activity, we performed simultaneous fUSI and neural recordings with Neuropixels probes in awake mice. fUSI signals strongly correlated with the slow (<0.3 Hz) fluctuations in the local firing rate and were closely predicted by the smoothed firing rate of local neurons, particularly putative inhibitory neurons. The optimal smoothing filter had a width of ∼3 s, matched the hemodynamic response function of awake mice, was invariant across mice and stimulus conditions, and was similar in the cortex and hippocampus. fUSI signals also matched neural firing spatially: firing rates were as highly correlated across hemispheres as fUSI signals. Thus, blood flow measured by ultrasound bears a simple and accurate relationship to neuronal firing.
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Affiliation(s)
| | - Michael Krumin
- UCL Institute of Ophthalmology, University College London, London WC1E 6AE, UK
| | - Charu Bai Reddy
- UCL Institute of Ophthalmology, University College London, London WC1E 6AE, UK
| | - Gabriel Montaldo
- Neuro-Electronics Research Flanders, 3001 Leuven, Belgium; Vlaams Instituut voor Biotechnologie (VIB), 3000 Leuven, Belgium; imec, 3001 Leuven, Belgium; Department of Neuroscience, KU Leuven, 3000 Leuven, Belgium
| | - Alan Urban
- Neuro-Electronics Research Flanders, 3001 Leuven, Belgium; Vlaams Instituut voor Biotechnologie (VIB), 3000 Leuven, Belgium; imec, 3001 Leuven, Belgium; Department of Neuroscience, KU Leuven, 3000 Leuven, Belgium
| | - Kenneth D Harris
- UCL Queen Square Institute of Neurology, University College London, London WC1E 6AE, UK
| | - Matteo Carandini
- UCL Institute of Ophthalmology, University College London, London WC1E 6AE, UK.
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Brain Connectivity and Network Analysis in Amyotrophic Lateral Sclerosis. Neurol Res Int 2022; 2022:1838682. [PMID: 35178253 PMCID: PMC8844436 DOI: 10.1155/2022/1838682] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 01/13/2022] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with no effective treatment or cure. ALS is characterized by the death of lower motor neurons (LMNs) in the spinal cord and upper motor neurons (UMNs) in the brain and their networks. Since the lower motor neurons are under the control of UMN and the networks, cortical degeneration may play a vital role in the pathophysiology of ALS. These changes that are not apparent on routine imaging with CT scans or MRI brain can be identified using modalities such as diffusion tensor imaging, functional MRI, arterial spin labelling (ASL), electroencephalogram (EEG), magnetoencephalogram (MEG), functional near-infrared spectroscopy (fNIRS), and positron emission tomography (PET) scan. They can help us generate a representation of brain networks and connectivity that can be visualized and parsed out to characterize and quantify the underlying pathophysiology in ALS. In addition, network analysis using graph measures provides a novel way of understanding the complex network changes occurring in the brain. These have the potential to become biomarker for the diagnosis and treatment of ALS. This article is a systematic review and overview of the various connectivity and network-based studies in ALS.
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White EJ, Kuplicki R, Stewart JL, Kirlic N, Yeh HW, Paulus MP, Aupperle RL. Latent variables for region of interest activation during the monetary incentive delay task. Neuroimage 2021; 230:117796. [PMID: 33503481 DOI: 10.1016/j.neuroimage.2021.117796] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 11/27/2020] [Accepted: 01/19/2021] [Indexed: 10/22/2022] Open
Abstract
BACKGROUND The Monetary Incentive Delay task (MID) has been used extensively to probe anticipatory reward processes. However, individual differences evident during this task may relate to other constructs such as general arousal or valence processing (i.e., anticipation of negative versus positive outcomes). This investigation used a latent variable approach to parse activation patterns during the MID within a transdiagnostic clinical sample. METHODS Participants were drawn from the first 500 individuals recruited for the Tulsa-1000 (T1000), a naturalistic longitudinal study of 1000 participants aged 18-55 (n = 476 with MID data). We employed a multiview latent analysis method, group factor analysis, to characterize factors within and across variable sets consisting of: (1) region of interest (ROI)-based blood oxygenation level-dependent (BOLD) contrasts during reward and loss anticipation; and (2) self-report measures of positive and negative valence and related constructs. RESULTS Three factors comprised of ROI indicators emerged to accounted for >43% of variance and loaded on variables representing: (1) general arousal or general activation; (2) valence, with dissociable responses to anticipation of win versus loss; and (3) region-specific activation, with dissociable activation in salience versus perceptual brain networks. Two additional factors were comprised of self-report variables, which appeared to represent arousal and valence. CONCLUSIONS Results indicate that multiview techniques to identify latent variables offer a novel approach for differentiating brain activation patterns during task engagement. Such approaches may offer insight into neural processing patterns through dimension reduction, be useful for probing individual differences, and aid in the development of optimal explanatory or predictive frameworks.
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Affiliation(s)
- Evan J White
- Laureate Institute for Brain Research, 6655 South Yale Avenue, Tulsa, OK 74136, USA.
| | - Rayus Kuplicki
- Laureate Institute for Brain Research, 6655 South Yale Avenue, Tulsa, OK 74136, USA
| | - Jennifer L Stewart
- Laureate Institute for Brain Research, 6655 South Yale Avenue, Tulsa, OK 74136, USA; Department of Community Medicine, Oxley Health Sciences, University of Tulsa, 800 South Tucker Drive, Tulsa, OK 74104, USA
| | - Namik Kirlic
- Laureate Institute for Brain Research, 6655 South Yale Avenue, Tulsa, OK 74136, USA
| | - Hung-Wen Yeh
- Pediatrics Department, Children's Mercy Kansas City, 2401 Gilham Road, Kansas City, MO 64108, USA
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- Laureate Institute for Brain Research, 6655 South Yale Avenue, Tulsa, OK 74136, USA
| | - Martin P Paulus
- Laureate Institute for Brain Research, 6655 South Yale Avenue, Tulsa, OK 74136, USA; Department of Community Medicine, Oxley Health Sciences, University of Tulsa, 800 South Tucker Drive, Tulsa, OK 74104, USA
| | - Robin L Aupperle
- Laureate Institute for Brain Research, 6655 South Yale Avenue, Tulsa, OK 74136, USA; Department of Community Medicine, Oxley Health Sciences, University of Tulsa, 800 South Tucker Drive, Tulsa, OK 74104, USA
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Rodan LH, Poublanc J, Fisher JA, Sobczyk O, Mikulis DJ, Tein I. L-arginine effects on cerebrovascular reactivity, perfusion and neurovascular coupling in MELAS (mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes) syndrome. PLoS One 2020; 15:e0238224. [PMID: 32881886 PMCID: PMC7470264 DOI: 10.1371/journal.pone.0238224] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 08/11/2020] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE We previously showed that MELAS patients have decreased cerebrovascular reactivity (CVR) (p≤ 0.002) and increased cerebral blood flow (CBF) (p<0.0026); changes correlated with disease severity and % mutant mtDNA (inversely for CVR; directly for CBF). We ran a prospective pilot in 3 MELAS sibs (m.3243A>G tRNALeu(UUR)) with variable % mutant blood mtDNA to assess effects of L-Arginine (L-Arg) (single dose and 6-wk steady-state trial) on regional CBF, arterial CVR and neurovascular coupling. METHODS Patients were studied with 3T MRI using arterial spin labeling (ASL) to measure CBF and changes in % Blood Oxygen Level Dependent (BOLD) signal to changes in arterial partial pressure of CO2 to measure CVR. Task fMRI consisted of an alternating black and white checkerboard to evaluate visual cortex response in MELAS and controls. RESULTS Following L-Arg, there was restoration of serum Arg (76-230 μM) in MELAS sibs and a trend towards increasing CVR in frontal and corresponding decrease in occipital cortex; CVR was unchanged globally. There was a 29-37% reduction in baseline CBF in one patient following 6 wks of L-Arg. Pre-treatment fMRI activation in response to visual cortex stimulus was markedly decreased in the same patient compared to controls in primary visual striate cortex V1 and extrastriate regions V2 to V5 with a marked increase toward control values following a single dose and 6 wks of L-Arg. CONCLUSION Proposed "healing" effect may be due to more efficient utilization of energy substrates with increased cellular energy balances and ensuing reduction in signalling pathways that augment flow in the untreated state. CLASSIFICATION OF EVIDENCE This prospective pilot study provides Class III evidence that oral L-Arginine (100 mg/kg single dose or 100 mg/kg three times daily po X 6 weeks) normalizes resting blood flow from elevated pre-treatment levels in patients with MELAS syndrome, selectively increases their CVR from reduced pre-treatment levels in regions most impaired at the expense of less abnormal regions, and normalizes reduced BOLD fMRI activation in response to visual cortex stimulus. CLINICAL TRIALS.GOV (NIH) NCT01603446.
