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Karat BG, Köhler S, Khan AR. Diffusion MRI of the Hippocampus. J Neurosci 2024; 44:e1705232024. [PMID: 38839341 PMCID: PMC11154849 DOI: 10.1523/jneurosci.1705-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Revised: 03/22/2024] [Accepted: 04/06/2024] [Indexed: 06/07/2024] Open
Abstract
The hippocampus is a brain structure that plays key roles in a variety of cognitive processes. Critically, a wide range of neurological disorders are associated with degeneration of the hippocampal microstructure, defined as neurons, dendrites, glial cells, and more. Thus, the hippocampus is a key target for methods that are sensitive to these microscale properties. Diffusion MRI is one such method, which can noninvasively probe neural architecture. Here we review the extensive use of diffusion MRI to capture hippocampal microstructure in both health and disease. The results of these studies indicate that (1) diffusion tensor imaging is sensitive but not specific to the hippocampal microstructure; (2) biophysical modeling of diffusion MRI signals is a promising avenue to capture more specific aspects of the hippocampal microstructure; (3) use of ultra-short diffusion times have shown unique laminar-specific microstructure and response to hippocampal injury; (4) dispersion of microstructure is likely abundant in the hippocampus; and (5) the angular richness of the diffusion MRI signal can be leveraged to improve delineation of the internal hippocampal circuitry. Overall, extant findings suggest that diffusion MRI offers a promising avenue for characterizing hippocampal microstructure.
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Affiliation(s)
- Bradley G Karat
- Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario N6A 3K7, Canada
- Neuroscience Graduate Program, University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Stefan Köhler
- Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario N6A 3K7, Canada
- Department of Psychology, University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Ali R Khan
- Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario N6A 3K7, Canada
- Western Institute for Neuroscience, University of Western Ontario, London, Ontario N6A 3K7, Canada
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2
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Dai E, Zhu A, Yang GK, Quah K, Tan ET, Fiveland E, Foo TKF, McNab JA. Frequency-dependent diffusion kurtosis imaging in the human brain using an oscillating gradient spin echo sequence and a high-performance head-only gradient. Neuroimage 2023; 279:120328. [PMID: 37586445 PMCID: PMC10529993 DOI: 10.1016/j.neuroimage.2023.120328] [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: 03/15/2023] [Revised: 07/17/2023] [Accepted: 08/12/2023] [Indexed: 08/18/2023] Open
Abstract
Measuring the time/frequency dependence of diffusion MRI is a promising approach to distinguish between the effects of different tissue microenvironments, such as membrane restriction, tissue heterogeneity, and compartmental water exchange. In this study, we measure the frequency dependence of diffusivity (D) and kurtosis (K) with oscillating gradient diffusion encoding waveforms and a diffusion kurtosis imaging (DKI) model in human brains using a high-performance, head-only MAGNUS gradient system, with a combination of b-values, oscillating frequencies (f), and echo time that has not been achieved in human studies before. Frequency dependence of diffusivity and kurtosis are observed in both global and local white matter (WM) and gray matter (GM) regions and characterized with a power-law model ∼Λ*fθ. The frequency dependences of diffusivity and kurtosis (including changes between fmin and fmax, Λ, and θ) vary over different WM and GM regions, indicating potential microstructural differences between regions. A trend of decreasing kurtosis over frequency in the short-time limit is successfully captured for in vivo human brains. The effects of gradient nonlinearity (GNL) on frequency-dependent diffusivity and kurtosis measurements are investigated and corrected. Our results show that the GNL has prominent scaling effects on the measured diffusivity values (3.5∼5.5% difference in the global WM and 6∼8% difference in the global cortex) and subsequently affects the corresponding power-law parameters (Λ, θ) while having a marginal influence on the measured kurtosis values (<0.05% difference) and power-law parameters (Λ, θ). This study expands previous OGSE studies and further demonstrates the translatability of frequency-dependent diffusivity and kurtosis measurements to human brains, which may provide new opportunities to probe human brain microstructure in health and disease.
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Affiliation(s)
- Erpeng Dai
- Department of Radiology, Stanford University, Stanford, CA, USA.
| | | | - Grant K Yang
- Department of Radiology, Stanford University, Stanford, CA, USA; Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - Kristin Quah
- Department of Radiology, Stanford University, Stanford, CA, USA; Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - Ek T Tan
- Department of Radiology and Imaging, Hospital for Special Surgery, New York, NY, USA
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3
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Salarinejad A, Esmaeilpour K, Shabani M, Jafarinejad-Farsangi S, Pardakhty A, Asadi-Shekaari M, Ahmadi-Zeidabadi M. Effect of l-Dopa in acute temozolomide-induced cognitive impairment in male mice: a possible antineuroinflammatory role. Behav Pharmacol 2023:00008877-990000000-00047. [PMID: 37401406 DOI: 10.1097/fbp.0000000000000733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2023]
Abstract
Temozolomide is used commonly in the treatment of some types of cancers, but it may also result in cognitive impairments such as memory deficits. l-Dopa, a well known medicine for the central nervous system, has been shown to have positive effects on some cognitive disorders. Here we sought to investigate the effect of l-Dopa on temozolomide-induced cognitive impairments. BALB/c mice were subjected to 3-days temozolomide and 6-days concomitant l-Dopa/benserazide administration in six groups (control, l-Dopa 25 mg/kg, l-Dopa 75 mg/kg, temozolomide, temozolomide + l-Dopa 25 mg/kg, and temozolomide + l-Dopa 75 mg/kg). Open field test, object location recognition, novel object recognition test, and shuttle-box test were carried out to determine the locomotor, anxiety-like behavior, and memory function of subjects. TNF-α and brain-derived neurotrophic factor (BDNF) gene expression in the hippocampus was measured by real-time PCR. Mice treated with temozolomide showed recognition memory impairment, along with hippocampal TNF-α and BDNF mRNA expression level raise, and detection of histological insults in hematoxylin and eosin hippocampal slides. Mice that received temozolomide + l-Dopa showed normal behavioral function and lower TNF-α and BDNF hippocampal mRNA expression levels, and histologically normal hippocampal CA1 region in comparison with mice in the temozolomide group. Our results provide evidence that l-Dopa prevents temozolomide-induced recognition memory deficit in mice at the acute phase probably via l-Dopa antineuroinflammatory effects.
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Affiliation(s)
| | | | | | | | - Abbas Pardakhty
- Pharmaceutics Research Center, Institute of Neuropharmacology, Kerman University of Medical Science, Kerman, Iran
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4
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Chen X, Zhang J, Wu Y, Tucker R, Baird GL, Domonoske R, Barrios-Anderson A, Lim YP, Bath K, Walsh EG, Stonestreet BS. Inter-alpha Inhibitor Proteins Ameliorate Brain Injury and Improve Behavioral Outcomes in a Sex-Dependent Manner After Exposure to Neonatal Hypoxia Ischemia in Newborn and Young Adult Rats. Neurotherapeutics 2022; 19:528-549. [PMID: 35290609 PMCID: PMC9226254 DOI: 10.1007/s13311-022-01217-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2022] [Indexed: 12/16/2022] Open
Abstract
Hypoxic-ischemic (HI) brain injury is a major contributor to neurodevelopmental morbidities. Inter-alpha inhibitor proteins (IAIPs) have neuroprotective effects on HI-related brain injury in neonatal rats. However, the effects of treatment with IAIPs on sequential behavioral, MRI, and histopathological abnormalities in the young adult brain after treatment with IAIPs in neonates remain to be determined. The objective of this study was to examine the neuroprotective effects of IAIPs at different neurodevelopmental stages from newborn to young adults after exposure of neonates to HI injury. IAIPs were given as 11-sequential 30-mg/kg doses to postnatal (P) day 7-21 rats after right common carotid artery ligation and exposure to 90 min of 8% oxygen. The resulting brain edema and injury were examined by T2-weighted magnetic resonance imaging (MRI) and cresyl violet staining, respectively. The mean T2 values of the ipsilateral hemisphere from MRI slices 6 to 10 were reduced in IAIP-treated HI males + females on P8, P9, and P10 and females on P8, P9, P10, and P14. IAIP treatment reduced hemispheric volume atrophy by 44.5 ± 29.7% in adult male + female P42 rats and improved general locomotor abilities measured by the righting reflex over time at P7.5, P8, and P9 in males + females and males and muscle strength/endurance measured by wire hang on P16 in males + females and females. IAIPs provided beneficial effects during the learning phase of the Morris water maze with females exhibiting beneficial effects. IAIPs confer neuroprotection from HI-related brain injury in neonates and even in adult rats and beneficial MRI and behavioral benefits in a sex-dependent manner.
