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Abstract
Positron emission tomography (PET) is a non-invasive imaging technology employed to describe metabolic, physiological, and biochemical processes in vivo. These include receptor availability, metabolic changes, neurotransmitter release, and alterations of gene expression in the brain. Since the introduction of dedicated small-animal PET systems along with the development of many novel PET imaging probes, the number of PET studies using rats and mice in basic biomedical research tremendously increased over the last decade. This article reviews challenges and advances of quantitative rodent brain imaging to make the readers aware of its physical limitations, as well as to inspire them for its potential applications in preclinical research. In the first section, we briefly discuss the limitations of small-animal PET systems in terms of spatial resolution and sensitivity and point to possible improvements in detector development. In addition, different acquisition and post-processing methods used in rodent PET studies are summarized. We further discuss factors influencing the test-retest variability in small-animal PET studies, e.g., different receptor quantification methodologies which have been mainly translated from human to rodent receptor studies to determine the binding potential and changes of receptor availability and radioligand affinity. We further review different kinetic modeling approaches to obtain quantitative binding data in rodents and PET studies focusing on the quantification of endogenous neurotransmitter release using pharmacological interventions. While several studies have focused on the dopamine system due to the availability of several PET tracers which are sensitive to dopamine release, other neurotransmitter systems have become more and more into focus and are described in this review, as well. We further provide an overview of latest genome engineering technologies, including the CRISPR/Cas9 and DREADD systems that may advance our understanding of brain disorders and function and how imaging has been successfully applied to animal models of human brain disorders. Finally, we review the strengths and opportunities of simultaneous PET/magnetic resonance imaging systems to study drug-receptor interactions and challenges for the translation of PET results from bench to bedside.
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D'Elia A, Schiavi S, Soluri A, Massari R, Soluri A, Trezza V. Role of Nuclear Imaging to Understand the Neural Substrates of Brain Disorders in Laboratory Animals: Current Status and Future Prospects. Front Behav Neurosci 2020; 14:596509. [PMID: 33362486 PMCID: PMC7759612 DOI: 10.3389/fnbeh.2020.596509] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 11/23/2020] [Indexed: 12/18/2022] Open
Abstract
Molecular imaging, which allows the real-time visualization, characterization and measurement of biological processes, is becoming increasingly used in neuroscience research. Scintigraphy techniques such as single photon emission computed tomography (SPECT) and positron emission tomography (PET) provide qualitative and quantitative measurement of brain activity in both physiological and pathological states. Laboratory animals, and rodents in particular, are essential in neuroscience research, providing plenty of models of brain disorders. The development of innovative high-resolution small animal imaging systems together with their radiotracers pave the way to the study of brain functioning and neurotransmitter release during behavioral tasks in rodents. The assessment of local changes in the release of neurotransmitters associated with the performance of a given behavioral task is a turning point for the development of new potential drugs for psychiatric and neurological disorders. This review addresses the role of SPECT and PET small animal imaging systems for a better understanding of brain functioning in health and disease states. Brain imaging in rodent models faces a series of challenges since it acts within the boundaries of current imaging in terms of sensitivity and spatial resolution. Several topics are discussed, including technical considerations regarding the strengths and weaknesses of both technologies. Moreover, the application of some of the radioligands developed for small animal nuclear imaging studies is discussed. Then, we examine the changes in metabolic and neurotransmitter activity in various brain areas during task-induced neural activation with special regard to the imaging of opioid, dopaminergic and cannabinoid receptors. Finally, we discuss the current status providing future perspectives on the most innovative imaging techniques in small laboratory animals. The challenges and solutions discussed here might be useful to better understand brain functioning allowing the translation of preclinical results into clinical applications.
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Affiliation(s)
- Annunziata D'Elia
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy.,Section of Biomedical Sciences and Technologies, Department of Science, University "Roma Tre", Rome, Italy
| | - Sara Schiavi
- Section of Biomedical Sciences and Technologies, Department of Science, University "Roma Tre", Rome, Italy
| | - Andrea Soluri
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy
| | - Roberto Massari
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy
| | - Alessandro Soluri
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy
| | - Viviana Trezza
- Section of Biomedical Sciences and Technologies, Department of Science, University "Roma Tre", Rome, Italy
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Tartaglione AM, Popoli P, Calamandrei G. Regenerative medicine in Huntington's disease: Strengths and weaknesses of preclinical studies. Neurosci Biobehav Rev 2017; 77:32-47. [PMID: 28223129 DOI: 10.1016/j.neubiorev.2017.02.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 01/26/2017] [Accepted: 02/17/2017] [Indexed: 01/22/2023]
Abstract
Huntington's disease (HD) is an inherited neurodegenerative disorder, characterized by impairment in motor, cognitive and psychiatric domains. Currently, there is no specific therapy to act on the onset or progression of HD. The marked neuronal death observed in HD is a main argument in favour of stem cells (SCs) transplantation as a promising therapeutic perspective to replace the population of lost neurons and restore the functionality of the damaged circuitry. The availability of rodent models of HD encourages the investigation of the restorative potential of SCs transplantation longitudinally. However, the results of preclinical studies on SCs therapy in HD are so far largely inconsistent; this hampers the individuation of the more appropriate model and precludes the comparative analysis of transplant efficacy on behavioural end points. Thus, this review will describe the state of the art of in vivo research on SCs therapy in HD, analysing in a translational perspective the strengths and weaknesses of animal studies investigating the therapeutic potential of cell transplantation on HD progression.
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Affiliation(s)
- A M Tartaglione
- Centre for Behavioral Sciences and Mental Health, Istituto Superiore di Sanità, Rome, Italy
| | - P Popoli
- National Centre for Medicines Research and Preclinical/Clinical Evaluation, Rome, Italy
| | - G Calamandrei
- Centre for Behavioral Sciences and Mental Health, Istituto Superiore di Sanità, Rome, Italy.
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Tartaglione AM, Armida M, Potenza RL, Pezzola A, Popoli P, Calamandrei G. Aberrant self-grooming as early marker of motor dysfunction in a rat model of Huntington's disease. Behav Brain Res 2016; 313:53-57. [PMID: 27374158 DOI: 10.1016/j.bbr.2016.06.058] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 06/27/2016] [Accepted: 06/29/2016] [Indexed: 12/20/2022]
Abstract
In the study of neurodegenerative diseases, rodent models provide experimentally accessible systems to study multiple pathogenetic aspects. The identification of early and robust behavioural changes is crucial to monitoring disease progression and testing potential therapeutic strategies in animals. Consistent experimental data support the translational value of rodent self-grooming as index of disturbed motor functions and perseverative behaviour patterns in different rodent models of brain disorders. Huntington's disease (HD) is a progressive neurodegenerative disorder, characterized by severe degeneration of basal ganglia, cognitive and psychiatric impairments and motor abnormalities. In the rat species, intrastriatal injection of the excitotoxin quinolinic acid (QA) mimics some of the neuroanatomical and behavioural changes found in HD, including the loss of GABAergic neurons and the appearance of motor and cognitive deficits. We show here that striatal damage induced by unilateral QA injection in dorsal striatum of rats triggers aberrant grooming behaviour as early as three weeks post-lesion in absence of other motor impairments: specifically, both quantitative (frequency and duration) and qualitative (the sequential pattern of movements) features of self-grooming behaviour were significantly altered in QA-lesioned rats placed in either the elevated plus-maze and the open-field. The consistent abnormalities in self-grooming recorded in two different experimental contexts support the use of this behavioural marker in rodent models of striatal damage such as HD, to assess the potential effects of drug and cell replacement therapy in the early stage of disease.
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Affiliation(s)
- Anna Maria Tartaglione
- Unit of Neurotoxicology and Neuroendocrinology, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy; Department of Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy
| | - Monica Armida
- Unit of Central Nervous System Pharmacology, Department of Therapeutic Research and Medicine Evaluation, Istituto Superiore di Sanità, Rome, Italy
| | - Rosa Luisa Potenza
- Unit of Central Nervous System Pharmacology, Department of Therapeutic Research and Medicine Evaluation, Istituto Superiore di Sanità, Rome, Italy
| | - Antonella Pezzola
- Unit of Central Nervous System Pharmacology, Department of Therapeutic Research and Medicine Evaluation, Istituto Superiore di Sanità, Rome, Italy
| | - Patrizia Popoli
- Unit of Central Nervous System Pharmacology, Department of Therapeutic Research and Medicine Evaluation, Istituto Superiore di Sanità, Rome, Italy
| | - Gemma Calamandrei
- Unit of Neurotoxicology and Neuroendocrinology, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy.