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Affiliation(s)
- Lance H. Rodan
- Division of Neurology, Dept. of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Julien Poublanc
- Dept. of Medical Imaging, The Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Joseph A. Fisher
- Dept. of Anesthesiology, University Health Network, University of Toronto, Toronto, Ontario, Canada
- Dept. of Physiology and Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada
- The Toronto General Hospital Medical Research Institute, Toronto, Ontario, Canada
| | - Olivia Sobczyk
- Dept. of Medical Imaging, The Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada
| | - David J. Mikulis
- Dept. of Medical Imaging, The Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Ingrid Tein
- Division of Neurology, Dept. of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
- Genetics and Genome Biology Program, The Research Institute, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
- Dept. of Laboratory Medicine and Pathobiology, The University of Toronto, Toronto, Ontario, Canada
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13
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Pei Y, Zhang Y, Zhu Y, Zhao Y, Zhou F, Huang M, Wu L, Gong H. Hyperconnectivity and High Temporal Variability of the Primary Somatosensory Cortex in Low-Back-Related Leg Pain: An fMRI Study of Static and Dynamic Functional Connectivity. J Pain Res 2020; 13:1665-1675. [PMID: 32753942 PMCID: PMC7351631 DOI: 10.2147/jpr.s242807] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 05/23/2020] [Indexed: 01/10/2023] Open
Abstract
Objective To investigate the functional connectivity (FC) and its variability in the primary somatosensory cortex (S1) of patients with low-back-related leg pain (LBLP) in the context of the persistent stimuli of pain and numbness. Patients and Methods We performed functional magnetic resonance imaging on LBLP patients (n = 26) and healthy controls (HCs; n = 34) at rest. We quantified and compared static FC (sFC) using a seed-based analysis strategy, with 6 predefined bilateral paired spherical regions of interest (ROIs) in the S1 cortex. Then, we captured the dynamic FC using sliding window correlation of ROIs in both the LBLP patients and HCs. Furthermore, we performed a correlational analysis between altered static and dynamic FC and clinical measures in LBLP patients. Results Compared with controls, the LBLP patients had 1) significantly increased static FC between the left S1back (the representation of the back in the S1) and right superior and middle frontal gyrus (SFG/MFG), between the left S1chest and right SFG/MFG, between right S1chest and right SFG/MFG, between the left S1face and right MFG, and between the right S1face and right inferior parietal lobule (P < 0.001, Gaussian random field theory correction); 2) increased dynamic FC only between the right S1finger and the left precentral and postcentral gyrus and between the right S1hand and the right precentral and postcentral gyrus (P < 0.01, Gaussian random field theory correction); and 3) a negative correlation between the Barthel index and the increased static FC between the left S1face and right inferior parietal lobule (P = 0.048). Conclusion The present study demonstrated the hyperconnectivity of the S1 cortex to the default mode and executive control network in a spatial pattern and an increase in the tendency for signal variability in the internal network connections of the S1 cortex in patients with LBLP.
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Affiliation(s)
- Yixiu Pei
- Department of Radiology, The First Affiliated Hospital, Nanchang University, Nanchang 330006, People's Republic of China.,Neuroradiology Laboratory, Jiangxi Province Medical Imaging Research Institute, Nanchang 330006, People's Republic of China
| | - Yong Zhang
- Department of Pain Clinic, The First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi Province 330006, People's Republic of China
| | - Yanyan Zhu
- Department of Radiology, The First Affiliated Hospital, Nanchang University, Nanchang 330006, People's Republic of China.,Neuroradiology Laboratory, Jiangxi Province Medical Imaging Research Institute, Nanchang 330006, People's Republic of China
| | - Yanlin Zhao
- Department of Radiology, The First Affiliated Hospital, Nanchang University, Nanchang 330006, People's Republic of China.,Neuroradiology Laboratory, Jiangxi Province Medical Imaging Research Institute, Nanchang 330006, People's Republic of China
| | - Fuqing Zhou
- Department of Radiology, The First Affiliated Hospital, Nanchang University, Nanchang 330006, People's Republic of China.,Neuroradiology Laboratory, Jiangxi Province Medical Imaging Research Institute, Nanchang 330006, People's Republic of China
| | - Muhua Huang
- Department of Radiology, The First Affiliated Hospital, Nanchang University, Nanchang 330006, People's Republic of China.,Neuroradiology Laboratory, Jiangxi Province Medical Imaging Research Institute, Nanchang 330006, People's Republic of China
| | - Lin Wu
- Department of Radiology, The First Affiliated Hospital, Nanchang University, Nanchang 330006, People's Republic of China.,Neuroradiology Laboratory, Jiangxi Province Medical Imaging Research Institute, Nanchang 330006, People's Republic of China
| | - Honghan Gong
- Department of Radiology, The First Affiliated Hospital, Nanchang University, Nanchang 330006, People's Republic of China.,Neuroradiology Laboratory, Jiangxi Province Medical Imaging Research Institute, Nanchang 330006, People's Republic of China
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14
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Lee AL. Advanced Imaging of Traumatic Brain Injury. Korean J Neurotrauma 2020; 16:3-17. [PMID: 32395447 PMCID: PMC7192808 DOI: 10.13004/kjnt.2020.16.e12] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 04/14/2020] [Indexed: 11/15/2022] Open
Abstract
Traumatic brain injury (TBI) is a major health and socio-economic problem worldwide that mainly affects young adults. Neuroimaging plays a critical role in the diagnosis and evaluation of patients with TBI. Some patients with mild TBI have variable neurological symptoms. In such patients, computed tomography and magnetic resonance imaging (MRI) can present normal findings. Advanced imaging techniques, such as diffusion tensor imaging, magnetic resonance spectroscopy, perfusion weighted imaging, or functional MRI, can reveal abnormalities that are not detected using conventional imaging methods. Here, I briefly review current neuroimaging for TBI and survey advanced imaging techniques in terms of structural and functional aspects, which include a few promising areas of TBI research.
