1
|
Shahid SS, Grecco GG, Atwood BK, Wu YC. Perturbed neurochemical and microstructural organization in a mouse model of prenatal opioid exposure: A multi-modal magnetic resonance study. PLoS One 2023; 18:e0282756. [PMID: 37471385 PMCID: PMC10358947 DOI: 10.1371/journal.pone.0282756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 07/08/2023] [Indexed: 07/22/2023] Open
Abstract
Methadone-based treatment for pregnant women with opioid use disorder is quite prevalent in the clinical environment. A number of clinical and animal model-based studies have reported cognitive deficits in infants prenatally exposed to methadone-based opioid treatments. However, the long-term impact of prenatal opioid exposure (POE) on pathophysiological mechanisms that govern neurodevelopmental impairment is not well understood. Using a translationally relevant mouse model of prenatal methadone exposure (PME), the aim of this study is to investigate the role of cerebral biochemistry and its possible association with regional microstructural organization in PME offspring. To understand these effects, 8-week-old male offspring with PME (n = 7) and prenatal saline exposure (PSE) (n = 7) were scanned in vivo on 9.4 Tesla small animal scanner. Single voxel proton magnetic resonance spectroscopy (1H-MRS) was performed in the right dorsal striatum (RDS) region using a short echo time (TE) Stimulated Echo Acquisition Method (STEAM) sequence. Neurometabolite spectra from the RDS was first corrected for tissue T1 relaxation and then absolute quantification was performed using the unsuppressed water spectra. High-resolution in vivo diffusion MRI (dMRI) for region of interest (ROI) based microstructural quantification was also performed using a multi-shell dMRI sequence. Cerebral microstructure was characterized using diffusion tensor imaging (DTI) and Bingham-neurite orientation dispersion and density imaging (Bingham-NODDI). MRS results in the RDS showed significant decrease in N-acetyl aspartate (NAA), taurine (tau), glutathione (GSH), total creatine (tCr) and glutamate (Glu) concentration levels in PME, compared to PSE group. In the same RDS region, mean orientation dispersion index (ODI) and intracellular volume fraction (VFIC) demonstrated positive associations with tCr in PME group. ODI also exhibited significant positive association with Glu levels in PME offspring. Significant reduction in major neurotransmitter metabolites and energy metabolism along with strong association between the neurometabolites and perturbed regional microstructural complexity suggest a possible impaired neuroadaptation trajectory in PME offspring which could be persistent even into late adolescence and early adulthood.
Collapse
Affiliation(s)
- Syed Salman Shahid
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States of America
| | - Gregory G. Grecco
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States of America
- Medical Scientist Training Program, Indiana University School of Medicine, Indianapolis, IN, United States of America
| | - Brady K. Atwood
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States of America
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, United States of America
| | - Yu-Chien Wu
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States of America
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, United States of America
| |
Collapse
|
2
|
Shahid SS, Grecco GG, Atwood BK, Wu YC. Perturbed neurochemical and microstructural organization in a mouse model of prenatal opioid exposure: a multi-modal magnetic resonance study. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.23.529659. [PMID: 36865153 PMCID: PMC9980104 DOI: 10.1101/2023.02.23.529659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Methadone-based treatment for pregnant women with opioid use disorder is quite prevalent in the clinical environment. A number of clinical and animal model-based studies have reported cognitive deficits in infants prenatally exposed to methadone-based opioid treatments. However, the long-term impact of prenatal opioid exposure (POE) on pathophysiological mechanisms that govern neurodevelopmental impairment is not well understood. Using a translationally relevant mouse model of prenatal methadone exposure (PME), the aim of this study is to investigate the role of cerebral biochemistry and its possible association with regional microstructural organization in PME offspring. To understand these effects, 8- week-old male offspring with PME (n=7) and prenatal saline exposure (PSE) (n=7) were scanned in vivo on 9.4 Tesla small animal scanner. Single voxel proton magnetic resonance spectroscopy ( 1 H-MRS) was performed in the right dorsal striatum (RDS) region using a short echo time (TE) Stimulated Echo Acquisition Method (STEAM) sequence. Neurometabolite spectra from the RDS was first corrected for tissue T1 relaxation and then absolute quantification was performed using the unsuppressed water spectra. High-resolution in vivo diffusion MRI (dMRI) for region of interest (ROI) based microstructural quantification was also performed using a multi-shell dMRI sequence. Cerebral microstructure was characterized using diffusion tensor imaging (DTI) and Bingham-neurite orientation dispersion and density imaging (Bingham-NODDI). MRS results in the RDS showed significant decrease in N-acetyl aspartate (NAA), taurine (tau), glutathione (GSH), total creatine (tCr) and glutamate (Glu) concentration levels in PME, compared to PSE group. In the same RDS region, mean orientation dispersion index (ODI) and intracellular volume fraction (VF IC ) demonstrated positive associations with tCr in PME group. ODI also exhibited significant positive association with Glu levels in PME offspring. Significant reduction in major neurotransmitter metabolites and energy metabolism along with strong association between the neurometabolites and perturbed regional microstructural complexity suggest a possible impaired neuroadaptation trajectory in PME offspring which could be persistent even into late adolescence and early adulthood.
