1
|
Oleson S, Cao J, Wang X, Liu Z. In vivo tracing of the ascending vagal projections to the brain with manganese enhanced magnetic resonance imaging. Front Neurosci 2023; 17:1254097. [PMID: 37781260 PMCID: PMC10540305 DOI: 10.3389/fnins.2023.1254097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 08/31/2023] [Indexed: 10/03/2023] Open
Abstract
Introduction The vagus nerve, the primary neural pathway mediating brain-body interactions, plays an essential role in transmitting bodily signals to the brain. Despite its significance, our understanding of the detailed organization and functionality of vagal afferent projections remains incomplete. Methods In this study, we utilized manganese-enhanced magnetic resonance imaging (MEMRI) as a non-invasive and in vivo method for tracing vagal nerve projections to the brainstem and assessing their functional dependence on cervical vagus nerve stimulation (VNS). Manganese chloride solution was injected into the nodose ganglion of rats, and T1-weighted MRI scans were performed at both 12 and 24 h after the injection. Results Our findings reveal that vagal afferent neurons can uptake and transport manganese ions, serving as a surrogate for calcium ions, to the nucleus tractus solitarius (NTS) in the brainstem. In the absence of VNS, we observed significant contrast enhancements of around 19-24% in the NTS ipsilateral to the injection side. Application of VNS for 4 h further promoted nerve activity, leading to greater contrast enhancements of 40-43% in the NTS. Discussion These results demonstrate the potential of MEMRI for high-resolution, activity-dependent tracing of vagal afferents, providing a valuable tool for the structural and functional assessment of the vagus nerve and its influence on brain activity.
Collapse
Affiliation(s)
- Steven Oleson
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States
| | - Jiayue Cao
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States
| | - Xiaokai Wang
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States
| | - Zhongming Liu
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States
- Department of Electrical Engineering Computer Science, University of Michigan, Ann Arbor, MI, United States
| |
Collapse
|
2
|
Fernández-Rodicio S, Ferro-Costas G, Sampedro-Viana A, Bazarra-Barreiros M, Ferreirós A, López-Arias E, Pérez-Mato M, Ouro A, Pumar JM, Mosqueira AJ, Alonso-Alonso ML, Castillo J, Hervella P, Iglesias-Rey R. Perfusion-weighted software written in Python for DSC-MRI analysis. Front Neuroinform 2023; 17:1202156. [PMID: 37593674 PMCID: PMC10431979 DOI: 10.3389/fninf.2023.1202156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 06/27/2023] [Indexed: 08/19/2023] Open
Abstract
Introduction Dynamic susceptibility-weighted contrast-enhanced (DSC) perfusion studies in magnetic resonance imaging (MRI) provide valuable data for studying vascular cerebral pathophysiology in different rodent models of brain diseases (stroke, tumor grading, and neurodegenerative models). The extraction of these hemodynamic parameters via DSC-MRI is based on tracer kinetic modeling, which can be solved using deconvolution-based methods, among others. Most of the post-processing software used in preclinical studies is home-built and custom-designed. Its use being, in most cases, limited to the institution responsible for the development. In this study, we designed a tool that performs the hemodynamic quantification process quickly and in a reliable way for research purposes. Methods The DSC-MRI quantification tool, developed as a Python project, performs the basic mathematical steps to generate the parametric maps: cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), signal recovery (SR), and percentage signal recovery (PSR). For the validation process, a data set composed of MRI rat brain scans was evaluated: i) healthy animals, ii) temporal blood-brain barrier (BBB) dysfunction, iii) cerebral chronic hypoperfusion (CCH), iv) ischemic stroke, and v) glioblastoma multiforme (GBM) models. The resulting perfusion parameters were then compared with data retrieved from the literature. Results A total of 30 animals were evaluated with our DSC-MRI quantification tool. In all the models, the hemodynamic parameters reported from the literature are reproduced and they are in the same range as our results. The Bland-Altman plot used to describe the agreement between our perfusion quantitative analyses and literature data regarding healthy rats, stroke, and GBM models, determined that the agreement for CBV and MTT is higher than for CBF. Conclusion An open-source, Python-based DSC post-processing software package that performs key quantitative perfusion parameters has been developed. Regarding the different animal models used, the results obtained are consistent and in good agreement with the physiological patterns and values reported in the literature. Our development has been built in a modular framework to allow code customization or the addition of alternative algorithms not yet implemented.
Collapse
Affiliation(s)
- Sabela Fernández-Rodicio
- Neuroimaging and Biotechnology Laboratory (NOBEL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | | | - Ana Sampedro-Viana
- Neuroimaging and Biotechnology Laboratory (NOBEL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Marcos Bazarra-Barreiros
- Neuroimaging and Biotechnology Laboratory (NOBEL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | | | - Esteban López-Arias
- Translational Stroke Laboratory (TREAT), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - María Pérez-Mato
- Neurological Sciences and Cerebrovascular Research Laboratory, Department of Neurology and Stroke Center, La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Universidad Autónoma de Madrid, Madrid, Spain
| | - Alberto Ouro
- NeuroAging Group (NEURAL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
- Centro de Investigación Biomédica en Red en Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
| | - José M. Pumar
- Neuroimaging and Biotechnology Laboratory (NOBEL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
- Department of Neuroradiology, Hospital Clínico Universitario, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Antonio J. Mosqueira
- Neuroimaging and Biotechnology Laboratory (NOBEL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
- Department of Neuroradiology, Hospital Clínico Universitario, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - María Luz Alonso-Alonso
- Neuroimaging and Biotechnology Laboratory (NOBEL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - José Castillo
- Neuroimaging and Biotechnology Laboratory (NOBEL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Pablo Hervella
- Neuroimaging and Biotechnology Laboratory (NOBEL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Ramón Iglesias-Rey
- Neuroimaging and Biotechnology Laboratory (NOBEL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| |
Collapse
|
3
|
Silvani A, Ghorayeb I, Manconi M, Li Y, Clemens S. Putative Animal Models of Restless Legs Syndrome: A Systematic Review and Evaluation of Their Face and Construct Validity. Neurotherapeutics 2023; 20:154-178. [PMID: 36536233 PMCID: PMC10119375 DOI: 10.1007/s13311-022-01334-4] [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] [Accepted: 12/02/2022] [Indexed: 12/24/2022] Open
Abstract
Restless legs syndrome (RLS) is a sensorimotor disorder that severely affects sleep. It is characterized by an urge to move the legs, which is often accompanied by periodic limb movements during sleep. RLS has a high prevalence in the population and is usually a life-long condition. While its origins remain unclear, RLS is initially highly responsive to treatment with dopaminergic agonists that target D2-like receptors, in particular D2 and D3, but the long-term response is often unsatisfactory. Over the years, several putative animal models for RLS have been developed, mainly based on the epidemiological and neurochemical link with iron deficiency, treatment efficacy of D2-like dopaminergic agonists, or genome-wide association studies that identified risk factors in the patient population. Here, we present the first systematic review of putative animal models of RLS, provide information about their face and construct validity, and report their role in deciphering the underlying pathophysiological mechanisms that may cause or contribute to RLS. We propose that identifying the causal links between genetic risk factors, altered organ functions, and changes to molecular pathways in neural circuitry will eventually lead to more effective new treatment options that bypass the side effects of the currently used therapeutics in RLS, especially for long-term therapy.
Collapse
Affiliation(s)
- Alessandro Silvani
- Department of Biomedical and Neuromotor Sciences, Alma Mater Studiorum - University of Bologna, Ravenna Campus, Ravenna, Italy
| | - Imad Ghorayeb
- Département de Neurophysiologie Clinique, Pôle Neurosciences Cliniques, CHU de Bordeaux, Bordeaux, France
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, UMR 5287, Université de Bordeaux, Bordeaux, France
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, UMR 5287, CNRS, Bordeaux, France
| | - Mauro Manconi
- Sleep Medicine Unit, Neurocenter of Southern Switzerland, EOC, Ospedale Civico, Lugano, Switzerland
- Department of Neurology, University Hospital, Inselspital, Bern, Switzerland
- Faculty of Biomedical Sciences, Università della Svizzera Italiana, Lugano, Switzerland
| | - Yuqing Li
- Department of Neurology, College of Medicine, Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL, USA
| | - Stefan Clemens
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, USA.
| |
Collapse
|
4
|
Meyer-Baese L, Watters H, Keilholz S. Spatiotemporal patterns of spontaneous brain activity: a mini-review. NEUROPHOTONICS 2022; 9:032209. [PMID: 35434180 PMCID: PMC9005199 DOI: 10.1117/1.nph.9.3.032209] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 03/04/2022] [Indexed: 06/14/2023]
Abstract
The brain exists in a state of constant activity in the absence of any external sensory input. The spatiotemporal patterns of this spontaneous brain activity have been studied using various recording and imaging techniques. This has enabled considerable progress to be made in elucidating the cellular and network mechanisms that are involved in the observed spatiotemporal dynamics. This mini-review outlines different spatiotemporal dynamic patterns that have been identified in four commonly used modalities: electrophysiological recordings, optical imaging, functional magnetic resonance imaging, and electroencephalography. Signal sources for each modality, possible sources of the observed dynamics, and future directions are also discussed.
Collapse
Affiliation(s)
- Lisa Meyer-Baese
- Emory University, Georgia Institute of Technology, Wallace H. Coulter Department of Biomedical Engineering, Atlanta, Georgia, United States
| | | | - Shella Keilholz
- Emory University, Georgia Institute of Technology, Wallace H. Coulter Department of Biomedical Engineering, Atlanta, Georgia, United States
| |
Collapse
|
5
|
Uselman TW, Medina CS, Gray HB, Jacobs RE, Bearer EL. Longitudinal manganese-enhanced magnetic resonance imaging of neural projections and activity. NMR IN BIOMEDICINE 2022; 35:e4675. [PMID: 35253280 PMCID: PMC11064873 DOI: 10.1002/nbm.4675] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 10/19/2021] [Accepted: 12/07/2021] [Indexed: 06/14/2023]
Abstract
Manganese-enhanced magnetic resonance imaging (MEMRI) holds exceptional promise for preclinical studies of brain-wide physiology in awake-behaving animals. The objectives of this review are to update the current information regarding MEMRI and to inform new investigators as to its potential. Mn(II) is a powerful contrast agent for two main reasons: (1) high signal intensity at low doses; and (2) biological interactions, such as projection tracing and neural activity mapping via entry into electrically active neurons in the living brain. High-spin Mn(II) reduces the relaxation time of water protons: at Mn(II) concentrations typically encountered in MEMRI, robust hyperintensity is obtained without adverse effects. By selectively entering neurons through voltage-gated calcium channels, Mn(II) highlights active neurons. Safe doses may be repeated over weeks to allow for longitudinal imaging of brain-wide dynamics in the same individual across time. When delivered by stereotactic intracerebral injection, Mn(II) enters active neurons at the injection site and then travels inside axons for long distances, tracing neuronal projection anatomy. Rates of axonal transport within the brain were measured for the first time in "time-lapse" MEMRI. When delivered systemically, Mn(II) enters active neurons throughout the brain via voltage-sensitive calcium channels and clears slowly. Thus behavior can be monitored during Mn(II) uptake and hyperintense signals due to Mn(II) uptake captured retrospectively, allowing pairing of behavior with neural activity maps for the first time. Here we review critical information gained from MEMRI projection mapping about human neuropsychological disorders. We then discuss results from neural activity mapping from systemic Mn(II) imaged longitudinally that have illuminated development of the tonotopic map in the inferior colliculus as well as brain-wide responses to acute threat and how it evolves over time. MEMRI posed specific challenges for image data analysis that have recently been transcended. We predict a bright future for longitudinal MEMRI in pursuit of solutions to the brain-behavior mystery.
Collapse
Affiliation(s)
- Taylor W. Uselman
- University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | | | - Harry B. Gray
- Beckman Institute, California Institute of Technology, Pasadena, California, USA
| | - Russell E. Jacobs
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Elaine L. Bearer
- University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
- Beckman Institute, California Institute of Technology, Pasadena, California, USA
| |
Collapse
|
6
|
Cho S, Roy A, Liu CJ, Idiyatullin D, Zhu W, Zhang Y, Zhu XH, O'Herron P, Leikvoll A, Chen W, Kara P, Uğurbil K. Cortical layer-specific differences in stimulus selectivity revealed with high-field fMRI and single-vessel resolution optical imaging of the primary visual cortex. Neuroimage 2022; 251:118978. [PMID: 35143974 PMCID: PMC9048976 DOI: 10.1016/j.neuroimage.2022.118978] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 01/26/2022] [Accepted: 02/05/2022] [Indexed: 11/23/2022] Open
Abstract
The mammalian neocortex exhibits a stereotypical laminar organization, with feedforward inputs arriving primarily into layer 4, local computations shaping response selectivity in layers 2/3, and outputs to other brain areas emanating via layers 2/3, 5 and 6. It cannot be assumed a priori that these signatures of laminar differences in neuronal circuitry are reflected in hemodynamic signals that form the basis of functional magnetic resonance imaging (fMRI). Indeed, optical imaging of single-vessel functional responses has highlighted the potential limits of using vascular signals as surrogates for mapping the selectivity of neural responses. Therefore, before fMRI can be employed as an effective tool for studying critical aspects of laminar processing, validation with single-vessel resolution is needed. The primary visual cortex (V1) in cats, with its precise neuronal functional micro-architecture, offers an ideal model system to examine laminar differences in stimulus selectivity across imaging modalities. Here we used cerebral blood volume weighted (wCBV) fMRI to examine if layer-specific orientation-selective responses could be detected in cat V1. We found orientation preference maps organized tangential to the cortical surface that typically extended across depth in a columnar fashion. We then examined arterial dilation and blood velocity responses to identical visual stimuli by using two- and three- photon optical imaging at single-vessel resolution-which provides a measure of the hemodynamic signals with the highest spatial resolution. Both fMRI and optical imaging revealed a consistent laminar response pattern in which orientation selectivity in cortical layer 4 was significantly lower compared to layer 2/3. This systematic change in selectivity across cortical layers has a clear underpinning in neural circuitry, particularly when comparing layer 4 to other cortical layers.