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Affiliation(s)
- Xiaodi Chen
- Department of Pediatrics, Infants Hospital of Rhode Island, Warren Alpert Medical School of Brown University, Women &101 Dudley Street, Providence, RI, 02905-2499, USA
| | - Jiyong Zhang
- Department of Pediatrics, Infants Hospital of Rhode Island, Warren Alpert Medical School of Brown University, Women &101 Dudley Street, Providence, RI, 02905-2499, USA
| | - Yuqi Wu
- Department of Pediatrics, Infants Hospital of Rhode Island, Warren Alpert Medical School of Brown University, Women &101 Dudley Street, Providence, RI, 02905-2499, USA
| | - Richard Tucker
- Department of Pediatrics, Infants Hospital of Rhode Island, Warren Alpert Medical School of Brown University, Women &101 Dudley Street, Providence, RI, 02905-2499, USA
| | - Grayson L Baird
- Department of Diagnostic Imaging, Biostatistics Core Lifespan Hospital System, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Rose Domonoske
- Department of Pediatrics, Infants Hospital of Rhode Island, Warren Alpert Medical School of Brown University, Women &101 Dudley Street, Providence, RI, 02905-2499, USA
| | - Adriel Barrios-Anderson
- Department of Pediatrics, Infants Hospital of Rhode Island, Warren Alpert Medical School of Brown University, Women &101 Dudley Street, Providence, RI, 02905-2499, USA
| | - Yow-Pin Lim
- ProThera Biologics, Inc, Providence, RI, USA
- Department of Pathology and Laboratory Medicine, Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Kevin Bath
- Division of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY, USA
- Department of Psychiatry, Columbia University Irving Medical College, New York, NY, USA
| | - Edward G Walsh
- Department of Neuroscience, Brown University, Providence, RI, USA
| | - Barbara S Stonestreet
- Department of Pediatrics, Infants Hospital of Rhode Island, Warren Alpert Medical School of Brown University, Women &101 Dudley Street, Providence, RI, 02905-2499, USA.
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5
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Liang Z, Lee CH, Arefin TM, Dong Z, Walczak P, Hai Shi S, Knoll F, Ge Y, Ying L, Zhang J. Virtual mouse brain histology from multi-contrast MRI via deep learning. eLife 2022; 11:72331. [PMID: 35088711 PMCID: PMC8837198 DOI: 10.7554/elife.72331] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 01/27/2022] [Indexed: 11/16/2022] Open
Abstract
1H MRI maps brain structure and function non-invasively through versatile contrasts that exploit inhomogeneity in tissue micro-environments. Inferring histopathological information from magnetic resonance imaging (MRI) findings, however, remains challenging due to absence of direct links between MRI signals and cellular structures. Here, we show that deep convolutional neural networks, developed using co-registered multi-contrast MRI and histological data of the mouse brain, can estimate histological staining intensity directly from MRI signals at each voxel. The results provide three-dimensional maps of axons and myelin with tissue contrasts that closely mimic target histology and enhanced sensitivity and specificity compared to conventional MRI markers. Furthermore, the relative contribution of each MRI contrast within the networks can be used to optimize multi-contrast MRI acquisition. We anticipate our method to be a starting point for translation of MRI results into easy-to-understand virtual histology for neurobiologists and provide resources for validating novel MRI techniques.
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Affiliation(s)
- Zifei Liang
- Department of Radiology, New York University School of Medicine, New York, United States
| | - Choong H Lee
- Department of Radiology, New York University School of Medicine, New York, United States
| | - Tanzil M Arefin
- Department of Radiology, New York University School of Medicine, New York, United States
| | - Zijun Dong
- Department of Radiology, New York University School of Medicine, New York, United States
| | - Piotr Walczak
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland, Baltimore, United States
| | - Song Hai Shi
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center
| | - Florian Knoll
- Department of Radiology, New York University School of Medicine, New York, United States
| | - Yulin Ge
- Department of Radiology, New York University School of Medicine, New York, United States
| | - Leslie Ying
- Departments of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, United States
| | - Jiangyang Zhang
- Department of Radiology, New York University School of Medicine, New York, United States
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6
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Gao F, Shen X, Zhang H, Ba R, Ma X, Lai C, Zhang J, Zhang Y, Wu D. Feasibility of oscillating and pulsed gradient diffusion MRI to assess neonatal hypoxia-ischemia on clinical systems. J Cereb Blood Flow Metab 2021; 41:1240-1250. [PMID: 32811261 PMCID: PMC8142137 DOI: 10.1177/0271678x20944353] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Diffusion-time- (td) dependent diffusion MRI (dMRI) extends our ability to characterize brain microstructure by measuring dMRI signals at varying td. The use of oscillating gradient (OG) is essential for accessing short td but is technically challenging on clinical MRI systems. This study aims to investigate the clinical feasibility and value of td-dependent dMRI in neonatal hypoxic-ischemic encephalopathy (HIE). Eighteen HIE neonates and six normal term-born neonates were scanned on a 3 T scanner, with OG-dMRI at an oscillating frequency of 33 Hz (equivalent td ≈ 7.5 ms) and pulsed gradient (PG)-dMRI at a td of 82.8 ms and b-value of 700 s/mm2. The td-dependence, as quantified by the difference in apparent diffusivity coefficients between OG- and PG-dMRI (ΔADC), was observed in the normal neonatal brains, and the ΔADC was higher in the subcortical white matter than the deep grey matter. In HIE neonates with severe and moderate injury, ΔADC significantly increased in the basal ganglia (BG) compared to the controls (23.7% and 10.6%, respectively). In contrast, the conventional PG-ADC showed a 12.6% reduction only in the severe HIE group. White matter edema regions also demonstrated increased ΔADC, where PG-ADC did not show apparent changes. Our result demonstrated that td-dependent dMRI provided high sensitivity in detecting moderate-to-severe HIE.