Collapse
|
3
|
Pépin J, de Longprez L, Trovero F, Brouillet E, Valette J, Flament J. Complementarity of gluCEST and 1 H-MRS for the study of mouse models of Huntington's disease. NMR IN BIOMEDICINE 2020; 33:e4301. [PMID: 32198958 DOI: 10.1002/nbm.4301] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 03/06/2020] [Accepted: 03/07/2020] [Indexed: 06/10/2023]
Abstract
Identification of relevant biomarkers is fundamental to understand biological processes of neurodegenerative diseases and to evaluate therapeutic efficacy. Atrophy of brain structures has been proposed as a biomarker, but it provides little information about biochemical events related to the disease. Here, we propose to identify early and relevant biomarkers by combining biological specificity provided by 1 H-MRS and high spatial resolution offered by gluCEST imaging. For this, two different genetic mouse models of Huntington's disease (HD)-the Ki140CAG model, characterized by a slow progression of the disease, and the R6/1 model, which mimics the juvenile form of HD-were used. Animals were scanned at 11.7 T using a protocol combining 1 H-MRS and gluCEST imaging. We measured a significant decrease in levels of N-acetyl-aspartate, a metabolite mainly located in the neuronal compartment, in HD animals, and the decrease seemed to be correlated with disease severity. In addition, variations of tNAA levels were correlated with striatal volumes in both models. Significant variations of glutamate levels were also observed in Ki140CAG but not in R6/1 mice. Thanks to its high resolution, gluCEST provided complementary insights, and we highlighted alterations in small brain regions such as the corpus callosum in Ki140CAG mice, whereas the glutamate level was unchanged in the whole brain of R6/1 mice. In this study, we showed that 1 H-MRS can provide key information about biological processes occurring in vivo but was limited by the spatial resolution. On the other hand, gluCEST may finely point to alterations in unexpected brain regions, but it can also be blind to disease processes when glutamate levels are preserved. This highlights in a practical context the complementarity of the two methods to study animal models of neurodegenerative diseases and to identify relevant biomarkers.