Collapse
Affiliation(s)
- Shinho Cho
- Center for Magnetic Resonance Research (CMRR), University of Minnesota, MN 55455, United States; Department of Radiology, University of Minnesota, MN 55455, United States
| | - Arani Roy
- Center for Magnetic Resonance Research (CMRR), University of Minnesota, MN 55455, United States; Department of Neuroscience, University of Minnesota, MN 55455, United States
| | - Chao J Liu
- Center for Magnetic Resonance Research (CMRR), University of Minnesota, MN 55455, United States; Department of Neuroscience, University of Minnesota, MN 55455, United States
| | - Djaudat Idiyatullin
- Center for Magnetic Resonance Research (CMRR), University of Minnesota, MN 55455, United States; Department of Radiology, University of Minnesota, MN 55455, United States
| | - Wei Zhu
- Center for Magnetic Resonance Research (CMRR), University of Minnesota, MN 55455, United States; Department of Radiology, University of Minnesota, MN 55455, United States
| | - Yi Zhang
- Center for Magnetic Resonance Research (CMRR), University of Minnesota, MN 55455, United States; Department of Radiology, University of Minnesota, MN 55455, United States
| | - Xiao-Hong Zhu
- Center for Magnetic Resonance Research (CMRR), University of Minnesota, MN 55455, United States; Department of Radiology, University of Minnesota, MN 55455, United States
| | - Phillip O'Herron
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, United States
| | - Austin Leikvoll
- Center for Magnetic Resonance Research (CMRR), University of Minnesota, MN 55455, United States; Department of Neuroscience, University of Minnesota, MN 55455, United States
| | - Wei Chen
- Center for Magnetic Resonance Research (CMRR), University of Minnesota, MN 55455, United States; Department of Radiology, University of Minnesota, MN 55455, United States
| | - Prakash Kara
- Center for Magnetic Resonance Research (CMRR), University of Minnesota, MN 55455, United States; Department of Neuroscience, University of Minnesota, MN 55455, United States; Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, United States.
| | - Kâmil Uğurbil
- Center for Magnetic Resonance Research (CMRR), University of Minnesota, MN 55455, United States; Department of Radiology, University of Minnesota, MN 55455, United States.
| |
Collapse
|
7
|
Zhang Y, Wang C, Tong S, Miao P. Separating single- and multiple-scattering components in laser speckle contrast imaging of tissue blood flow. BIOMEDICAL OPTICS EXPRESS 2022; 13:2881-2895. [PMID: 35774341 PMCID: PMC9203116 DOI: 10.1364/boe.453412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 05/02/2023]
Abstract
Random matrix theory provides new insights into multiple scattering in random media. In a recent study, we demonstrated the statistical separation of single- and multiple-scattering components based on a Wishart random matrix. The first- and second-order moments were estimated with a Wishart random matrix constructed using dynamically backscattered speckle images. In this study, this new strategy was applied to laser speckle contrast imaging (LSCI) of in vivo blood flow. The random matrix-based method was adopted and parameterized using electric field Monte Carlo simulations and in vitro blood flow phantom experiments. The new method was further applied to in vivo experiments, demonstrating the benefits of separating the single- and multiple-scattering components, and the method was compared with the traditional temporal laser speckle contrast analysis (LASCA) method. More specifically, the new method separates the stimulus-induced functional changes in blood flow and tissue perfusion in the superficial (<2l t , l t is the transport mean free path) and deep layers (1l t ∼ 7l t ), extending LSCI to the evaluation of functional and pathological changes.
Collapse
Affiliation(s)
- Yifan Zhang
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Cheng Wang
- School of Mathematical Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Shanbao Tong
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Peng Miao
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| |
Collapse
|
8
|
Bach P, Schuster R, Koopmann A, Vollstaedt-Klein S, Spanagel R, Kiefer F. Plasma calcium concentration during detoxification predicts neural cue-reactivity and craving during early abstinence in alcohol-dependent patients. Eur Arch Psychiatry Clin Neurosci 2022; 272:341-348. [PMID: 33630132 PMCID: PMC8866328 DOI: 10.1007/s00406-021-01240-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 02/12/2021] [Indexed: 11/26/2022]
Abstract
Recent studies on the pathophysiology of alcohol dependence suggest a link between peripheral calcium concentrations and alcohol craving. Here, we investigated the association between plasma calcium concentration, cue-induced brain activation, and alcohol craving. Plasma calcium concentrations were measured at the onset of inpatient detoxification in a sample of N = 115 alcohol-dependent patients. Alcohol cue-reactivity was assessed during early abstinence (mean 11.1 days) using a functional magnetic resonance imaging (fMRI) alcohol cue-reactivity task. Multiple regression analyses and bivariate correlations between plasma calcium concentrations, clinical craving measures and neural alcohol cue-reactivity (CR) were tested. Results show a significant negative correlation between plasma calcium concentrations and compulsive alcohol craving. Higher calcium levels predicted higher alcohol cue-induced brain response in a cluster of frontal brain areas, including the dorsolateral prefrontal cortex (dlPFC), the anterior prefrontal cortex (alPFC), and the inferior (IFG) and middle frontal gyri (MFG). In addition, functional brain activation in those areas correlated negatively with craving for alcohol during fMRI. Higher peripheral calcium concentrations during withdrawal predicted increased alcohol cue-induced brain activation in frontal brain areas, which are associated with craving inhibition and cognitive control functions. This might indicate that higher plasma calcium concentrations at onset of detoxification could modulate craving inhibition during early abstinence.Trial registration number: DRKS00003388; date of registration: 14.12.2011.
Collapse
Affiliation(s)
- Patrick Bach
- Department of Addictive Behavior and Addiction Medicine, Medical Faculty Mannheim, Heidelberg University, Central Institute of Mental Health, Square J5, 68159, Mannheim, Germany
- Feuerlein Center on Translational Addiction Medicine, Heidelberg University, Heidelberg, Germany
| | - Rilana Schuster
- Department of Addictive Behavior and Addiction Medicine, Medical Faculty Mannheim, Heidelberg University, Central Institute of Mental Health, Square J5, 68159, Mannheim, Germany.
- Feuerlein Center on Translational Addiction Medicine, Heidelberg University, Heidelberg, Germany.
- Spinal Cord Injury Center, Heidelberg University Hospital, Schlierbacher Landstraße 200 a, 69118, Heidelberg, Germany.
| | - Anne Koopmann
- Department of Addictive Behavior and Addiction Medicine, Medical Faculty Mannheim, Heidelberg University, Central Institute of Mental Health, Square J5, 68159, Mannheim, Germany
- Feuerlein Center on Translational Addiction Medicine, Heidelberg University, Heidelberg, Germany
| | - Sabine Vollstaedt-Klein
- Department of Addictive Behavior and Addiction Medicine, Medical Faculty Mannheim, Heidelberg University, Central Institute of Mental Health, Square J5, 68159, Mannheim, Germany
- Feuerlein Center on Translational Addiction Medicine, Heidelberg University, Heidelberg, Germany
| | - Rainer Spanagel
- Medical Faculty Mannheim, Heidelberg University, Institute of Psychopharmacology, Central Institute of Mental Health, Heidelberg, Germany
| | - Falk Kiefer
- Department of Addictive Behavior and Addiction Medicine, Medical Faculty Mannheim, Heidelberg University, Central Institute of Mental Health, Square J5, 68159, Mannheim, Germany
- Feuerlein Center on Translational Addiction Medicine, Heidelberg University, Heidelberg, Germany
| |
Collapse
|
9
|
Early fMRI responses to somatosensory and optogenetic stimulation reflect neural information flow. Proc Natl Acad Sci U S A 2021; 118:2023265118. [PMID: 33836602 PMCID: PMC7980397 DOI: 10.1073/pnas.2023265118] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
fMRI has revolutionized how neuroscientists investigate human brain functions and networks. To further advance understanding of brain functions, identifying the direction of information flow, such as thalamocortical versus corticothalamic projections, is critical. Because the early hemodynamic response at microvessels near active neurons can be detected by ultrahigh field fMRI, we propose using the onset times of fMRI responses to discern the information flow. This approach was confirmed by observing the ultrahigh spatiotemporal resolution BOLD fMRI responses to bottom-up somatosensory stimulation and top-down optogenetic stimulation of the primary motor cortex in anesthetized mice. Because ultrahigh field MRI is increasingly available, ultrahigh spatiotemporal fMRI will significantly facilitate the investigation of functional circuits in humans. Blood oxygenation level–dependent (BOLD) functional magnetic resonance imaging (fMRI) has been widely used to localize brain functions. To further advance understanding of brain functions, it is critical to understand the direction of information flow, such as thalamocortical versus corticothalamic projections. For this work, we performed ultrahigh spatiotemporal resolution fMRI at 15.2 T of the mouse somatosensory network during forepaw somatosensory stimulation and optogenetic stimulation of the primary motor cortex (M1). Somatosensory stimulation induced the earliest BOLD response in the ventral posterolateral nucleus (VPL), followed by the primary somatosensory cortex (S1) and then M1 and posterior thalamic nucleus. Optogenetic stimulation of excitatory neurons in M1 induced the earliest BOLD response in M1, followed by S1 and then VPL. Within S1, the middle cortical layers responded to somatosensory stimulation earlier than the upper or lower layers, whereas the upper cortical layers responded earlier than the other two layers to optogenetic stimulation in M1. The order of early BOLD responses was consistent with the canonical understanding of somatosensory network connections and cannot be explained by regional variabilities in the hemodynamic response functions measured using hypercapnic stimulation. Our data demonstrate that early BOLD responses reflect the information flow in the mouse somatosensory network, suggesting that high-field fMRI can be used for systems-level network analyses.
Collapse
|
10
|
Carli S, Chaabane L, Butti C, De Palma C, Aimar P, Salio C, Vignoli A, Giustetto M, Landsberger N, Frasca A. In vivo magnetic resonance spectroscopy in the brain of Cdkl5 null mice reveals a metabolic profile indicative of mitochondrial dysfunctions. J Neurochem 2021; 157:1253-1269. [PMID: 33448385 DOI: 10.1111/jnc.15300] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 10/24/2020] [Accepted: 01/07/2021] [Indexed: 12/12/2022]
Abstract
Mutations in the X-linked CDKL5 gene cause CDKL5 deficiency disorder (CDD), a severe neurodevelopmental condition mainly characterized by infantile epileptic encephalopathy, intellectual disability, and autistic features. The molecular mechanisms underlying the clinical symptoms remain largely unknown and the identification of reliable biomarkers in animal models will certainly contribute to increase our comprehension of CDD as well as to assess the efficacy of therapeutic strategies. Here, we used different Magnetic Resonance (MR) methods to disclose structural, functional, or metabolic signatures of Cdkl5 deficiency in the brain of adult mice. We found that loss of Cdkl5 does not cause cerebral atrophy but affects distinct brain areas, particularly the hippocampus. By in vivo proton-MR spectroscopy (MRS), we revealed in the Cdkl5 null brain a metabolic dysregulation indicative of mitochondrial dysfunctions. Accordingly, we unveiled a significant reduction in ATP levels and a decrease in the expression of complex IV of mitochondrial electron transport chain. Conversely, the number of mitochondria appeared preserved. Importantly, we reported a significant defect in the activation of one of the major regulators of cellular energy balance, the adenosine monophosphate-activated protein kinase (AMPK), that might contribute to the observed metabolic impairment and become an interesting therapeutic target for future preclinical trials. In conclusion, MRS revealed in the Cdkl5 null brain the presence of a metabolic dysregulation suggestive of a mitochondrial dysfunction that permitted to foster our comprehension of Cdkl5 deficiency and brought our interest towards targeting mitochondria as therapeutic strategy for CDD.
Collapse
Affiliation(s)
- Sara Carli
- Neuroscience Division, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Linda Chaabane
- Institute of Experimental Neurology (INSPE) and Experimental Imaging Center (CIS), IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Clarissa Butti
- Neuroscience Division, IRCCS San Raffaele Scientific Institute, Milan, Italy.,Molecular Nociception Group, Wolfson Institute for Biomedical Research (WIBR), University College London, London, UK
| | - Clara De Palma
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Segrate (Milan), Italy
| | - Patrizia Aimar
- Department of Veterinary Sciences, University of Turin, Grugliasco, Italy
| | - Chiara Salio
- Department of Veterinary Sciences, University of Turin, Grugliasco, Italy
| | - Aglaia Vignoli
- Epilepsy Center-Child Neuropsychiatric Unit, ASST Santi Paolo e Carlo, Department of Health Sciences, University of Milan, Milan, Italy
| | - Maurizio Giustetto
- Department of Neuroscience, University of Turin, Turin, Italy.,National Institute of Neuroscience-Italy, Turin, Italy
| | - Nicoletta Landsberger
- Neuroscience Division, IRCCS San Raffaele Scientific Institute, Milan, Italy.,Department of Medical Biotechnology and Translational Medicine, University of Milan, Segrate (Milan), Italy
| | - Angelisa Frasca
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Segrate (Milan), Italy
| |
Collapse
|
11
|
Markuerkiaga I, Marques JP, Bains LJ, Norris DG. An in-vivo study of BOLD laminar responses as a function of echo time and static magnetic field strength. Sci Rep 2021; 11:1862. [PMID: 33479362 PMCID: PMC7820587 DOI: 10.1038/s41598-021-81249-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 12/22/2020] [Indexed: 11/18/2022] Open
Abstract
Layer specific functional MRI requires high spatial resolution data. To compensate the associated poor signal to noise ratio it is common to integrate the signal from voxels at a given cortical depth. If the region is sufficiently large then physiological noise will be the dominant noise source. In this work, activation profiles in response to the same visual stimulus are compared at 1.5 T, 3 T and 7 T using a multi-echo, gradient echo (GE) FLASH sequence, with a 0.75 mm isotropic voxel size and the cortical integration approach. The results show that after integrating over a cortical volume of 40, 60 and 100 mm3 (at 7 T, 3 T, and 1.5 T, respectively), the signal is in the physiological noise dominated regime. The activation profiles obtained are similar for equivalent echo times. BOLD-like noise is found to be the dominant source of physiological noise. Consequently, the functional contrast to noise ratio is not strongly echo-time or field-strength dependent. We conclude that laminar GE-BOLD fMRI at lower field strengths is feasible but that larger patches of cortex will need to be examined, and that the acquisition efficiency is reduced.