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Mu S, Wang J, Zhou G, Peng W, He Z, Zhao Z, Mo C, Qu J, Zhang J. Transplantation of induced pluripotent stem cells improves functional recovery in Huntington's disease rat model. PLoS One 2014; 9:e101185. [PMID: 25054283 PMCID: PMC4108311 DOI: 10.1371/journal.pone.0101185] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2014] [Accepted: 06/03/2014] [Indexed: 11/19/2022] Open
Abstract
UNLABELLED The purpose of this study was to determine the functional recovery of the transplanted induced pluripotent stem cells in a rat model of Huntington's disease with use of 18F-FDG microPET/CT imaging. METHODS In a quinolinic acid-induced rat model of striatal degeneration, induced pluripotent stem cells were transplanted into the ipsilateral lateral ventricle ten days after the quinolinic acid injection. The response to the treatment was evaluated by serial 18F-FDG PET/CT scans and Morris water maze test. Histological analyses and Western blotting were performed six weeks after stem cell transplantation. RESULTS After induced pluripotent stem cells transplantation, higher 18F-FDG accumulation in the injured striatum was observed during the 4 to 6-weeks period compared with the quinolinic acid-injected group, suggesting the metabolic recovery of injured striatum. The induced pluripotent stem cells transplantation improved learning and memory function (and striatal atrophy) of the rat in six week in the comparison with the quinolinic acid-treated controls. In addition, immunohistochemical analysis demonstrated that transplanted stem cells survived and migrated into the lesioned area in striatum, and most of the stem cells expressed protein markers of neurons and glial cells. CONCLUSION Our findings show that induced pluripotent stem cells can survive, differentiate to functional neurons and improve partial striatal function and metabolism after implantation in a rat Huntington's disease model.
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Affiliation(s)
- Shuhua Mu
- College of Optoelectronics Engineering, Shenzhen University, Shenzhen, China
- School of Medicine, Shenzhen University, Shenzhen, China
| | - Jiachuan Wang
- School of Medicine, Shenzhen University, Shenzhen, China
| | - Guangqian Zhou
- School of Medicine, Shenzhen University, Shenzhen, China
| | - Wenda Peng
- College of Optoelectronics Engineering, Shenzhen University, Shenzhen, China
| | - Zhendan He
- School of Medicine, Shenzhen University, Shenzhen, China
| | - Zhenfu Zhao
- School of Medicine, Shenzhen University, Shenzhen, China
| | - CuiPing Mo
- School of Medicine, Shenzhen University, Shenzhen, China
| | - Junle Qu
- College of Optoelectronics Engineering, Shenzhen University, Shenzhen, China
| | - Jian Zhang
- College of Optoelectronics Engineering, Shenzhen University, Shenzhen, China
- School of Medicine, Shenzhen University, Shenzhen, China
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Mishra J, Kumar A. Improvement of Mitochondrial Function by Paliperidone Attenuates Quinolinic Acid-Induced Behavioural and Neurochemical Alterations in Rats: Implications in Huntington’s Disease. Neurotox Res 2014; 26:363-81. [DOI: 10.1007/s12640-014-9469-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Revised: 04/08/2014] [Accepted: 04/08/2014] [Indexed: 11/29/2022]
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Van Camp N, Blockx I, Camón L, de Vera N, Verhoye M, Veraart J, Van Hecke W, Martínez E, Soria G, Sijbers J, Planas AM, Van der Linden A. A complementary diffusion tensor imaging (DTI)-histological study in a model of Huntington's disease. Neurobiol Aging 2012; 33:945-59. [DOI: 10.1016/j.neurobiolaging.2010.07.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Revised: 06/30/2010] [Accepted: 07/03/2010] [Indexed: 10/19/2022]
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Virdee K, Cumming P, Caprioli D, Jupp B, Rominger A, Aigbirhio FI, Fryer TD, Riss PJ, Dalley JW. Applications of positron emission tomography in animal models of neurological and neuropsychiatric disorders. Neurosci Biobehav Rev 2012; 36:1188-216. [PMID: 22342372 DOI: 10.1016/j.neubiorev.2012.01.009] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 01/26/2012] [Accepted: 01/31/2012] [Indexed: 01/08/2023]
Abstract
Positron emission tomography (PET) provides dynamic images of the biodistribution of radioactive tracers in the brain. Through application of the principles of compartmental analysis, tracer uptake can be quantified in terms of specific physiological processes such as cerebral blood flow, cerebral metabolic rate, and the availability of receptors in brain. Whereas early PET studies in animal models of brain diseases were hampered by the limited spatial resolution of PET instruments, dedicated small-animal instruments now provide molecular images of rodent brain with resolution approaching 1mm, the theoretic limit of the method. Major applications of PET for brain research have consisted of studies of animal models of neurological disorders, notably Parkinson's disease (PD), Alzheimer's disease (AD), and Huntington's disease (HD), stroke, epilepsy and traumatic brain injury; these studies have particularly benefited from selective neurochemical lesion models (PD), and also transgenic rodent models (AD, HD). Due to their complex and uncertain pathophysiologies, corresponding models of neuropsychiatric disorders have proven more difficult to establish. Historically, there has been an emphasis on PET studies of dopamine transmission, as assessed with a range of tracers targeting dopamine synthesis, plasma membrane transporters, and receptor binding sites. However, notable recent breakthroughs in molecular imaging include the development of greatly improved tracers for subtypes of serotonin, cannabinoid, and metabotropic glutamate receptors, as well as noradrenaline transporters, amyloid-β and neuroinflammatory changes. This article reviews the considerable recent progress in preclinical PET and discusses applications relevant to a number of neurological and neuropsychiatric disorders in humans.
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Affiliation(s)
- Kanwar Virdee
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK
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Gabbay V, Ely BA, Babb J, Liebes L. The possible role of the kynurenine pathway in anhedonia in adolescents. J Neural Transm (Vienna) 2012; 119:253-60. [PMID: 21786117 PMCID: PMC3679652 DOI: 10.1007/s00702-011-0685-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 07/02/2011] [Indexed: 11/26/2022]
Abstract
To address the heterogeneous nature of adolescent major depression (MDD), we investigated anhedonia, a core symptom of MDD. We recently reported activation of the kynurenine pathway (KP), a central neuroimmunological pathway which metabolizes tryptophan (TRP) into kynurenine (KYN) en route to several neurotoxins, in a group of highly anhedonic MDD adolescents. In this study, we aimed to extend our prior work and examine the relationship between KP activity and anhedonia, measured quantitatively, in a group of MDD adolescents and in a combined group of MDD and healthy control adolescents. Thirty-six adolescents with MDD (22 medication-free) and 20 controls were included in the analysis. Anhedonia scores were generated based on clinician- and subject-rated assessments and a semi-structured clinician interview. Blood KP metabolites, collected in the AM after an overnight fast, were measured using high-performance liquid chromatography. The rate-limiting enzyme of the KP, indoleamine 2,3-dioxygenase (IDO), was estimated by the ratio of KYN/TRP. Pearson correlation tests were used to assess correlations between anhedonia scores and KP measures while controlling for MDD severity. IDO activity and anhedonia scores were positively correlated in the group psychotropic medication-free adolescents with MDD (r = 0.42, P = 0.05) and in a combined group of MDD subjects and healthy controls (including medicated patients: r = 0.30, P = 0.02; excluding medicated patients: r = 0.44, P = 0.004). In conclusions, our findings provide further support for the role for the KP, particularly IDO, in anhedonia in adolescent MDD. These results emphasize the importance of dimensional approaches in the investigation of psychiatric disorders.
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Affiliation(s)
- Vilma Gabbay
- Department of Child and Adolescent Psychiatry, NYU Child Study Center, NYU School of Medicine, New York University Langone Medical Center, 577 First Avenue, New York, NY 10016, USA.
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Vázquez N, Gómez-Vallejo V, Calvo J, Padro D, Llop J. Synthesis of D2 receptor ligand analogs incorporating one dicarba-closo-dodecaborane unit. Tetrahedron Lett 2011. [DOI: 10.1016/j.tetlet.2010.11.161] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Attenuation of proinflammatory cytokines and apoptotic process by verapamil and diltiazem against quinolinic acid induced Huntington like alterations in rats. Brain Res 2011; 1372:115-26. [DOI: 10.1016/j.brainres.2010.11.060] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Revised: 11/15/2010] [Accepted: 11/18/2010] [Indexed: 01/22/2023]
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Kalonia H, Kumar P, Kumar A. Comparative neuroprotective profile of statins in quinolinic acid induced neurotoxicity in rats. Behav Brain Res 2010; 216:220-8. [PMID: 20696189 DOI: 10.1016/j.bbr.2010.07.040] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Revised: 07/28/2010] [Accepted: 07/31/2010] [Indexed: 01/09/2023]
Abstract
A possible neuroprotective role has been recently suggested for 3H3MGCoA reductase inhibitors (statins). Here, we sought to determine neuroprotective effect of statins in quinolinic acid induced neurotoxicity in rats. Rats were surgically administered quinolinic acid and treated with Atorvastatin (10, 20 mg/kg), simvastatin (15, 30 mg/kg) and fluvastatin (5, 10 mg/kg) once daily up to 3 weeks. Atorvastatin (10, 20 mg/kg), simvastatin (30 mg/kg) and fluvastatin (10 mg/kg) treatment significantly attenuated the quinolinic acid induced behavioral (locomotor activity, rotarod performance and beam walk test), biochemical (lipid peroxidation, nitrite concentration, SOD and catalase), mitochondrial enzyme complex alterations in rats suggesting their free radical scavenging potential. Additionally, atorvastatin (10, 20 mg/kg), simvastatin (30 mg/kg) and fluvastatin (10 mg/kg) significantly decrease the TNF-α level and striatal lesion volume in quinolinic acid treated animals indicating their anti-inflammatory effects. In comparing the protective effect of different statins, atorvastatin is effective at both the doses while simvastatin and fluvastatins at respective lower doses were not able to produce the protective effect in quinolinic acid treated animals. These modulations can account, at least partly, for the beneficial effect of statins in our rodent model of striatal degeneration. Our findings show that statins could be explored as possible neuroprotective agents for neurodegenerative disorders such as HD.