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Affiliation(s)
- Fusheng Gao
- Department of Radiology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Xiaoxia Shen
- Department of Neonatal Intensive Care Unit, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Hongxi Zhang
- Department of Radiology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Ruicheng Ba
- Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, China
| | - Xiaolu Ma
- Department of Neonatal Intensive Care Unit, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Can Lai
- Department of Radiology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Jiangyang Zhang
- Department of Radiology, New York University School of Medicine, New York, NY, USA
| | - Yi Zhang
- Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, China
| | - Dan Wu
- Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, China
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7
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Xu J. Probing neural tissues at small scales: Recent progress of oscillating gradient spin echo (OGSE) neuroimaging in humans. J Neurosci Methods 2020; 349:109024. [PMID: 33333089 PMCID: PMC10124150 DOI: 10.1016/j.jneumeth.2020.109024] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 12/16/2022]
Abstract
The detection sensitivity of diffusion MRI (dMRI) is dependent on diffusion times. A shorter diffusion time can increase the sensitivity to smaller length scales. However, the conventional dMRI uses the pulse gradient spin echo (PGSE) sequence that probes relatively long diffusion times only. To overcome this, the oscillating gradient spin echo (OGSE) sequence has been developed to probe much shorter diffusion times with hardware limitations on preclinical and clinical MRI systems. The OGSE sequence has been previously used on preclinical animal MRI systems. Recently, several studies have translated the OGSE sequence to humans on clinical MRI systems and achieved new information that is invisible using conventional PGSE sequence. This paper provides an overview of the recent progress of the OGSE neuroimaging in humans, including the technical improvements in the translation of the OGSE sequence to human imaging and various applications in different neurological disorders and stroke. Some possible future directions of the OGSE sequence are also discussed.
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Affiliation(s)
- Junzhong Xu
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, 37232, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, 37232, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, 37232, USA; Department of Physics and Astronomy, Vanderbilt University, Nashville, TN, 37232, USA.
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8
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de Almeida W, Confortim HD, Deniz BF, Miguel PM, Vieira MC, Bronauth L, Dos Santos AS, Bertoldi K, Siqueira IR, Pereira LO. Acrobatic exercise recovers object recognition memory impairment in hypoxic-ischemic rats. Int J Dev Neurosci 2020; 81:60-70. [PMID: 33135304 DOI: 10.1002/jdn.10075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 10/17/2020] [Accepted: 10/28/2020] [Indexed: 11/08/2022] Open
Abstract
Neonatal hypoxia-ischemia (HI) can lead to cognitive impairments and motor dysfunction. Acrobatic exercises (AE) were proposing as therapeutic option to manage HI motor deficits, however, the cognitive effects after this treatment are still poorly understood. Therefore, we evaluated the effects of AE protocol on memory impairments and brain plasticity markers after Rice-Vannucci HI rodent model. Wistar rats on the 7th postnatal day (PND) were submitted to HI model and after weaning (PND22) were trained for 5 weeks with AE protocol, then subsequently submitted to cognitive tests. Our results showed recovery in novel object recognition (NOR) memory, but not, spatial Morris Water Maze (WM) memory after AE treatment in HI rats. BDNF and synaptophysin neuroplasticity markers indicate plastic alterations in the hippocampus and striatum, with maintenance of synaptophysin despite the reduction of total volume tissue, besides, hippocampal HI-induced ipsilateral BDNF increased, and striatum contralateral BDNF decreased were noted. Nevertheless, the exercise promoted functional recovery and seems to be a promising strategy for HI treatment, however, future studies identifying neuroplastic pathway for this improvement are needed.
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Affiliation(s)
- Wellington de Almeida
- Programa de Pós-Graduação em Neurociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Departamento de Ciências Morfológicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Heloísa Deola Confortim
- Programa de Pós-Graduação em Neurociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,UNIVEL Centro Universitário, Cascavel, Brazil
| | - Bruna Ferrary Deniz
- Programa de Pós-Graduação em Neurociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Departamento de Ciências Morfológicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Patrícia Maidana Miguel
- Programa de Pós-Graduação em Neurociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Departamento de Ciências Morfológicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Milene Cardoso Vieira
- Departamento de Ciências Morfológicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Loise Bronauth
- Departamento de Ciências Morfológicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Adriana Souza Dos Santos
- Programa de Pós-Graduação em Neurociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Departamento de Ciências Morfológicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Karine Bertoldi
- Departamento de Farmacologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Ionara Rodrigues Siqueira
- Departamento de Farmacologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Programa de Pós-Graduação em Ciências Biológicas, Fisiologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Lenir Orlandi Pereira
- Programa de Pós-Graduação em Neurociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Departamento de Ciências Morfológicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
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Namgyal D, Chandan K, Sultan A, Aftab M, Ali S, Mehta R, El-Serehy HA, Al-Misned FA, Sarwat M. Dim Light at Night Induced Neurodegeneration and Ameliorative Effect of Curcumin. Cells 2020; 9:cells9092093. [PMID: 32933226 PMCID: PMC7565558 DOI: 10.3390/cells9092093] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 08/28/2020] [Accepted: 09/05/2020] [Indexed: 12/16/2022] Open
Abstract
It is a well-known fact that following a proper routine light/dark or diurnal rhythm controls almost all biological processes. With the introduction of modern lighting and artificial illumination systems, continuous exposure to light at night may lead to the disruption of diurnal rhythm. However, the effect of light during the night on brain anatomy, physiology, and human body functions is less explored and poorly understood. In this study, we have evaluated the effect of exposure to dim light (5 lux) at night (dLAN) on Swiss Albino mice over a duration of three consecutive weeks. Results have revealed that exposure to dLAN led to an impairment of cognitive and non-cognitive behaviour, oxidative stress–mediated elevation of lipid peroxidation, and reduction of superoxide dismutase and catalase activity. It also led to the downregulation of hippocampal proteins (BDNF, Synapsin II and DCX) at both protein and mRNA level. Additionally, there was downregulation of CREB and SIRT1 mRNAs and neurodegeneration-associated miRNA21a-5p and miRNA34a-5p. The pyramidal and cortical neurons started showing pyknotic and chromatolysis characteristics. However, a dose of curcumin administered to the mice positively modulated these parameters in our experimental animals. We proposed the modulatory role of curcumin in addressing the deleterious effects of dLAN.
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Affiliation(s)
- Dhondup Namgyal
- Amity Institute of Neuropsychology and Neuroscience, Amity University, Noida UP 201303, India; (D.N.); (R.M.)
- Amity Institute of Pharmacy, Amity University, Noida UP 201303, India;
| | - Kumari Chandan
- Amity Institute of Pharmacy, Amity University, Noida UP 201303, India;
| | - Armiya Sultan
- Center for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi 110025, India;
| | - Mehreen Aftab
- Amity Institute of Molecular Medicine and Stem Cell Research, Amity University, Noida UP 201303, India;
| | - Sher Ali
- School of Basic Sciences and Research, Department of Life Sciences, Sharda University, Greater Noida, Uttar Pradesh 201310, India;
| | - Rachna Mehta
- Amity Institute of Neuropsychology and Neuroscience, Amity University, Noida UP 201303, India; (D.N.); (R.M.)
| | - Hamed A. El-Serehy
- Department of Zoology, College of Science, King Saud University, Riyadh l1451, Saudi Arabia; (H.A.E.-S.); (F.A.A.-M.)
| | - Fahad A. Al-Misned
- Department of Zoology, College of Science, King Saud University, Riyadh l1451, Saudi Arabia; (H.A.E.-S.); (F.A.A.-M.)