Collapse
Affiliation(s)
- Irati Markuerkiaga
- Donders Centre for Cognitive Neuroimaging, Radboud University, Nijmegen, The Netherlands
| | - José P Marques
- Donders Centre for Cognitive Neuroimaging, Radboud University, Nijmegen, The Netherlands
| | - Lauren J Bains
- Donders Centre for Cognitive Neuroimaging, Radboud University, Nijmegen, The Netherlands
| | - David G Norris
- Donders Centre for Cognitive Neuroimaging, Radboud University, Nijmegen, The Netherlands. .,Erwin L. Hahn Institute for Magnetic Resonance Imaging, 45141, Essen, Germany.
| |
Collapse
|
12
|
Li Y, Li R, Liu M, Nie Z, Muir ER, Duong TQ. MRI study of cerebral blood flow, vascular reactivity, and vascular coupling in systemic hypertension. Brain Res 2020; 1753:147224. [PMID: 33358732 DOI: 10.1016/j.brainres.2020.147224] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 09/30/2020] [Accepted: 11/27/2020] [Indexed: 01/14/2023]
Abstract
Chronic hypertension alters cerebrovascular function, which can lead to neurovascular pathologies and increased susceptibility to neurological disorders. The purpose of this study was to utilize in vivo MRI methods with corroborating immunohistology to evaluate neurovascular dysfunction due to progressive chronic hypertension. The spontaneously hypertensive rat (SHR) model at different stages of hypertension was studied to evaluate: i) basal cerebral blood flow (CBF), ii) cerebrovascular reactivity (CVR) assessed by CBF and blood-oxygenation level dependent (BOLD) signal changes to hypercapnia, iii) neurovascular coupling from CBF and BOLD changes to forepaw stimulation, and iv) damage of neurovascular unit (NVU) components (microvascular, astrocyte and neuron densities). Comparisons were made with age-matched normotensive Wistar Kyoto (WKY) rats. In 10-week SHR (mild hypertension), basal CBF was higher (p < 0.05), CVR trended higher, and neurovascular coupling response was higher (p < 0.05), compared to normotensive rats. In 40-week SHR (severe hypertension), basal CBF, CVR, and neurovascular coupling response were reversed to similar or below normotensive rats, and were significantly different from 10-week SHR (p < 0.05). Immunohistological analysis found significantly reduced microvascular density, increased astrocytes, and reduced neuronal density in SHR at 40 weeks (p < 0.05) but not at 10 weeks (p > 0.05) in comparison to age-matched controls. In conclusion, we observed a bi-phasic basal CBF, CVR and neurovascular coupling response from early to late hypertension using in vivo MRI, with significant changes prior to changes in the NVU components from histology. MRI provides clinically relevant data that might be useful to characterize neurovascular pathogenesis on the brain in hypertension.
Collapse
Affiliation(s)
- Yunxia Li
- Department of Neurology, Tongji Hospital, Tongji University School of Medicine, Shanghai, China
| | - Renren Li
- Department of Neurology, Tongji Hospital, Tongji University School of Medicine, Shanghai, China
| | - Meng Liu
- Department of Neurology, Tongji Hospital, Tongji University School of Medicine, Shanghai, China
| | - Zhiyu Nie
- Department of Neurology, Tongji Hospital, Tongji University School of Medicine, Shanghai, China.
| | - Eric R Muir
- Department of Radiology, Renaissance School of Medicine, Stony Brook University Hospital, Stony Brook, NY, USA
| | - Tim Q Duong
- Department of Radiology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY, USA.
| |
Collapse
|
13
|
Fukuda M, Poplawsky AJ, Kim SG. Time-dependent spatial specificity of high-resolution fMRI: insights into mesoscopic neurovascular coupling. Philos Trans R Soc Lond B Biol Sci 2020; 376:20190623. [PMID: 33190606 PMCID: PMC7741035 DOI: 10.1098/rstb.2019.0623] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
High-resolution functional magnetic resonance imaging (fMRI) is becoming increasingly popular because of the growing availability of ultra-high magnetic fields which are capable of improving sensitivity and spatial resolution. However, it is debatable whether increased spatial resolutions for haemodynamic-based techniques, like fMRI, can accurately detect the true location of neuronal activity. We have addressed this issue in functional columns and layers of animals with haemoglobin-based optical imaging and different fMRI contrasts, such as blood oxygenation level-dependent, cerebral blood flow and cerebral blood volume fMRI. In this review, we describe empirical evidence primarily from our own studies on how well these fMRI signals are spatially specific to the neuronally active site and discuss insights into neurovascular coupling at the mesoscale. This article is part of the theme issue 'Key relationships between non-invasive functional neuroimaging and the underlying neuronal activity'.
Collapse
Affiliation(s)
- Mitsuhiro Fukuda
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Seong-Gi Kim
- Center for Neuroscience Imaging Research, Institute for Basic Science, Suwon, South Korea.,Department of Biomedical Engineering, Sungkyunkwan University, Suwon, South Korea
| |
Collapse
|
14
|
Krishnan V, Xu J, Mendoza AG, Koretsky A, Anderson SA, Pelled G. High-resolution MEMRI characterizes laminar specific ascending and descending spinal cord pathways in rats. J Neurosci Methods 2020; 340:108748. [PMID: 32335077 PMCID: PMC7281828 DOI: 10.1016/j.jneumeth.2020.108748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 04/19/2020] [Accepted: 04/19/2020] [Indexed: 11/17/2022]
Abstract
BACKGROUND The spinal cord is composed of nine distinct cellular laminae that currently can only be visualized by histological methods. Developing imaging methods that can visualize laminar architecture in-vivo is of significant interest. Manganese enhanced magnetic resonance imaging (MEMRI) yields valuable architectural and functional information about the brain and has great potential in characterizing neural pathways in the spinal cord. Here we apply MEMRI to visualize laminae architecture in the thoracic region of the spinal cord with ultra-high resolution. NEW METHOD Manganese chloride (MnCl2) was delivered systemically and imaging of the lumbar and thoracic spinal cord levels was acquired in high field, 11.7 T MRI scanner, 48 h following MnCl2 administration. RESULTS Here we demonstrate laminar specific signal enhancement in the spinal cord of rats administered with MnCl2 with 69 μm in-plane resolution. We also report reduced T1 values over time in MnCl2 groups across laminae IIX. COMPARISONS WITH EXISTING METHODS This is the first study to demonstrate that MEMRI is capable of identifying spinal laminae at a high resolution of 69 μm in a living animal. This would enable the visualization of architecture and function of distinct regions with improved resolution, in healthy and diseased animal models. CONCLUSIONS The regions with the largest T1 enhancements were observed to correspond to laminae that contain either high cell density or large motor neurons, making MEMRI an excellent tool for studying spinal cord architecture, physiology and function in different animal models.
Collapse
Affiliation(s)
- Vijai Krishnan
- Department of Biomedical Engineering, Michigan State University, East Lansing, MI, United States; The Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, United States
| | - Jiadi Xu
- Johns Hopkins Medicine Department of Radiology and Radiological Science, Baltimore, MD, United States
| | - Albert German Mendoza
- Johns Hopkins Medicine Department of Radiology and Radiological Science, Baltimore, MD, United States
| | - Alan Koretsky
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Stasia A Anderson
- National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States
| | - Galit Pelled
- Department of Biomedical Engineering, Michigan State University, East Lansing, MI, United States; The Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, United States; Department of Radiology, Michigan State University, East Lansing, MI, United States; Johns Hopkins Medicine Department of Radiology and Radiological Science, Baltimore, MD, United States.
| |
Collapse
|
15
|
Lyu S, Xing H, DeAndrade MP, Perez PD, Yokoi F, Febo M, Walters AS, Li Y. The Role of BTBD9 in the Cerebellum, Sleep-like Behaviors and the Restless Legs Syndrome. Neuroscience 2020; 440:85-96. [PMID: 32446853 DOI: 10.1016/j.neuroscience.2020.05.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 04/27/2020] [Accepted: 05/14/2020] [Indexed: 12/28/2022]
Abstract
Recent genome-wide association studies (GWAS) have found cerebellum as a top hit for sleep regulation. Restless legs syndrome (RLS) is a sleep-related sensorimotor disorder characterized by uncomfortable sensations in the extremities, generally at night, which are often relieved by movements. Clinical studies have found that RLS patients have structural and functional abnormalities in the cerebellum. However, whether and how cerebellar pathology contributes to sleep regulation and RLS is not known. GWAS identified polymorphisms in BTBD9 conferring a higher risk of sleep disruption and RLS. Knockout of the BTBD9 homolog in mice (Btbd9) and fly results in motor restlessness and sleep disruption. We performed manganese-enhanced magnetic resonance imaging on the Btbd9 knockout mice and found decreased neural activities in the cerebellum, especially in lobules VIII, X, and the deep cerebellar nuclei. Electrophysiological recording of Purkinje cells (PCs) from Btbd9 knockout mice revealed an increased number of non-tonic PCs. Tonic PCs showed increased spontaneous activity and intrinsic excitability. To further investigate the cerebellar contribution to RLS and sleep-like behaviors, we generated PC-specific Btbd9 knockout mice (Btbd9 pKO) and performed behavioral studies. Btbd9 pKO mice showed significant motor restlessness during the rest phase but not in the active phase. Btbd9 pKO mice also had an increased probability of waking at rest. Unlike the Btbd9 knockout mice, there was no increased thermal sensation in the Btbd9 pKO. Our results indicate that the Btbd9 knockout influences the PC activity; dysfunction in the cerebellum may contribute to the motor restlessness found in the Btbd9 knockout mice.
Collapse
Affiliation(s)
- Shangru Lyu
- Norman Fixel Institute for Neurological Diseases, Department of Neurology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Hong Xing
- Norman Fixel Institute for Neurological Diseases, Department of Neurology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Mark P DeAndrade
- Norman Fixel Institute for Neurological Diseases, Department of Neurology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Pablo D Perez
- Department of Psychiatry, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Fumiaki Yokoi
- Norman Fixel Institute for Neurological Diseases, Department of Neurology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Marcelo Febo
- Department of Psychiatry, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Arthur S Walters
- Division of Sleep Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Yuqing Li
- Norman Fixel Institute for Neurological Diseases, Department of Neurology, College of Medicine, University of Florida, Gainesville, FL, USA.
| |
Collapse
|
16
|
The Role of BTBD9 in Striatum and Restless Legs Syndrome. eNeuro 2019; 6:ENEURO.0277-19.2019. [PMID: 31444227 PMCID: PMC6787346 DOI: 10.1523/eneuro.0277-19.2019] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 07/22/2019] [Accepted: 08/02/2019] [Indexed: 12/23/2022] Open
Abstract
Restless legs syndrome (RLS) is a sensory-motor neurological disorder characterized by uncomfortable sensations in the extremities, generally at night, which is often relieved by movements. Genome-wide association studies (GWAS) have identified mutations in BTBD9 conferring a higher risk of RLS. Knockout of the BTBD9 homolog in mice (Btbd9) and fly results in motor restlessness and sleep disruption. Clinical studies have found RLS patients have structural and functional abnormalities in the striatum; however, whether and how striatal pathology contributes to the pathogenesis of RLS is not known. Here, we used fMRI to map regions of altered synaptic activity in basal ganglia of systematic Btbd9 knock-out (KO) mice. We further dissected striatal circuits using patch-clamp electrophysiological recordings in brain slices. Two different mouse models were generated to test the effect of specific knockout of Btbd9 in either striatal medium spiny neurons (MSNs) or cholinergic interneurons (ChIs) using the electrophysiological recording, motor and sensory behavioral tests. We found that Btbd9 KO mice showed enhanced neural activity in the striatum, increased postsynaptic currents in the MSNs, and decreased excitability of the striatal ChIs. Knocking out Btbd9 specifically in the striatal MSNs, but not the ChIs, led to rest-phase specific motor restlessness, sleep disturbance, and increased thermal sensation in mice, which are consistent with results obtained from the Btbd9 KO mice. Our data establish the role of Btbd9 in regulating the activity of striatal neurons. Increased activity of the striatal MSNs, possibly through modulation by the striatal ChIs, contributes to the pathogenesis of RLS.
Collapse
|
17
|
Laminar specific fMRI reveals directed interactions in distributed networks during language processing. Proc Natl Acad Sci U S A 2019; 116:21185-21190. [PMID: 31570628 DOI: 10.1073/pnas.1907858116] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Interactions between top-down and bottom-up information streams are integral to brain function but challenging to measure noninvasively. Laminar resolution, functional MRI (lfMRI) is sensitive to depth-dependent properties of the blood oxygen level-dependent (BOLD) response, which can be potentially related to top-down and bottom-up signal contributions. In this work, we used lfMRI to dissociate the top-down and bottom-up signal contributions to the left occipitotemporal sulcus (LOTS) during word reading. We further demonstrate that laminar resolution measurements could be used to identify condition-specific distributed networks on the basis of whole-brain connectivity patterns specific to the depth-dependent BOLD signal. The networks corresponded to top-down and bottom-up signal pathways targeting the LOTS during word reading. We show that reading increased the top-down BOLD signal observed in the deep layers of the LOTS and that this signal uniquely related to the BOLD response in other language-critical regions. These results demonstrate that lfMRI can reveal important patterns of activation that are obscured at standard resolution. In addition to differences in activation strength as a function of depth, we also show meaningful differences in the interaction between signals originating from different depths both within a region and with the rest of the brain. We thus show that lfMRI allows the noninvasive measurement of directed interaction between brain regions and is capable of resolving different connectivity patterns at submillimeter resolution, something previously considered to be exclusively in the domain of invasive recordings.
