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Wang Y, Tsai CH, Chu TS, Hung YT, Lee MY, Chen HH, Chen LT, Ger TR, Wang YH, Chiang NJ, Liao LD. Revisiting the cerebral hemodynamics of awake, freely moving rats with repeated ketamine self-administration using a miniature photoacoustic imaging system. NEUROPHOTONICS 2022; 9:045003. [PMID: 36338453 PMCID: PMC9623815 DOI: 10.1117/1.nph.9.4.045003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Accepted: 09/21/2022] [Indexed: 06/16/2023]
Abstract
SIGNIFICANCE Revealing the dynamic associations between brain functions and behaviors is a significant challenge in neurotechnology, especially for awake subjects. Imaging cerebral hemodynamics in awake animal models is important because the collected data more realistically reflect human disease states. AIM We previously reported a miniature head-mounted scanning photoacoustic imaging (hmPAI) system. In the present study, we utilized this system to investigate the effects of ketamine on the cerebral hemodynamics of normal rats and rats subjected to prolonged ketamine self-administration. APPROACH The cortical superior sagittal sinus (SSS) was continuously monitored. The full-width at half-maximum (FWHM) of the photoacoustic (PA) A-line signal was used as an indicator of the SSS diameter, and the number of pixels in PA B-scan images was used to investigate changes in the cerebral blood volume (CBV). RESULTS We observed a significantly higher FWHM (blood vessel diameter) and CBV in normal rats injected with ketamine than in normal rats injected with saline. For rats subjected to prolonged ketamine self-administration, no significant changes in either the blood vessel diameter or CBV were observed. CONCLUSIONS The lack of significant change in prolonged ketamine-exposed rats was potentially due to an increased ketamine tolerance. Our device can reliably detect changes in the dilation of cortical blood vessels and the CBV. This study validates the utility of the developed hmPAI system in an awake, freely moving rat model for behavioral, cognitive, and preclinical cerebral disease studies.
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Affiliation(s)
- Yuhling Wang
- National Health Research Institutes, Institute of Biomedical Engineering and Nanomedicine, Zhunan Town, Miaoli County, Taiwan
| | - Chia-Hua Tsai
- National Health Research Institutes, Institute of Biomedical Engineering and Nanomedicine, Zhunan Town, Miaoli County, Taiwan
| | - Tsung-Sheng Chu
- National Health Research Institutes, Institute of Biomedical Engineering and Nanomedicine, Zhunan Town, Miaoli County, Taiwan
- Chung Yuan Christian University, Department of Biomedical Engineering, Taoyuan City, Taiwan
| | - Yun-Ting Hung
- National Health Research Institutes, Center for Neuropsychiatric Research, Zhunan Town, Miaoli County, Taiwan
| | - Mei-Yi Lee
- National Health Research Institutes, Center for Neuropsychiatric Research, Zhunan Town, Miaoli County, Taiwan
| | - Hwei-Hsien Chen
- National Health Research Institutes, Center for Neuropsychiatric Research, Zhunan Town, Miaoli County, Taiwan
| | - Li-Tzong Chen
- Kaohsiung Medical University, Kaohsiung Medical University Hospital, Kaohsiung City, Taiwan
- National Health Research Institutes, National Institute of Cancer Research, Zhunan Town, Miaoli County, Taiwan
| | - Tzong-Rong Ger
- Chung Yuan Christian University, Department of Biomedical Engineering, Taoyuan City, Taiwan
| | - Yung-Hsuan Wang
- National Health Research Institutes, National Institute of Cancer Research, Zhunan Town, Miaoli County, Taiwan
| | - Nai-Jung Chiang
- National Health Research Institutes, National Institute of Cancer Research, Zhunan Town, Miaoli County, Taiwan
- Taipei Veterans General Hospital, Department of Oncology, Taipei City, Taiwan
| | - Lun-De Liao
- National Health Research Institutes, Institute of Biomedical Engineering and Nanomedicine, Zhunan Town, Miaoli County, Taiwan
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Takamura Y, Kakuta H. In Vivo Receptor Visualization and Evaluation of Receptor Occupancy with Positron Emission Tomography. J Med Chem 2021; 64:5226-5251. [PMID: 33905258 DOI: 10.1021/acs.jmedchem.0c01714] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Positron emission tomography (PET) is useful for noninvasive in vivo visualization of disease-related receptors, for evaluation of receptor occupancy to determine an appropriate drug dosage, and for proof-of-concept of drug candidates in translational research. For these purposes, the specificity of the PET tracer for the target receptor is critical. Here, we review work in this area, focusing on the chemical structures of reported PET tracers, their Ki/Kd values, and the physical properties relevant to target receptor selectivity. Among these physical properties, such as cLogP, cLogD, molecular weight, topological polar surface area, number of hydrogen bond donors, and pKa, we focus especially on LogD and LogP as important physical properties that can be easily compared across a range of studies. We discuss the success of PET tracers in evaluating receptor occupancy and consider likely future developments in the field.