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Affiliation(s)
- A Leum Lee
- Department of Radiology, Soonchunhyang University Bucheon Hospital, Korea
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15
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Ghosts in machine learning for cognitive neuroscience: Moving from data to theory. Neuroimage 2018; 180:88-100. [DOI: 10.1016/j.neuroimage.2017.08.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 07/17/2017] [Accepted: 08/04/2017] [Indexed: 12/17/2022] Open
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16
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Time of Day Differences in Neural Reward Functioning in Healthy Young Men. J Neurosci 2017; 37:8895-8900. [PMID: 28842409 DOI: 10.1523/jneurosci.0918-17.2017] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 07/05/2017] [Accepted: 07/31/2017] [Indexed: 11/21/2022] Open
Abstract
Reward function appears to be modulated by the circadian system, but little is known about the neural basis of this interaction. Previous research suggests that the neural reward response may be different in the afternoon; however, the direction of this effect is contentious. Reward response may follow the diurnal rhythm in self-reported positive affect, peaking in the early afternoon. An alternative is that daily reward response represents a type of prediction error, with neural reward activation relatively high at times of day when rewards are unexpected (i.e., early and late in the day). The present study measured neural reward activation in the context of a validated reward task at 10.00 h, 14.00 h, and 19.00 h in healthy human males. A region of interest BOLD fMRI protocol was used to investigate the diurnal waveform of activation in reward-related brain regions. Multilevel modeling found, as expected, a highly significant quadratic time-of-day effect focusing on the left putamen (p < 0.001). Consistent with the "prediction error" hypothesis, activation was significantly higher at 10.00 h and 19.00 h compared with 14.00 h. It is provisionally concluded that the putamen may be particularly important in endogenous priming of reward motivation at different times of day, with the pattern of activation consistent with circadian-modulated reward expectancies in neural pathways (i.e., greater activation to reward stimuli at unexpected times of day). This study encourages further research into circadian modulation of reward and underscores the methodological importance of accounting for time of day in fMRI protocols.SIGNIFICANCE STATEMENT This is one of the first studies to use a repeated-measures imaging procedure to explore the diurnal rhythm of reward activation. Although self-reported reward (most often operationalized as positive affect) peaks in the afternoon, the present findings indicate that neural activation is lowest at this time. We conclude that the diurnal neural activation pattern may reflect a prediction error of the brain, where rewards at unexpected times (10.00 h and 19.00 h) elicit higher activation in reward brain regions than at expected (14.00 h) times. These data also have methodological significance, suggesting that there may be a time of day influence, which should be accounted for in neural reward studies.
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17
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Cohen-Adad J. Functional Magnetic Resonance Imaging of the Spinal Cord: Current Status and Future Developments. Semin Ultrasound CT MR 2017; 38:176-186. [DOI: 10.1053/j.sult.2016.07.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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18
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Tal Z, Geva R, Amedi A. Positive and Negative Somatotopic BOLD Responses in Contralateral Versus Ipsilateral Penfield Homunculus. Cereb Cortex 2017; 27:962-980. [PMID: 28168279 PMCID: PMC6093432 DOI: 10.1093/cercor/bhx024] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 01/17/2017] [Indexed: 11/20/2022] Open
Abstract
One of the basic properties of sensory cortices is their topographical organization. Most imaging studies explored this organization using the positive blood oxygenation level-dependent (BOLD) signal. Here, we studied the topographical organization of both positive and negative BOLD in contralateral and ipsilateral primary somatosensory cortex (S1). Using phase-locking mapping methods, we verified the topographical organization of contralateral S1, and further showed that different body segments elicit pronounced negative BOLD responses in both hemispheres. In the contralateral hemisphere, we found a sharpening mechanism in which stimulation of a given body segment triggered a gradient of activation with a significant deactivation in more remote areas. In the ipsilateral cortex, deactivation was not only located in the homolog area of the stimulated parts but rather was widespread across many parts of S1. Additionally, analysis of resting-state functional magnetic resonance imaging signal showed a gradient of connectivity to the neighboring contralateral body parts as well as to the ipsilateral homologous area for each body part. Taken together, our results indicate a complex pattern of baseline and activity-dependent responses in the contralateral and ipsilateral sides. Both primary sensory areas were characterized by unique negative BOLD responses, suggesting that they are an important component in topographic organization of sensory cortices.
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Affiliation(s)
- Zohar Tal
- Department of Medical Neurobiology, Institute of Medical Research Israel – Canada (IMRIC), Faculty of Medicine
| | - Ran Geva
- Department of Medical Neurobiology, Institute of Medical Research Israel – Canada (IMRIC), Faculty of Medicine
| | - Amir Amedi
- Department of Medical Neurobiology, Institute of Medical Research Israel – Canada (IMRIC), Faculty of Medicine
- The Edmond and Lily Safra Center for Brain Science (ELSC)
- Program of Cognitive Science, The Hebrew University of Jerusalem, Jerusalem 91220, Israel
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19
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Gervois P, Wolfs E, Ratajczak J, Dillen Y, Vangansewinkel T, Hilkens P, Bronckaers A, Lambrichts I, Struys T. Stem Cell-Based Therapies for Ischemic Stroke: Preclinical Results and the Potential of Imaging-Assisted Evaluation of Donor Cell Fate and Mechanisms of Brain Regeneration. Med Res Rev 2016; 36:1080-1126. [DOI: 10.1002/med.21400] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 05/27/2016] [Accepted: 06/17/2016] [Indexed: 12/15/2022]
Affiliation(s)
- Pascal Gervois
- Morphology Research Group, Biomedical Research Institute, Hasselt University; Campus Diepenbeek; Bioville Diepenbeek Belgium
| | - Esther Wolfs
- Morphology Research Group, Biomedical Research Institute, Hasselt University; Campus Diepenbeek; Bioville Diepenbeek Belgium
| | - Jessica Ratajczak
- Morphology Research Group, Biomedical Research Institute, Hasselt University; Campus Diepenbeek; Bioville Diepenbeek Belgium
| | - Yörg Dillen
- Morphology Research Group, Biomedical Research Institute, Hasselt University; Campus Diepenbeek; Bioville Diepenbeek Belgium
| | - Tim Vangansewinkel
- Morphology Research Group, Biomedical Research Institute, Hasselt University; Campus Diepenbeek; Bioville Diepenbeek Belgium
| | - Petra Hilkens
- Morphology Research Group, Biomedical Research Institute, Hasselt University; Campus Diepenbeek; Bioville Diepenbeek Belgium
| | - Annelies Bronckaers
- Morphology Research Group, Biomedical Research Institute, Hasselt University; Campus Diepenbeek; Bioville Diepenbeek Belgium
| | - Ivo Lambrichts
- Morphology Research Group, Biomedical Research Institute, Hasselt University; Campus Diepenbeek; Bioville Diepenbeek Belgium
| | - Tom Struys
- Morphology Research Group, Biomedical Research Institute, Hasselt University; Campus Diepenbeek; Bioville Diepenbeek Belgium
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20
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Shakir A, Aksoy D, Mlynash M, Harris OA, Albers GW, Hirsch KG. Prognostic Value of Quantitative Diffusion-Weighted MRI in Patients with Traumatic Brain Injury. J Neuroimaging 2015; 26:103-8. [DOI: 10.1111/jon.12286] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 07/09/2015] [Indexed: 11/29/2022] Open
Affiliation(s)
- Afaaf Shakir
- Stanford University School of Medicine; Stanford CA
| | - Didem Aksoy
- Stanford University School of Medicine, Department of Radiology; Stanford Stroke Center; Stanford CA
| | - Michael Mlynash
- Stanford University School of Medicine, Department of Neurology; Stanford Stroke Center; Stanford CA
| | - Odette A. Harris
- Stanford University School of Medicine; Department of Neurosurgery; Stanford CA
| | - Gregory W. Albers
- Stanford University School of Medicine, Department of Neurology, Director; Stanford Stroke Center; Stanford CA
| | - Karen G. Hirsch
- Stanford University School of Medicine, Department of Neurology, Director; Neurocritical Care; Stanford CA
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21
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Cerebral hyperperfusion and decreased cerebrovascular reactivity correlate with neurologic disease severity in MELAS. Mitochondrion 2015; 22:66-74. [DOI: 10.1016/j.mito.2015.03.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 02/17/2015] [Accepted: 03/06/2015] [Indexed: 12/19/2022]
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22
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Veldsman M, Cumming T, Brodtmann A. Beyond BOLD: optimizing functional imaging in stroke populations. Hum Brain Mapp 2014; 36:1620-36. [PMID: 25469481 DOI: 10.1002/hbm.22711] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 11/14/2014] [Accepted: 11/25/2014] [Indexed: 12/11/2022] Open
Abstract
Blood oxygenation level-dependent (BOLD) signal changes are often assumed to directly reflect neural activity changes. Yet the real relationship is indirect, reliant on numerous assumptions, and subject to several sources of noise. Deviations from the core assumptions of BOLD contrast functional magnetic resonance imaging (fMRI), and their implications, have been well characterized in healthy populations, but are frequently neglected in stroke populations. In addition to conspicuous local structural and vascular changes after stroke, there are many less obvious challenges in the imaging of stroke populations. Perilesional ischemic changes, remodeling in regions distant to lesion sites, and diffuse perfusion changes all complicate interpretation of BOLD signal changes in standard fMRI protocols. Most stroke patients are also older than the young populations on which assumptions of neurovascular coupling and the typical analysis pipelines are based. We present a review of the evidence to show that the basic assumption of neurovascular coupling on which BOLD-fMRI relies does not capture the complex changes arising from stroke, both pathological and recovery related. As a result, estimating neural activity using the canonical hemodynamic response function is inappropriate in a number of contexts. We review methods designed to better estimate neural activity in stroke populations. One promising alternative to event-related fMRI is a resting-state-derived functional connectivity approach. Resting-state fMRI is well suited to stroke populations because it makes no performance demands on patients and is capable of revealing network-based pathology beyond the lesion site.