Collapse
|
18
|
|
19
|
Jung WB, Shim HJ, Kim SG. Mouse BOLD fMRI at ultrahigh field detects somatosensory networks including thalamic nuclei. Neuroimage 2019; 195:203-214. [DOI: 10.1016/j.neuroimage.2019.03.063] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 03/14/2019] [Accepted: 03/27/2019] [Indexed: 01/16/2023] Open
|
20
|
Deng W, Faiq MA, Liu C, Adi V, Chan KC. Applications of Manganese-Enhanced Magnetic Resonance Imaging in Ophthalmology and Visual Neuroscience. Front Neural Circuits 2019; 13:35. [PMID: 31156399 PMCID: PMC6530364 DOI: 10.3389/fncir.2019.00035] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Accepted: 04/26/2019] [Indexed: 12/21/2022] Open
Abstract
Understanding the mechanisms of vision in health and disease requires knowledge of the anatomy and physiology of the eye and the neural pathways relevant to visual perception. As such, development of imaging techniques for the visual system is crucial for unveiling the neural basis of visual function or impairment. Magnetic resonance imaging (MRI) offers non-invasive probing of the structure and function of the neural circuits without depth limitation, and can help identify abnormalities in brain tissues in vivo. Among the advanced MRI techniques, manganese-enhanced MRI (MEMRI) involves the use of active manganese contrast agents that positively enhance brain tissue signals in T1-weighted imaging with respect to the levels of connectivity and activity. Depending on the routes of administration, accumulation of manganese ions in the eye and the visual pathways can be attributed to systemic distribution or their local transport across axons in an anterograde fashion, entering the neurons through voltage-gated calcium channels. The use of the paramagnetic manganese contrast in MRI has a wide range of applications in the visual system from imaging neurodevelopment to assessing and monitoring neurodegeneration, neuroplasticity, neuroprotection, and neuroregeneration. In this review, we present four major domains of scientific inquiry where MEMRI can be put to imperative use — deciphering neuroarchitecture, tracing neuronal tracts, detecting neuronal activity, and identifying or differentiating glial activity. We deliberate upon each category studies that have successfully employed MEMRI to examine the visual system, including the delivery protocols, spatiotemporal characteristics, and biophysical interpretation. Based on this literature, we have identified some critical challenges in the field in terms of toxicity, and sensitivity and specificity of manganese enhancement. We also discuss the pitfalls and alternatives of MEMRI which will provide new avenues to explore in the future.
Collapse
Affiliation(s)
- Wenyu Deng
- NYU Langone Eye Center, Department of Ophthalmology, NYU School of Medicine, NYU Langone Health, New York University, New York, NY, United States
| | - Muneeb A Faiq
- NYU Langone Eye Center, Department of Ophthalmology, NYU School of Medicine, NYU Langone Health, New York University, New York, NY, United States
| | - Crystal Liu
- NYU Langone Eye Center, Department of Ophthalmology, NYU School of Medicine, NYU Langone Health, New York University, New York, NY, United States
| | - Vishnu Adi
- NYU Langone Eye Center, Department of Ophthalmology, NYU School of Medicine, NYU Langone Health, New York University, New York, NY, United States
| | - Kevin C Chan
- NYU Langone Eye Center, Department of Ophthalmology, NYU School of Medicine, NYU Langone Health, New York University, New York, NY, United States.,Department of Radiology, NYU School of Medicine, NYU Langone Health, New York University, New York, NY, United States.,Center for Neural Science, Faculty of Arts and Science, New York University, New York, NY, United States
| |
Collapse
|
21
|
Androuin A, Abada YS, Ly M, Santin M, Petiet A, Epelbaum S, Bertrand A, Delatour B. Activity-induced MEMRI cannot detect functional brain anomalies in the APPxPS1-Ki mouse model of Alzheimer's disease. Sci Rep 2019; 9:1140. [PMID: 30718666 PMCID: PMC6361936 DOI: 10.1038/s41598-018-37980-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 12/10/2018] [Indexed: 12/02/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common cause of dementia. Aside neuropathological lesions, abnormal neuronal activity and brain metabolism are part of the core symptoms of the disease. Activity-induced Manganese-Enhanced Magnetic Resonance Imaging (MEMRI) has been proposed as a powerful approach to visualize evoked brain activity in rodents. Here, we evaluated the relevance of MEMRI in measuring neuronal (dys-)function in the APPxPS1 knocked-in (KI) mouse model of AD. Brain anomalies were firstly demonstrated in APPxPS1-Ki mice using cognitive testing (memory impairment) and histological mapping of immediate early gene products (decreased density of fos-positive neurons). Paradoxically, MEMRI analyses were not able to confirm the occurrence of neuronal hypoactivities in vivo. We then performed a neuropathological analysis that highlighted an abnormal increased permeability of the blood-brain barrier (BBB) in APPxPS1-Ki mice. We hypothesized that diffuse weakening of the BBB results in an uncontrolled diffusion of the MR contrast agent and a lack of correlation between manganese accumulation and neuronal activity. These results bring to light a limitation of the activity-induced MEMRI approach when applied to the APPxPS1-Ki mouse model as well as other mouse models harboring a compromised BBB.
Collapse
Affiliation(s)
- Alexandre Androuin
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Université Pierre et Marie Curie, Sorbonne Universités, Paris, France
| | - Yah-Se Abada
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Université Pierre et Marie Curie, Sorbonne Universités, Paris, France
| | - Myriam Ly
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Université Pierre et Marie Curie, Sorbonne Universités, Paris, France.,Institut Roche, Boulogne-Billancourt, France
| | - Mathieu Santin
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Université Pierre et Marie Curie, Sorbonne Universités, Paris, France.,Center for Neuroimaging Research, Institut du Cerveau et de la Moelle épinière, Paris, France
| | - Alexandra Petiet
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Université Pierre et Marie Curie, Sorbonne Universités, Paris, France.,Center for Neuroimaging Research, Institut du Cerveau et de la Moelle épinière, Paris, France
| | - Stéphane Epelbaum
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Université Pierre et Marie Curie, Sorbonne Universités, Paris, France.,Centre des Maladies Cognitives et Comportementales, Sorbonne Universités, Hôpital de la Salpêtrière, Paris, France.,Aramis Project Team, Inria Research Center of Paris, Paris, France
| | - Anne Bertrand
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Université Pierre et Marie Curie, Sorbonne Universités, Paris, France.,Aramis Project Team, Inria Research Center of Paris, Paris, France
| | - Benoît Delatour
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Université Pierre et Marie Curie, Sorbonne Universités, Paris, France.
| |
Collapse
|
22
|
Cloyd RA, Koren SA, Abisambra JF. Manganese-Enhanced Magnetic Resonance Imaging: Overview and Central Nervous System Applications With a Focus on Neurodegeneration. Front Aging Neurosci 2018; 10:403. [PMID: 30618710 PMCID: PMC6300587 DOI: 10.3389/fnagi.2018.00403] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Accepted: 11/23/2018] [Indexed: 12/16/2022] Open
Abstract
Manganese-enhanced magnetic resonance imaging (MEMRI) rose to prominence in the 1990s as a sensitive approach to high contrast imaging. Following the discovery of manganese conductance through calcium-permeable channels, MEMRI applications expanded to include functional imaging in the central nervous system (CNS) and other body systems. MEMRI has since been employed in the investigation of physiology in many animal models and in humans. Here, we review historical perspectives that follow the evolution of applied MRI research into MEMRI with particular focus on its potential toxicity. Furthermore, we discuss the more current in vivo investigative uses of MEMRI in CNS investigations and the brief but decorated clinical usage of chelated manganese compound mangafodipir in humans.
Collapse
Affiliation(s)
- Ryan A Cloyd
- Department of Physiology, University of Kentucky, Lexington, KY, United States.,College of Medicine, University of Kentucky, Lexington, KY, United States.,Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, United States
| | - Shon A Koren
- Department of Physiology, University of Kentucky, Lexington, KY, United States.,Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, United States.,Department of Neuroscience & Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL, United States
| | - Jose F Abisambra
- Department of Physiology, University of Kentucky, Lexington, KY, United States.,Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, United States.,Department of Neuroscience & Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL, United States.,Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, United States
| |
Collapse
|
23
|
Kim SY, Heo H, Kim DH, Kim HJ, Oh SH. Neural Plastic Changes in the Subcortical Auditory Neural Pathway after Single-Sided Deafness in Adult Mice: A MEMRI Study. BIOMED RESEARCH INTERNATIONAL 2018; 2018:8624745. [PMID: 30599000 PMCID: PMC6287207 DOI: 10.1155/2018/8624745] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 10/30/2018] [Accepted: 11/09/2018] [Indexed: 01/14/2023]
Abstract
Single-sided deafness (SSD) induces cortical neural plastic changes according to duration of deafness. However, it is still unclear how the auditory cortical changes accompany the subcortical neural changes. The present study aimed to find the neural plastic changes in the cortical and subcortical auditory system following adult-onset single-sided deafness (SSD) using Mn-enhanced magnetic resonance imaging (MEMRI). B57BL/6 mice (postnatal 8-week-old) were divided into three groups: the SSD-4-week group (postnatal 12-week-old, n = 11), the SSD-8-week group (postnatal 16-week-old, n = 11), and a normal-hearing control group (postnatal 8-week-old, n = 9). The left cochlea was ablated in the SSD groups. White Gaussian noise was delivered for 24 h before MEMRI acquisition. T1-weighted MRI data were analyzed from the cochlear nucleus (CN), superior olivary complex (SOC), lateral lemniscus (LL), inferior colliculus (IC), medial geniculate body (MG), and auditory cortex (AC). The differences in relative Mn2+-enhanced signal intensities (Mn2+SI) and laterality were analyzed between the groups. Four weeks after the SSD procedure, the ipsilateral side of the SSD showed significantly lower Mn2+SI in the CN than the control group. On the other hand, the contralateral side of the SSD demonstrated significantly lower Mn2+SI in the SOC, LL, and IC. These decreased Mn2+SI values were partially recovered at 8 weeks after the SSD procedure. The interaural Mn2+SI differences representing the interaural dominance were highest in CN and then became less prominently higher in the auditory neural system. The SSD-8-week group still showed interaural differences in the CN, LL, and IC. In contrast, the MG and AC did not show any significant intergroup or interaural differences in Mn2+SI. In conclusion, subcortical auditory neural activities were decreased after SSD, and the interaural differences were diluted in the higher auditory nervous system. These findings were attenuated with time. Subcortical auditory neural changes after SSD may contribute to the change in tinnitus severity and the outcomes of cochlear implantation in SSD patients.
Collapse
Affiliation(s)
- So Young Kim
- Department of Otorhinolaryngology-Head & Neck Surgery, CHA Bundang Medical Center, CHA University, Seongnam, Republic of Korea
| | - Hwon Heo
- Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea
| | - Doo Hee Kim
- Department of Otorhinolaryngology-Head & Neck Surgery, Seoul National University Hospital, Seoul, Republic of Korea
- Department of Brain Science, Seoul National University, Seoul, Republic of Korea
| | - Hyun Jin Kim
- Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea
| | - Seung-ha Oh
- Department of Otorhinolaryngology-Head & Neck Surgery, Seoul National University Hospital, Seoul, Republic of Korea
- Department of Brain Science, Seoul National University, Seoul, Republic of Korea
| |
Collapse
|
24
|
Dopfel D, Zhang N. Mapping stress networks using functional magnetic resonance imaging in awake animals. Neurobiol Stress 2018; 9:251-263. [PMID: 30450389 PMCID: PMC6234259 DOI: 10.1016/j.ynstr.2018.06.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Revised: 05/27/2018] [Accepted: 06/26/2018] [Indexed: 12/15/2022] Open
Abstract
The neurobiology of stress is studied through behavioral neuroscience, endocrinology, neuronal morphology and neurophysiology. There is a shift in focus toward progressive changes throughout stress paradigms and individual susceptibility to stress that requires methods that allow for longitudinal study design and study of individual differences in stress response. Functional magnetic resonance imaging (fMRI), with the advantages of noninvasiveness and a large field of view, can be used for functionally mapping brain-wide regions and circuits critical to the stress response, making it suitable for longitudinal studies and understanding individual variability of short-term and long-term consequences of stress exposure. In addition, fMRI can be applied to both animals and humans, which is highly valuable in translating findings across species and examining whether the physiology and neural circuits involved in the stress response are conserved in mammals. However, compared to human fMRI studies, there are a number of factors that are essential for the success of fMRI studies in animals. This review discussed the use of fMRI in animal studies of stress. It reviewed advantages, challenges and technical considerations of the animal fMRI methodology as well as recent literature of stress studies using fMRI in animals. It also highlighted the development of combining fMRI with other methods and the future potential of fMRI in animal studies of stress. We conclude that animal fMRI studies, with their flexibility, low cost and short time frame compared to human studies, are crucial to advancing our understanding of the neurobiology of stress.
Collapse
Affiliation(s)
- David Dopfel
- Department of Biomedical Engineering, Pennsylvania State University, University Park, PA, 16802, USA
| | - Nanyin Zhang
- Department of Biomedical Engineering, Pennsylvania State University, University Park, PA, 16802, USA
- The Huck Institutes of Life Sciences, Pennsylvania State University, University Park, PA, 16802, USA
| |
Collapse
|
25
|
Perez PD, Hall G, Zubcevic J, Febo M. Cocaine differentially affects synaptic activity in memory and midbrain areas of female and male rats: an in vivo MEMRI study. Brain Imaging Behav 2018; 12:201-216. [PMID: 28236167 DOI: 10.1007/s11682-017-9691-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Manganese enhanced magnetic resonance imaging (MEMRI) has been previously used to determine the effect of acute cocaine on calcium-dependent synaptic activity in male rats. However, there have been no MEMRI studies examining sex differences in the functional neural circuits affected by repeated cocaine. In the present study, we used MEMRI to investigate the effects of repeated cocaine on brain activation in female and male rats. Adult female and male rats were scanned at 4.7 Tesla three days after final treatment with saline, a single cocaine injection (15 mg kg-1, i.p. × 1 day) or repeated cocaine injections (15 mg kg-1, i.p. × 10 days). A day before imaging rats were provided with an i.p. injection of manganese chloride (70 mg kg-1). Cocaine produced effects on MEMRI activity that were dependent on sex. In females, we observed that a single cocaine injection reduced MEMRI activity in hippocampal CA3, ventral tegmental area (VTA), and median Raphé, whereas repeated cocaine increased MEMRI activity in dentate gyrus and interpeduncular nucleus. In males, repeated cocaine reduced MEMRI activity in VTA. Overall, it appeared that female rats showed a general trend towards increase MEMRI activity with single cocaine and reduced activity with repeated exposure, while male rats showed a trend towards opposite effects. Our results provide evidence for sex differences in the in vivo neural response to cocaine, which involves primarily hippocampal, amygdala and midbrain areas.
Collapse
Affiliation(s)
- Pablo D Perez
- Department of Psychiatry, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Gabrielle Hall
- Department of Psychiatry, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Jasenka Zubcevic
- Department of Physiological Sciences, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Marcelo Febo
- Department of Psychiatry, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, 32610, USA.