Collapse
Affiliation(s)
- Jérémy Pépin
- Commissariat à l'Energie Atomique (CEA), Direction de la Recherche Fondamentale (DRF), Institut de biologie François Jacob, Molecular Imaging Research Center (MIRCen), Université Paris-Saclay, Fontenay-aux-Roses, France
- Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, UMR 9199, Neurodegenerative Diseases Laboratory, Fontenay-aux-Roses, France
| | - Lucie de Longprez
- Commissariat à l'Energie Atomique (CEA), Direction de la Recherche Fondamentale (DRF), Institut de biologie François Jacob, Molecular Imaging Research Center (MIRCen), Université Paris-Saclay, Fontenay-aux-Roses, France
- Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, UMR 9199, Neurodegenerative Diseases Laboratory, Fontenay-aux-Roses, France
| | | | - Emmanuel Brouillet
- Commissariat à l'Energie Atomique (CEA), Direction de la Recherche Fondamentale (DRF), Institut de biologie François Jacob, Molecular Imaging Research Center (MIRCen), Université Paris-Saclay, Fontenay-aux-Roses, France
- Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, UMR 9199, Neurodegenerative Diseases Laboratory, Fontenay-aux-Roses, France
| | - Julien Valette
- Commissariat à l'Energie Atomique (CEA), Direction de la Recherche Fondamentale (DRF), Institut de biologie François Jacob, Molecular Imaging Research Center (MIRCen), Université Paris-Saclay, Fontenay-aux-Roses, France
- Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, UMR 9199, Neurodegenerative Diseases Laboratory, Fontenay-aux-Roses, France
| | - Julien Flament
- Commissariat à l'Energie Atomique (CEA), Direction de la Recherche Fondamentale (DRF), Institut de biologie François Jacob, Molecular Imaging Research Center (MIRCen), Université Paris-Saclay, Fontenay-aux-Roses, France
- Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, UMR 9199, Neurodegenerative Diseases Laboratory, Fontenay-aux-Roses, France
| |
Collapse
|
4
|
Dehghani M, Kunz N, Lei H. Diffusion behavior of cerebral metabolites of congenital portal systemic shunt mice assessed noninvasively by diffusion-weighted 1 H magnetic resonance spectroscopy. NMR IN BIOMEDICINE 2020; 33:e4198. [PMID: 31765073 DOI: 10.1002/nbm.4198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 08/27/2019] [Accepted: 09/13/2019] [Indexed: 06/10/2023]
Abstract
Diffusion-weighted 1 H-MRS (DW-MRS) allows for noninvasive investigation of the cellular compartmentalization of cerebral metabolites. DW-MRS applied to the congenital portal systemic shunt (PSS) mouse brain may provide specific insight into alterations of cellular restrictions associated with PSS in humans. At 14.1 T, adult male PSS and their age-matched healthy (Ctrl) mice were studied using DW-MRS covering b-values ranging from 0 to 45 ms/μm2 to determine the diffusion behavior of abundant metabolites. The remarkable sensitivity and spectral resolution, in combination with very high diffusion weighting, allowed for precise measurement of the diffusion properties of endogenous N-acetyl-aspartate, total creatine, myo-inositol, total choline with extension to glutamine and glutamate in mouse brains, in vivo. Most metabolites had comparable diffusion properties in PSS and Ctrl mice, suggesting that intracellular distribution space for these metabolites was not affected in the model. The slightly different diffusivity of the slow decaying component of taurine (0.015 ± 0.003 μm2 /ms in PSS vs 0.021 ± 0.002 μm2 /ms in Ctrl, P < 0.05) might support a cellular redistribution of taurine in the PSS mouse brain.
Collapse
Affiliation(s)
- Masoumeh Dehghani
- Laboratory of Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Department of Psychiatry, McGill University, Montreal, Canada
| | - Nicolas Kunz
- Center for Biomedical Imaging (CIBM), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Hongxia Lei
- Center for Biomedical Imaging (CIBM), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| |
Collapse
|
5
|
Palombo M, Shemesh N, Ronen I, Valette J. Insights into brain microstructure from in vivo DW-MRS. Neuroimage 2018; 182:97-116. [DOI: 10.1016/j.neuroimage.2017.11.028] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Revised: 10/09/2017] [Accepted: 11/15/2017] [Indexed: 12/27/2022] Open
|
6
|
Bonvento G, Valette J, Flament J, Mochel F, Brouillet E. Imaging and spectroscopic approaches to probe brain energy metabolism dysregulation in neurodegenerative diseases. J Cereb Blood Flow Metab 2017; 37:1927-1943. [PMID: 28276944 PMCID: PMC5464722 DOI: 10.1177/0271678x17697989] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 01/10/2017] [Accepted: 02/06/2017] [Indexed: 12/14/2022]
Abstract
Changes in energy metabolism are generally considered to play an important role in neurodegenerative diseases such as Alzheimer's, Parkinson's, and Huntington's diseases. Whether these changes are causal or simply a part of self-defense mechanisms is a matter of debate. Furthermore, energy defects have often been discussed solely in the context of their probable neuronal origin without considering the cellular heterogeneity of the brain. Recent data point towards the existence of a tri-cellular compartmentation of brain energy metabolism between neurons, astrocytes, and oligodendrocytes, each cell type having a distinctive metabolic profile. Still, the number of methods to follow energy metabolism in patients is extremely limited and existing clinical techniques are blind to most cellular processes. There is a need to better understand how brain energy metabolism is regulated in health and disease through experiments conducted at different scales in animal models to implement new methods in the clinical setting. The purpose of this review is to offer a brief overview of the broad spectrum of methodological approaches that have emerged in recent years to probe energy metabolism in more detail. We conclude that multi-modal neuroimaging is needed to follow non-cell autonomous energy metabolism dysregulation in neurodegenerative diseases.