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Affiliation(s)
- Michele Veldsman
- The Florey Institute for Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
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23
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Wintermark M, Sanelli PC, Anzai Y, Tsiouris AJ, Whitlow CT. Imaging evidence and recommendations for traumatic brain injury: advanced neuro- and neurovascular imaging techniques. AJNR Am J Neuroradiol 2014; 36:E1-E11. [PMID: 25424870 DOI: 10.3174/ajnr.a4181] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
SUMMARY Neuroimaging plays a critical role in the evaluation of patients with traumatic brain injury, with NCCT as the first-line of imaging for patients with traumatic brain injury and MR imaging being recommended in specific settings. Advanced neuroimaging techniques, including MR imaging DTI, blood oxygen level-dependent fMRI, MR spectroscopy, perfusion imaging, PET/SPECT, and magnetoencephalography, are of particular interest in identifying further injury in patients with traumatic brain injury when conventional NCCT and MR imaging findings are normal, as well as for prognostication in patients with persistent symptoms. These advanced neuroimaging techniques are currently under investigation in an attempt to optimize them and substantiate their clinical relevance in individual patients. However, the data currently available confine their use to the research arena for group comparisons, and there remains insufficient evidence at the time of this writing to conclude that these advanced techniques can be used for routine clinical use at the individual patient level. TBI imaging is a rapidly evolving field, and a number of the recommendations presented will be updated in the future to reflect the advances in medical knowledge.
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Affiliation(s)
- M Wintermark
- From the Division of Neuroradiology (M.W.), Stanford University, Palo Alto, California
| | - P C Sanelli
- Department of Radiology (P.C.S.), North Shore-LIJ Health System, Manhasset, New York
| | - Y Anzai
- Department of Radiology (Y.A.), University of Washington, Seattle, Washington
| | - A J Tsiouris
- Department of Radiology (A.J.T.), Weill Cornell Medical College, New York-Presbyterian Hospital, New York, New York
| | - C T Whitlow
- Department of Radiology and Translational Science Institute (C.T.W.), Wake Forest School of Medicine, Winston-Salem, North Carolina
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24
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Vigneau‐Roy N, Bernier M, Descoteaux M, Whittingstall K. Regional variations in vascular density correlate with resting-state and task-evoked blood oxygen level-dependent signal amplitude. Hum Brain Mapp 2014; 35:1906-20. [PMID: 23843266 PMCID: PMC6869285 DOI: 10.1002/hbm.22301] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 02/12/2013] [Accepted: 03/18/2013] [Indexed: 12/24/2022] Open
Abstract
Functional magnetic resonance imaging (fMRI) has become one of the primary tools used for noninvasively measuring brain activity in humans. For the most part, the blood oxygen level-dependent (BOLD) contrast is used, which reflects the changes in hemodynamics associated with active brain tissue. The main advantage of the BOLD signal is that it is relatively easy to measure and thus is often used as a proxy for comparing brain function across population groups (i.e., control vs. patient). However, it is particularly weighted toward veins whose structural architecture is known to vary considerably across the brain. This makes it difficult to interpret whether differences in BOLD between cortical areas reflect true differences in neural activity or vascular structure. We therefore investigated how regional variations of vascular density (VAD) relate to the amplitude of resting-state and task-evoked BOLD signals. To address this issue, we first developed an automated method for segmenting veins in images acquired with susceptibility-weighted imaging, allowing us to visualize the venous vascular tree across the brain. In 19 healthy subjects, we then applied voxel-based morphometry (VBM) to T1-weighted images and computed regional measures of gray matter density (GMD). We found that, independent of spatial scale, regional variations in resting-state and task-evoked fMRI amplitudes were better correlated to VAD compared to GMD. Using a general linear model (GLM), it was observed that the bulk of regional variance in resting-state activity could be modeled by VAD. Cortical areas whose resting-state activity was most suppressed by VAD correction included Cuneus, Precuneus, Culmen, and BA 9, 10, and 47. Taken together, our results suggest that resting-state BOLD signals are significantly related to the underlying structure of the brain vascular system. Calibrating resting BOLD activity by venous structure may result in a more accurate interpretation of differences observed between cortical areas and/or individuals.
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Affiliation(s)
- Nicolas Vigneau‐Roy
- Department of Nuclear Medicine and RadiobiologyFaculty of Medicine and Health ScienceSherbrooke Molecular Imaging CenterUniversité de SherbrookeSherbrookeQuebecCanada
| | - Michaël Bernier
- Department of Nuclear Medicine and RadiobiologyFaculty of Medicine and Health ScienceSherbrooke Molecular Imaging CenterUniversité de SherbrookeSherbrookeQuebecCanada
- Department of Diagnostic RadiologyFaculty of Medicine and Health ScienceUniversité de SherbrookeSherbrookeQuebecCanada
| | - Maxime Descoteaux
- Computer Science DepartmentFaculty of ScienceUniversité de Sherbrooke, Université, SherbrookeQuebecCanada
| | - Kevin Whittingstall
- Department of Nuclear Medicine and RadiobiologyFaculty of Medicine and Health ScienceSherbrooke Molecular Imaging CenterUniversité de SherbrookeSherbrookeQuebecCanada
- Department of Diagnostic RadiologyFaculty of Medicine and Health ScienceUniversité de SherbrookeSherbrookeQuebecCanada
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25
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Boubela RN, Kalcher K, Nasel C, Moser E. Scanning fast and slow: current limitations of 3 Tesla functional MRI and future potential. FRONTIERS IN PHYSICS 2014; 2:00001. [PMID: 28164083 PMCID: PMC5291320 DOI: 10.3389/fphy.2014.00001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Functional MRI at 3T has become a workhorse for the neurosciences, e.g., neurology, psychology, and psychiatry, enabling non-invasive investigation of brain function and connectivity. However, BOLD-based fMRI is a rather indirect measure of brain function, confounded by physiology related signals, e.g., head or brain motion, brain pulsation, blood flow, intermixed with susceptibility differences close or distant to the region of neuronal activity. Even though a plethora of preprocessing strategies have been published to address these confounds, their efficiency is still under discussion. In particular, physiological signal fluctuations closely related to brain supply may mask BOLD signal changes related to "true" neuronal activation. Here we explore recent technical and methodological advancements aimed at disentangling the various components, employing fast multiband vs. standard EPI, in combination with fast temporal ICA. Our preliminary results indicate that fast (TR <0.5 s) scanning may help to identify and eliminate physiologic components, increasing tSNR and functional contrast. In addition, biological variability can be studied and task performance better correlated to other measures. This should increase specificity and reliability in fMRI studies. Furthermore, physiological signal changes during scanning may then be recognized as a source of information rather than a nuisance. As we are currently still undersampling the complexity of the brain, even at a rather coarse macroscopic level, we should be very cautious in the interpretation of neuroscientific findings, in particular when comparing different groups (e.g., age, sex, medication, pathology, etc.). From a technical point of view our goal should be to sample brain activity at layer specific resolution with low TR, covering as much of the brain as possible without violating SAR limits. We hope to stimulate discussion toward a better understanding and a more quantitative use of fMRI.