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Affiliation(s)
- Harikesh Kalonia
- Pharmacology Division, University Institute of Pharmaceutical Sciences, UGC Centre of Advanced Study, Panjab University, Chandigarh 160014, India
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Casteels C, Martinez E, Bormans G, Camon L, de Vera N, Baekelandt V, Planas AM, Van Laere K. Type 1 cannabinoid receptor mapping with [18F]MK-9470 PET in the rat brain after quinolinic acid lesion: a comparison to dopamine receptors and glucose metabolism. Eur J Nucl Med Mol Imaging 2010; 37:2354-63. [PMID: 20680268 DOI: 10.1007/s00259-010-1574-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Accepted: 07/15/2010] [Indexed: 12/11/2022]
Abstract
PURPOSE Several lines of evidence imply early alterations in metabolic, dopaminergic and endocannabinoid neurotransmission in Huntington's disease (HD). Using [18F]MK-9470 and small animal PET, we investigated cerebral changes in type 1 cannabinoid (CB1) receptor binding in the quinolinic acid (QA) rat model of HD in relation to glucose metabolism, dopamine D2 receptor availability and amphetamine-induced turning behaviour. METHODS Twenty-one Wistar rats (11 QA and 10 shams) were investigated. Small animal PET acquisitions were conducted on a Focus 220 with approximately 18 MBq of [18F]MK-9470, [18F]FDG and [11C]raclopride. Relative glucose metabolism and parametric CB1 receptor and D2 binding images were anatomically standardized to Paxinos space and analysed voxel-wise using Statistical Parametric Mapping (SPM2). RESULTS In the QA model, [18F]MK-9470 uptake, glucose metabolism and D2 receptor binding were reduced in the ipsilateral caudate-putamen by 7, 35 and 77%, respectively (all p<2.10(-5)), while an increase for these markers was observed on the contralateral side (>5%, all p<7.10(-4)). [18F]MK-9470 binding was also increased in the cerebellum (p=2.10(-5)), where it was inversely correlated to the number of ipsiversive turnings (p=7.10(-6)), suggesting that CB1 receptor upregulation in the cerebellum is related to a better functional outcome. Additionally, glucose metabolism was relatively increased in the contralateral hippocampus, thalamus and sensorimotor cortex (p=1.10(-6)). CONCLUSION These data point to in vivo changes in endocannabinoid transmission, specifically for CB1 receptors in the QA model, with involvement of the caudate-putamen, but also distant regions of the motor circuitry, including the cerebellum. These data also indicate the occurrence of functional plasticity on metabolism, D2 and CB1 neurotransmission in the contralateral hemisphere.
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Affiliation(s)
- Cindy Casteels
- Division of Nuclear Medicine, KU Leuven and University Hospital Leuven, Leuven, Belgium.
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Momosaki S, Imamoto N, Hosoi R, Sawada Y, Abe K, Zhang MR, Inoue O. PK11195 might selectively suppress the quinolinic acid-induced enhancement of anaerobic glycolysis in glial cells. Brain Res 2010; 1340:18-23. [PMID: 20435022 DOI: 10.1016/j.brainres.2010.04.063] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Revised: 04/22/2010] [Accepted: 04/23/2010] [Indexed: 01/01/2023]
Abstract
PK11195 was previously reported to attenuate the quinolinic acid (QUIN)-induced enhancement of glucose metabolism in rat brain. In the present study, the effect of PK11195 or anesthesia on [(14)C]2-deoxyglucose ([(14)C]DG) uptake was investigated in order to determine whether the QUIN-induced enhancement of glucose metabolism occurred in glial cells or neurons. We confirmed that the microinjection of QUIN caused a significant enhancement of [(14)C]DG uptake at 2h after the infusion, while the co-injection of PK11195 and QUIN almost completely suppressed this enhancement of [(14)C]DG uptake. No effect of chloral hydrate anesthesia on the QUIN-induced enhancement of [(14)C]DG uptake was observed. In contrast to rats treated with QUIN, PK11195 did not affect the enhancement of [(14)C]DG uptake induced by fluorocitrate (FC); however, chloral hydrate anesthesia completely suppressed the FC-induced increase in [(14)C]DG uptake. These results indicated that the enhancement of glucose metabolism induced by QUIN mainly occurred in glial cells, and the neuroprotective effect of PK11195 in rats injected with QUIN might be related to the suppression of anaerobic glycolysis in glial cells.
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Affiliation(s)
- Sotaro Momosaki
- Division of Health Sciences, Graduate School of Medicine, Osaka University, 1-7 Yamada-oka, Suita, Osaka 565-0871, Japan.
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Van Camp N, Vreys R, Van Laere K, Lauwers E, Beque D, Verhoye M, Casteels C, Verbruggen A, Debyser Z, Mortelmans L, Sijbers J, Nuyts J, Baekelandt V, Van der Linden A. Morphologic and functional changes in the unilateral 6-hydroxydopamine lesion rat model for Parkinson's disease discerned with microSPECT and quantitative MRI. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2010; 23:65-75. [PMID: 20169465 DOI: 10.1007/s10334-010-0198-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2008] [Revised: 01/11/2010] [Accepted: 01/18/2010] [Indexed: 11/28/2022]
Abstract
OBJECT In the present study, we aimed to evaluate the impact of neurodegeneration of the nigrostriatal tract in a rodent model of Parkinson's disease on the different MR contrasts (T(2), T(1), CBF and CBV) measured in the striatum. MATERIAL AND METHODS Animals were injected with 6-hydroxydopamine (6OHDA) in the substantia nigra resulting in massive loss of nigrostriatal neurons and hence dopamine depletion in the ipsilateral striatum. Using 7T MRI imaging, we have quantified T(2), T(1), CBF and CBV in the striata of 6OHDA and control rats. To validate the lesion size, behavioral testing, dopamine transporter muSPECT and tyrosine hydroxylase staining were performed. RESULTS No significant differences were demonstrated in the absolute MRI values between 6OHDA animals and controls; however, 6OHDA animals showed significant striatal asymmetry for all MRI parameters in contrast to controls. CONCLUSIONS These PD-related asymmetry ratios might be the result of counteracting changes in both intact and affected striatum and allowed us to diagnose PD lesions. As lateralization is known to occur also in PD patients and might be expected in transgenic PD models as well, we propose that MR-derived asymmetry ratios in the striatum might be a useful tool for in vivo phenotyping of animal models of PD.
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Affiliation(s)
- Nadja Van Camp
- Bio-Imaging Lab, University of Antwerp, Groenenborgerlaan 171, Antwerp, Belgium.
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Kalonia H, Kumar P, Kumar A, Nehru B. Effect of caffeic acid and rofecoxib and their combination against intrastriatal quinolinic acid induced oxidative damage, mitochondrial and histological alterations in rats. Inflammopharmacology 2009; 17:211-9. [PMID: 19633993 DOI: 10.1007/s10787-009-0012-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2009] [Accepted: 07/08/2009] [Indexed: 01/01/2023]
Abstract
Oxidative stress has long been implicated in the neurotoxic effects of glutamate acting through N-methyl-D-aspartate (NMDA) receptors. Therefore, present study has been designed to explore the effect of rofecoxib and caffeic acid on the involvement of oxidative stress, mitochondrial dysfunction and neuronal linked with NMDA receptor-mediated excitotoxicity. Caffeic acid, is a well-known antioxidant flavanoid, implicate anti-inflammatory and immunomodulatory like actions. The present study is an attempt to investigate the antioxidant-like effect of caffeic acid and rofecoxib and their combination against QA-induced oxidative damage, mitochondrial dysfunction and histological alterations. Intrastriatal injection of quinolinic acid (300 nmol) significantly increased oxidative stress (raised lipid peroxidation, nitrite concentration, depleted SOD and catalase), altered mitochondrial complex enzyme activities and histological alteration in the ex vivo striatum. Caffeic acid (5 and 10 mg/kg, p.o.) and rofecoxib (10 and 20 mg/kg, p.o.) treatment for 21 days significantly attenuated oxidative damage and impairment in mitochondrial activities of complex enzymes in the ex vivo striatum. Further, combination of sub effective doses of rofecoxib (10 mg/kg, p.o.) and caffeic acid (5 mg/kg, p.o.) potentiated their protective effect which was significant as compared to their effect per se. The present study suggests the therapeutic effect of caffeic acid and rofecoxib combination against QA-induced ex vivo oxidative damage, mitochondrial and histological alterations in rats.