- Center for Addiction Research and Education (CARE), University of Florida, Gainesville, FL, USA.
| |
Collapse
|
26
|
Uğurbil K. Imaging at ultrahigh magnetic fields: History, challenges, and solutions. Neuroimage 2018; 168:7-32. [PMID: 28698108 PMCID: PMC5758441 DOI: 10.1016/j.neuroimage.2017.07.007] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 07/05/2017] [Accepted: 07/07/2017] [Indexed: 01/06/2023] Open
Abstract
Following early efforts in applying nuclear magnetic resonance (NMR) spectroscopy to study biological processes in intact systems, and particularly since the introduction of 4 T human scanners circa 1990, rapid progress was made in imaging and spectroscopy studies of humans at 4 T and animal models at 9.4 T, leading to the introduction of 7 T and higher magnetic fields for human investigation at about the turn of the century. Work conducted on these platforms has provided numerous technological solutions to challenges posed at these ultrahigh fields, and demonstrated the existence of significant advantages in signal-to-noise ratio and biological information content. Primary difference from lower fields is the deviation from the near field regime at the radiofrequencies (RF) corresponding to hydrogen resonance conditions. At such ultrahigh fields, the RF is characterized by attenuated traveling waves in the human body, which leads to image non-uniformities for a given sample-coil configuration because of destructive and constructive interferences. These non-uniformities were initially considered detrimental to progress of imaging at high field strengths. However, they are advantageous for parallel imaging in signal reception and transmission, two critical technologies that account, to a large extend, for the success of ultrahigh fields. With these technologies and improvements in instrumentation and imaging methods, today ultrahigh fields have provided unprecedented gains in imaging of brain function and anatomy, and started to make inroads into investigation of the human torso and extremities. As extensive as they are, these gains still constitute a prelude to what is to come given the increasingly larger effort committed to ultrahigh field research and development of ever better instrumentation and techniques.
Collapse
Affiliation(s)
- Kamil Uğurbil
- Center for Magnetic Resonance Research (CMRR), University of Minnesota Medical School, Minneapolis, MN 55455, USA.
| |
Collapse
|
27
|
Jahrling JB, Lin AL, DeRosa N, Hussong SA, Van Skike CE, Girotti M, Javors M, Zhao Q, Maslin LA, Asmis R, Galvan V. mTOR drives cerebral blood flow and memory deficits in LDLR -/- mice modeling atherosclerosis and vascular cognitive impairment. J Cereb Blood Flow Metab 2018; 38:58-74. [PMID: 28511572 PMCID: PMC5757441 DOI: 10.1177/0271678x17705973] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 02/01/2017] [Accepted: 02/27/2017] [Indexed: 12/14/2022]
Abstract
We recently showed that mTOR attenuation blocks progression and abrogates established cognitive deficits in Alzheimer's disease (AD) mouse models. These outcomes were associated with the restoration of cerebral blood flow (CBF) and brain vascular density (BVD) resulting from relief of mTOR inhibition of NO release. Recent reports suggested a role of mTOR in atherosclerosis. Because mTOR drives aging and vascular dysfunction is a universal feature of aging, we hypothesized that mTOR may contribute to brain vascular and cognitive dysfunction associated with atherosclerosis. We measured CBF, BVD, cognitive function, markers of inflammation, and parameters of cardiovascular disease in LDLR-/- mice fed maintenance or high-fat diet ± rapamycin. Cardiovascular pathologies were proportional to severity of brain vascular dysfunction. Aortic atheromas were reduced, CBF and BVD were restored, and cognitive dysfunction was attenuated potentially through reduction in systemic and brain inflammation following chronic mTOR attenuation. Our studies suggest that mTOR regulates vascular integrity and function and that mTOR attenuation may restore neurovascular function and cardiovascular health. Together with our previous studies in AD models, our data suggest mTOR-driven vascular damage may be a mechanism shared by age-associated neurological diseases. Therefore, mTOR attenuation may have promise for treatment of cognitive impairment in atherosclerosis.
Collapse
Affiliation(s)
- Jordan B Jahrling
- Department of Cellular and Integrative
Physiology and The Barshop Institute for Longevity and Aging Studies, University of
Texas Health Science Center at San Antonio, TX, USA
| | - Ai-Ling Lin
- Sanders-Brown Center on Aging,
Department of Pharmacology and Nutritional Sciences and Department of Biomedical
Engineering, University of Kentucky, KY, USA
| | - Nicholas DeRosa
- Department of Cellular and Integrative
Physiology and The Barshop Institute for Longevity and Aging Studies, University of
Texas Health Science Center at San Antonio, TX, USA
| | - Stacy A Hussong
- Department of Cellular and Integrative
Physiology and The Barshop Institute for Longevity and Aging Studies, University of
Texas Health Science Center at San Antonio, TX, USA
| | - Candice E Van Skike
- Department of Cellular and Integrative
Physiology and The Barshop Institute for Longevity and Aging Studies, University of
Texas Health Science Center at San Antonio, TX, USA
| | - Milena Girotti
- Department of Pharmacology, University
of Texas Health Science Center at San Antonio, TX, USA
| | - Martin Javors
- Department of Psychiatry, University of
Texas Health Science Center at San Antonio, TX, USA
| | - Qingwei Zhao
- Department of Medicine, University of
Texas Health Science Center at San Antonio, TX, USA
| | - Leigh Ann Maslin
- Department of Clinical Laboratory
Sciences, University of Texas Health Science Center at San Antonio, TX, USA
| | - Reto Asmis
- Department of Clinical Laboratory
Sciences, University of Texas Health Science Center at San Antonio, TX, USA
- Department of Biochemistry, University
of Texas Health Science Center at San Antonio, TX, USA
| | - Veronica Galvan
- Department of Cellular and Integrative
Physiology and The Barshop Institute for Longevity and Aging Studies, University of
Texas Health Science Center at San Antonio, TX, USA
| |
Collapse
|
28
|
Wainford RD. How to Reduce Dietary Salt Intake: Just Add Spice? Hypertension 2017; 70:1087-1088. [PMID: 29089369 DOI: 10.1161/hypertensionaha.117.10025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Richard David Wainford
- From the Department of Pharmacology & Experimental Therapeutics and The Whitaker Cardiovascular Institute, Boston University School of Medicine, MA.
| |
Collapse
|
29
|
Li Q, Cui Y, Jin R, Lang H, Yu H, Sun F, He C, Ma T, Li Y, Zhou X, Liu D, Jia H, Chen X, Zhu Z. Enjoyment of Spicy Flavor Enhances Central Salty-Taste Perception and Reduces Salt Intake and Blood Pressure. Hypertension 2017; 70:1291-1299. [PMID: 29089370 DOI: 10.1161/hypertensionaha.117.09950] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Revised: 07/11/2017] [Accepted: 08/28/2017] [Indexed: 11/16/2022]
Abstract
High salt intake is a major risk factor for hypertension and is associated with cardiovascular events. Most countries exhibit a traditionally high salt intake; thus, identification of an optimal strategy for salt reduction at the population level may have a major impact on public health. In this multicenter, random-order, double-blind observational and interventional study, subjects with a high spice preference had a lower salt intake and blood pressure than subjects who disliked spicy food. The enjoyment of spicy flavor enhanced salt sensitivity and reduced salt preference. Salt intake and salt preference were related to the regional metabolic activity in the insula and orbitofrontal cortex (OFC) of participants. Administration of capsaicin-the major spicy component of chili pepper-enhanced the insula and OFC metabolic activity in response to high-salt stimuli, which reversed the salt intensity-dependent differences in the metabolism of the insula and OFC. In animal study, OFC activity was closely associated with salt preference, and salty-taste information processed in the OFC was affected in the presence of capsaicin. Thus, interventions related to this region may alter the salt preference in mice through fiber fluorometry and optogenetic techniques. In conclusion, enjoyment of spicy foods may significantly reduce individual salt preference, daily salt intake, and blood pressure by modifying the neural processing of salty taste in the brain. Application of spicy flavor may be a promising behavioral intervention for reducing high salt intake and blood pressure.
Collapse
Affiliation(s)
- Qiang Li
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Collaborative Innovation Center for Brain Science, Chongqing Institute of Hypertension (Q.L., Y.C., H.L., H.Y., F.S., C.H., T.M., Y.L., X.Z., D.L., Z.Z.), Department of Medical Image, Daping Hospital (R.J.), and Brain Research Center (X.C.), Third Military Medical University, China; and Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences (H.J.)
| | - Yuanting Cui
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Collaborative Innovation Center for Brain Science, Chongqing Institute of Hypertension (Q.L., Y.C., H.L., H.Y., F.S., C.H., T.M., Y.L., X.Z., D.L., Z.Z.), Department of Medical Image, Daping Hospital (R.J.), and Brain Research Center (X.C.), Third Military Medical University, China; and Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences (H.J.)
| | - Rongbing Jin
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Collaborative Innovation Center for Brain Science, Chongqing Institute of Hypertension (Q.L., Y.C., H.L., H.Y., F.S., C.H., T.M., Y.L., X.Z., D.L., Z.Z.), Department of Medical Image, Daping Hospital (R.J.), and Brain Research Center (X.C.), Third Military Medical University, China; and Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences (H.J.).
| | - Hongmei Lang
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Collaborative Innovation Center for Brain Science, Chongqing Institute of Hypertension (Q.L., Y.C., H.L., H.Y., F.S., C.H., T.M., Y.L., X.Z., D.L., Z.Z.), Department of Medical Image, Daping Hospital (R.J.), and Brain Research Center (X.C.), Third Military Medical University, China; and Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences (H.J.)
| | - Hao Yu
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Collaborative Innovation Center for Brain Science, Chongqing Institute of Hypertension (Q.L., Y.C., H.L., H.Y., F.S., C.H., T.M., Y.L., X.Z., D.L., Z.Z.), Department of Medical Image, Daping Hospital (R.J.), and Brain Research Center (X.C.), Third Military Medical University, China; and Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences (H.J.)
| | - Fang Sun
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Collaborative Innovation Center for Brain Science, Chongqing Institute of Hypertension (Q.L., Y.C., H.L., H.Y., F.S., C.H., T.M., Y.L., X.Z., D.L., Z.Z.), Department of Medical Image, Daping Hospital (R.J.), and Brain Research Center (X.C.), Third Military Medical University, China; and Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences (H.J.)
| | - Chengkang He
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Collaborative Innovation Center for Brain Science, Chongqing Institute of Hypertension (Q.L., Y.C., H.L., H.Y., F.S., C.H., T.M., Y.L., X.Z., D.L., Z.Z.), Department of Medical Image, Daping Hospital (R.J.), and Brain Research Center (X.C.), Third Military Medical University, China; and Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences (H.J.)
| | - Tianyi Ma
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Collaborative Innovation Center for Brain Science, Chongqing Institute of Hypertension (Q.L., Y.C., H.L., H.Y., F.S., C.H., T.M., Y.L., X.Z., D.L., Z.Z.), Department of Medical Image, Daping Hospital (R.J.), and Brain Research Center (X.C.), Third Military Medical University, China; and Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences (H.J.)
| | - Yingsha Li
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Collaborative Innovation Center for Brain Science, Chongqing Institute of Hypertension (Q.L., Y.C., H.L., H.Y., F.S., C.H., T.M., Y.L., X.Z., D.L., Z.Z.), Department of Medical Image, Daping Hospital (R.J.), and Brain Research Center (X.C.), Third Military Medical University, China; and Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences (H.J.)
| | - Xunmei Zhou
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Collaborative Innovation Center for Brain Science, Chongqing Institute of Hypertension (Q.L., Y.C., H.L., H.Y., F.S., C.H., T.M., Y.L., X.Z., D.L., Z.Z.), Department of Medical Image, Daping Hospital (R.J.), and Brain Research Center (X.C.), Third Military Medical University, China; and Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences (H.J.)
| | - Daoyan Liu
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Collaborative Innovation Center for Brain Science, Chongqing Institute of Hypertension (Q.L., Y.C., H.L., H.Y., F.S., C.H., T.M., Y.L., X.Z., D.L., Z.Z.), Department of Medical Image, Daping Hospital (R.J.), and Brain Research Center (X.C.), Third Military Medical University, China; and Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences (H.J.)
| | - Hongbo Jia
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Collaborative Innovation Center for Brain Science, Chongqing Institute of Hypertension (Q.L., Y.C., H.L., H.Y., F.S., C.H., T.M., Y.L., X.Z., D.L., Z.Z.), Department of Medical Image, Daping Hospital (R.J.), and Brain Research Center (X.C.), Third Military Medical University, China; and Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences (H.J.)
| | - Xiaowei Chen
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Collaborative Innovation Center for Brain Science, Chongqing Institute of Hypertension (Q.L., Y.C., H.L., H.Y., F.S., C.H., T.M., Y.L., X.Z., D.L., Z.Z.), Department of Medical Image, Daping Hospital (R.J.), and Brain Research Center (X.C.), Third Military Medical University, China; and Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences (H.J.)
| | - Zhiming Zhu
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Collaborative Innovation Center for Brain Science, Chongqing Institute of Hypertension (Q.L., Y.C., H.L., H.Y., F.S., C.H., T.M., Y.L., X.Z., D.L., Z.Z.), Department of Medical Image, Daping Hospital (R.J.), and Brain Research Center (X.C.), Third Military Medical University, China; and Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences (H.J.).
| |
Collapse
|
30
|
Topping GJ, Yung A, Schaffer P, Hoehr C, Kornelsen R, Kozlowski P, Sossi V. Manganese concentration mapping in the rat brain with MRI, PET, and autoradiography. Med Phys 2017; 44:4056-4067. [PMID: 28444763 DOI: 10.1002/mp.12300] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 03/21/2017] [Accepted: 04/11/2017] [Indexed: 12/27/2022] Open
Abstract
PURPOSE Mn2+ is used as a contrast agent and marker for neuronal activity with magnetic resonance imaging (MRI) in rats and mice, but its accumulation is generally not assessed quantitatively. In this work, nonradioactive Mn and 52 Mn are injected simultaneously in rats, and imaged with MRI, positron emission tomography (PET) and autoradiography (AR). Mn distributions are compared between modalities, to assess the potential and limitations on quantification of Mn with MRI, and to investigate the potential of multimodal measurement of Mn accumulation. METHODS MRI (in vivo), PET (in vivo and post mortem), and AR (ex vivo) were acquired of rat brains, for which animals received simultaneous intraperitoneal (IP) or intracerebrovertricular (ICV)-targeted injections containing the positron-emitting radionuclide 52 Mn and additional nonradioactive MnCl2 , which acts as an MRI contrast agent. Pre and postinjection MR images were fit for the longitudinal relaxation rate (R1), coregistered, and subtracted to generate R1 difference maps, which are expected to be proportional to change in Mn concentration in tissue. AR and PET images were coregistered to smoothed R1 difference maps. RESULTS Similar spatial distributions were seen across modalities, with Mn accumulation in the colliculus, near the injection site, and in the 4th ventricle. There was no 52 Mn accumulation measurable with PET in the brain after IP injection. In areas of very highly localized and concentrated 52 Mn accumulation in PET or AR, consistent increases of R1 were not seen with MRI. Scatter plots of corresponding voxel R1 difference and PET or AR signal intensity were generated and fit with least squares linear models within anatomical regions. Linear correlations were observed, particularly in regions away from very highly localized and concentrated Mn accumulation at the injection site and the 4th ventricle. Accounting for radioactive decay of 52 Mn, the MnCl2 longitudinal relaxivity was between 4.0 and 5.1 s-1 /mM, which is within 22% of the in vitro relaxivity. CONCLUSIONS This proof-of-concept study demonstrates that MR has strong potential for quantitative assessment of Mn accumulation in the brain, although local discrepancies from linear correlation suggest limitations to this use of MR in areas of inflammation or very high concentrations of Mn. These discrepancies also suggest that a combination of modalities may have additional utility for discriminating between different pools of Mn accumulation in tissue.