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Affiliation(s)
- Roland N. Boubela
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
- MR Center of Excellence, Medical University of Vienna, Vienna, Austria
| | - Klaudius Kalcher
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
- MR Center of Excellence, Medical University of Vienna, Vienna, Austria
| | - Christian Nasel
- MR Center of Excellence, Medical University of Vienna, Vienna, Austria
- Department of Radiology, State Clinical Center Danube District, Tulln, Austria
| | - Ewald Moser
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
- MR Center of Excellence, Medical University of Vienna, Vienna, Austria
- Brain Behavior Laboratory, Department Psychiatry, University of Pennsylvania Medical Center, Philadelphia, PA, USA
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26
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Spatiotemporal hemodynamic response functions derived from physiology. J Theor Biol 2014; 347:118-36. [PMID: 24398024 DOI: 10.1016/j.jtbi.2013.12.027] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 11/28/2013] [Accepted: 12/27/2013] [Indexed: 12/12/2022]
Abstract
Probing neural activity with functional magnetic resonance imaging (fMRI) relies upon understanding the hemodynamic response to changes in neural activity. Although existing studies have extensively characterized the temporal hemodynamic response, less is understood about the spatial and spatiotemporal hemodynamic responses. This study systematically characterizes the spatiotemporal response by deriving the hemodynamic response due to a short localized neural drive, i.e., the spatiotemporal hemodynamic response function (stHRF) from a physiological model of hemodynamics based on a poroelastic model of cortical tissue. In this study, the model's boundary conditions are clarified and a resulting nonlinear hemodynamic wave equation is derived. From this wave equation, damped linear hemodynamic waves are predicted from the stHRF. The main features of these waves depend on two physiological parameters: wave propagation speed, which depends on mean cortical stiffness, and damping which depends on effective viscosity. Some of these predictions were applied and validated in a companion study (Aquino et al., 2012). The advantages of having such a theory for the stHRF include improving the interpretation of spatiotemporal dynamics in fMRI data; improving estimates of neural activity with fMRI spatiotemporal deconvolution; and enabling wave interactions between hemodynamic waves to be predicted and exploited to improve the signal to noise ratio of fMRI.
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Dodd GT, Worth AA, Hodkinson DJ, Srivastava RK, Lutz B, Williams SR, Luckman SM. Central functional response to the novel peptide cannabinoid, hemopressin. Neuropharmacology 2013; 71:27-36. [PMID: 23542442 DOI: 10.1016/j.neuropharm.2013.03.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 02/19/2013] [Accepted: 03/07/2013] [Indexed: 02/05/2023]
Abstract
Hemopressin is the first peptide ligand to be described for the CB₁ cannabinoid receptor. Hemopressin acts as an inverse agonist in vivo and can cross the blood-brain barrier to both inhibit appetite and induce antinociception. Despite being highly effective, synthetic CB₁ inverse agonists are limited therapeutically due to unwanted, over dampening of central reward pathways. However, hemopressin appears to have its effect on appetite by affecting satiety rather than reward, suggesting an alternative mode of action which might avoid adverse side effects. Here, to resolve the neuronal circuitry mediating hemopressin's actions, we have combined blood-oxygen-level-dependent, pharmacological-challenge magnetic resonance imaging with c-Fos functional activity mapping to compare brain regions responsive to systemic administration of hemopressin and the synthetic CB₁ inverse agonist, AM251. Using these complementary methods, we demonstrate that hemopressin activates distinct neuronal substrates within the brain, focused mainly on the feeding-related circuits of the mediobasal hypothalamus and in nociceptive regions of the periaqueductal grey (PAG) and dorsal raphe (DR). In contrast to AM251, there is a distinct lack of activation of the brain reward centres, such as the ventral tegmental area, nucleus accumbens and orbitofrontal cortex, which normally form a functional activity signature for the central action of synthetic CB₁ receptor inverse agonists. Thus, hemopressin modulates the function of key feeding-related brain nuclei of the mediobasal hypothalamus, and descending pain pathways of the PAG and DR, and not higher limbic structures. Thus, hemopressin may offer behaviourally selective effects on nociception and appetite, without engaging reward pathways.
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Affiliation(s)
- Garron T Dodd
- Faculty of Life Sciences, University of Manchester, AV Hill Building, Oxford Road, Manchester M13 9PT, UK.
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28
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Variations in the temporal pattern of perforant pathway stimulation control the activity in the mesolimbic pathway. Neuroimage 2013; 64:43-60. [DOI: 10.1016/j.neuroimage.2012.09.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 08/31/2012] [Accepted: 09/01/2012] [Indexed: 11/23/2022] Open
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29
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Schäfer K, Blankenburg F, Kupers R, Grüner JM, Law I, Lauritzen M, Larsson HB. Negative BOLD signal changes in ipsilateral primary somatosensory cortex are associated with perfusion decreases and behavioral evidence for functional inhibition. Neuroimage 2012; 59:3119-27. [DOI: 10.1016/j.neuroimage.2011.11.085] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Revised: 11/21/2011] [Accepted: 11/22/2011] [Indexed: 11/25/2022] Open
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30
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Shitara H, Shinozaki T, Takagishi K, Honda M, Hanakawa T. Time course and spatial distribution of fMRI signal changes during single-pulse transcranial magnetic stimulation to the primary motor cortex. Neuroimage 2011; 56:1469-79. [PMID: 21396457 DOI: 10.1016/j.neuroimage.2011.03.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2010] [Revised: 02/27/2011] [Accepted: 03/03/2011] [Indexed: 11/25/2022] Open
Abstract
Simultaneous transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) may advance the understanding of neurophysiological mechanisms of TMS. However, it remains unclear if TMS induces fMRI signal changes consistent with the standard hemodynamic response function (HRF) in both local and remote regions. To address this issue, we delivered single-pulse TMS to the left M1 during simultaneous recoding of electromyography and time-resolved fMRI in 36 healthy participants. First, we examined the time-course of fMRI signals during supra- and subthreshold single-pulse TMS in comparison with those during voluntary right hand movement and electrical stimulation to the right median nerve (MNS). All conditions yielded comparable time-courses of fMRI signals, showing that HRF would generally provide reasonable estimates for TMS-evoked activity in the motor areas. However, a clear undershoot following the signal peak was observed only during subthreshold TMS in the left M1, suggesting a small but meaningful difference between the locally and remotely TMS-evoked activities. Second, we compared the spatial distribution of activity across the conditions. Suprathreshold TMS-evoked activity overlapped not only with voluntary movement-related activity but also partially with MNS-induced activity, yielding overlapped areas of activity around the stimulated M1. The present study has provided the first experimental evidence that motor area activity during suprathreshold TMS likely includes activity for processing of muscle afferents. A method should be developed to control the effects of muscle afferents for fair interpretation of TMS-induced motor area activity during suprathreshold TMS to M1.