Collapse
Affiliation(s)
- Gilles Bonvento
- Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), Département de la Recherche Fondamentale (DRF), Institut d’Imagerie Biomédicale (I2BM), Molecular Imaging Research Center (MIRCen), CNRS UMR 9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Julien Valette
- Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), Département de la Recherche Fondamentale (DRF), Institut d’Imagerie Biomédicale (I2BM), Molecular Imaging Research Center (MIRCen), CNRS UMR 9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses, France
| | - Julien Flament
- Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), Département de la Recherche Fondamentale (DRF), Institut d’Imagerie Biomédicale (I2BM), Molecular Imaging Research Center (MIRCen), CNRS UMR 9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses, France
- INSERM US 27, Molecular Imaging Research Center (MIRCen), Fontenay-aux-Roses, France
| | - Fanny Mochel
- INSERM U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Université Paris 6, Institut du Cerveau et de la Moelle épinière, Paris, France
- Department of Genetics, AP-HP Hôpital Pitié-Salpêtrière, Paris, France
- University Pierre and Marie Curie, Neurometabolic Research Group, Paris, France
| | - Emmanuel Brouillet
- Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), Département de la Recherche Fondamentale (DRF), Institut d’Imagerie Biomédicale (I2BM), Molecular Imaging Research Center (MIRCen), CNRS UMR 9199, Université Paris-Sud, Université Paris-Saclay, Fontenay-aux-Roses, France
| |
Collapse
|
7
|
Liot G, Valette J, Pépin J, Flament J, Brouillet E. Energy defects in Huntington's disease: Why “in vivo” evidence matters. Biochem Biophys Res Commun 2017; 483:1084-1095. [DOI: 10.1016/j.bbrc.2016.09.065] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 09/13/2016] [Indexed: 01/12/2023]
|
8
|
Pépin J, Francelle L, Carrillo-de Sauvage MA, de Longprez L, Gipchtein P, Cambon K, Valette J, Brouillet E, Flament J. In vivo imaging of brain glutamate defects in a knock-in mouse model of Huntington's disease. Neuroimage 2016; 139:53-64. [PMID: 27318215 DOI: 10.1016/j.neuroimage.2016.06.023] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 06/10/2016] [Accepted: 06/14/2016] [Indexed: 10/21/2022] Open
Abstract
Huntington's disease (HD) is an inherited neurodegenerative disease characterized by motor, cognitive and psychiatric symptoms. Atrophy of the striatum has been proposed for several years as a biomarker to assess disease progression in HD gene carriers. However, it does not provide any information about the biological mechanisms linked to HD pathogenesis. Changes in brain metabolites have been also consistently seen in HD patients and animal models using Magnetic Resonance Spectroscopy (MRS), but metabolite measurements are generally limited to a single voxel. In this study, we used Chemical Exchange Saturation Transfer imaging of glutamate (gluCEST) in order to map glutamate distribution in the brain of a knock-in mouse model (Ki140CAG) with a precise anatomical resolution. We demonstrated that both heterozygous and homozygous mice with pathological CAG repeat expansion in gene encoding huntingtin exhibited an atrophy of the striatum and a significant alteration of their metabolic profile in the striatum as compared to wild type littermate controls. The striatal decrease was then confirmed by gluCEST imaging. Surprisingly, CEST imaging also revealed that the corpus callosum was the most affected structure in both genotype groups, suggesting that this structure could be highly vulnerable in HD. We evaluated for the first time gluCEST imaging as a potential biomarker of HD and demonstrated its potential for characterizing metabolic defects in neurodegenerative diseases in specific regions.