Collapse
Affiliation(s)
- Geoffrey J Topping
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, V6T 2B5, Canada.,Klinikum rechts der Isar, Nuklearmedizinische Klinik und Poliklinik, Technische Universität München, München, 81675, Germany
| | - Andrew Yung
- MRI Research Centre, University of British Columbia, Vancouver, British Columbia, V6T 2B5, Canada
| | - Paul Schaffer
- Nuclear Medicine, TRIUMF, Vancouver, British Columbia, V6T 2A3, Canada
| | - Cornelia Hoehr
- Nuclear Medicine, TRIUMF, Vancouver, British Columbia, V6T 2A3, Canada
| | - Rick Kornelsen
- Pacific Parkinson's Research Centre, University of British Columbia, Vancouver, British Columbia, V6T 2B5, Canada
| | - Piotr Kozlowski
- MRI Research Centre, University of British Columbia, Vancouver, British Columbia, V6T 2B5, Canada
| | - Vesna Sossi
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, V6T 2B5, Canada
| |
Collapse
|
31
|
Poplawsky AJ, Fukuda M, Kim SG. Foundations of layer-specific fMRI and investigations of neurophysiological activity in the laminarized neocortex and olfactory bulb of animal models. Neuroimage 2017; 199:718-729. [PMID: 28502845 DOI: 10.1016/j.neuroimage.2017.05.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 05/02/2017] [Accepted: 05/11/2017] [Indexed: 12/25/2022] Open
Abstract
Laminar organization of neuronal circuits is a recurring feature of how the brain processes information. For instance, different layers compartmentalize different cell types, synaptic activities, and have unique intrinsic and extrinsic connections that serve as units for specialized signal processing. Functional MRI is an invaluable tool to investigate laminar processing in the in vivo human brain, but it measures neuronal activity indirectly by way of the hemodynamic response. Therefore, the accuracy of high-resolution laminar fMRI depends on how precisely it can measure localized microvascular changes nearest to the site of evoked activity. To determine the specificity of fMRI responses to the true neurophysiological responses across layers, the flexibility to invasive procedures in animal models has been necessary. In this review, we will examine different fMRI contrasts and their appropriate uses for layer-specific fMRI, and how localized laminar processing was examined in the neocortex and olfactory bulb. Through collective efforts, it was determined that microvessels, including capillaries, are regulated within single layers and that several endogenous and contrast-enhanced fMRI contrast mechanisms can separate these neural-specific vascular changes from the nonspecific, especially cerebral blood volume-weighted fMRI with intravenous contrast agent injection. We will also propose some open questions that are relevant for the successful implementation of layer-specific fMRI and its potential future directions to study laminar processing when combined with optogenetics.
Collapse
Affiliation(s)
- Alexander John Poplawsky
- Neuroimaging Laboratory, Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Mitsuhiro Fukuda
- Neuroimaging Laboratory, Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Seong-Gi Kim
- Center for Neuroscience Imaging Research, Institute of Basic Science, Suwon 440-746, Republic of Korea; Department of Biomedical Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea
| |
Collapse
|
32
|
Keilholz SD, Pan WJ, Billings J, Nezafati M, Shakil S. Noise and non-neuronal contributions to the BOLD signal: applications to and insights from animal studies. Neuroimage 2016; 154:267-281. [PMID: 28017922 DOI: 10.1016/j.neuroimage.2016.12.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 10/21/2016] [Accepted: 12/08/2016] [Indexed: 01/08/2023] Open
Abstract
The BOLD signal reflects hemodynamic events within the brain, which in turn are driven by metabolic changes and neural activity. However, the link between BOLD changes and neural activity is indirect and can be influenced by a number of non-neuronal processes. Motion and physiological cycles have long been known to affect the BOLD signal and are present in both humans and animal models. Differences in physiological baseline can also contribute to intra- and inter-subject variability. The use of anesthesia, common in animal studies, alters neural activity, vascular tone, and neurovascular coupling. Most intriguing, perhaps, are the contributions from other processes that do not appear to be neural in origin but which may provide information about other aspects of neurophysiology. This review discusses different types of noise and non-neuronal contributors to the BOLD signal, sources of variability for animal studies, and insights to be gained from animal models.
Collapse
Affiliation(s)
- Shella D Keilholz
- Wallace H. Coulter Department of Biomedical Engineering, Emory University/Georgia Institute of Technology, Atlanta, GA, United States; Neuroscience Program, Emory University, Atlanta, GA, United States.
| | - Wen-Ju Pan
- Wallace H. Coulter Department of Biomedical Engineering, Emory University/Georgia Institute of Technology, Atlanta, GA, United States
| | - Jacob Billings
- Neuroscience Program, Emory University, Atlanta, GA, United States
| | - Maysam Nezafati
- Wallace H. Coulter Department of Biomedical Engineering, Emory University/Georgia Institute of Technology, Atlanta, GA, United States
| | - Sadia Shakil
- Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, United States
| |
Collapse
|
33
|
Gálosi R, Szalay C, Aradi M, Perlaki G, Pál J, Steier R, Lénárd L, Karádi Z. Identifying non-toxic doses of manganese for manganese-enhanced magnetic resonance imaging to map brain areas activated by operant behavior in trained rats. Magn Reson Imaging 2016; 37:122-133. [PMID: 27889621 DOI: 10.1016/j.mri.2016.11.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 11/21/2016] [Accepted: 11/22/2016] [Indexed: 12/13/2022]
Abstract
Manganese-enhanced magnetic resonance imaging (MEMRI) offers unique advantages such as studying brain activation in freely moving rats, but its usefulness has not been previously evaluated during operant behavior training. Manganese in a form of MnCl2, at a dose of 20mg/kg, was intraperitoneally infused. The administration was repeated and separated by 24h to reach the dose of 40mg/kg or 60mg/kg, respectively. Hepatotoxicity of the MnCl2 was evaluated by determining serum aspartate aminotransferase, alanine aminotransferase, total bilirubin, albumin and protein levels. Neurological examination was also carried out. The animals were tested in visual cue discriminated operant task. Imaging was performed using a 3T clinical MR scanner. T1 values were determined before and after MnCl2 administrations. Manganese-enhanced images of each animal were subtracted from their baseline images to calculate decrease in the T1 value (ΔT1) voxel by voxel. The subtracted T1 maps of trained animals performing visual cue discriminated operant task, and those of naive rats were compared. The dose of 60mg/kg MnCl2 showed hepatotoxic effect, but even these animals did not exhibit neurological symptoms. The dose of 20 and 40mg/kg MnCl2 increased the number of omissions and did not affect the accuracy of performing the visual cue discriminated operant task. Using the accumulated dose of 40mg/kg, voxels with a significant enhanced ΔT1 value were detected in the following brain areas of the visual cue discriminated operant behavior performed animals compared to those in the controls: the visual, somatosensory, motor and premotor cortices, the insula, cingulate, ectorhinal, entorhinal, perirhinal and piriform cortices, hippocampus, amygdala with amygdalohippocampal areas, dorsal striatum, nucleus accumbens core, substantia nigra, and retrorubral field. In conclusion, the MEMRI proved to be a reliable method to accomplish brain activity mapping in correlation with the operant behavior of freely moving rodents.
Collapse
Affiliation(s)
- Rita Gálosi
- Institute of Physiology, Medical School of University of Pécs, Pécs, Hungary.
| | - Csaba Szalay
- Institute of Physiology, Medical School of University of Pécs, Pécs, Hungary.
| | | | - Gábor Perlaki
- Neurosurgery Clinic, Medical School of University of Pécs, Pécs, Hungary; Pécs Diagnostic Center, Pécs, Hungary
| | - József Pál
- Neurosurgery Clinic, Medical School of University of Pécs, Pécs, Hungary
| | - Roy Steier
- Neurosurgery Clinic, Medical School of University of Pécs, Pécs, Hungary.
| | - László Lénárd
- Institute of Physiology, Medical School of University of Pécs, Pécs, Hungary; Molecular Neuroendocrinology and Neurophysiology Research Group, Szentágothai Research Center, University of Pécs, Pécs, Hungary
| | - Zoltán Karádi
- Institute of Physiology, Medical School of University of Pécs, Pécs, Hungary; Molecular Neuroendocrinology and Neurophysiology Research Group, Szentágothai Research Center, University of Pécs, Pécs, Hungary
| |
Collapse
|
34
|
Zhang X, Li CX. Arterial spin labeling perfusion magnetic resonance imaging of non-human primates. Quant Imaging Med Surg 2016; 6:573-581. [PMID: 27942478 DOI: 10.21037/qims.2016.10.05] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Non-human primates (NHPs) resemble most aspects of humans in brain physiology and anatomy and are excellent animal models for translational research in neuroscience, biomedical research and pharmaceutical development. Cerebral blood flow (CBF) offers essential physiological information of the brain to examine the abnormal functionality in NHP models with cerebral vascular diseases and neurological disorders or dementia. Arterial spin labeling (ASL) perfusion MRI techniques allow for high temporal and spatial CBF measurement and are intensively used in studies of animals and humans. In this article, current high-resolution ASL perfusion MRI techniques for quantitative evaluation of brain physiology and function in NHPs are described and their applications and limitation are discussed as well.
Collapse
Affiliation(s)
- Xiaodong Zhang
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA;; Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA, 30329, USA
| | - Chun-Xia Li
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA
| |
Collapse
|
35
|
Cardenas DP, Muir ER, Duong TQ. MRI of cerebral blood flow under hyperbaric conditions in rats. NMR IN BIOMEDICINE 2016; 29:961-968. [PMID: 27192391 PMCID: PMC4998963 DOI: 10.1002/nbm.3555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 03/03/2016] [Accepted: 04/11/2016] [Indexed: 06/05/2023]
Abstract
Hyperbaric oxygen (HBO) therapy has a number of clinical applications. However, the effects of acute HBO on basal cerebral blood flow (CBF) and neurovascular coupling are not well understood. This study explored the use of arterial spin labeling MRI to evaluate changes in baseline and forepaw stimulus-evoked CBF responses in rats (n = 8) during normobaric air (NB), normobaric oxygen (NBO) (100% O2 ), 3 atm absolute (ATA) hyperbaric air (HB) and 3 ATA HBO conditions. T1 was also measured, and the effects of changes in T1 caused by increasing oxygen on the CBF calculation were investigated. The major findings were as follows: (i) increased inhaled oxygen concentrations led to a reduced respiration rate; (ii) increased dissolved paramagnetic oxygen had significant effects on blood and tissue T1 , which affected the CBF calculation using the arterial spin labeling method; (iii) the differences in blood T1 had a larger effect than the differences in tissue T1 on CBF calculation; (iv) if oxygen-induced changes in blood and tissue T1 were not taken into account, CBF was underestimated by 33% at 3 ATA HBO, 10% at NBO and <5% at HB; (v) with correction, CBF values under HBO, HB and NBO were similar (p > 0.05) and all were higher than CBF under NB by ~40% (p < 0.05), indicating that hypercapnia from the reduced respiration rate masks oxygen-induced vasoconstriction, although blood gas was not measured; and (vi) substantial stimulus-evoked CBF increases were detected under HBO, similar to NB, supporting the notion that activation-induced CBF regulation in the brain does not operate through an oxygen-sensing mechanism. CBF MRI provides valuable insights into the effects of oxygen on basal CBF and neurovascular coupling under hyperbaric conditions. Copyright © 2016 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Damon P. Cardenas
- Research Imaging Institute, University of Texas Health Science Center, San Antonio, TX, USA
- Graduate School of Biomedical Science, University of Texas at San Antonio, San Antonio, TX, USA
| | - Eric R. Muir
- Research Imaging Institute, University of Texas Health Science Center, San Antonio, TX, USA
- Department of Ophthalmology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Timothy Q. Duong
- Research Imaging Institute, University of Texas Health Science Center, San Antonio, TX, USA
- Department of Ophthalmology, University of Texas Health Science Center, San Antonio, TX, USA
- South Texas Veterans Health Care System, Department of Veterans Affairs, San Antonio, TX, USA
| |
Collapse
|
36
|
Shen Q, Huang S, Duong TQ. T2*-weighted fMRI time-to-peak of oxygen challenge in ischemic stroke. J Cereb Blood Flow Metab 2016; 36:283-91. [PMID: 26661164 PMCID: PMC4759668 DOI: 10.1177/0271678x15606461] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 07/11/2015] [Indexed: 11/16/2022]
Abstract
T2 (*)-weighted MRI of transient oxygen challenge (OC) showed exaggerated OC percent changes in the ischemic tissue at risk compared to normal tissue. One ambiguity is that regions with high vascular density also showed exaggerated OC percent changes. This study explored time-to-peak (TTP) of the OC percent changes to improve the utility of T2 (*)-weighted OC MRI. Experiments were performed longitudinally at 30 min, 150 min and 24 h after transient (60-min) stroke in rats. Ischemic core, normal, and mismatch tissue were classified pixel-by-pixel based on apparent diffusion coefficient and cerebral blood flow. Major findings were: (i) Delayed OC TTP was localized to and corresponded well with the perfusion-diffusion mismatch. (ii) By contrast, the exaggerated OC percent changes were less localized, with changes not only in the at-risk tissue but also in some areas of the contralesional hemisphere with venous vessel origins. (iii) The OC time-course of the mismatch tissue was biphasic, with a faster initial increase followed by a slower increase. (iv) At-risk tissue with delayed TTP and exaggerated OC was normal after reperfusion and the at-risk tissue was mostly (83 ± 18%) rescued by reperfusion as indicated by normal 24-h T2. OC TTP offers unique information toward better characterization of at-risk tissue in ischemic stroke.