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Affiliation(s)
- H Shitara
- Department of Functional Brain Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Japan
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31
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Yin H, Liu Y, Li M, Hu D. Hemodynamic observation and spike recording explain the neuronal deactivation origin of negative response in rat. Brain Res Bull 2010; 84:157-62. [PMID: 21147201 DOI: 10.1016/j.brainresbull.2010.12.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 12/06/2010] [Accepted: 12/06/2010] [Indexed: 11/17/2022]
Abstract
Functional brain research has shown that the cerebral response to an external stimulus contains positive and negative signals. The positive signals are well studied, whereas explanations for the negative signals remain controversial. In this study, negative response was investigated using intrinsic optical imaging (OI) and a multi-electrode array (MEA) in rat with a hindlimb stimulus. The negative hemodynamic response (NHR) signals were measured by OI in contralateral and ipsilateral primary somatosensory forelimb, primary and secondary motor, and primary and secondary visual cortex areas. The spatial presentation of NHR signals showed diversity across subjects under an identical experimental paradigm. The NHR signals in different cortical areas had similar time courses but were in the opposite direction of the positive hemodynamic response (PHR) signals, and the amplitude of NHR signals was significantly smaller than that of PHR signals. Electrophysiological recording using an MEA in an NHR cortex area showed that spike activities decreased significantly during external stimulation, suggesting that the neuronal activity reduction has a strong relationship with the NHR signals. Our results highlight the importance of a negative response in a hemodynamics-based interpretation of neuroimaging signals.
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Affiliation(s)
- Haibing Yin
- Department of Automatic Control, College of Mechatronics and Automation, National University of Defense Technology, Changsha, Hunan 410073, PR China
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32
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Drysdale P, Huber J, Robinson P, Aquino K. Spatiotemporal BOLD dynamics from a poroelastic hemodynamic model. J Theor Biol 2010; 265:524-34. [DOI: 10.1016/j.jtbi.2010.05.026] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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33
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Abstract
AbstractAnderson's meta-analysis of fMRI data is subject to a potential confound. Areas identified as active may make no functional contribution to the task being studied, or may indicate regions involved in the coordination of functional networks rather than information processing per se. I suggest a way in which fMRI adaptation studies might provide a useful test between these alternatives.
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Abstract
We address here the use of EEG and fMRI, and their combination, in order to estimate the full spatiotemporal patterns of activity on the cortical surface in the absence of any particular assumptions on this activity such as stimulation times. For handling such a high-dimension inverse problem, we propose the use of (1) a global forward model of how these measures are functions of the “neural activity” of a large number of sources distributed on the cortical surface, formalized as a dynamical system, and (2) adaptive filters, as a natural solution to solve this inverse problem iteratively along the temporal dimension. This estimation framework relies on realistic physiological models, uses EEG and fMRI in a symmetric manner, and takes into account both their temporal and spatial information. We use the Kalman filter and smoother to perform such an estimation on realistic artificial data and demonstrate that the algorithm can handle the high dimensionality of these data and that it succeeds in solving this inverse problem, combining efficiently the information provided by the two modalities (this information being naturally predominantly temporal for EEG and spatial for fMRI). It performs particularly well in reconstructing a random temporally and spatially smooth activity spread over the cortex. The Kalman filter and smoother show some limitations, however, which call for the development of more specific adaptive filters. First, they do not cope well with the strong nonlinearity in the model that is necessary for an adequate description of the relation between cortical electric activities and the metabolic demand responsible for fMRI signals. Second, they fail to estimate a sparse activity (i.e., presenting sharp peaks at specific locations and times). Finally their computational cost remains high. We use schematic examples to explain these limitations and propose further developments of our method to overcome them.
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Affiliation(s)
- Thomas Deneux
- Odyssée Team, Ecole Normale Supérieure, Département d'Informatique, 75005 Paris, France; and Weizmann Institute of Science, Department of Neurobiology, 76100 Rehovot, Israel
| | - Olivier Faugeras
- NeuroMathComp Team, Institut National de Recherche en Informatique et Automatique, France; and Ecole Normale Supérieure, Département d'Informatique, 75005 Paris, France
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36
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Strelnikov K. Neuroimaging and neuroenergetics: Brain activations as information-driven reorganization of energy flows. Brain Cogn 2010; 72:449-56. [PMID: 20092923 DOI: 10.1016/j.bandc.2009.12.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Revised: 09/18/2009] [Accepted: 12/26/2009] [Indexed: 10/19/2022]
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37
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Dodd GT, Williams SR, Luckman SM. Functional magnetic resonance imaging and c-Fos mapping in rats following a glucoprivic dose of 2-deoxy-D-glucose. J Neurochem 2010; 113:1123-32. [PMID: 20236391 DOI: 10.1111/j.1471-4159.2010.06671.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The glucose analogue, 2-deoxy-D-glucose (2-DG) is an inhibitor of glycolysis and, when administered systemically or centrally, induces glucoprivation leading to counter-regulatory responses, including increased feeding behaviour. Investigations into how the brain responds to glucoprivation could have important therapeutic potential, as disruptions or defects in the defence of the brain's 'glucostatic' circuitry may be partly responsible for pathological conditions resulting from diabetes and obesity. To define the 'glucostat' brain circuitry further we have combined blood-oxygen-level-dependent pharmacological-challenge magnetic resonance imaging (phMRI) with whole-brain c-Fos functional activity mapping to characterise brain regions responsive to an orexigenic dose of 2-DG [200 mg/kg; subcutaneous (s.c.)]. For phMRI, rats were imaged using a T(2)*-weighted gradient echo in a 7T magnet for 60 min under alpha-chloralose anaesthesia, whereas animals for immunohistochemistry were unanaesthetised and freely behaving. These complementary methods demonstrated functional brain activity in a number of previously characterised glucose-sensing brain regions such as those in the hypothalamus and brainstem following administration of 2-DG compared with vehicle. As the study mapped whole-brain functional responses, it also identified the orbitofrontal cortex and striatum (nucleus accumbens and ventral pallidum) as novel 2-DG-responsive brain regions. These regions make up a corticostriatal connection with the hypothalamus, by which aspects of motivation, salience and reward can impinge on the hypothalamic control of feeding behaviour. This study, therefore, provides further evidence for a common integrated circuit involved in the induction of feeding behaviour, and illustrates the valuable potential of phMRI in investigating central pharmacological actions.