Collapse
Affiliation(s)
- Jérémy Pépin
- Commissariat à l'Energie Atomique (CEA), Direction de la Recherche Fondamentale (DRF), Institut d'Imagerie Biomédicale (I2BM), Molecular Imaging Research Center (MIRCen), F-92260 Fontenay-aux-Roses, France; Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, UMR 9199, Neurodegenerative Diseases Laboratory, F-92260 Fontenay-aux-Roses, France
| | - Laetitia Francelle
- Commissariat à l'Energie Atomique (CEA), Direction de la Recherche Fondamentale (DRF), Institut d'Imagerie Biomédicale (I2BM), Molecular Imaging Research Center (MIRCen), F-92260 Fontenay-aux-Roses, France; Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, UMR 9199, Neurodegenerative Diseases Laboratory, F-92260 Fontenay-aux-Roses, France
| | - Maria-Angeles Carrillo-de Sauvage
- Commissariat à l'Energie Atomique (CEA), Direction de la Recherche Fondamentale (DRF), Institut d'Imagerie Biomédicale (I2BM), Molecular Imaging Research Center (MIRCen), F-92260 Fontenay-aux-Roses, France; Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, UMR 9199, Neurodegenerative Diseases Laboratory, F-92260 Fontenay-aux-Roses, France
| | - Lucie de Longprez
- Commissariat à l'Energie Atomique (CEA), Direction de la Recherche Fondamentale (DRF), Institut d'Imagerie Biomédicale (I2BM), Molecular Imaging Research Center (MIRCen), F-92260 Fontenay-aux-Roses, France; Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, UMR 9199, Neurodegenerative Diseases Laboratory, F-92260 Fontenay-aux-Roses, France
| | - Pauline Gipchtein
- Commissariat à l'Energie Atomique (CEA), Direction de la Recherche Fondamentale (DRF), Institut d'Imagerie Biomédicale (I2BM), Molecular Imaging Research Center (MIRCen), F-92260 Fontenay-aux-Roses, France; Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, UMR 9199, Neurodegenerative Diseases Laboratory, F-92260 Fontenay-aux-Roses, France
| | - Karine Cambon
- Commissariat à l'Energie Atomique (CEA), Direction de la Recherche Fondamentale (DRF), Institut d'Imagerie Biomédicale (I2BM), Molecular Imaging Research Center (MIRCen), F-92260 Fontenay-aux-Roses, France; Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, UMR 9199, Neurodegenerative Diseases Laboratory, F-92260 Fontenay-aux-Roses, France
| | - Julien Valette
- Commissariat à l'Energie Atomique (CEA), Direction de la Recherche Fondamentale (DRF), Institut d'Imagerie Biomédicale (I2BM), Molecular Imaging Research Center (MIRCen), F-92260 Fontenay-aux-Roses, France; Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, UMR 9199, Neurodegenerative Diseases Laboratory, F-92260 Fontenay-aux-Roses, France
| | - Emmanuel Brouillet
- Commissariat à l'Energie Atomique (CEA), Direction de la Recherche Fondamentale (DRF), Institut d'Imagerie Biomédicale (I2BM), Molecular Imaging Research Center (MIRCen), F-92260 Fontenay-aux-Roses, France; Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, UMR 9199, Neurodegenerative Diseases Laboratory, F-92260 Fontenay-aux-Roses, France
| | - Julien Flament
- Commissariat à l'Energie Atomique (CEA), Direction de la Recherche Fondamentale (DRF), Institut d'Imagerie Biomédicale (I2BM), Molecular Imaging Research Center (MIRCen), F-92260 Fontenay-aux-Roses, France; Institut national de la santé et de la recherche médicale (Inserm), UMS 27, F-92260 Fontenay-aux-Roses, France.
| |
Collapse
|
9
|
Palombo M, Ligneul C, Najac C, Le Douce J, Flament J, Escartin C, Hantraye P, Brouillet E, Bonvento G, Valette J. New paradigm to assess brain cell morphology by diffusion-weighted MR spectroscopy in vivo. Proc Natl Acad Sci U S A 2016; 113:6671-6. [PMID: 27226303 PMCID: PMC4914152 DOI: 10.1073/pnas.1504327113] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The brain is one of the most complex organs, and tools are lacking to assess its cellular morphology in vivo. Here we combine original diffusion-weighted magnetic resonance (MR) spectroscopy acquisition and novel modeling strategies to explore the possibility of quantifying brain cell morphology noninvasively. First, the diffusion of cell-specific metabolites is measured at ultra-long diffusion times in the rodent and primate brain in vivo to observe how cell long-range morphology constrains metabolite diffusion. Massive simulations of particles diffusing in synthetic cells parameterized by morphometric statistics are then iterated to fit experimental data. This method yields synthetic cells (tentatively neurons and astrocytes) that exhibit striking qualitative and quantitative similarities with histology (e.g., using Sholl analysis). With our approach, we measure major interspecies difference regarding astrocytes, whereas dendritic organization appears better conserved throughout species. This work suggests that the time dependence of metabolite diffusion coefficient allows distinguishing and quantitatively characterizing brain cell morphologies noninvasively.