| | - Maryam Sarwat
- Amity Institute of Pharmacy, Amity University, Noida UP 201303, India;
- Correspondence: Correspondence: ; Tel.: +91-12-0439-2472
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10
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Namgyal D, Ali S, Mehta R, Sarwat M. The neuroprotective effect of curcumin against Cd-induced neurotoxicity and hippocampal neurogenesis promotion through CREB-BDNF signaling pathway. Toxicology 2020; 442:152542. [PMID: 32735850 DOI: 10.1016/j.tox.2020.152542] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 07/14/2020] [Accepted: 07/25/2020] [Indexed: 02/07/2023]
Abstract
Heavy metal neurotoxicity is one of the major challenges in today's era due to the large scale and widespread mechanisation of the production. However, the causative factors responsible for neurotoxicity are neither known nor do we have the availability of therapeutic approaches to deal with it. One of the major causative agents of neurotoxicity is a non-essential transition heavy metal, Cadmium (Cd), that reaches the central nervous system (CNS) through the nasal mucosa and olfactory pathway causing adverse structural and functional effects. In this study, we explored the neuroprotective efficacy of plant derived Curcumin which is reported to have pleiotropic biological activity including anti-oxidant, anti-inflammatory, anti-apoptotic, anti-carcinogenic and anti-angiogenic effects. Four different concentrations of curcumin (20, 40, 80 and 160 mg/kg of the body weight) were used to assess the behavioural, biochemical, hippocampal proteins (BDNF, CREB, DCX and Synapsin II) and histological changes in Swiss Albino mice that were pre-treated with Cd (2.5 mg/kg). The findings showed that Cd exposure led to the behavioural impairment through oxidative stress, reduction of hippocampal neurogenesis associated proteins, and degeneration of CA3 and cortical neurons. However, treatment of different curcumin concentrations had effectively restored the behavioural changes in Cd-exposed mice through regulation of oxidative stress and up-regulation of hippocampal proteins in a dose-dependent manner. Significantly, a dose of 160 mg/kg body weight was found to be glaringly effective. From this study, we infer that curcumin reverses the adverse effects of neurotoxicity induced by Cd and promotes neurogenesis.
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Affiliation(s)
- Dhondup Namgyal
- Amity Institute of Neuropsychology and Neuroscience, Amity University, Noida, UP, 201303, India; Amity Institute of Pharmacy, Amity University, Noida, UP, 201303, India
| | - Sher Ali
- Center for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi, 110025, India
| | - Rachna Mehta
- Amity Institute of Neuropsychology and Neuroscience, Amity University, Noida, UP, 201303, India
| | - Maryam Sarwat
- Amity Institute of Pharmacy, Amity University, Noida, UP, 201303, India.
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Wu D, Liu D, Hsu YC, Li H, Sun Y, Qin Q, Zhang Y. Diffusion-prepared 3D gradient spin-echo sequence for improved oscillating gradient diffusion MRI. Magn Reson Med 2020; 85:78-88. [PMID: 32643240 DOI: 10.1002/mrm.28401] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/03/2020] [Accepted: 06/07/2020] [Indexed: 12/22/2022]
Abstract
PURPOSE Oscillating gradient (OG) enables the access of short diffusion times for time-dependent diffusion MRI (dMRI); however, it poses several technical challenges for clinical use. This study proposes a 3D oscillating gradient-prepared gradient spin-echo (OGprep-GRASE) sequence to improve SNR and shorten acquisition time for OG dMRI on clinical scanners. METHODS The 3D OGprep-GRASE sequence consisted of global saturation, diffusion encoding, fat saturation, and GRASE readout modules. Multiplexed sensitivity-encoding reconstruction was used to correct the phase errors between multiple shots. We compared the scan time and SNR of the proposed sequence and the conventional 2D-EPI sequence for OG dMRI at 30-90-mm slice coverage. We also examined the time-dependent diffusivity changes with OG dMRI acquired at frequencies of 50 Hz and 25 Hz and pulsed-gradient dMRI at diffusion times of 30 ms and 60 ms. RESULTS The OGprep-GRASE sequence reduced the scan time by a factor of 1.38, and increased the SNR by 1.74-2.27 times compared with 2D EPI for relatively thick slice coverage (60-90 mm). The SNR gain led to improved diffusion-tensor reconstruction in the multishot protocols. Image distortion in 2D-EPI images was also reduced in GRASE images. Diffusivity measurements from the pulsed-gradient dMRI and OG dMRI showed clear diffusion-time dependency in the white matter and gray matter of the human brain, using both the GRASE and EPI sequences. CONCLUSION The 3D OGprep-GRASE sequence improved scan time and SNR and reduced image distortion compared with the 2D multislice acquisition for OG dMRI on a 3T clinical system, which may facilitate the clinical translation of time-dependent dMRI.
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Affiliation(s)
- Dan Wu
- Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, Zhejiang, China
| | - Dapeng Liu
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,F.M. Kirby Research Csenter for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Yi-Cheng Hsu
- MR Collaboration, Siemens Healthcare China, Shanghai, China
| | - Haotian Li
- Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yi Sun
- MR Collaboration, Siemens Healthcare China, Shanghai, China
| | - Qin Qin
- The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,F.M. Kirby Research Csenter for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Yi Zhang
- Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, Zhejiang, China.,Department of Neurology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
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12
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Aggarwal M, Smith MD, Calabresi PA. Diffusion-time dependence of diffusional kurtosis in the mouse brain. Magn Reson Med 2020; 84:1564-1578. [PMID: 32022313 DOI: 10.1002/mrm.28189] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 01/06/2020] [Accepted: 01/07/2020] [Indexed: 12/28/2022]
Abstract
PURPOSE To investigate diffusion-time dependency of diffusional kurtosis in the mouse brain using pulsed-gradient spin-echo (PGSE) and oscillating-gradient spin-echo (OGSE) sequences. METHODS 3D PGSE and OGSE kurtosis tensor data were acquired from ex vivo brains of adult, cuprizone-treated, and age-matched control mice with diffusion-time (tD ) ~ 20 ms and frequency (f) = 70 Hz, respectively. Further, 2D acquisitions were performed at multiple times/frequencies ranging from f = 140 Hz to tD = 30 ms with b-values up to 4000 s/mm2 . Monte Carlo simulations were used to investigate the coupled effects of varying restriction size and permeability on time/frequency-dependence of kurtosis with both diffusion-encoding schemes. Simulations and experiments were further performed to investigate the effect of varying number of cycles in OGSE waveforms. RESULTS Kurtosis and diffusivity maps exhibited significant region-specific changes with diffusion time/frequency across both gray and white matter areas. PGSE- and OGSE-based kurtosis maps showed reversed contrast between gray matter regions in the cerebellar and cerebral cortex. Localized time/frequency-dependent changes in kurtosis tensor metrics were found in the splenium of the corpus callosum in cuprizone-treated mouse brains, corresponding to regional demyelination seen with histological assessment. Monte Carlo simulations showed that kurtosis estimates with pulsed- and oscillating-gradient waveforms differ in their sensitivity to exchange. Both simulations and experiments showed dependence of kurtosis on number of cycles in OGSE waveforms for non-zero permeability. CONCLUSION The results show significant time/frequency-dependency of diffusional kurtosis in the mouse brain, which can provide sensitivity to probe intrinsic cellular heterogeneity and pathological alterations in gray and white matter.