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Affiliation(s)
- Harikesh Kalonia
- Pharmacology Division, University Institute of Pharmaceutical Sciences, UGC Centre of Advance Study, Panjab University, Chandigarh, India
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Effect of prenatal manganese intoxication on [(3)H]glucose uptake in the brain of rats lesioned as neonates with 6-hydroxydopamine. Pharmacol Rep 2009; 61:558-63. [PMID: 19605956 DOI: 10.1016/s1734-1140(09)70099-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2008] [Revised: 05/08/2009] [Indexed: 11/21/2022]
Abstract
In the present study we examined the effects of prenatal manganese (Mn) intoxication on [(3)H]glucose uptake in the brain of rats lesioned as neonates with 6-hydroxydopamine (6-OHDA). MnCl(2) . 4H(2)O (10,000 ppm) was added to the drinking water of pregnant Wistar rats for the duration of pregnancy. On the day of parturition, Mn was discontinued as an additive to the drinking water. The control group consisted of rats that consumed water without Mn. Three days after birth, rats in both groups (control and Mn) were pretreated with desipramine hydrochloride (20 mg/kg) and pargyline hydrochloride (50 mg/kg) and injected bilaterally icv with one of three doses of 6-OHDA hydrobromide (15 mug, 30 mug or 67 mug base form in saline on each side) or with saline (control). 6-[(3)H]-D-glucose (500 muCi/kg, ip) was administered to male offspring in adulthood; after 15 min, brain specimens were taken (frontal cortex, hippocampus, striatum, thalamus with hypothalamus, pons and cerebellum) for determination of radioactivity in a liquid scintillation counter. Low dose 6-OHDA (15 mug icv) increased [(3)H]glucose uptake in all brain regions (p < 0.05) in both control and Mn-intoxicated animals. In rats lesioned with a moderate dose of 6-OHDA (30 mug icv), [(3)H]glucose uptake was unaltered in both control and Mn-exposed rats. High dose 6-OHDA (67 mug icv) reduced [(3)H]glucose uptake in all brain regions of Mn-exposed rats (except for cerebellum) compared with the saline group (all, p < 0.05). There was no change in regional brain uptake of [(3)H]glucose in control rats. In conclusion, this study shows that mild neuronal insult (15 mug icv 6-OHDA) increased glucose uptake in the brain while severe damage (concomitant 60 mug icv 6-OHDA and Mn treatment) significantly diminished this process.
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Amitani M, Ohashi A, Hatazawa J, Gee A, Inoue O. Effect of PK11195 on attenuating the enhancement of glucose utilization induced by quinolinic acid infusion in the rat brain. Synapse 2008; 62:253-8. [PMID: 18236472 DOI: 10.1002/syn.20485] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
PK11195, a selective PBR ligand, has been reported to exert a protective effect against the neuronal damage induced by the intrastriatal infusion of quinolinic acid, an excitatory amino acid. The neuroprotective effect of PK11195 observed at 48 h after the infusion was mediated by the inhibition of microglial activation. The aim of this study is to search the mechanism for the effect of PK11195 other than the inhibition of activation of microglia. In this study, the effect of PK11195 on glucose metabolism as well as neuroprotection in the early phase (2 h) after the injection of quinolinic acid was examined. Intrastriatal injection of quinolinic acid (60 nmol/microL) alone caused a significant enhancement of [(14)C]DG utilization in the infused striatum (about 160% vs. the contralateral side). This enhancement of glucose utilization might be due to an increase in phosphorylation rate of [(14)C]DG rather than delivery process from the plasma into the brain, since the initial uptake of [(14)C]DG (1 min) was not changed by quinolinic acid. Coinjection of PK11195 (10 nmol/microL) completely blocked the enhancement of [(14)C]DG uptake induced by quinolinic acid. The attenuating effect of PK11195 on glucose metabolic disturbance induced by quinolinic acid seemed to be related to voltage-dependent anion channels (VDAC), which are component of the PBR complex and associated with the regulation of hexokinase activity. PK11195 also showed neuroprotective effect at 2 h after the infusion of quinolinic acid, despite no significant activation of microglia was observed at this time-point. Thus, the neuroprotection of PK11195 might be related to normalization of the metabolic disturbance by the excitatory amino acid.
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Affiliation(s)
- Misato Amitani
- Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka, Japan.
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19
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Dubois A, Hérard AS, Flandin G, Duchesnay E, Besret L, Frouin V, Hantraye P, Bonvento G, Delzescaux T. Quantitative validation of voxel-wise statistical analyses of autoradiographic rat brain volumes: application to unilateral visual stimulation. Neuroimage 2007; 40:482-494. [PMID: 18234520 DOI: 10.1016/j.neuroimage.2007.11.054] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2007] [Revised: 11/23/2007] [Accepted: 11/28/2007] [Indexed: 10/22/2022] Open
Abstract
PET scanners devoted to in vivo functional study have recently been developed, but autoradiography remains the reference technique for assessing cerebral glucose metabolism (CMRGlu) in rodents. Autoradiographs are conventionally subjected to region of interest (ROI) analysis, which is intrinsically hypothesis-driven and therefore not suitable for whole-brain investigation. Voxel-wise statistical methods of analysis have long been used to determine differences in brain activity during in vivo functional neuroimaging experiments. They have also recently been applied to 3D reconstructed autoradiographic volume images from rat brains. We present here a fully automated analysis for autoradiographic data combining (1) computerized procedures for the acquisition and 3D reconstruction of postmortem volume images and (2) spatial normalization followed by classical whole-brain voxel-wise statistical analysis. We also describe an additional procedure for characterizing functional differences between the right and left hemispheres of the brain. We compared two spatial normalization techniques and evaluated how the effect of choosing a particular normalization technique impacted on the statistical analysis. We also propose a small volume correction analysis to address the problem of multiple statistical comparisons. Lastly, we investigated the reliability of such analyses, by comparing their results qualitatively and quantitatively with those previously obtained with our semiautomated ROI-based analysis [Dubois, A., Dauguet, J., Herard, A.-S., Besret, L., Duchesnay, E., Frouin, V., Hantraye, P., Bonvento, G., Delzescaux, T., 2007. Automated three-dimensional analysis of histologic and autoradiographic rat brain sections: application to an activation study. J. Cereb. Blood Flow Metab. 27 (10), 1742-1755.]. Both voxel-wise statistical analyses led to the detection of consistent interhemispheric differences in CMRGlu. This work demonstrates the potential value and robustness of voxel-wise statistical methods for analyzing autoradiographic data sets.
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Affiliation(s)
- Albertine Dubois
- CEA-DSV-I2BM-MIRCen, 4 place du Général Leclerc, 91401 Orsay Cedex, France.
| | - Anne-Sophie Hérard
- CEA-DSV-I2BM-MIRCen, 4 place du Général Leclerc, 91401 Orsay Cedex, France
| | - Guillaume Flandin
- CEA-DSV-I2BM-Neurospin-LNAO, CEA Saclay, Bat 145, 91191 Gif-sur-Yvette, France
| | - Edouard Duchesnay
- CEA-DSV-I2BM-Neurospin-LNAO, CEA Saclay, Bat 145, 91191 Gif-sur-Yvette, France
| | | | | | - Philippe Hantraye
- CEA-DSV-I2BM-MIRCen, 4 place du Général Leclerc, 91401 Orsay Cedex, France
| | - Gilles Bonvento
- CEA-DSV-I2BM-MIRCen, 4 place du Général Leclerc, 91401 Orsay Cedex, France
| | - Thierry Delzescaux
- CEA-DSV-I2BM-MIRCen, 4 place du Général Leclerc, 91401 Orsay Cedex, France
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Moresco RM, Lavazza T, Belloli S, Lecchi M, Pezzola A, Todde S, Matarrese M, Carpinelli A, Turolla E, Zimarino V, Popoli P, Malgaroli A, Fazio F. Quinolinic acid induced neurodegeneration in the striatum: a combined in vivo and in vitro analysis of receptor changes and microglia activation. Eur J Nucl Med Mol Imaging 2007; 35:704-15. [PMID: 18080815 DOI: 10.1007/s00259-007-0651-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2007] [Accepted: 11/04/2007] [Indexed: 10/22/2022]
Abstract
PURPOSE Huntington's disease (HD) is a progressive neurodegenerative disorder, which is characterised by prominent neuronal cell loss in the basal ganglia with motor and cognitive disturbances. One of the most well-studied pharmacological models of HD is produced by local injection in the rat brain striatum of the excitotoxin quinolinic acid (QA), which produces many of the distinctive features of this human neurodegenerative disorder. Here, we report a detailed analysis, obtained both in vivo and in vitro of this pharmacological model of HD. MATERIALS AND METHODS By combining emission tomography (PET) with autoradiographic and immunocytochemical confocal laser techniques, we quantified in the QA-injected striatum the temporal behavior (from 1 to 60 days from the excitotoxic insult) of neuronal cell density and receptor availability (adenosine A(2A) and dopamine D(2) receptors) together with the degree of microglia activation. RESULTS Both approaches showed a loss of adenosine A(2A) and dopamine D(2) receptors paralleled by an increase of microglial activation. CONCLUSION This combined longitudinal analysis of the disease progression, which suggested an impairment of neurotransmission, neuronal integrity and a reversible activation of brain inflammatory processes, might represent a more quantitative approach to compare the differential effects of treatments in slowing down or reversing HD in rodent models with potential applications to human patients.