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Affiliation(s)
- Yuta Takamura
- Division of Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Hiroki Kakuta
- Division of Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
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3
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Bærentzen S, Casado-Sainz A, Lange D, Shalgunov V, Tejada IM, Xiong M, L'Estrade ET, Edgar FG, Lee H, Herth MM, Palner M. The Chemogenetic Receptor Ligand Clozapine N-Oxide Induces in vivo Neuroreceptor Occupancy and Reduces Striatal Glutamate Levels. Front Neurosci 2019; 13:187. [PMID: 31001069 PMCID: PMC6456655 DOI: 10.3389/fnins.2019.00187] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 02/15/2019] [Indexed: 12/24/2022] Open
Abstract
Chemogenetic studies with the ligand clozapine N-oxide (CNO) are predicated upon the assumption that CNO is devoid of actions at natural neuroreceptors. However, recent evidence shows that CNO may be converted back to clozapine (CLZ) in vivo, which could yield plasma concentrations that may be sufficient to occupy inter alia dopamine D2/3 and serotonin 5HT2A receptors in living brain. To test this phenomenon, we measured striatal dopamine D2/3 receptor occupancy with [18F]fallypride PET and serotonin 5HT2A occupancy ex vivo using [18F]MH.MZ. We found a CNO dose-dependent effect on the availability of both neuroreceptor sites. In parallel MR spectroscopy experiments, we found that CNO reduced creatine + phosphcreatine (Cr+PCr) and increased N-acetylaspartate + N-acetylaspartylglutamate (NAA+NAAG) signals in the prefrontal cortex, and also reduced the glutamate signal in dorsal striatum, with peak effect at 2 mg/kg. Thus, our findings suggest that conversion of CNO to CLZ in living rats imparts significant occupancy at endogenous neuroreceptors and significant changes to neurometabolite levels.
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Affiliation(s)
- Simone Bærentzen
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark.,Center for Translational Neuromedicine, University of Copenhagen, Copenhagen, Denmark
| | - Agata Casado-Sainz
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
| | - Denise Lange
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark.,Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Vladimir Shalgunov
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | | | - Mengfei Xiong
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark.,Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Elina T L'Estrade
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark.,Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark.,Radiation Physics, Nuclear Medicine Physics Unit, Skånes University Hospital, Lund, Sweden
| | - Fraser G Edgar
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Hedok Lee
- Department of Anesthesiology and Pediatric Anesthesiology, Yale University, New Haven, CT, United States
| | - Matthias M Herth
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark.,Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital, Copenhagen, Denmark
| | - Mikael Palner
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark.,Center for Translational Neuromedicine, University of Copenhagen, Copenhagen, Denmark
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Kyme AZ, Angelis GI, Eisenhuth J, Fulton RR, Zhou V, Hart G, Popovic K, Akhtar M, Ryder WJ, Clemens KJ, Balleine BW, Parmar A, Pascali G, Perkins G, Meikle SR. Open-field PET: Simultaneous brain functional imaging and behavioural response measurements in freely moving small animals. Neuroimage 2018; 188:92-101. [PMID: 30502443 DOI: 10.1016/j.neuroimage.2018.11.051] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 11/01/2018] [Accepted: 11/27/2018] [Indexed: 10/27/2022] Open
Abstract
A comprehensive understanding of how the brain responds to a changing environment requires techniques capable of recording functional outputs at the whole-brain level in response to external stimuli. Positron emission tomography (PET) is an exquisitely sensitive technique for imaging brain function but the need for anaesthesia to avoid motion artefacts precludes concurrent behavioural response studies. Here, we report a technique that combines motion-compensated PET with a robotically-controlled animal enclosure to enable simultaneous brain imaging and behavioural recordings in unrestrained small animals. The technique was used to measure in vivo displacement of [11C]raclopride from dopamine D2 receptors (D2R) concurrently with changes in the behaviour of awake, freely moving rats following administration of unlabelled raclopride or amphetamine. The timing and magnitude of [11C]raclopride displacement from D2R were reliably estimated and, in the case of amphetamine, these changes coincided with a marked increase in stereotyped behaviours and hyper-locomotion. The technique, therefore, allows simultaneous measurement of changes in brain function and behavioural responses to external stimuli in conscious unrestrained animals, giving rise to important applications in behavioural neuroscience.