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Affiliation(s)
- Manisha Aggarwal
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Matthew D Smith
- Departments of Neurology and Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Peter A Calabresi
- Departments of Neurology and Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland
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13
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Maxwell JR, Zimmerman AJ, Pavlik N, Newville JC, Carlin K, Robinson S, Brigman JL, Northington FJ, Jantzie LL. Neonatal Hypoxic-Ischemic Encephalopathy Yields Permanent Deficits in Learning Acquisition: A Preclinical Touchscreen Assessment. Front Pediatr 2020; 8:289. [PMID: 32582593 PMCID: PMC7291343 DOI: 10.3389/fped.2020.00289] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 05/07/2020] [Indexed: 12/13/2022] Open
Abstract
Neonatal hypoxic-ischemic encephalopathy (HIE) remains a common problem world-wide for infants born at term. The impact of HIE on long-term outcomes, especially into adulthood, is not well-described. To facilitate identification of biobehavioral biomarkers utilizing a translational platform, we sought to investigate the impact of HIE on executive function and cognitive outcomes into adulthood utilizing a murine model of HIE. HIE mice (unilateral common carotid artery occlusion to induce ischemia, followed by hypoxia with a FiO2 of 0.08 for 45 min) and control mice were tested on discrimination and reversal touchscreen tasks (using their noses) shown to be sensitive to loss of basal ganglia or cortical function, respectively. We hypothesized that the HIE injury would result in deficits in reversal learning, revealing complex cognitive and executive functioning impairments. Following HIE, mice had a mild discrimination impairment as measured by incorrect responses but were able to learn the paradigm to similar levels as controls. During reversal, HIE mice required significantly more total trials, errors and correction trials across the paradigm. Analysis of specific stages showed that reversal impairments in HIE were driven by significant increases in all measured parameters during the late learning, striatal-mediated portion of the task. Together, these results support the concept that HIE occurring during the neonatal period results in abnormal neurodevelopment that persists into adulthood, which can impact efficient associated learning. Further, these data show that utilization of an established model of HIE coupled with touchscreen learning provides valuable information for screening therapeutic interventions that could mitigate these deficits to improve the long-term outcomes of this vulnerable population.
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Affiliation(s)
- Jessie R Maxwell
- Department of Pediatrics, University of New Mexico, Albuquerque, NM, United States.,Department of Neurosciences, University of New Mexico, Albuquerque, NM, United States
| | - Amber J Zimmerman
- Department of Neurosciences, University of New Mexico, Albuquerque, NM, United States
| | - Nathaniel Pavlik
- Department of Pediatrics, University of New Mexico, Albuquerque, NM, United States
| | - Jessie C Newville
- Department of Neurosciences, University of New Mexico, Albuquerque, NM, United States
| | - Katherine Carlin
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Shenandoah Robinson
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Jonathan L Brigman
- Department of Neurosciences, University of New Mexico, Albuquerque, NM, United States
| | - Frances J Northington
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Lauren L Jantzie
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, United States.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States.,Department of Neurology, Kennedy Krieger Institute, Baltimore, MD, United States
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14
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Chavez-Valdez R, Emerson P, Goffigan-Holmes J, Kirkwood A, Martin LJ, Northington FJ. Delayed injury of hippocampal interneurons after neonatal hypoxia-ischemia and therapeutic hypothermia in a murine model. Hippocampus 2019; 28:617-630. [PMID: 29781223 DOI: 10.1002/hipo.22965] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 05/03/2018] [Accepted: 05/13/2018] [Indexed: 01/29/2023]
Abstract
Delayed hippocampal injury and memory impairments follow neonatal hypoxia-ischemia (HI) despite the use of therapeutic hypothermia (TH). Death of hippocampal pyramidal cells occurs acutely after HI, but characterization of delayed cell death and injury of interneurons (INs) is unknown. We hypothesize that injury of INs after HI is: (i) asynchronous to that of pyramidal cells, (ii) independent of injury severity, and (iii) unresponsive to TH. HI was induced in C57BL6 mice at p10 with unilateral right carotid ligation and 45 min of hypoxia (FiO2 = 0.08). Mice were randomized to normothermia (36 °C, NT) or TH (31 °C) for 4 hr after HI and anesthesia-exposed shams were use as controls. Brains were studied at 24 hr (p11) or 8 days (p18) after HI. Vglut1, GAD65/67, PSD95, parvalbumin (PV) and calbindin-1 (Calb1) were measured. Cell death was assessed using cresyl violet staining and TUNEL assay. Hippocampal atrophy and astroglyosis at p18 were used to assess injury severity and to correlate with number of PV + INs. VGlut1 level decreased by 30% at 24 hr after HI, while GAD65/67 level decreased by ∼50% in forebrain 8 days after HI, a decrease localized in CA1 and CA3. PSD95 levels decreased in forebrain by 65% at 24 hr after HI and remained low 8 days after HI. PV + INs increased in numbers (per mm2 ) and branching between p11 and p18 in sham mice but not in NT and TH mice, resulting in 21-52% fewer PV + INs in injured mice at p18. Calb1 protein and mRNA were also reduced in HI injured mice at p18. At p18, somatodendritic attrition of INs was evident in all injured mice without evidence of cell death. Neither hippocampal atrophy nor astroglyosis correlated with the number of PV + INs at p18. Thus, HI exposure has long lasting effects in the hippocampus impairing the development of the GABAergic system with only partial protection by TH independent of the degree of hippocampal injury. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Raul Chavez-Valdez
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Paul Emerson
- Department of Neuroscience, The Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, Maryland
| | - Janasha Goffigan-Holmes
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Alfredo Kirkwood
- Department of Neuroscience, The Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, Maryland
| | - Lee J Martin
- Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, Maryland.,Department of Pathology, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Frances J Northington
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, Maryland
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15
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Jisa KA, Clarey DD, Peeples ES. Magnetic Resonance Imaging Findings of Term and Preterm Hypoxic-Ischemic Encephalopathy: A Review of Relevant Animal Models and Correlation to Human Imaging. Open Neuroimag J 2018; 12:55-65. [PMID: 30450146 PMCID: PMC6198416 DOI: 10.2174/1874440001812010055] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 08/07/2018] [Accepted: 09/16/2018] [Indexed: 11/22/2022] Open
Abstract
Background: Neonatal hypoxic-ischemic encephalopathy is brain injury caused by decreased perfusion and oxygen delivery that most commonly occurs in the context of delivery complications such as umbilical cord compression or placental abruption. Imaging is a key component for guiding treatment and prediction of prognosis, and the most sensitive clinical imaging modality for the brain injury patterns seen in hypoxic-ischemic encephalopathy is magnetic resonance imaging. Objective: The goal of this review is to compare magnetic resonance imaging findings demonstrated in the available animal models of hypoxic-ischemic encephalopathy to those found in preterm (≤ 36 weeks) and term (>36 weeks) human neonates with hypoxic-ischemic encephalopathy, with special attention to the strengths and weaknesses of each model. Methods: A structured literature search was performed independently by two authors and the results of the searches were compiled. Animal model, human brain age equivalency, mechanism of injury, and area of brain injury were recorded for comparison to imaging findings in preterm and term human neonates with hypoxic-ischemic encephalopathy. Conclusion: Numerous animal models have been developed to better elicit the expected findings that occur after HIE by allowing investigators to control many of the clinical variables that result in injury. Although modeling the same disease process, magnetic resonance imaging findings in the animal models vary with the species and methods used to induce hypoxia and ischemia. The further development of animal models of HIE should include a focus on comparing imaging findings, and not just pathologic findings, to human studies.