Collapse
Affiliation(s)
- Qiang Shen
- Research Imaging Institute, University of Texas Health Science Center, San Antonio, TX, USA Department of Ophthalmology, University of Texas Health Science Center, San Antonio, TX, USA Department of Radiology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Shiliang Huang
- Research Imaging Institute, University of Texas Health Science Center, San Antonio, TX, USA
| | - Timothy Q Duong
- Research Imaging Institute, University of Texas Health Science Center, San Antonio, TX, USA Department of Ophthalmology, University of Texas Health Science Center, San Antonio, TX, USA Department of Radiology, University of Texas Health Science Center, San Antonio, TX, USA South Texas Veterans Health Care System, Department of Veterans Affairs, San Antonio, TX, USA
| |
Collapse
|
37
|
Shen Q, Watts LT, Li W, Duong TQ. Magnetic Resonance Imaging in Experimental Traumatic Brain Injury. Methods Mol Biol 2016; 1462:645-58. [PMID: 27604743 DOI: 10.1007/978-1-4939-3816-2_35] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Traumatic brain injury (TBI) is a leading cause of death and disability in the USA. Common causes of TBI include falls, violence, injuries from wars, and vehicular and sporting accidents. The initial direct mechanical damage in TBI is followed by progressive secondary injuries such as brain swelling, perturbed cerebral blood flow (CBF), abnormal cerebrovascular reactivity (CR), metabolic dysfunction, blood-brain-barrier disruption, inflammation, oxidative stress, and excitotoxicity, among others. Magnetic resonance imaging (MRI) offers the means to noninvasively probe many of these secondary injuries. MRI has been used to image anatomical, physiological, and functional changes associated with TBI in a longitudinal manner. This chapter describes controlled cortical impact (CCI) TBI surgical procedures, a few common MRI protocols used in TBI imaging, and, finally, image analysis pertaining to experimental TBI imaging in rats.
Collapse
Affiliation(s)
- Qiang Shen
- Research Imaging Institute, University of Texas Health Science Center, 8403 Floyd Curl Dr, San Antonio, TX, 78229, USA. .,Department of Ophthalmology, University of Texas Health Science Center, San Antonio, TX, USA. .,Department of Radiology, University of Texas Health Science Center, San Antonio, TX, USA.
| | - Lora Tally Watts
- Research Imaging Institute, University of Texas Health Science Center, 8403 Floyd Curl Dr, San Antonio, TX, 78229, USA.,Departments of Cellular and Structure Biology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Wei Li
- Research Imaging Institute, University of Texas Health Science Center, 8403 Floyd Curl Dr, San Antonio, TX, 78229, USA.,Department of Ophthalmology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Timothy Q Duong
- Research Imaging Institute, University of Texas Health Science Center, 8403 Floyd Curl Dr, San Antonio, TX, 78229, USA. .,Department of Ophthalmology, University of Texas Health Science Center, San Antonio, TX, USA. .,Department of Radiology, University of Texas Health Science Center, San Antonio, TX, USA. .,Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio, TX, USA.
| |
Collapse
|
38
|
Lau C, Pienkowski M, Zhang JW, McPherson B, Wu EX. Chronic exposure to broadband noise at moderate sound pressure levels spatially shifts tone-evoked responses in the rat auditory midbrain. Neuroimage 2015; 122:44-51. [DOI: 10.1016/j.neuroimage.2015.07.065] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 07/10/2015] [Accepted: 07/24/2015] [Indexed: 02/09/2023] Open
|
39
|
Berkowitz BA, Bissig D, Roberts R. MRI of rod cell compartment-specific function in disease and treatment in vivo. Prog Retin Eye Res 2015; 51:90-106. [PMID: 26344734 DOI: 10.1016/j.preteyeres.2015.09.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 08/26/2015] [Accepted: 09/01/2015] [Indexed: 10/23/2022]
Abstract
Rod cell oxidative stress is a major pathogenic factor in retinal disease, such as diabetic retinopathy (DR) and retinitis pigmentosa (RP). Personalized, non-destructive, and targeted treatment for these diseases remains elusive since current imaging methods cannot analytically measure treatment efficacy against rod cell compartment-specific oxidative stress in vivo. Over the last decade, novel MRI-based approaches that address this technology gap have been developed. This review summarizes progress in the development of MRI since 2006 that enables earlier evaluation of the impact of disease on rod cell compartment-specific function and the efficacy of anti-oxidant treatment than is currently possible with other methods. Most of the new assays of rod cell compartment-specific function are based on endogenous contrast mechanisms, and this is expected to facilitate their translation into patients with DR and RP, and other oxidative stress-based retinal diseases.
Collapse
Affiliation(s)
- Bruce A Berkowitz
- Dept. of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, USA; Dept. Of Ophthalmology, Wayne State University School of Medicine, Detroit, MI, USA.
| | - David Bissig
- Dept. of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Robin Roberts
- Dept. Of Ophthalmology, Wayne State University School of Medicine, Detroit, MI, USA
| |
Collapse
|
40
|
Muir ER, Chandra SB, De La Garza BH, Velagapudi C, Abboud HE, Duong TQ. Layer-Specific Manganese-Enhanced MRI of the Diabetic Rat Retina in Light and Dark Adaptation at 11.7 Tesla. Invest Ophthalmol Vis Sci 2015; 56:4006-12. [PMID: 26098468 DOI: 10.1167/iovs.14-16128] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To employ high-resolution manganese-enhanced MRI (MEMRI) to study abnormal calcium activity in different cell layers in streptozotocin-induced diabetic rat retinas, and to determine whether MEMRI detects changes at earlier time points than previously reported. METHODS Sprague-Dawley rats were studied 14 days (n = 8) and 30 days (n = 5) after streptozotocin (STZ) or vehicle (n = 7) injection. Manganese-enhanced MRI at 20 × 20 × 700 μm, in which contrast is based on manganese as a calcium analogue and an MRI contrast agent, was obtained in light and dark adaptation of the retina in the same animals in which one eye was covered and the fellow eye was not. The MEMRI activity encoding of the light and dark adaptation was achieved in awake conditions and imaged under anesthesia. RESULTS Manganese-enhanced MRI showed three layers, corresponding to the inner retina, outer retina, and the choroid. In normal animals, the outer retina showed higher MEMRI activity in dark compared to light; the inner retina displayed lower activity in dark compared to light; and the choroid showed no difference in activity. Manganese-enhanced MRI activity changed as early as 14 days after hyperglycemia and decreased with duration of hyperglycemia in the outer retina in dark relative to light adaptation. The choroid also had altered MEMRI activity at 14 days, which returned to normal by 30 days. No differences in MEMRI activity were detected in the inner retina. CONCLUSIONS Manganese-enhanced MRI detects progressive reduction in calcium activity with duration of hyperglycemia in the outer retina as early as 14 days after hyperglycemia, earlier than any other time point reported in the literature.
Collapse
Affiliation(s)
- Eric R Muir
- Research Imaging Institute, University of Texas Health Science Center, San Antonio, Texas, United States 2Departments of Ophthalmology, Radiology, and Physiology, University of Texas Health Science Center, San Antonio, Texas, United States
| | - Saurav B Chandra
- Research Imaging Institute, University of Texas Health Science Center, San Antonio, Texas, United States
| | - Bryan H De La Garza
- Research Imaging Institute, University of Texas Health Science Center, San Antonio, Texas, United States
| | - Chakradhar Velagapudi
- Department of Medicine, University of Texas Health Science Center, San Antonio, Texas, United States
| | - Hanna E Abboud
- Department of Medicine, University of Texas Health Science Center, San Antonio, Texas, United States
| | - Timothy Q Duong
- Research Imaging Institute, University of Texas Health Science Center, San Antonio, Texas, United States 2Departments of Ophthalmology, Radiology, and Physiology, University of Texas Health Science Center, San Antonio, Texas, United States 4South Texas Ve
| |
Collapse
|
41
|
Macey PM. Altered Resting Cerebral Blood Flow in Obstructive Sleep Apnea: A Helpful Change or Not? Sleep 2015; 38:1345-7. [PMID: 26285008 DOI: 10.5665/sleep.4962] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 07/29/2015] [Indexed: 11/03/2022] Open
Affiliation(s)
- Paul M Macey
- UCLA School of Nursing; Brain Research Institute, University of California at Los Angeles, Los Angeles, CA
| |
Collapse
|
42
|
Malheiros JM, Paiva FF, Longo BM, Hamani C, Covolan L. Manganese-Enhanced MRI: Biological Applications in Neuroscience. Front Neurol 2015. [PMID: 26217304 PMCID: PMC4498388 DOI: 10.3389/fneur.2015.00161] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Magnetic resonance imaging (MRI) is an excellent non-invasive tool to investigate biological systems. The administration of the paramagnetic divalent ion manganese (Mn2+) enhances MRI contrast in vivo. Due to similarities between Mn2+ and calcium (Ca2+), the premise of manganese-enhanced MRI (MEMRI) is that the former may enter neurons and other excitable cells through voltage-gated Ca2+ channels. As such, MEMRI has been used to trace neuronal pathways, define morphological boundaries, and study connectivity in morphological and functional imaging studies. In this article, we provide a brief overview of MEMRI and discuss recently published data to illustrate the usefulness of this method, particularly in animal models.
Collapse
Affiliation(s)
- Jackeline Moraes Malheiros
- Department of Physiology, Universidade Federal de São Paulo - UNIFESP , São Paulo , Brazil ; Centro de Imagens e Espectroscopia In vivo por Ressonância Magnética, Institute of Physics of São Carlos, Universidade de São Paulo , São Carlos , Brazil
| | - Fernando Fernandes Paiva
- Centro de Imagens e Espectroscopia In vivo por Ressonância Magnética, Institute of Physics of São Carlos, Universidade de São Paulo , São Carlos , Brazil
| | - Beatriz Monteiro Longo
- Department of Physiology, Universidade Federal de São Paulo - UNIFESP , São Paulo , Brazil
| | - Clement Hamani
- Department of Physiology, Universidade Federal de São Paulo - UNIFESP , São Paulo , Brazil ; Research Imaging Centre, Centre for Addiction and Mental Health , Toronto, ON , Canada ; Centre for Addiction and Mental Health, Campbell Family Mental Health Research Institute , Toronto, ON , Canada
| | - Luciene Covolan
- Department of Physiology, Universidade Federal de São Paulo - UNIFESP , São Paulo , Brazil
| |
Collapse
|
43
|
Manganese-Enhanced MRI Reflects Both Activity-Independent and Activity-Dependent Uptake within the Rat Habenulomesencephalic Pathway. PLoS One 2015; 10:e0127773. [PMID: 26009889 PMCID: PMC4443977 DOI: 10.1371/journal.pone.0127773] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 04/20/2015] [Indexed: 11/19/2022] Open
Abstract
Manganese-enhanced magnetic resonance imaging (MEMRI) is a powerful technique for assessing the functional connectivity of neurons within the central nervous system. Despite the widely held proposition that MEMRI signal is dependent on neuronal activity, few studies have directly tested this implicit hypothesis. In the present series of experiments, MnCl2 was injected into the habenula of urethane-anesthetized rats alone or in combination with drugs known to alter neuronal activity by modulating specific voltage- and/or ligand-gated ion channels. Continuous quantitative T1 mapping was used to measure Mn2+ accumulation in the interpeduncular nucleus, a midline structure in which efferents from the medial habenula terminate. Microinjection of MnCl2 into the habenular complex using a protocol that maintained spontaneous neuronal activity resulted in a time-dependent increase in MEMRI signal intensity in the interpeduncular nucleus consistent with fast axonal transport of Mn2+ between these structures. Co-injection of the excitatory amino-acid agonist AMPA, increased the Mn2+-enhanced signal intensity within the interpeduncular nucleus. AMPA-induced increases in MEMRI signal were attenuated by co-injection of either the sodium channel blocker, TTX, or broad-spectrum Ca2+ channel blocker, Ni2+, and were occluded in the presence of both channel blockers. However, neither Ni2+ nor TTX, alone or in combination, attenuated the increase in signal intensity following injection of Mn2+ into the habenula. These results support the premise that changes in neuronal excitability are reflected by corresponding changes in MEMRI signal intensity. However, they also suggest that basal rates of Mn2+ uptake by neurons in the medial habenula may also occur via activity-independent mechanisms.
Collapse
|
44
|
Talley Watts L, Shen Q, Deng S, Chemello J, Duong TQ. Manganese-Enhanced Magnetic Resonance Imaging of Traumatic Brain Injury. J Neurotrauma 2015; 32:1001-10. [PMID: 25531419 DOI: 10.1089/neu.2014.3737] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Calcium dysfunction is involved in secondary traumatic brain injury (TBI). Manganese-enhanced MRI (MEMRI), in which the manganese ion acts as a calcium analog and a MRI contrast agent, was used to study rats subjected to a controlled cortical impact. Comparisons were made with conventional T2 MRI, sensorimotor behavior, and immunohistology. The major findings were: (1) Low-dose manganese (29 mg/kg) yielded excellent contrast with no negative effects on behavior scores relative to vehicle; (2) T1-weighted MEMRI was hyperintense in the impact area at 1-3 h, hypointense on day 2, and markedly hypointense with a hyperintense area surrounding the core on days 7 and/or 14, in contrast to the vehicle group, which did not show a biphasic profile; (3) in the hyperacute phase, the area of hyperintense T1-weighted MEMRI was larger than that of T2 MRI; (4) glial fibrillary acidic protein staining revealed that the MEMRI signal void in the impact core and the hyperintense area surrounding the core on day 7 and/or 14 corresponded to tissue cavitation and reactive gliosis, respectively; (5) T2 MRI showed little contrast in the impact core at 2 h, hyperintense on day 2 (indicative of vasogenic edema), hyperintense in some animals but pseudonormalized in others on day 7 and/or 14; (6) behavioral deficit peaked on day 2. We concluded that MEMRI detected early excitotoxic injury in the hyperacute phase, preceding vasogenic edema. In the subacute phase, MEMRI detected contrast consistent with tissue cavitation and reactive gliosis. MEMRI offers novel contrasts of biological processes that complement conventional MRI in TBI.