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Affiliation(s)
- R M Moresco
- IBFM-CNR, University of Milan Bicocca, Nuclear Medicine Department, San Raffaele Scientific Institute, Milano, Italy.
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21
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Sakiyama Y, Hatano K, Tajima T, Kato T, Kawasumi Y, Suzuki M, Ito K. An atlas-based image registration method for dopamine receptor imaging with PET in rats. Ann Nucl Med 2007; 21:455-62. [DOI: 10.1007/s12149-007-0049-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2007] [Accepted: 06/11/2007] [Indexed: 10/22/2022]
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Ma Y, Eidelberg D. Functional imaging of cerebral blood flow and glucose metabolism in Parkinson's disease and Huntington's disease. Mol Imaging Biol 2007; 9:223-33. [PMID: 17334854 PMCID: PMC4455550 DOI: 10.1007/s11307-007-0085-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Brain imaging of cerebral blood flow and glucose metabolism has been playing key roles in describing pathophysiology of Parkinson's disease (PD) and Huntington's disease (HD), respectively. Many biomarkers have been developed in recent years to investigate the abnormality in molecular substrate, track the time course of disease progression, and evaluate the efficacy of novel experimental therapeutics. A growing body of literature has emerged on neurobiology of these two movement disorders in resting states and in response to brain activation tasks. In this paper, we review the latest applications of these approaches in patients and normal volunteers at rest conditions. The discussions focus on brain mapping studies with univariate and multivariate statistical analyses on a voxel basis. In particular, we present data to validate the reproducibility and reliability of unique spatial covariance patterns related with PD and HD.
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Affiliation(s)
- Yilong Ma
- Center for Neurosciences, Feinstein Institute for Medical Research, North Shore-Long Island Jewish Health System, New York University School of Medicine, Manhasset, NY, USA.
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23
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Dubois A, Dauguet J, Herard AS, Besret L, Duchesnay E, Frouin V, Hantraye P, Bonvento G, Delzescaux T. Automated three-dimensional analysis of histological and autoradiographic rat brain sections: application to an activation study. J Cereb Blood Flow Metab 2007; 27:1742-55. [PMID: 17377517 DOI: 10.1038/sj.jcbfm.9600470] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Besides the newly developed positron emission tomography scanners (microPET) dedicated to the in vivo functional study of small animals, autoradiography remains the reference technique widely used for functional brain imaging and the gold standard for the validation of in vivo results. The analysis of autoradiographic data is classically achieved in two dimensions (2D) using a section-by-section approach, is often limited to few sections and the delineation of the regions of interest to be analysed is directly performed on autoradiographic sections. In addition, such approach of analysis does not accommodate the possible anatomical shifts linked to dissymmetry associated with the sectioning process. This classic analysis is time-consuming, operator-dependent and can therefore lead to non-objective and non-reproducible results. In this paper, we have developed an automated and generic toolbox for processing of autoradiographic and corresponding histological rat brain sections based on a three-step approach, which involves: (1) an optimized digitization dealing with hundreds of autoradiographic and histological sections; (2) a robust reconstruction of the volumes based on a reliable registration method; and (3) an original 3D-geometry-based approach to analysis of anatomical and functional post-mortem data. The integration of the toolbox under a unified environment (in-house software BrainVISA, http://brainvisa.info) with a graphic interface enabled a robust and operator-independent exploitation of the overall anatomical and functional information. We illustrated the substantial qualitative and quantitative benefits obtained by applying our methodology to an activation study (rats, n=5, under unilateral visual stimulation).
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Abstract
The use of molecular imaging techniques in the central nervous system (CNS) has a rich history. Most of the important developments in imaging-such as computed tomography, magnetic resonance imaging, single photon emission computed tomography, and positron emission tomography-began with neuropsychiatric applications. These techniques and modalities were then found to be useful for imaging other organs involved with various disease processes. Molecular imaging of the CNS has enabled scientists and researchers to understand better the basic biology of brain function and the way in which various disease processes affect the brain. Unlike other organs, the brain is not easily accessible, and it has a highly selective barrier at the endothelial cell level known as the blood-brain barrier. Furthermore, the brain is the most complex cellular network known to exist. Various neurotransmitters act in either an excitatory or an inhibitory fashion on adjacent neurons through a multitude of mechanisms. The various neuronal systems and the myriad of neurotransmitter systems become altered in many diseases. Some of the most devastating diseases, including Alzheimer disease, Parkinson disease, brain tumors, psychiatric disease, and numerous degenerative neurologic diseases, affect only the brain. Molecular neuroimaging will be critical to the future understanding and treatment of these diseases. Molecular neuroimaging of the brain shows tremendous promise for clinical application. In this article, the current state and clinical applications of molecular neuroimaging will be reviewed.
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Affiliation(s)
- Dima A Hammoud
- Department of Radiology, Johns Hopkins University School of Medicine, 1550 Orleans St, CRB-2, Room 492, Baltimore, MD 21231, USA
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25
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Casteels C, Lauwers E, Bormans G, Baekelandt V, Van Laere K. Metabolic-dopaminergic mapping of the 6-hydroxydopamine rat model for Parkinson's disease. Eur J Nucl Med Mol Imaging 2007; 35:124-34. [PMID: 17906859 DOI: 10.1007/s00259-007-0558-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2007] [Accepted: 07/25/2007] [Indexed: 11/29/2022]
Abstract
PURPOSE The unilateral 6-hydroxydopamine (6-OHDA) lesion rat model is a well-known acute model for Parkinson's disease (PD). Its validity has been supported by invasive histology, behavioral studies and electrophysiology. Here, we have characterized this model in vivo by multitracer imaging [glucose metabolism and dopamine transporter (DAT)] in relation to behavioral and histological parameters. METHODS Eighteen female adult Wistar rats (eight 6-OHDA-lesioned, ten controls) were investigated using multitracer [(18)F]-fluoro-2-deoxy-D: -glucose (FDG) and [(18)F]-FECT {2'-[(18)F]-fluoroethyl-(1R-2-exo-3-exe)-8-methyl-3-(4-chlorophenyl)-8-azabicyclo(3.2.1)-octane-2-carboxylate} small animal positron emission tomography (PET). Relative glucose metabolism and parametric DAT binding images were anatomically standardized to Paxinos space and analyzed on a voxel-basis using SPM2: , supplemented by a template-based predefined volumes-of-interest approach. Behavior was characterized by the limb-use asymmetry test; dopaminergic innervation was validated by in vitro tyrosine hydroxylase staining. RESULTS In the 6-OHDA model, significant glucose hypometabolism is present in the ipsilateral sensory-motor cortex (-6.3%; p = 4 x 10(-6)). DAT binding was severely decreased in the ipsilateral caudate-putamen, nucleus accumbens and substantia nigra (all p < 5 x 10(-9)), as confirmed by the behavioral and histological outcomes. Correlation analysis revealed a positive relationship between the degree of DAT impairment and the change in glucose metabolism in the ipsilateral hippocampus (p = 3 x 10(-5)), while cerebellar glucose metabolism was inversely correlated to the level of DAT impairment (p < 3 x 10(-4)). CONCLUSIONS In vivo cerebral mapping of 6-OHDA-lesioned rats using [(18)F]-FDG and [(18)F]-FECT small animal PET shows molecular-functional correspondence to the cortico-subcortical network impairments observed in PD patients. This provides a further molecular validation supporting the validity of the 6-OHDA lesion model to mimic multiple aspects of human PD.
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Affiliation(s)
- Cindy Casteels
- Division of Nuclear Medicine, KU Leuven and University Hospital Leuven, Leuven, Belgium.