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Affiliation(s)
- Garron T Dodd
- Faculty of Life Sciences, AV Hill Building, University of Manchester, Oxford Road, Manchester, UK
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38
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Lippert MT, Steudel T, Ohl F, Logothetis NK, Kayser C. Coupling of neural activity and fMRI-BOLD in the motion area MT. Magn Reson Imaging 2010; 28:1087-94. [PMID: 20171035 DOI: 10.1016/j.mri.2009.12.028] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2009] [Revised: 12/16/2009] [Accepted: 12/21/2009] [Indexed: 12/28/2022]
Abstract
The fMRI-BOLD contrast is widely used to study the neural basis of sensory perception and cognition. This signal, however, reflects neural activity only indirectly, and the detailed mechanisms of neurovascular coupling and the neurophysiological correlates of the BOLD signal remain debated. Here we investigate the coupling of BOLD and electrophysiological signals in the motion area MT of the macaque monkey by simultaneously recording both signals. Our results demonstrate that a prominent neuronal response property of area MT, so-called motion opponency, can be used to induce dissociations of BOLD and neuronal firing. During the presentation of a stimulus optimally driving the local neurons, both field potentials [local field potentials (LFPs)] and spiking activity [multi-unit activity (MUA)] correlated with the BOLD signal. When introducing the motion opponency stimulus, however, correlations of MUA with BOLD were much reduced, and LFPs were a much better predictor of the BOLD signal than MUA. In addition, for a subset of recording sites we found positive BOLD and LFP responses in the presence of decreases in MUA, regardless of the stimulus used. Together, these results demonstrate that correlations between BOLD and MUA are dependent on the particular site and stimulus paradigm, and foster the notion that the fMRI-BOLD signal reflects local dendrosomatic processing and synaptic activity rather than principal neuron spiking responses.
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Affiliation(s)
- Michael T Lippert
- Max Planck Institute for Biological Cybernetics, Spemannstrasse 38, Tübingen, Germany.
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39
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Van Vugt DA. Brain imaging studies of appetite in the context of obesity and the menstrual cycle. Hum Reprod Update 2009; 16:276-92. [DOI: 10.1093/humupd/dmp051] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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40
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Simultaneous Dynamic Blood Oxygen Level-Dependent Magnetic Resonance Imaging of Foot and Calf Muscles. Invest Radiol 2009; 44:741-7. [DOI: 10.1097/rli.0b013e3181b248f9] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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41
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Rosa MJ, Kilner J, Blankenburg F, Josephs O, Penny W. Estimating the transfer function from neuronal activity to BOLD using simultaneous EEG-fMRI. Neuroimage 2009; 49:1496-509. [PMID: 19778619 PMCID: PMC2793371 DOI: 10.1016/j.neuroimage.2009.09.011] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Revised: 09/03/2009] [Accepted: 09/11/2009] [Indexed: 11/29/2022] Open
Abstract
Previous studies using combined electrical and hemodynamic measurements of brain activity, such as EEG and (BOLD) fMRI, have yielded discrepant results regarding the relationship between neuronal activity and the associated BOLD response. In particular, some studies suggest that this link, or transfer function, depends on the frequency content of neuronal activity, while others suggest that total neuronal power accounts for the changes in BOLD. Here we explored this dependency by comparing different frequency-dependent and -independent transfer functions, using simultaneous EEG-fMRI. Our results suggest that changes in BOLD are indeed associated with changes in the spectral profile of neuronal activity and that these changes do not arise from one specific spectral band. Instead they result from the dynamics of the various frequency components together, in particular, from the relative power between high and low frequencies. Understanding the nature of the link between neuronal activity and BOLD plays a crucial role in improving the interpretability of BOLD images as well as on the design of more robust and realistic models for the integration of EEG and fMRI.
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Affiliation(s)
- M J Rosa
- Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, University College London, 12 Queen Square, WC1N 3BG, UK.
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42
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Huppert TJ, Allen MS, Diamond SG, Boas DA. Estimating cerebral oxygen metabolism from fMRI with a dynamic multicompartment Windkessel model. Hum Brain Mapp 2009; 30:1548-67. [PMID: 18649348 DOI: 10.1002/hbm.20628] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Stimulus evoked changes in cerebral blood flow, volume, and oxygenation arise from responses to underlying neuronally mediated changes in vascular tone and cerebral oxygen metabolism. There is increasing evidence that the magnitude and temporal characteristics of these evoked hemodynamic changes are additionally influenced by the local properties of the vasculature including the levels of baseline cerebral blood flow, volume, and blood oxygenation. In this work, we utilize a physiologically motivated vascular model to describe the temporal characteristics of evoked hemodynamic responses and their expected relationships to the structural and biomechanical properties of the underlying vasculature. We use this model in a temporal curve-fitting analysis of the high-temporal resolution functional MRI data to estimate the underlying cerebral vascular and metabolic responses in the brain. We present evidence for the feasibility of our model-based analysis to estimate transient changes in the cerebral metabolic rate of oxygen (CMRO(2)) in the human motor cortex from combined pulsed arterial spin labeling (ASL) and blood oxygen level dependent (BOLD) MRI. We examine both the numerical characteristics of this model and present experimental evidence to support this model by examining concurrently measured ASL, BOLD, and near-infrared spectroscopy to validate the calculated changes in underlying CMRO(2).
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Affiliation(s)
- Theodore J Huppert
- Department of Radiology, University of Pittsburgh, UPMC Presbyterian, 200 Lothrop St., Pittsburgh, PA 15213, USA.
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43
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Lee SD, Koh DW, Kwon KW, Lee HJ, Lang Y, Shin HC, Kim BM. Hemodynamic Responses of Rat Brain Measured by Near-infrared Spectroscopy During Various Whisker Stimulations. ACTA ACUST UNITED AC 2009. [DOI: 10.3807/josk.2009.13.1.166] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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44
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Van der Linden A, Van Meir V, Boumans T, Poirier C, Balthazart J. MRI in small brains displaying extensive plasticity. Trends Neurosci 2009; 32:257-66. [PMID: 19307029 DOI: 10.1016/j.tins.2009.01.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Revised: 12/18/2008] [Accepted: 01/06/2009] [Indexed: 01/28/2023]
Abstract
Manganese-enhanced magnetic resonance imaging (ME-MRI), blood oxygen-level-dependent functional MRI (BOLD fMRI) and diffusion tensor imaging (DTI) can now be applied to animal species as small as mice or songbirds. These techniques confirmed previous findings but are also beginning to reveal new phenomena that were difficult or impossible to study previously. These imaging techniques will lead to major technical and conceptual advances in systems neurosciences. We illustrate these new developments with studies of the song control and auditory systems in songbirds, a spatially organized neuronal circuitry that mediates the acquisition, production and perception of complex learned vocalizations. This neural system is an outstanding model for studying vocal learning, brain steroid hormone action, brain plasticity and lateralization of brain function.
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45
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Keller CJ, Cash SS, Narayanan S, Wang C, Kuzniecky R, Carlson C, Devinsky O, Thesen T, Doyle W, Sassaroli A, Boas DA, Ulbert I, Halgren E. Intracranial microprobe for evaluating neuro-hemodynamic coupling in unanesthetized human neocortex. J Neurosci Methods 2009; 179:208-18. [PMID: 19428529 DOI: 10.1016/j.jneumeth.2009.01.036] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Revised: 01/27/2009] [Accepted: 01/29/2009] [Indexed: 10/21/2022]
Abstract
Measurement of the blood-oxygen-level dependent (BOLD) response with fMRI has revolutionized cognitive neuroscience and is increasingly important in clinical care. The BOLD response reflects changes in deoxy-hemoglobin concentration, blood volume, and blood flow. These hemodynamic changes ultimately result from neuronal firing and synaptic activity, but the linkage between these domains is complex, poorly understood, and may differ across species, cortical areas, diseases, and cognitive states. We describe here a technique that can measure neural and hemodynamic changes simultaneously from cortical microdomains in waking humans. We utilize a "laminar optode," a linear array of microelectrodes for electrophysiological measures paired with a micro-optical device for hemodynamic measurements. Optical measurements include laser Doppler to estimate cerebral blood flow as well as point spectroscopy to estimate oxy- and deoxy-hemoglobin concentrations. The microelectrode array records local field potential gradients (PG) and multi-unit activity (MUA) at 24 locations spanning the cortical depth, permitting estimation of population trans-membrane current flows (Current Source Density, CSD) and population cell firing in each cortical lamina. Comparison of the laminar CSD/MUA profile with the origins and terminations of cortical circuits allows activity in specific neuronal circuits to be inferred and then directly compared to hemodynamics. Access is obtained in epileptic patients during diagnostic evaluation for surgical therapy. Validation tests with relatively well-understood manipulations (EKG, breath-holding, cortical electrical stimulation) demonstrate the expected responses. This device can provide a new and robust means for obtaining detailed, quantitative data for defining neurovascular coupling in awake humans.