Collapse
Affiliation(s)
- Marco Palombo
- MIRCen, Institut d'Imagerie Biomédicale, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique et aux Energies Alternatives, F-92260 Fontenay-aux-Roses, France; Unité Mixte de Recherche (UMR) 9199 (Neurodegenerative Diseases Laboratory), Université Paris-Sud, Université Paris-Saclay, CNRS, F-92260 Fontenay-aux-Roses, France;
| | - Clémence Ligneul
- MIRCen, Institut d'Imagerie Biomédicale, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique et aux Energies Alternatives, F-92260 Fontenay-aux-Roses, France; Unité Mixte de Recherche (UMR) 9199 (Neurodegenerative Diseases Laboratory), Université Paris-Sud, Université Paris-Saclay, CNRS, F-92260 Fontenay-aux-Roses, France
| | - Chloé Najac
- MIRCen, Institut d'Imagerie Biomédicale, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique et aux Energies Alternatives, F-92260 Fontenay-aux-Roses, France; Unité Mixte de Recherche (UMR) 9199 (Neurodegenerative Diseases Laboratory), Université Paris-Sud, Université Paris-Saclay, CNRS, F-92260 Fontenay-aux-Roses, France
| | - Juliette Le Douce
- MIRCen, Institut d'Imagerie Biomédicale, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique et aux Energies Alternatives, F-92260 Fontenay-aux-Roses, France; Unité Mixte de Recherche (UMR) 9199 (Neurodegenerative Diseases Laboratory), Université Paris-Sud, Université Paris-Saclay, CNRS, F-92260 Fontenay-aux-Roses, France
| | - Julien Flament
- MIRCen, Institut d'Imagerie Biomédicale, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique et aux Energies Alternatives, F-92260 Fontenay-aux-Roses, France; Unité Mixte de Service (UMS) 27, INSERM, F-92260 Fontenay-aux-Roses, France
| | - Carole Escartin
- MIRCen, Institut d'Imagerie Biomédicale, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique et aux Energies Alternatives, F-92260 Fontenay-aux-Roses, France; Unité Mixte de Recherche (UMR) 9199 (Neurodegenerative Diseases Laboratory), Université Paris-Sud, Université Paris-Saclay, CNRS, F-92260 Fontenay-aux-Roses, France
| | - Philippe Hantraye
- MIRCen, Institut d'Imagerie Biomédicale, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique et aux Energies Alternatives, F-92260 Fontenay-aux-Roses, France; Unité Mixte de Recherche (UMR) 9199 (Neurodegenerative Diseases Laboratory), Université Paris-Sud, Université Paris-Saclay, CNRS, F-92260 Fontenay-aux-Roses, France; Unité Mixte de Service (UMS) 27, INSERM, F-92260 Fontenay-aux-Roses, France
| | - Emmanuel Brouillet
- MIRCen, Institut d'Imagerie Biomédicale, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique et aux Energies Alternatives, F-92260 Fontenay-aux-Roses, France; Unité Mixte de Recherche (UMR) 9199 (Neurodegenerative Diseases Laboratory), Université Paris-Sud, Université Paris-Saclay, CNRS, F-92260 Fontenay-aux-Roses, France
| | - Gilles Bonvento
- MIRCen, Institut d'Imagerie Biomédicale, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique et aux Energies Alternatives, F-92260 Fontenay-aux-Roses, France; Unité Mixte de Recherche (UMR) 9199 (Neurodegenerative Diseases Laboratory), Université Paris-Sud, Université Paris-Saclay, CNRS, F-92260 Fontenay-aux-Roses, France
| | - Julien Valette
- MIRCen, Institut d'Imagerie Biomédicale, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique et aux Energies Alternatives, F-92260 Fontenay-aux-Roses, France; Unité Mixte de Recherche (UMR) 9199 (Neurodegenerative Diseases Laboratory), Université Paris-Sud, Université Paris-Saclay, CNRS, F-92260 Fontenay-aux-Roses, France;
| |
Collapse
|
10
|