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26
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Strome EM, Doudet DJ. Animal Models of Neurodegenerative Disease: Insights from In vivo Imaging Studies. Mol Imaging Biol 2007; 9:186-95. [PMID: 17357857 DOI: 10.1007/s11307-007-0093-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Animal models have been used extensively to understand the etiology and pathophysiology of human neurodegenerative diseases, and are an essential component in the development of therapeutic interventions for these disorders. In recent years, technical advances in imaging modalities such as positron emission tomography (PET) and magnetic resonance imaging (MRI) have allowed the use of these techniques for the evaluation of functional, neurochemical, and anatomical changes in the brains of animals. Combining animal models of neurodegenerative disorders with neuroimaging provides a powerful tool to follow the disease process, to examine compensatory mechanisms, and to investigate the effects of potential treatments preclinically to derive knowledge that will ultimately inform our clinical decisions. This article reviews the literature on the use of PET and MRI in animal models of Parkinson's disease, Huntington's disease, and Alzheimer's disease, and evaluates the strengths and limitations of brain imaging in animal models of neurodegenerative diseases.
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Affiliation(s)
- Elissa M Strome
- Pacific Parkinson's Research Centre, University of British Columbia, Vancouver, Canada.
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27
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Nikolaus S, Larisch R, Beu M, Antke C, Kley K, Forutan F, Wirrwar A, Müller HW. Investigating the Dopaminergic Synapse In Vivo. II. Molecular Imaging Studies in Small Laboratory Animals. Rev Neurosci 2007; 18:473-504. [DOI: 10.1515/revneuro.2007.18.6.473] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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28
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Schiffer WK, Mirrione MM, Biegon A, Alexoff DL, Patel V, Dewey SL. Serial microPET measures of the metabolic reaction to a microdialysis probe implant. J Neurosci Methods 2006; 155:272-84. [PMID: 16519945 DOI: 10.1016/j.jneumeth.2006.01.027] [Citation(s) in RCA: 144] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2005] [Revised: 01/23/2006] [Accepted: 01/23/2006] [Indexed: 10/24/2022]
Abstract
Despite the widespread use of chronic brain implants in experimental and clinical settings, the effects of these long-term procedures on brain metabolism and receptor expression remain largely unknown. Under the hypothesis that intracerebral microdialysis transiently alters tissue metabolism, we performed a series of 18FDG microPET scans prior to and following surgical implantation of microdialysis cannulae. Parallel microPET measures using the competitive dopamine (DA) D2 receptor antagonist, 11C-raclopride, provided an assay of DA stability in these same animals. 18FDG scans were performed prior to microdialysis cannulation and again at 2, 12, 24, 48, 120, 168, 360 and 500 h (0.2, 0.5, 1, 2, 5, 7, 15 and 25 days). Separate animals received a sham surgery and the control group had no surgical intervention. For the first 24 h (scans at 2, 12 and 24 h post-surgery) uptake was reduced in both hemispheres. However, by 48 h, contralateral uptake had returned to pre-surgical levels. The striking finding was that from 48 to 500 h, the microdialysis cannulation produced widespread ipsilateral reductions in 18FDG uptake that encompassed the entire hemisphere. Despite the extent and persistence of these reductions, 11C-raclopride binding and ECF DA concentrations remained stable.
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Affiliation(s)
- Wynne K Schiffer
- Graduate Program in Neuroscience, Department of Neurobiology & Behavior, Stony Brook University, Stony Brook, NY 11794-5230, USA.
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29
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Visnyei K, Tatsukawa KJ, Erickson RI, Simonian S, Oknaian N, Carmichael ST, Kornblum HI. Neural progenitor implantation restores metabolic deficits in the brain following striatal quinolinic acid lesion. Exp Neurol 2006; 197:465-74. [PMID: 16310773 DOI: 10.1016/j.expneurol.2005.10.023] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2005] [Revised: 10/10/2005] [Accepted: 10/13/2005] [Indexed: 01/10/2023]
Abstract
Neural progenitor transplantation is a potential treatment for neurodegenerative diseases, including Huntington's disease (HD). In the current study, we tested the potential of rat embryonic neural progenitors expanded in vitro as therapy in the rat quinolinic acid-lesioned striatum, a model that demonstrates some of the pathological features of HD. We used positron emission tomography (PET) to demonstrate that the intrastriatal injection of cultured rat neural progenitors results in improved metabolic function in the striatum and overlying cortex when compared to media-injected controls. Transplanted progenitors were capable of surviving, migrating long distances and differentiating into neurons and glia. The cortices of transplanted animals contained greater numbers of neurons in regions that had shown metabolic improvement. However, histological analysis revealed that only a small fraction of these increased neurons could be accounted for by engrafted cells, indicating that the metabolic sparing was likely the result of a trophic action of the transplanted cells on the host. Behavioral testing of the implanted animals did not reveal improvement in apomorphine-induced rotation. These data demonstrate that progenitor cell implantation results in enhanced metabolic function and sparing of neuron number, but that these functions do not necessarily result in the restoration of complex circuitry.
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Affiliation(s)
- Koppany Visnyei
- Department of Molecular and Medical Pharmacology, UCLA School of Medicine, Los Angeles, CA 90095, USA
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BROWNELL ANNALIISA, CHEN IRISY, WANG XUKUI, YU MEIXIANG, JENKINS BRUCEG. Neurotoxicity-Induced Changes in Striatal Dopamine Receptor Function. Ann N Y Acad Sci 2006. [DOI: 10.1111/j.1749-6632.2003.tb07484.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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31
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Bauer A, Zilles K, Matusch A, Holzmann C, Riess O, von Hörsten S. Regional and subtype selective changes of neurotransmitter receptor density in a rat transgenic for the Huntington's disease mutation. J Neurochem 2005; 94:639-50. [PMID: 16033418 DOI: 10.1111/j.1471-4159.2005.03169.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Huntington's disease (HD) is an autosomal dominantly inherited progressive neurodegenerative disorder caused by a CAG/polyglutamine repeat expansion in the gene encoding the huntingtin protein. We have recently generated a rat model transgenic for HD, which displays a slowly progressive phenotype resembling the human adult-onset type of disease. In this study we systematically assessed the distribution and density of 17 transmitter receptors in the brains of 2-year-old rats using quantitative multi-tracer autoradiography and high-resolution positron emission tomography. Heterozygous animals expressed increased densities of M(2) acetylcholine (increase of 148 +/- 16% of controls; p > 0.001; n = 7), nicotine (increase of 149 +/- 16% of controls; p > 0.01; n = 6), and alpha(2) noradrenergic receptors (increase of 141 +/- 15% of controls; p > 0.001; n = 6), respectively. Densities of these receptors were decreased in homozygous animals. Decreases of receptor density in both hetero- and homozygous animals were found for M1 acetylcholine, 5-HT 2A serotonin, A 2A adenosine, D1 and D2 dopamine, and GABA(A) receptors, respectively. Other investigated receptor systems showed small changes or were not affected. The present data suggest that the moderate increase of CAG/polyglutamine repeat expansions in the present rat model of Huntington's disease is characterized by subtype-selective and region-specific changes of neuroreceptor densities. In particular, there is evidence for a contribution of predominantly presynaptically localized cholinergic and noradrenergic receptors in the response to Huntington's disease pathology.
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Affiliation(s)
- Andreas Bauer
- Institute of Medicine, Research Center Jülich, Jülich, Germany.
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32
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Wang X, Sarkar A, Cicchetti F, Yu M, Zhu A, Jokivarsi K, Saint-Pierre M, Brownell AL. Cerebral PET imaging and histological evidence of transglutaminase inhibitor cystamine induced neuroprotection in transgenic R6/2 mouse model of Huntington's disease. J Neurol Sci 2005; 231:57-66. [PMID: 15792822 DOI: 10.1016/j.jns.2004.12.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2004] [Revised: 12/13/2004] [Accepted: 12/15/2004] [Indexed: 10/25/2022]
Abstract
To investigate efficacy of cystamine induced neuroprotection, we conducted PET imaging studies of cerebral glucose metabolism with [(18)F]FDG (2-deoxy-2-[(18)F]fluoro-d-glucose) and striatal dopamine D2 receptor function with [(11)C]raclopride in R6/2 transgenic Huntington mice. In the control mice, exponentially decreasing glucose utilization was observed in the striatum N(str) [SUV]=(41.75+/-11.80)(58,str)*exp(-(0.041+/-0.007)*t [days]); cortex N(cort) [SUV]=24.14+/-3.66)(58,cort)*exp(-(0.043+/-0.007)*t [days]); and cerebellum N(cer) [SUV]=(34.97+/-10.58)(58,cer)*exp(-(0.037+/-0.008)*t [days]) as a function of age starting at 58 days. Given that the underlying degeneration rate in the cystamine treated mice is similar to that observed in control animals, the protection coefficient (beta) calculated from the equation N(t)=N(58)*exp(-(1-beta)*k*t) was 0.133+/-0.035 for the striatum; 0.122+/-0.028 for the cortex and 0.224+/-00.042 for the cerebellum with a dose of 100 mg/kg. The 50 mg/kg cystamine dose provided significant protection only for the striatum and only minor protection was obtained using lower doses. Striatal binding potential of [(11)C]raclopride was 1.059+/-0.030 in the control mice, and enhanced in the cystamine treated animals in a dose dependent manner up to 1.245+/-0.063 using the 100 mg/kg dose. Histological analysis confirmed cystamine induced neuroprotection of striatal and cortical neurons and Nissl staining revealed that formation of cellular inclusions was reversed in a dose dependent manner. Cerebral imaging and histological evidence support the use of cystamine as a neuroprotective agent for Huntington's disease (HD) pathology.