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Affiliation(s)
- Kyle A Jisa
- Department of Pediatrics, University of Nebraska Medical Center, Omaha, NE, United States
| | - Dillon D Clarey
- Department of Pediatrics, University of Nebraska Medical Center, Omaha, NE, United States
| | - Eric S Peeples
- Department of Pediatrics, University of Nebraska Medical Center, Omaha, NE, United States
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16
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Salas J, Reddy N, Orru E, Carson KA, Chavez-Valdez R, Burton VJ, Stafstrom CE, Northington FJ, Huisman TAGM. The Role of Diffusion Tensor Imaging in Detecting Hippocampal Injury Following Neonatal Hypoxic-Ischemic Encephalopathy. J Neuroimaging 2018; 29:252-259. [PMID: 30325083 DOI: 10.1111/jon.12572] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Revised: 09/12/2018] [Accepted: 10/03/2018] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND AND PURPOSE Neonatal hypoxic-ischemic injury of the brain and resultant encephalopathy (HIE) leads to major developmental impairments by school age. Conventional/anatomical MRI often fails to detect hippocampal injury in mild cases. We hypothesize that diffusion tensor imaging (DTI) has greater sensitivity for identifying subtle hippocampal injury. METHODS We retrospectively analyzed DTI data collected from a cohort of neonates with HIE and controls. Conventional MRI sequences were classified qualitatively according to severity using a modified Barkovich scale. Using multivariate linear regression, we compared hippocampal DTI scalars of HIE patients and controls. Spearman correlation was used to test the association of DTI scalars in the hippocampal and thalamic regions. A multiple regression analysis tested the association of the DTI scalars with short-term outcomes. RESULTS Fifty-five neonates with HIE (42% males) and 13 controls (54% males) were included. Hippocampal DTI scalars were similar between HIE and control groups, even when restricting the HIE group to those with moderate-to-severe injury (8 subjects). DTI scalars of the thalamus were significantly lower in the moderate-to-severely affected patients compared to controls (right fractional anisotropy [FA] .148 vs. .182, P = .01; left FA .147 vs. .181, P = .03). Hippocampal and thalamic DTI scalars were correlated (P < .001). Hippocampal DTI scalars were not associated with short-term outcomes. CONCLUSIONS Quantitative DTI analysis of the hippocampus in neonates following HIE is a feasible technique to examine neuronal injury. Although DTI scalars were useful in identifying thalamic injury in our cohort, hippocampal DTI analysis did not provide additional information regarding hippocampal injury following HIE.
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Affiliation(s)
- Jacqueline Salas
- Division of Neonatology, Department of Pediatrics, The Johns Hopkins University School of Medicine, The Charlotte R. Bloomberg Children's Center, Baltimore, MD.,Neuro-Intensive Care Nursery Group, The Johns Hopkins School of Medicine, Baltimore, MD
| | - Nihaal Reddy
- Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD
| | - Emanuele Orru
- Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD
| | - Kathryn A Carson
- Department of Epidemiology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
| | - Raul Chavez-Valdez
- Division of Neonatology, Department of Pediatrics, The Johns Hopkins University School of Medicine, The Charlotte R. Bloomberg Children's Center, Baltimore, MD.,Neuro-Intensive Care Nursery Group, The Johns Hopkins School of Medicine, Baltimore, MD
| | - Vera Joanna Burton
- Neuro-Intensive Care Nursery Group, The Johns Hopkins School of Medicine, Baltimore, MD.,Department of Neurology and Developmental Medicine, Kennedy Krieger Institute, Baltimore, MD
| | - Carl E Stafstrom
- Neuro-Intensive Care Nursery Group, The Johns Hopkins School of Medicine, Baltimore, MD.,Division of Pediatric Neurology, Department of Neurology, The Johns Hopkins School of Medicine, Baltimore, MD
| | - Frances J Northington
- Division of Neonatology, Department of Pediatrics, The Johns Hopkins University School of Medicine, The Charlotte R. Bloomberg Children's Center, Baltimore, MD.,Neuro-Intensive Care Nursery Group, The Johns Hopkins School of Medicine, Baltimore, MD
| | - Thierry A G M Huisman
- Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD.,Neuro-Intensive Care Nursery Group, The Johns Hopkins School of Medicine, Baltimore, MD
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17
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Wu D, Li Q, Northington FJ, Zhang J. Oscillating gradient diffusion kurtosis imaging of normal and injured mouse brains. NMR IN BIOMEDICINE 2018; 31:e3917. [PMID: 29601111 PMCID: PMC5980785 DOI: 10.1002/nbm.3917] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 02/07/2018] [Accepted: 02/13/2018] [Indexed: 05/25/2023]
Abstract
Recent advances in diffusion MRI employ multiple diffusion encoding schemes with varying diffusion direction, weighting, and diffusion time to investigate specific microstructural properties in biological tissues. In this study, we examined time-dependent diffusion kurtosis contrast in adult mouse brains and in neonatal mouse brains after hypoxic-ischemic (HI) injury. In vivo diffusion kurtosis maps were acquired with a short diffusion time using an oscillating gradient spin echo (OGSE) sequence at 100 Hz and with a relatively long diffusion time (20 ms) using a pulsed gradient spin echo (PGSE) sequence. In the adult mouse brain, we found that the cortex and hippocampus showed larger differences between OGSE kurtosis and PGSE kurtosis than major white matter tracts. In neonatal mouse brains with unilateral HI injury, the OGSE kurtosis map overall provided stronger edema contrast than the PGSE kurtosis map, and the differences between OGSE and PGSE kurtosis measurements in the edema region reflected heterogeneity of injury. This is the first in vivo study that has demonstrated multi-direction OGSE kurtosis contrasts in the mouse brain. Comparing PGSE and OGSE kurtosis measures may provide additional information on microstructural changes after ischemic stroke.
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Affiliation(s)
- Dan Wu
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21205, USA
- Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, China
| | - Qiang Li
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21205, USA
- Department of Radiology, Tangdu Hospital, Fourth Military Medical University, Xi’an, Shaanxi 710038, China
| | - Frances J. Northington
- Division of Neonatology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21205, USA
| | - Jiangyang Zhang
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY 10016, USA
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18
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Stolp HB, Ball G, So PW, Tournier JD, Jones M, Thornton C, Edwards AD. Voxel-wise comparisons of cellular microstructure and diffusion-MRI in mouse hippocampus using 3D Bridging of Optically-clear histology with Neuroimaging Data (3D-BOND). Sci Rep 2018; 8:4011. [PMID: 29507311 PMCID: PMC5838167 DOI: 10.1038/s41598-018-22295-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 02/07/2018] [Indexed: 12/11/2022] Open
Abstract
A key challenge in medical imaging is determining a precise correspondence between image properties and tissue microstructure. This comparison is hindered by disparate scales and resolutions between medical imaging and histology. We present a new technique, 3D Bridging of Optically-clear histology with Neuroimaging Data (3D-BOND), for registering medical images with 3D histology to overcome these limitations. Ex vivo 120 × 120 × 200 μm resolution diffusion-MRI (dMRI) data was acquired at 7 T from adult C57Bl/6 mouse hippocampus. Tissue was then optically cleared using CLARITY and stained with cellular markers and confocal microscopy used to produce high-resolution images of the 3D-tissue microstructure. For each sample, a dense array of hippocampal landmarks was used to drive registration between upsampled dMRI data and the corresponding confocal images. The cell population in each MRI voxel was determined within hippocampal subregions and compared to MRI-derived metrics. 3D-BOND provided robust voxel-wise, cellular correlates of dMRI data. CA1 pyramidal and dentate gyrus granular layers had significantly different mean diffusivity (p > 0.001), which was related to microstructural features. Overall, mean and radial diffusivity correlated with cell and axon density and fractional anisotropy with astrocyte density, while apparent fibre density correlated negatively with axon density. Astrocytes, axons and blood vessels correlated to tensor orientation.