Collapse
Affiliation(s)
- Lora Talley Watts
- 1 Research Imaging Institute, University of Texas Health Science Center , San Antonio, Texas.,2 Department of Cellular and Structure Biology, University of Texas Health Science Center , San Antonio, Texas.,3 Department of Neurology, University of Texas Health Science Center , San Antonio, Texas
| | - Qiang Shen
- 1 Research Imaging Institute, University of Texas Health Science Center , San Antonio, Texas.,4 Department of Ophthalmology, University of Texas Health Science Center , San Antonio, Texas
| | - Shengwen Deng
- 1 Research Imaging Institute, University of Texas Health Science Center , San Antonio, Texas
| | - Jonathan Chemello
- 1 Research Imaging Institute, University of Texas Health Science Center , San Antonio, Texas
| | - Timothy Q Duong
- 1 Research Imaging Institute, University of Texas Health Science Center , San Antonio, Texas.,4 Department of Ophthalmology, University of Texas Health Science Center , San Antonio, Texas.,5 South Texas Veterans Health Care System , San Antonio, Texas
| |
Collapse
|
45
|
Shen Q, Huang S, Duong TQ. Ultra-high spatial resolution basal and evoked cerebral blood flow MRI of the rat brain. Brain Res 2014; 1599:126-36. [PMID: 25557404 DOI: 10.1016/j.brainres.2014.12.049] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 12/19/2014] [Accepted: 12/23/2014] [Indexed: 11/18/2022]
Abstract
Cerebral blood flow (CBF) is tightly coupled to metabolism and neural activity under normal physiological conditions, and is often perturbed in disease states. The goals of this study were to implement a high-resolution (up to 50×38μm(2)) CBF MRI protocol of the rat brain, create a digital CBF atlas, report CBF values for 30+ brain structures based on the atlas, and explore applications of high-resolution CBF fMRI of forepaw stimulation. Excellent blood-flow contrasts were observed among different cortical and subcortical structures. CBF MRI showed column-like alternating bright and dark bands in the neocortices, reflecting the layout of descending arterioles and ascending venules, respectively. CBF MRI also showed lamina-like alternating bright and dark layers across the cortical thicknesses, consistent with the underlying vascular density. CBF profiles across the cortical thickness showed two peaks in layers IV and VI and a shallow trough in layer V. Whole-brain CBF was about 0.89ml/g/min, with the highest CBF values found amongst the neocortical structures (1ml/g/min, range: 0.89-1.16ml/g/min) and the lowest CBF values in the corpus callosum (0.32ml/g/min), yielding a gray:white matter CBF ratio of 3.1. CBF fMRI responses peaked across layers IV-V, whereas the BOLD fMRI responses showed a peak in the superficial layers II-III. High-resolution basal CBF MRI, evoked CBF fMRI, and CBF brain atlas can be used to study neurological disorders (such as ischemic stroke).
Collapse
Affiliation(s)
- Qiang Shen
- Research Imaging Institute, University of Texas Health Science Center, San Antonio, 8403 Floyd Curl Dr, TX 78229, United States; Department of Ophthalmology, University of Texas Health Science Center, San Antonio, TX, United States
| | - Shiliang Huang
- Research Imaging Institute, University of Texas Health Science Center, San Antonio, 8403 Floyd Curl Dr, TX 78229, United States
| | - Timothy Q Duong
- Research Imaging Institute, University of Texas Health Science Center, San Antonio, 8403 Floyd Curl Dr, TX 78229, United States; Department of Ophthalmology, University of Texas Health Science Center, San Antonio, TX, United States; Department of Radiology, University of Texas Health Science Center, San Antonio, TX, United States; Department of Physiology, University of Texas Health Science Center, San Antonio, TX, United States; South Texas Veterans Health Care System, San Antonio, TX, United States.
| |
Collapse
|
46
|
Auffret M, Samim I, Lepore M, Gruetter R, Just N. Quantitative activity-induced manganese-dependent MRI for characterizing cortical layers in the primary somatosensory cortex of the rat. Brain Struct Funct 2014; 221:695-707. [PMID: 25366973 DOI: 10.1007/s00429-014-0933-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 10/24/2014] [Indexed: 11/29/2022]
Abstract
The ability of Mn(2+) to follow Ca(2+) pathways upon stimulation transform them into remarkable surrogate markers of neuronal activity using activity-induced manganese-dependent MRI (AIM-MRI). In the present study, a precise follow-up of physiological parameters during MnCl2 and mannitol infusions improved the reproducibility of AIM-MRI allowing in-depth evaluation of the technique. Pixel-by-pixel T1 data were investigated using histogram distributions in the barrel cortex (BC) and the thalamus before and after Mn(2+) infusion, after blood brain barrier opening and after BC activation. Mean BC T1 values dropped significantly upon trigeminal nerve (TGN) stimulation (-38 %, P = 0.02) in accordance with previous literature findings. T1 histogram distributions showed that 34 % of T1s in the range 600-1500 ms after Mn(2+ )+ mannitol infusions shifted to 50-350 ms after TGN stimulation corresponding to a twofold increase of the percentage of pixels with the lowest T1s in BC. Moreover, T1 changes in response to stimulation increased significantly from superficial cortical layers (I-III) to deeper layers (V-VI). Cortical cytoarchitecture detection during a functional paradigm was performed extending the potential of AIM-MRI. Quantitative AIM-MRI could thus offer a means to interpret local neural activity across cortical layers while identification of the role of calcium dynamics in vivo during brain activation could play a key role in resolving neurovascular coupling mechanisms.
Collapse
Affiliation(s)
- Matthieu Auffret
- Laboratory for Functional and Metabolic Imaging (LIFMET), Centre d'Imagerie Biomédicale-Animal Imaging and Technology Core (CIBM-AIT), Ecole Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
| | - Idrees Samim
- Laboratory for Functional and Metabolic Imaging (LIFMET), Centre d'Imagerie Biomédicale-Animal Imaging and Technology Core (CIBM-AIT), Ecole Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
| | - Mario Lepore
- Laboratory for Functional and Metabolic Imaging (LIFMET), Centre d'Imagerie Biomédicale-Animal Imaging and Technology Core (CIBM-AIT), Ecole Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
| | - Rolf Gruetter
- Laboratory for Functional and Metabolic Imaging (LIFMET), Centre d'Imagerie Biomédicale-Animal Imaging and Technology Core (CIBM-AIT), Ecole Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
| | - Nathalie Just
- Laboratory for Functional and Metabolic Imaging (LIFMET), Centre d'Imagerie Biomédicale-Animal Imaging and Technology Core (CIBM-AIT), Ecole Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland.
| |
Collapse
|
47
|
Abstract
A plethora of magnetic resonance (MR) techniques developed in the last two decades provide unique and noninvasive measurement capabilities for studies of basic brain function and brain diseases in humans. Animal model experiments have been an indispensible part of this development. MR imaging and spectroscopy measurements have been employed in animal models, either by themselves or in combination with complementary and often invasive techniques, to enlighten us about the information content of such MR methods and/or verify observations made in the human brain. They have also been employed, with or independently of human efforts, to examine mechanisms underlying pathological developments in the brain, exploiting the wealth of animal models available for such studies. In this endeavor, the desire to push for ever-higher spatial and/or spectral resolution, better signal-to-noise ratio, and unique image contrast has inevitably led to the introduction of increasingly higher magnetic fields. As a result, today, animal model studies are starting to be conducted at magnetic fields ranging from ~ 11 to 17 Tesla, significantly enhancing the armamentarium of tools available for the probing brain function and brain pathologies.
Collapse
Affiliation(s)
- Gülin Öz
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, USA
| | | | | |
Collapse
|
48
|
Chan MW, Nathanael G, Kis A, Amirabadi A, Zhong A, Rayner T, Weiss R, Detzler G, Jong R, Gahunia H, Moineddin R, Crawley A, Doria AS. Systematic protocol for assessment of the validity of BOLD MRI in a rabbit model of inflammatory arthritis at 1.5 tesla. Pediatr Radiol 2014; 44:566-75. [PMID: 24366603 DOI: 10.1007/s00247-013-2844-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 10/04/2013] [Accepted: 11/15/2013] [Indexed: 11/25/2022]
Abstract
BACKGROUND Blood-oxygen-level-dependent (BOLD) MRI has the potential to identify regions of early hypoxic and vascular joint changes in inflammatory arthritis. There is no standard protocol for analysis of BOLD MRI measurements in musculoskeletal disorders. OBJECTIVE To optimize the following BOLD MRI reading parameters: (1) statistical threshold values (low, r > 0.01 versus high, r > 0.2); (2) summary measures of BOLD contrast (percentage of activated voxels [PT%] versus percentage signal difference between on-and-off signal intensities [diff_on_off]); and (3) direction of BOLD response (positive, negative and positive + negative). MATERIALS AND METHODS Using BOLD MRI protocols at 1.5 T, arthritic (n = 21) and contralateral (n = 21) knees of 21 juvenile rabbits were imaged at baseline and on days 1, 14 and 28 after a unilateral intra-articular injection of carrageenan. Nine non-injected rabbits served as external control knees (n = 18). By comparing arthritic to contralateral knees, receiver operating characteristic curves were used to determine diagnostic accuracy. RESULTS Using diff_on_off and positive + negative responses, a threshold of r > 0.01 was more accurate than r > 0.2 (P = 0.03 at day 28). Comparison of summary measures yielded no statistically significant difference (P > 0.05). Although positive + negative (AUC = 0.86 at day 28) and negative responses (AUC = 0.90 at day 28) for PT% were the most diagnostically accurate, positive + negative responses for diff_on_off (AUC = 0.78 at day 28) also had acceptable accuracy. CONCLUSIONS The most clinically relevant reading parameters included a lower threshold of r > 0.01 and a positive + negative BOLD response. We propose that diff_on_off is a more clinically relevant summary measure of BOLD MRI, while PT% can be used as an ancillary measure.
Collapse
Affiliation(s)
- Michael W Chan
- Department of Diagnostic Imaging, The Hospital for Sick Children, 555 University Ave., Toronto, Canada, M5G 1X8
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Li SJ, Jiang L, Fu X, Huang S, Huang YN, Li XR, Chen JW, Li Y, Luo HL, Wang F, Ou SY, Jiang YM. Pallidal index as biomarker of manganese brain accumulation and associated with manganese levels in blood: a meta-analysis. PLoS One 2014; 9:e93900. [PMID: 24718592 PMCID: PMC3981755 DOI: 10.1371/journal.pone.0093900] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Accepted: 03/09/2014] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVE The current study was designed to evaluate the sensitivity, feasibility, and effectiveness of the pallidal index (PI) serving as a biomarker of brain manganese (Mn) accumulation, which would be used as an early diagnosis criteria for Mn neurotoxicity. METHODS The weighted mean difference (WMD) of the PI between control and Mn-exposed groups was estimated by using a random-effects or fixed-effects meta-analysis with 95% confidence interval (CI) performed by STATA software version 12.1. Moreover, the R package "metacor" was used to estimate correlation coefficients between PI and blood Mn (MnB). RESULTS A total of eight studies with 281 occupationally Mn-exposed workers met the inclusion criteria. Results were pooled and performed with the Meta-analysis. Our data indicated that the PI of the exposed group was significantly higher than that of the control (WMD: 7.76; 95% CI: 4.86, 10.65; I2 = 85.7%, p<0.0001). A random effects model was used to perform meta-analysis. These findings were remarkably robust in the sensitivity analysis, and publication bias was shown in the included studies. Seven out of the eight studies reported the Pearson correlation (r) values. Significantly positive correlation between PI and MnB was observed (r = 0.42; 95% CI, 0.31, 0.52). CONCLUSIONS PI can be considered as a sensitive, feasible, effective and semi-quantitative index in evaluating brain Mn accumulation. MnB can also augment the evaluation of brain Mn accumulation levels in the near future. However, the results should be interpreted with caution.
Collapse
Affiliation(s)
- Shao-Jun Li
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Li Jiang
- Department of Radiotherapy, the First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Xue Fu
- School of Health Sciences, Purdue University, West Lafayette, Indiana, United States of America
| | - Shuang Huang
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Yan-Ni Huang
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Xiang-Rong Li
- Department of Radiology, the First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Jing-Wen Chen
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Yong Li
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Hai-Lan Luo
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Fang Wang
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Shi-Yan Ou
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Yue-Ming Jiang
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
- * E-mail:
| |
Collapse
|
50
|
Manganese enhanced magnetic resonance imaging (MEMRI): a powerful new imaging method to study tinnitus. Hear Res 2014; 311:49-62. [PMID: 24583078 DOI: 10.1016/j.heares.2014.02.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 02/05/2014] [Accepted: 02/10/2014] [Indexed: 12/31/2022]
Abstract
Manganese enhanced magnetic resonance imaging (MEMRI) is a method used primarily in basic science experiments to advance the understanding of information processing in central nervous system pathways. With this mechanistic approach, manganese (Mn(2+)) acts as a calcium surrogate, whereby voltage-gated calcium channels allow for activity driven entry of Mn(2+) into neurons. The detection and quantification of neuronal activity via Mn(2+) accumulation is facilitated by "hemodynamic-independent contrast" using high resolution MRI scans. This review emphasizes initial efforts to-date in the development and application of MEMRI for evaluating tinnitus (the perception of sound in the absence of overt acoustic stimulation). Perspectives from leaders in the field highlight MEMRI related studies by comparing and contrasting this technique when tinnitus is induced by high-level noise exposure and salicylate administration. Together, these studies underscore the considerable potential of MEMRI for advancing the field of auditory neuroscience in general and tinnitus research in particular. Because of the technical and functional gaps that are filled by this method and the prospect that human studies are on the near horizon, MEMRI should be of considerable interest to the auditory research community. This article is part of a Special Issue entitled <Annual Reviews 2014>.
Collapse
|