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Affiliation(s)
- Xukui Wang
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
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Schiffer WK, Alexoff DL, Shea C, Logan J, Dewey SL. Development of a simultaneous PET/microdialysis method to identify the optimal dose of 11C-raclopride for small animal imaging. J Neurosci Methods 2004; 144:25-34. [PMID: 15848236 PMCID: PMC2669956 DOI: 10.1016/j.jneumeth.2004.10.016] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2004] [Accepted: 10/11/2004] [Indexed: 11/22/2022]
Abstract
In the field of small animal positron emission tomography (PET), the assumptions underlying human and primate kinetic models may not be sustained in rodents. That is, the threshold dose at which a pharmacologic response occurs may be lower in small animals. In order to define this relationship, we combined microPET imaging using 11C-raclopride with microdialysis measures of extracellular fluid (ECF) dopamine (DA). In addition, we performed a series of studies in which a known mass of raclopride was microinfused into one striatum prior to a high specific activity (SA) systemic injection of 11C-raclopride. This single-injection approach provided a high and low SA region of radiotracer binding in the same animal during the same scanning session. Our data demonstrate that the binding potential (BP) declines above 3.5 pmol/ml (0.35 microg), with an ED50 of 8.55+/-5.62 pmol/ml. These data also provide evidence that BP may be compromised by masses of raclopride below 2.0 pmol/ml (0.326 microg). Increases in ECF DA were produced by mass doses of raclopride over 3.9 pmol/ml (0.329 microg) with an ED50 of 8.53+/-2.48 pmol/ml. Taken together, it appears that an optimal range of raclopride mass exists between 2.0 and 3.5 pmol/ml, around which the measured BP can be compromised by system sensitivity, endogenous DA, or excessive competition with unlabeled compound.
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Affiliation(s)
- Wynne K Schiffer
- Department of Neurobiology and Behavior, State University of New York at Stony Brook, NY 11794-5230, USA.
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34
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Scattoni ML, Valanzano A, Popoli P, Pezzola A, Reggio R, Calamandrei G. Progressive behavioural changes in the spatial open-field in the quinolinic acid rat model of Huntington's disease. Behav Brain Res 2004; 152:375-83. [PMID: 15196806 DOI: 10.1016/j.bbr.2003.10.021] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2003] [Revised: 10/17/2003] [Accepted: 10/20/2003] [Indexed: 10/26/2022]
Abstract
Huntington's disease (HD) is a progressive neurodegenerative disorder, characterized by severe degeneration of basal ganglia, motor abnormalities, impaired cognitive functions and emotional disturbances. Intrastriatal injection of the excitotoxin quinolinic acid (QA), an N-methyl-D-aspartate receptor agonist, appears to reproduce in rats some of the clinical features of human HD, included motor and behavioural deficits. Aim of this study was to assess whether the behavioural alterations described in the QA rat model of HD progressed over time. We analysed the effects of bilateral striatal injection of QA (300 nmol/1 microl) to adult rats in the spatial open-field test, a nonaversive task in which exploratory activity and responses to both spatial rearrangement of familiar objects and object novelty are measured. Rats were tested 2 weeks, 2 and 6 months after the QA lesion. Lesioned rats showed progressive alterations in performance in this task. Whereas sham and QA rats did not markedly differ 2 weeks post-lesion, lesioned rats were significantly more active than controls 2 and 6 months after surgery. Specifically, frequency and duration of rearing and wall rearing increased progressively over time, while grooming was enhanced at 2 months post-lesion only. Spatial and object novelty discrimination was not affected. These results show that a single injection of QA excitotoxin can induce behavioural changes that progress over time. The main implication of these findings is that, besides genetic mice models of HD, QA-lesioned rats may represent a suitable mean to test the ability of new drugs to slow down disease progression.
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Affiliation(s)
- Maria Luisa Scattoni
- Comparative Psychology Section, Laboratory of Pathophysiology, Istituto Superiore di Sanità, Viale Regina Elena 299, I-00161 Rome, Italy
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Alexoff DL, Vaska P, Logan J. Imaging dopamine receptors in the rat striatum with the MicroPET R4: kinetic analysis of [11C]raclopride binding using graphical methods. Methods Enzymol 2004; 385:213-28. [PMID: 15130741 DOI: 10.1016/s0076-6879(04)85012-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Affiliation(s)
- David L Alexoff
- Department of Chemistry, Brookhaven National Laboratory, Upton, NY 11973, USA
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36
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Nikolaus S, Beu M, Vosberg H, Müller HW, Larisch R. Quantitative analysis of dopamine D2 receptor kinetics with small animal positron emission tomography. Methods Enzymol 2004; 385:228-39. [PMID: 15130742 DOI: 10.1016/s0076-6879(04)85013-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Affiliation(s)
- Susanne Nikolaus
- Clinic of Nuclear Medicine, University Hospital Düsseldorf, 40225 Düsseldorf, Germany
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37
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Affiliation(s)
- Louise van der Weerd
- RCS Unit of Biophysics, Intitute of Child Health, University College London, United Kingdom
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38
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Stefanova N, Lundblad M, Tison F, Poewe W, Cenci MA, Wenning GK. Effects of pulsatile L-DOPA treatment in the double lesion rat model of striatonigral degeneration (multiple system atrophy). Neurobiol Dis 2004; 15:630-9. [PMID: 15056471 DOI: 10.1016/j.nbd.2003.11.025] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2003] [Revised: 11/07/2003] [Accepted: 11/18/2003] [Indexed: 11/21/2022] Open
Abstract
We examined the role of a striatal lesion in the development of L-DOPA-induced abnormal involuntary movements (AIMs) using the double lesion rat model of striatonigral degeneration (SND), the underlying neuropathological substrate of parkinsonism associated with multiple system atrophy (MSA-P), in comparison to a Parkinson's disease (PD) rat model. L-DOPA administration reliably induced AIMs in SND and PD rats in a dose-dependent fashion. AIMs occurred significantly earlier in SND compared to PD rats. There was a mild, but significant, transient increase of orolingual AIMs during the first week of low-dose L-DOPA treatment in SND. Whereas L-DOPA significantly improved contralateral forelimb akinesia in PD rats, there was no beneficial effect in SND rats. Striatal FosB/Delta FosB up-regulation in SND and PD rats correlated with the severity of L-DOPA-induced dyskinesias. Pulsatile L-DOPA administration in the double lesion SND rat model replicates salient features of the human disease MSA-P, including loss of the anti-akinetic L-DOPA response and induction of dyskinesias with transient orolingual predominance.
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Affiliation(s)
- N Stefanova
- Department of Neurology, University Hospital of Innsbruck, Innsbruck, Austria
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39
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Ma B, Sherman PS, Moskwa JE, Koeppe RA, Kilbourn MR. Sensitivity of [11C]N-methylpyrrolidinyl benzilate ([11C]NMPYB) to endogenous acetylcholine: PET imaging vs tissue sampling methods. Nucl Med Biol 2004; 31:393-7. [PMID: 15093808 DOI: 10.1016/j.nucmedbio.2003.12.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2003] [Accepted: 12/20/2003] [Indexed: 11/17/2022]
Abstract
Administration of phenserine, an acetylcholinesterase inhibitor, raises endogenous brain acetylcholine levels and has been previously shown to reduce in vivo binding of the muscarinic cholinergic receptor antagonist [(11)C]N-methylpyrrolidinyl benzilate ([(11)C]NMPYB) in the awake rat brain. In this study, phenserine pretreatment was studied in both awake and isoflurane-anesthetized rats using the techniques of ex vivo dissection or in vivo microPET imaging. In ex vivo dissection experiments, a statistically significant 10% inhibition of [(11)C]NMPYB binding could be demonstrated in both awake and anesthetized animals after phenserine pretreatment, showing no deleterious effect of using isoflurane anesthesia. However, microPET imaging in anesthetized animals failed to successfully demonstrate inhibition of [(11)C]NMPYB binding following the identical phenserine treatment protocol. These results demonstrate that in small numbers of subjects ex vivo dissection may be a more sensitive experimental method for determining small changes of in vivo radiotracer binding in this model of neurotransmitter competition for brain receptor sites.