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Affiliation(s)
- H B Stolp
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, St Thomas' Hospital, King's College London, London, SE1 7EH, United Kingdom.,Department of Comparative Biomedical Science, Royal Veterinary College, London, NW1 0TU, United Kingdom
| | - G Ball
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, St Thomas' Hospital, King's College London, London, SE1 7EH, United Kingdom.,Developmental Imaging, Clinical Sciences, Murdoch Children's Research Institute, Melbourne, 3052, Australia
| | - P-W So
- Department of Neuroimaging, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, SE5 9NU, United Kingdom
| | - J-D Tournier
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, St Thomas' Hospital, King's College London, London, SE1 7EH, United Kingdom
| | - M Jones
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, St Thomas' Hospital, King's College London, London, SE1 7EH, United Kingdom
| | - C Thornton
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, St Thomas' Hospital, King's College London, London, SE1 7EH, United Kingdom.
| | - A D Edwards
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, St Thomas' Hospital, King's College London, London, SE1 7EH, United Kingdom
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19
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Dixon BJ, Chen D, Zhang Y, Flores J, Malaguit J, Nowrangi D, Zhang JH, Tang J. Intranasal Administration of Interferon Beta Attenuates Neuronal Apoptosis via the JAK1/STAT3/BCL-2 Pathway in a Rat Model of Neonatal Hypoxic-Ischemic Encephalopathy. ASN Neuro 2016; 8:1759091416670492. [PMID: 27683877 PMCID: PMC5043595 DOI: 10.1177/1759091416670492] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 07/25/2016] [Accepted: 08/22/2016] [Indexed: 12/17/2022] Open
Abstract
Neonatal hypoxic-ischemic encephalopathy (HIE) is an injury that often leads to detrimental neurological deficits. Currently, there are no established therapies for HIE and it is critical to develop treatments that provide protection after HIE. The objective of this study was to investigate the ability of interferon beta (IFNβ) to provide neuroprotection and reduce apoptosis after HIE. Postnatal Day 10 rat pups were subjected to unilateral carotid artery ligation followed by 2.5 hr of exposure to hypoxia (8% O2). Intranasal administration of human recombinant IFNβ occurred 2 hr after HIE and infarct volume, body weight, neurobehavioral tests, histology, immunohistochemistry, brain water content, blood-brain barrier permeability, enzyme-linked immunosorbent assay, and Western blot were all used to evaluate various parameters. The results showed that both IFNβ and the Type 1 interferon receptor expression decreases after HIE. Intranasal administration of human recombinant IFNβ was able to be detected in the central nervous system and was able to reduce brain infarction volumes and improve neurological behavior tests 24 hr after HIE. Western blot analysis also revealed that human recombinant IFNβ treatment stimulated Stat3 and Bcl-2 expression leading to a decrease in cleaved caspase-3 expression after HIE. Positive Fluoro-Jade C staining also demonstrated that IFNβ treatment was able to decrease neuronal apoptosis. Furthermore, the beneficial effects of IFNβ treatment were reversed when a Stat3 inhibitor was applied. Also an intraperitoneal administration of human recombinant IFNβ into the systemic compartment was unable to confer the same protective effects as intranasal IFNβ treatment.
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Affiliation(s)
- Brandon J Dixon
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, CA, USA
| | - Di Chen
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, CA, USA
| | - Yang Zhang
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, CA, USA
| | - Jerry Flores
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, CA, USA
| | - Jay Malaguit
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, CA, USA
| | - Derek Nowrangi
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, CA, USA
| | - John H Zhang
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, CA, USA Department of Neurosurgery, Loma Linda University School of Medicine, CA, USA
| | - Jiping Tang
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, CA, USA
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20
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Wu D, Zhang J. The Effect of Microcirculatory Flow on Oscillating Gradient Diffusion MRI and Diffusion Encoding with Dual-Frequency Orthogonal Gradients (DEFOG). Magn Reson Med 2016; 77:1583-1592. [PMID: 27080566 DOI: 10.1002/mrm.26242] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 02/28/2016] [Accepted: 03/28/2016] [Indexed: 12/23/2022]
Abstract
PURPOSE We investigated the effect of microcirculatory flow on oscillating gradient spin echo (OGSE) diffusion MRI at low b-values and developed a diffusion preparation method called diffusion encoding with dual-frequency orthogonal gradients (DEFOG) to suppress the effect. METHODS Compared to conventional OGSE sequences, DEFOG adds a pulsed gradient that is orthogonal to the oscillating gradient and has a moderate diffusion weighting (e.g., 300 s/mm2 ). In vivo MRI data were acquired from adult mouse brains (n = 5) on an 11.7 Tesla scanner, with diffusion times from 23.2 to 0.83 ms and b-values from 50 to 700 s/mm2 . RESULTS Apparent diffusion coefficients (ADCs) measured using a conventional OGSE sequence at low b-values (< 200 mm2 /s) were significantly higher than those measured at moderate b-values (> 300 mm2 /s), potentially due to contributions from microcirculatory flow. In comparison, OGSE ADCs measured using the DEFOG method at low b-values were comparable to those measured at moderate b-values. The effect of microcirculatory flow on diffusion signals was diffusion time-dependent, and this dependency may reflect the capillary geometry and blood flow velocity in the mouse cortex. CONCLUSION Microcirculatory flow affects OGSE diffusion MRI measurements at low b-values, and this effect can be suppressed using the DEFOG method. Magn Reson Med 77:1583-1592, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Dan Wu
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Jiangyang Zhang
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
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Xu J, Li H, Li K, Harkins KD, Jiang X, Xie J, Kang H, Dortch RD, Anderson AW, Does MD, Gore JC. Fast and simplified mapping of mean axon diameter using temporal diffusion spectroscopy. NMR IN BIOMEDICINE 2016; 29:400-410. [PMID: 27077155 PMCID: PMC4832578 DOI: 10.1002/nbm.3484] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Mapping axon diameter is of interest for the potential diagnosis and monitoring of various neuronal pathologies. Advanced diffusion-weighted MRI methods have been developed to measure mean axon diameters non-invasively, but suffer major drawbacks that prevent their direct translation into clinical practice, such as complex non-linear data fitting and, more importantly, long scanning times that are usually not tolerable for most human subjects. In the current study, temporal diffusion spectroscopy using oscillating diffusion gradients was used to measure mean axon diameters with high sensitivity to small axons in the central nervous system. Axon diameters have been found to be correlated with a novel metric, DDR⊥ (the rate of dispersion of the perpendicular diffusion coefficient with gradient frequency), which is a model-free quantity that does not require complex data analyses and can be obtained from two diffusion coefficient measurements in clinically relevant times with conventional MRI machines. A comprehensive investigation including computer simulations and animal experiments ex vivo showed that measurements of DDR⊥ agree closely with histological data. In humans in vivo, DDR⊥ was also found to correlate well with reported mean axon diameters in human corpus callosum, and the total scan time was only about 8 min. In conclusion, DDR⊥ may have potential to serve as a fast, simple and model-free approach to map the mean axon diameter of white matter in clinics for assessing axon diameter changes.
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Affiliation(s)
- Junzhong Xu
- Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, USA; Department of Physics and Astronomy, Vanderbilt University, Nashville, TN, USA.