Cohen DM, Bergman RN. Estimation of metabolic flux from dominant rate constants in vivo: application to brain and heart. Metab Eng 2004; 6:59-74. [PMID: 14734256 DOI: 10.1016/j.ymben.2003.10.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In an earlier paper (Cohen and Bergman, Am. J. Physiol. 268 (1995) E397), we explored the relationship between the exponents in the exponential curve fit to isotopic enrichment versus time and the fractional turnover rate of the largest metabolic pool in the pathway. Here we present the analysis on a more rigorous footing and apply it to questions of cerebral and cardiac metabolism. Our emphasis in this paper is to describe and justify mathematically an approach for analysis of metabolic dynamics, not with the intention of replacing the use of numerical software for estimation of flux rates but for giving the scientist the opportunity to examine the system in an approximate manner, and thereby to check not only that the results of the numerical solution are the correct solutions to the equations but also that the equations portray the correct simplification of the metabolic pathway. We introduce the "dominant rate constant" as a tool for deriving algebraic formulas relating rates of metabolic flux, sizes of metabolic pools, and the dynamics of isotopic enrichment. Illustrations of such algebraic formulas are provided for the rates of the citric acid cycle (CAC), glycolysis and glutamine synthesis in brain, as well as the rate of the CAC in heart. In addition, we prove that formulas for estimation of rates of glycolysis and of the CAC depend critically on the fractional turnover rates of lactate and glutamate, respectively. The justification for analysis of simulated data is that we are studying the effects of simplifications of metabolic models on the accuracy of estimation of metabolic pathways. Our use of the dominant rate constant is an analytical convenience that allows us to assess proposed simplifications of metabolic pathways.
Collapse
Affiliation(s)
- David M Cohen
- Department of Chemistry, University of Houston, 136 Lamar Fleming Building, Houston, TX 77204-5003, USA.
| | | |
Collapse
|
11
|
Petroff OAC, Errante LD, Rothman DL, Kim JH, Spencer DD. Glutamate-glutamine cycling in the epileptic human hippocampus. Epilepsia 2002; 43:703-10. [PMID: 12102672 DOI: 10.1046/j.1528-1157.2002.38901.x] [Citation(s) in RCA: 137] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE Several findings suggest that energy metabolism and the glutamate-glutamine cycle may be impaired in epilepsy. Positron emission tomography often shows interictal hypometabolism of the epileptogenic hippocampus. In vivo microdialysis studies show that seizure-associated glutamate release is doubled, and clearance is slowed. We hypothesized that the glutamate-glutamine cycle between neurons and glia may be decreased in the epileptic human hippocampus. METHODS A 20% solution of 2-13C-glucose was infused before resection of the epileptogenic hippocampus. Blood glucose isotopic fractions were measured every 30 min. Blood and brain specimens were frozen quickly; perchloric acid extracts of the small metabolites were prepared and analyzed by proton and carbon magnetic resonance spectroscopy (MRS) at 11.75 Tesla. RESULTS Standard histology showed 12 with hippocampal sclerosis and five with minimal neuron loss. The relative rates of glutamate-glutamine cycling with respect to glutamate synthesis were decreased in biopsies affected by hippocampal sclerosis (mean, 0.08; 95% confidence interval, 0.04-0.12) compared with those with minimal neuron loss (0.52; 95% CI, 0.30-0.75). Mean cellular glutamate concentrations were higher in minimal neuron loss (8.9 mM; 95% CI, 7.4-10.4) than hippocampal sclerosis (7.3 mM; 95% CI, 5.9-8.7). Cellular glutamine concentrations (mean, 2.8 mM; 95% CI, 2.4-3.2; n = 17) were the same in all groups. CONCLUSIONS The epileptogenic, gliotic human hippocampus appears to be characterized metabolically by slow rates of glutamate-glutamine cycling, decreased glutamine content, and a relative increase in glutamate content. We hypothesize that the low rate of glutamate-glutamine cycling that results from a failure of glial glutamate detoxification could account for slow glutamate clearance from synapses and continuing low-grade excitotoxicity.