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Affiliation(s)
- Corey J Keller
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA.
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46
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Lee JH, Marzelli M, Jolesz FA, Yoo SS. Automated classification of fMRI data employing trial-based imagery tasks. Med Image Anal 2009; 13:392-404. [PMID: 19233711 DOI: 10.1016/j.media.2009.01.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2007] [Revised: 11/19/2008] [Accepted: 01/09/2009] [Indexed: 10/21/2022]
Abstract
Automated interpretation and classification of functional MRI (fMRI) data is an emerging research field that enables the characterization of underlying cognitive processes with minimal human intervention. In this work, we present a method for the automated classification of human thoughts reflected on a trial-based paradigm using fMRI with a significantly shortened data acquisition time (less than one minute). Based on our preliminary experience with various cognitive imagery tasks, six characteristic thoughts were chosen as target tasks for the present work: right-hand motor imagery, left-hand motor imagery, right foot motor imagery, mental calculation, internal speech/word generation, and visual imagery. These six tasks were performed by five healthy volunteers and functional images were obtained using a T(*)(2)-weighted echo planar imaging (EPI) sequence. Feature vectors from activation maps, necessary for the classification of neural activity, were automatically extracted from the regions that were consistently and exclusively activated for a given task during the training process. Extracted feature vectors were classified using the support vector machine (SVM) algorithm. Parameter optimization, using a k-fold cross validation scheme, allowed the successful recognition of the six different categories of administered thought tasks with an accuracy of 74.5% (mean)+/-14.3% (standard deviation) across all five subjects. Our proposed study for the automated classification of fMRI data may be utilized in further investigations to monitor/identify human thought processes and their potential link to hardware/computer control.
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Affiliation(s)
- Jong-Hwan Lee
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
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47
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Majos A, Bogorodzki P, Piatkowska-Janko E, Wolak T, Kurjata R, Stefańczyk L. Functional imaging with MR T1 contrast: a feasibility study with blood-pool contrast agent. Eur Radiol 2008; 19:898-903. [PMID: 18987862 DOI: 10.1007/s00330-008-1210-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2008] [Revised: 08/20/2008] [Accepted: 08/23/2008] [Indexed: 10/21/2022]
Abstract
The aim of this study was to prove the concept of using a long intravenous half-life blood-pool T1 contrast agent as a new functional imaging method. For each of ten healthy subjects, two dynamic magnetic resonance (MR) protocols were carried out: (1) a reference run with a typical T2* echo-planar imaging (EPI) sequence based on the blood oxygenation level-dependent (BOLD) effect and (2) a run with a T1-sensitive three-dimensional (3D) gradient-echo (GRE) sequence using cerebral blood volume (CBV) contrast after intravenous administration of a contrast agent containing a chelate of gadolinium diethylene-triamine-pentaacetate with a phosphono-oxymethyl substituent. All sequences were performed during the execution of a block-type finger-tapping paradigm. SPM5 software was used for statistical analysis. For both runs maximum activations (peak Z-score = 5.5, cluster size 3,449 voxels) were localized in the left postcentral gyrus. Visual inspection of respective signal amplitudes suggests the T1 contrast to be substantially smaller than EPI (0.5% vs 1%). A new functional imaging method with potentially smaller image artefacts due to the nature of CBV contrast and characteristics of the T1 sequence was proposed and verified.
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Affiliation(s)
- Agata Majos
- Radiology Department, Medical University of Lodz, Lodz, Poland.
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48
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Pharmacological MRI in animal models: A useful tool for 5-HT research? Neuropharmacology 2008; 55:1038-47. [DOI: 10.1016/j.neuropharm.2008.08.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2008] [Revised: 08/06/2008] [Accepted: 08/07/2008] [Indexed: 01/19/2023]
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49
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Minzenberg MJ, Fan J, New AS, Tang CY, Siever LJ. Frontolimbic structural changes in borderline personality disorder. J Psychiatr Res 2008; 42:727-33. [PMID: 17825840 PMCID: PMC2708084 DOI: 10.1016/j.jpsychires.2007.07.015] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2007] [Accepted: 07/18/2007] [Indexed: 10/22/2022]
Abstract
OBJECTIVE Frontolimbic dysfunction is observed in borderline personality disorder (BPD), with responses to emotional stimuli that are exaggerated in the amygdala and impaired in the anterior cingulate cortex (ACC). This pattern of altered function is consistent with animal models of stress responses and depression, where hypertrophic changes in the amygdala and atrophic changes in the ACC are observed. We tested the hypothesis that BPD patients exhibit gross structural changes that parallel the respective increases in amygdala activation and impairment of rostral/subgenual ACC activation. METHODS Twelve unmedicated outpatients with BPD by DSM-IV and 12 normal control (NC) subjects underwent a high-resolution T1-weighted structural MRI scan. Relative gray matter concentration (GMC) in spatially-normalized images was evaluated by standard voxel-based morphometry, with voxel-wise subject group comparisons by t test constrained to amygdala and rostral/subgenual ACC. RESULTS The BPD group was significantly higher than NC in GMC in the amygdala. In contrast, the BPD group showed significantly lower GMC than the NC group in left rostral/subgenual ACC. CONCLUSIONS This sample of BPD patients exhibits gross structural changes in gray matter in cortical and subcortical limbic regions that parallel the regional distribution of altered functional activation to emotional stimuli among these same subjects. While the histological basis for GMC changes in adult clinical populations is poorly-known at present, the observed pattern is consistent with the direction of change, in animal models of anxiety and depression, of neuronal number and/or morphological complexity in both the amygdala (where it is increased) and ACC (where it is decreased).
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Abstract
Dementia represents a heterogeneous term that has evolved to describe the behavioral syndromes associated with a variety of clinical and neuropathological changes during continuing degenerative disease of the brain. As such, there lacks a clear consensus regarding the neuropsychological and other constituent characteristics associated with various cerebrovascular changes in this disease process. But increasing this knowledge has given more insights into memory deterioration in patients suffering from Alzheimer's disease and other subtypes of dementia. The author reviews current knowledge of the physiological coupling between cerebral blood flow and metabolism in the light of state-of-the-art-imaging methods and its changes in dementia with special reference to Alzheimer's disease. Different imaging techniques are discussed with respect to their visualizing effect of biochemical, cellular, and/or structural changes in dementia. The pathophysiology of dementia in advanced age is becoming increasingly understood by revealing the underlying basis of neuropsychological changes with current imaging techniques, genetic and pathological features, which suggests that alterations of (neuro) vascular regulatory mechanisms may lead to brain dysfunction and disease. The current view is that cerebrovascular deregulation is seen as a contributor to cerebrovascular pathologies, such as stroke, but also to neurodegenerative conditions, such as Alzheimer's disease. The better understanding of these (patho) physiological mechanisms may open an approach to new interventional strategies in dementia to enhance neurovascular repair and to protect neurovascular coupling.
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