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Affiliation(s)
- Bing Ma
- Division of Nuclear Medicine, Department of Radiology, University of Michigan Medical School, 3480 Kresge III Building, Ann Arbor, MI 48109, USA
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40
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Luyt LG, Bigott HM, Welch MJ, Katzenellenbogen JA. 7α- and 17α-Substituted estrogens containing tridentate tricarbonyl rhenium/Technetium complexes: synthesis of estrogen receptor imaging agents and evaluation using microPET with technetium-94m. Bioorg Med Chem 2003; 11:4977-89. [PMID: 14604660 DOI: 10.1016/j.bmc.2003.09.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
To develop technetium and rhenium-labeled imaging agents for estrogen receptor (ER) positive breast tumors, we have prepared tridentate metal tricarbonyl chelates substituted at the 7alpha- and 17alpha-positions of estradiol. Some of the Re(CO)(3) conjugates have high binding for the ER in vitro. The in vivo biodistribution of the highest affinity of these novel metal tricarbonyl conjugates, prepared as the (94m)Tc labeled analogue, was evaluated by tissue dissection and microPET imaging. Although target tissue-selective uptake was not apparent, it is notable that microPET imaging identified the stomach as a major site of activity deposition, a site that might have been missed by standard tissue distribution studies.
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Affiliation(s)
- Leonard G Luyt
- Department of Chemistry, University of Illinois, 600 South Mathews Avenue, Urbana, IL 61801, USA
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Blake P, Johnson B, VanMeter JW. Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT): Clinical Applications. J Neuroophthalmol 2003; 23:34-41. [PMID: 12616088 DOI: 10.1097/00041327-200303000-00009] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Positron emission tomography and single-photon emission computed tomography are nuclear imaging modalities that excel in depicting the biological function of tissue. Unlike structural imaging methods, they provide functional diagnostic information about brain neoplasms, stroke, neurodegenerative disorders, epilepsy, cortical visual loss, and migraine.
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Affiliation(s)
- Pamela Blake
- Department of Neurology, Center for the Study of Learning, Georgetown University Medical Center, Washington, USA.
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Abstract
The main aim of this review is to describe some of the many animal models that have proved to be valuable from a neuroimaging perspective. This paper complements other articles in this volume, with a focus on animal models of the pathology of human brain disorders for investigations with modern non-invasive neuroimaging techniques. The use of animal model systems forms a fundamental part of neuroscience research efforts to improve the prevention, diagnosis, understanding and treatment of neurological conditions. Without such models it would be impossible to investigate such topics as the underlying mechanisms of neuronal cell damage and death, or to screen compounds for possible anticonvulsant properties. The adequacy of any one particular model depends on the suitability of information gained during experimental conditions. It is important, therefore, to understand the various types of animal model available and choose an appropriate model for the research question.
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Affiliation(s)
- Mark F Lythgoe
- RCS Unit of Biophysics, Institute of Child Health, University College London, UK
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Blum D, Galas MC, Gall D, Cuvelier L, Schiffmann SN. Striatal and Cortical Neurochemical Changes Induced by Chronic Metabolic Compromise in the 3-Nitropropionic Model of Huntington's Disease. Neurobiol Dis 2002; 10:410-26. [PMID: 12270701 DOI: 10.1006/nbdi.2002.0512] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In the present study, we aimed to determine the time-course of neurochemical changes occurring following metabolic impairments produced by 3-nitropropionic (3NP) acid in a rat model of Huntington's disease. We found that the occurrence of striatal lesions was accompanied by (1) strong transcriptional alterations within the degenerative lateral striatum, (2) receptor upregulations within the preserved medial striatum, and (3) transcriptional increases within the unaltered cerebral cortex. These phenomena were preceded by transcriptional modifications in striatal subareas prone to degeneration even before the lesion was visible but not in the overlying cortex, known to be spared in this model. Of great interest, the density of A(2A) receptor binding sites, located on striato-pallidal neurons, was (1) downregulated at the time of worsening of symptoms and (2) strongly upregulated within the spared medial striatum after the lesion occurrence. This study therefore highlights the differential neurochemical responses produced by 3NP depending on the fate of the metabolically inhibited area and strongly suggests the involvement of A(2A) receptors in the development of striatal pathology under metabolic compromise.
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Affiliation(s)
- David Blum
- Laboratoire de Neurophysiologie, ULB-Erasme, CP601, 808 Route de Lennik, 1070 Brussels, Belgium.
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Grachev ID, Thomas PS, Ramachandran TS. Decreased levels of N-acetylaspartate in dorsolateral prefrontal cortex in a case of intractable severe sympathetically mediated chronic pain (complex regional pain syndrome, type I). Brain Cogn 2002; 49:102-13. [PMID: 12027396 DOI: 10.1006/brcg.2001.1489] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In our previous in vivo proton magnetic resonance spectroscopy ((1)H MRS) study we found reduced levels of N-acetylaspartate in dorsolateral prefrontal cortex of chronic back pain patients. This study tests whether these chemical abnormalities can be detected in other pain states. Using (1)H MRS, we measured levels for N-acetylaspartate and other identifiable chemicals relative to creatine in four bilateral brain regions, including dorsolateral prefrontal cortex, orbitofrontal cortex, cingulate, and thalamus, in a case of intractable severe sympathetically mediated chronic pain [complex regional pain syndrome (CRPS) type I]. The subject's chemical variations in the brain were compared to the same regional chemicals in 10 normal subjects (age- and sex-matched). Univariate statistics showed reduced levels of N-acetylaspartate in bilateral dorsolateral prefrontal cortex and increased levels of myo-inositol in left orbitofrontal cortex of the patient with intractable severe CRPS type I. These data support our original hypothesis that depletion of N-acetylaspartate in dorsolateral prefrontal cortex is a chemical marker of chronic pain, indicating for neuronal degeneration. Unpredicted changes of orbitofrontal myo-inositol may be related to the specific mood/affective state in an extreme pain perception. This is the first report, which identifies chemical markers in the prefrontal cortex for objective measurement and monitoring of CRPS type I. This information might lead to valuable insights into diagnosis and future effective interventions of CRPS type I (e.g., prefrontal brain stimulation).
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Affiliation(s)
- Igor D Grachev
- Department of Radiology, State University of New York Upstate Medical University, Syracuse 13210, USA.
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45
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Abstract
The most recent findings in the elucidation of the molecular pathology of Huntington's disease are reviewed. Particular interest has been paid to the role of huntingtin and its associated proteins in excitotoxicity mediated via NMDA and kainate receptors.
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Affiliation(s)
- S Davies
- Department of Medicine, Division of Medical Science, University of Birmingham, Birmingham B15 2TH, UK
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46
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Tkác I, Keene CD, Pfeuffer J, Low WC, Gruetter R. Metabolic changes in quinolinic acid-lesioned rat striatum detected non-invasively by in vivo (1)H NMR spectroscopy. J Neurosci Res 2001; 66:891-8. [PMID: 11746416 DOI: 10.1002/jnr.10112] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Intrastriatal injection of quinolinic acid (QA) provides an animal model of Huntington disease. In vivo (1)H NMR spectroscopy was used to measure the neurochemical profile non-invasively in seven animals 5 days after unilateral injection of 150 nmol of QA. Concentration changes of 16 metabolites were measured from 22 microl volume at 9.4 T. The increase of glutamine ((+25 +/- 14)%, mean +/- SD, n = 7) and decrease of glutamate (-12 +/- 5)%, N-acetylaspartate (-17 +/- 6)%, taurine (-14 +/- 6)% and total creatine (-9 +/- 3%) were discernible in each individual animal (P < 0.005, paired t-test). Metabolite concentrations in control striata were in excellent agreement with biochemical literature. The change in glutamate plus glutamine was not significant, implying a shift in the glutamate-glutamine interconversion, consistent with a metabolic defect at the level of neuronal-glial metabolic trafficking. The most significant indicator of the lesion, however, were the changes in glutathione ((-19 +/- 9)%, P < 0.002)), consistent with oxidative stress. From a comparison with biochemical literature we conclude that high-resolution in vivo (1)H NMR spectroscopy accurately reflects the neurochemical changes induced by a relatively modest dose of QA, which permits one to longitudinally follow mitochondrial function, oxidative stress and glial-neuronal metabolic trafficking as well as the effects of treatment in this model of Huntington disease.
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Affiliation(s)
- I Tkác
- Department of Radiology, University of Minnesota, 2021 6th Street SE, Minneapolis, MN 55455, USA
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Abstract
Noninvasive imaging technologies provide a unique window on the anatomy, physiology and function of living organisms. Imaging systems and methods have been developed for the study of small animal model systems that offer exciting new possibilities in neuroscience. Advances in magnetic resonance microscopy and positron emission tomography, and their applications in brain imaging, have provided many benefits to neurobiology, ranging from detailed in vivo neuroanatomy to the measurement of specific molecular targets.
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Affiliation(s)
- R E Jacobs
- Biological Imaging Center, Beckman Institute, California Institute of Technology, Pasadena, CA 91125, USA.
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Peñuelas Sánchez I. [PET radiopharmaceuticals]. REVISTA ESPANOLA DE MEDICINA NUCLEAR 2001; 20:477-98; quiz 499-501. [PMID: 11578585 DOI: 10.1016/s0212-6982(01)71997-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- I Peñuelas Sánchez
- Unidad de Radiofarmacia, Servicio de Medicina Nuclear, Clínica Universitaria de Navarra, Spain.
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