Collapse
Affiliation(s)
- Ognen A C Petroff
- Department of Neurology, Yale University, New Haven, Connecticut 06520-8018, USA.
| | | | | | | | | |
Collapse
|
12
|
Errante LD, Williamson A, Spencer DD, Petroff OAC. Gabapentin and vigabatrin increase GABA in the human neocortical slice. Epilepsy Res 2002; 49:203-10. [PMID: 12076841 DOI: 10.1016/s0920-1211(02)00034-7] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The effects of antiepileptic drugs, gabapentin and vigabatrin, on gamma-aminobutyric acid (GABA) concentrations were studied in human (n=14) and rat (n=6) neocortical slice preparations. In this study, neocortical slices were incubated with gabapentin, vigabatrin or no drugs for 3 h in an oxygenated environment. Proton magnetic resonance spectroscopy (MRS) of perchloric acid (PCA) extracts was used to measure GABA concentrations. Vigabatrin increased cellular GABA concentrations in both human and rat neocortical slices by 62% (P<0.001) and 88% (P<0.03), respectively. Gabapentin significantly increased GABA concentrations by 13% (P<0.02) in human neocortical slices made from tissue resected during epilepsy surgery. However, in the rat neocortical slice exposed to the same conditions as the human tissue, gabapentin did not increase GABA significantly. These results confirm our MRS studies in vivo that gabapentin increases GABA levels in epileptic patients, but has minimal or no effect in a healthy rodent model. Caution must be used in extrapolating negative results obtained in rodent models to the human condition.
Collapse
Affiliation(s)
- Laura D Errante
- Department of Neurology, Yale University School of Medicine, P.O. Box 208018, New Haven, CT 06520-8018, USA
| | | | | | | |
Collapse
|
13
|
Petroff OA, Pleban LA, Spencer DD. Symbiosis between in vivo and in vitro NMR spectroscopy: the creatine, N-acetylaspartate, glutamate, and GABA content of the epileptic human brain. Magn Reson Imaging 1995; 13:1197-211. [PMID: 8750337 DOI: 10.1016/0730-725x(95)02033-p] [Citation(s) in RCA: 113] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
High resolution 1H NMR spectroscopy was used to analyze temporal lobe biopsies obtained from patients with epilepsy. Heat-stabilized cerebrum, dialyzed cytosolic macromolecules, and perchloric acid extracts were studied using one- and two-dimensional spectroscopy. Anterior temporal lobe neocortex was enriched in GABA, glutamate, alanine, N-acetylaspartate, and creatine. Subjacent white matter was enriched in aspartate, glutamine, and inositol. The N-acetylaspartate/creatine mole ratio was lower in anterior temporal neocortex with mesial (0.66) than neocortical (0.80) temporal lobe epilepsy. Human brain biopsy samples were separated into crude and refined synaptosomes, neuronal cell bodies, and glia using density gradient centrifugation. Neuronal fractions were enriched in glutamate and N-acetylaspartate. Glial cell fractions were enriched in lactate, glutamine, and inositol. The creatine content was the same in biopsied epileptic cortex (8.8-8.9 mmol/kg) and normal in vivo occipital lobe (8.9 mmol/kg). Glutamate content was higher in epileptic cortex at biopsy (10.1-10.5 mmol/kg) than normal in vivo occipital lobe (8.8 mmol/kg). GABA content was higher in biopsies of epileptic cortex (2.3-2.2 mmol/kg) than in normal in vivo occipital lobe (1.2 mmol/kg). N-acetylaspartate content was lower in biopsied epileptic temporal cortex (5.8-6.8 mmol/kg) than normal in vivo occipital lobe (8.9 mmol/kg). Paired in vivo and ex vivo measurements are critical for a firm understanding of the changes seen in the 1H-spectra from patients with epilepsy.
Collapse
Affiliation(s)
- O A Petroff
- Department of Neurology, Yale University, New Haven, CT 06510, USA
| | | | | |
Collapse
|