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22
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Imaging microstructural damage and plasticity in the hippocampus during epileptogenesis. Neuroscience 2015; 309:162-72. [DOI: 10.1016/j.neuroscience.2015.04.054] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 03/28/2015] [Accepted: 04/21/2015] [Indexed: 12/19/2022]
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Li H, Jiang X, Wang F, Xu J, Gore JC. Structural information revealed by the dispersion of ADC with frequency. Magn Reson Imaging 2015; 33:1083-1090. [PMID: 26117695 DOI: 10.1016/j.mri.2015.06.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 06/20/2015] [Indexed: 01/18/2023]
Abstract
Diffusion MRI provides a non-invasive means to characterize tissue microstructure at varying length scales. Temporal diffusion spectra reveal how the apparent diffusion coefficient (ADC) varies with frequency. When measured using oscillating gradient spin echo sequences, the manner in which ADC disperses with gradient frequency (which is related to the reciprocal of diffusion time) provides information on the characteristic dimensions of restricting structures within the medium. For example, the dispersion of ADC with oscillating gradient frequency (ΔfADC) has been shown to correlate with axon sizes in white matter and provide novel tissue contrast in images of mouse hippocampus and cerebellum. However, despite increasing interest in applying frequency-dependent ADC to derive novel information on tissue, the interpretations of ADC spectra are not always clear. In this study, the relation between ADC spectra and restricting dimensions are further elucidated and used to derive novel image contrast related to the sizes of intrinsic microstructures.
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Affiliation(s)
- Hua Li
- Institute of Imaging Science, Vanderbilt University, Nashville, TN, 37232, USA; Department of Physics and Astronomy, Vanderbilt University, Nashville, TN, 37232, USA
| | - Xiaoyu Jiang
- Institute of Imaging Science, Vanderbilt University, Nashville, TN, 37232, USA; Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, 37232, USA
| | - Feng Wang
- Institute of Imaging Science, Vanderbilt University, Nashville, TN, 37232, USA; Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, 37232, USA
| | - Junzhong Xu
- Institute of Imaging Science, Vanderbilt University, Nashville, TN, 37232, USA; Department of Physics and Astronomy, Vanderbilt University, Nashville, TN, 37232, USA; Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, 37232, USA
| | - John C Gore
- Institute of Imaging Science, Vanderbilt University, Nashville, TN, 37232, USA; Department of Physics and Astronomy, Vanderbilt University, Nashville, TN, 37232, USA; Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, 37232, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, 37232, USA; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA.
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Jiang X, Li H, Xie J, Zhao P, Gore JC, Xu J. Quantification of cell size using temporal diffusion spectroscopy. Magn Reson Med 2015; 75:1076-85. [PMID: 25845851 DOI: 10.1002/mrm.25684] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 01/15/2015] [Accepted: 02/11/2015] [Indexed: 01/01/2023]
Abstract
PURPOSE A new approach has been developed to quantify cell sizes and intracellular volume fractions using temporal diffusion spectroscopy with diffusion-weighted acquisitions. METHODS Temporal diffusion spectra may be used to characterize tissue microstructure by measuring the effects of restrictions over a range of diffusion times. Oscillating gradients have been used previously to probe variations on cellular and subcellular scales, but their ability to accurately measure cell sizes larger than 10 μm is limited. By combining measurements made using oscillating gradient spin echo (OGSE) and a conventional pulsed gradient spin echo (PGSE) acquisition with a single, relatively long diffusion time, we can accurately quantify cell sizes and intracellular volume fractions. RESULTS Based on a two compartment model (incorporating intra- and extracellular spaces), accurate estimates of cell sizes and intracellular volume fractions were obtained in vitro for (i) different cell types with sizes ranging from 10 to 20 μm, (ii) different cell densities, and (iii) before and after anticancer treatment. CONCLUSION Hybrid OGSE-PGSE acquisitions sample a larger region of temporal diffusion spectra and can accurately quantify cell sizes over a wide range. Moreover, the maximum gradient strength used was lower than 15 G/cm, suggesting that this approach is translatable to practical MR imaging.
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Affiliation(s)
- Xiaoyu Jiang
- Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Hua Li
- Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA.,Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee, USA
| | - Jingping Xie
- Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Ping Zhao
- Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - John C Gore
- Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA.,Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee, USA.,Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - Junzhong Xu
- Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA.,Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee, USA
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Wu D, Martin LJ, Northington FJ, Zhang J. Oscillating gradient diffusion MRI reveals unique microstructural information in normal and hypoxia-ischemia injured mouse brains. Magn Reson Med 2014; 72:1366-74. [PMID: 25168861 DOI: 10.1002/mrm.25441] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 08/08/2014] [Accepted: 08/14/2014] [Indexed: 12/28/2022]
Abstract
PURPOSE We investigated whether oscillating gradient diffusion MRI (dMRI) can provide information on brain microstructural changes after formaldehyde fixation and after hypoxic-ischemic (HI) injury beyond that provided by conventional dMRI. METHODS Pulsed gradient spin echo (PGSE) and oscillating gradient spin echo (OGSE) dMRI of the adult mouse brain was performed in vivo (50-200 Hz, b = 600 mm(2)/s), and a similar protocol was applied to neonatal mouse brains at 24 h after unilateral hypoxia-ischemia. Animals were perfusion fixed with 4% paraformaldehyde for ex vivo dMRI and histology. RESULTS Apparent diffusion coefficients (ADCs) measured in the live adult mouse brain presented tissue-dependent frequency-dependence. In vivo OGSE-ADC maps at high oscillating frequencies (>100 Hz) showed clear contrast between the molecular layer and granule cell layer in the adult mouse cerebellum. Formaldehyde fixation significantly altered the temporal diffusion spectra in several brain regions. In neonatal mouse brains with HI injury, in vivo ADC measurements from edema regions showed diminished edema contrasts at 200 Hz compared with the PGSE results. Histology showed severe tissue swelling and necrosis in the edema regions. CONCLUSION The results demonstrate the unique ability of OGSE-dMRI in delineating tissue microstructures at different spatial scales.
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Affiliation(s)
- Dan Wu
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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26
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Li H, Gore JC, Xu J. Fast and robust measurement of microstructural dimensions using temporal diffusion spectroscopy. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2014; 242:4-9. [PMID: 24583517 PMCID: PMC4008665 DOI: 10.1016/j.jmr.2014.02.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Revised: 01/29/2014] [Accepted: 02/02/2014] [Indexed: 05/22/2023]
Abstract
Mapping axon sizes non-invasively is of interest for neuroscientists and may have significant clinical potential because nerve conduction velocity is directly dependent on axon size. Current approaches to measuring axon sizes using diffusion-weighted MRI, e.g. q-space imaging with pulsed gradient spin echo (PGSE) sequences usually require long scan times and high q-values to detect small axons (diameter <2μm). The oscillating gradient spin echo (OGSE) method has been shown to be able to achieve very short diffusion times and hence may be able to detect smaller axons with high sensitivity. In the current study, OGSE experiments were performed to measure the inner diameters of hollow microcapillaries with a range of sizes (∼1.5-19.3μm) that mimic axons in the human central nervous system. The results suggest that OGSE measurements, even with only moderately high frequencies, are highly sensitive to compartment sizes, and a minimum of two ADC values with different frequencies may be sufficient to extract the microcapillary size accurately. This suggests that the OGSE method may serve as a fast and robust measurement method for mapping axon sizes non-invasively.
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Affiliation(s)
- Hua Li
- Institute of Imaging Science, Vanderbilt University, Nashville, TN 37232, USA; Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37232, USA
| | - John C Gore
- Institute of Imaging Science, Vanderbilt University, Nashville, TN 37232, USA; Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37232, USA; Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN 37232, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37232, USA; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Junzhong Xu
- Institute of Imaging Science, Vanderbilt University, Nashville, TN 37232, USA; Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN 37232, USA.
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