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Affiliation(s)
- Andre Z Kyme
- Biomedical Engineering, School of Aerospace, Mechanical & Mechatronic Engineering, Faculty of Engineering and IT, The University of Sydney, Sydney, NSW, 2006, Australia; Imaging Physics Laboratory, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia; Faculty of Health Sciences, The University of Sydney, Sydney, NSW, 2006, Australia.
| | - Georgios I Angelis
- Imaging Physics Laboratory, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia; Faculty of Health Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
| | - John Eisenhuth
- Faculty of Health Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Roger R Fulton
- Imaging Physics Laboratory, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia; Faculty of Health Sciences, The University of Sydney, Sydney, NSW, 2006, Australia; Department of Medical Physics, Westmead Hospital, Sydney, NSW, 2145, Australia
| | - Victor Zhou
- Imaging Physics Laboratory, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Genevra Hart
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Kata Popovic
- Imaging Physics Laboratory, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia; Faculty of Health Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Mahmood Akhtar
- Imaging Physics Laboratory, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia; Faculty of Health Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
| | - William J Ryder
- Imaging Physics Laboratory, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia; Faculty of Health Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Kelly J Clemens
- School of Psychology, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Bernard W Balleine
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Arvind Parmar
- Imaging Physics Laboratory, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia; Australian Nuclear Science and Technology Organisation, Sydney, NSW, 2234, Australia
| | - Giancarlo Pascali
- Imaging Physics Laboratory, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia; Australian Nuclear Science and Technology Organisation, Sydney, NSW, 2234, Australia
| | - Gary Perkins
- Australian Nuclear Science and Technology Organisation, Sydney, NSW, 2234, Australia
| | - Steven R Meikle
- Imaging Physics Laboratory, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia; Faculty of Health Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
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5
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Mutual activation of glutamatergic mGlu 4 and muscarinic M 4 receptors reverses schizophrenia-related changes in rodents. Psychopharmacology (Berl) 2018; 235:2897-2913. [PMID: 30054675 PMCID: PMC6182605 DOI: 10.1007/s00213-018-4980-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 07/17/2018] [Indexed: 02/05/2023]
Abstract
RATIONALE Metabotropic glutamate receptors and muscarinic M4 receptors have been proposed as novel targets for various brain disorders, including schizophrenia. Both receptors are coupled to Go/i proteins and are expressed in brain circuits that are important in schizophrenia. Therefore, their mutual activation may be an effective treatment and allow minimizing the doses of ligands required for optimal activity. OBJECTIVES In the present studies, subactive doses of mGlu4 and M4 activators (LSP4-2022 and VU152100, respectively) were administered to investigate the mutual interaction between mGlu4 and M4 receptors in animal models of schizophrenia. METHODS The behavioral tests used were MK-801-induced hyperactivity, (±)-2.5-dimethoxy-4-iodoamphetamine hydrochloride (DOI)-induced head twitches, the modified forced swim test, and MK-801-induced disruptions of social interactions and novel object recognition. DOI-induced spontaneous excitatory postsynaptic currents (sEPSCs) in brain slices and positron emission tomography (PET) in were used to establish the ability of these compounds to modulate the glutamatergic and dopaminergic systems. Rotarod was used to assess putative adverse effects. RESULTS The mutual administration of subactive doses of LSP4-2022 and VU152100 exerted similar antipsychotic-like efficacy in animals as observed for active doses of both compounds, indicating their additive actions. VU152100 inhibited the DOI-induced frequency (but not amplitude) of sEPSCs in the frontal cortex, confirming presynaptic regulation of glutamate release. Both compounds reversed amphetamine-induced decrease in D2 receptor levels in the striatum, as measured with [18F]fallypride. The compounds did not induce any motor impartments when measured in rotarod test. CONCLUSIONS Based on our results, the simultaneous activation of M4 and mGlu4 receptors is beneficial in reversing MK-801- and amphetamine-induced schizophrenia-related changes in animals.
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“Domain gauges”: A reference system for multivariate profiling of brain fMRI activation patterns induced by psychoactive drugs in rats. Neuroimage 2015. [DOI: 10.1016/j.neuroimage.2015.02.032 [doi]] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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7
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Bruns A, Mueggler T, Künnecke B, Risterucci C, Prinssen EP, Wettstein JG, von Kienlin M. “Domain gauges”: A reference system for multivariate profiling of brain fMRI activation patterns induced by psychoactive drugs in rats. Neuroimage 2015. [DOI: 10.1016/j.neuroimage.2015.02.032 [doi].] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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8
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Ota M, Ogawa S, Kato K, Wakabayashi C, Kunugi H. Methamphetamine-sensitized rats show augmented dopamine release to methylphenidate stimulation: a positron emission tomography using [18F]fallypride. Psychiatry Res 2015; 232:92-7. [PMID: 25703679 DOI: 10.1016/j.pscychresns.2015.01.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 10/10/2014] [Accepted: 01/28/2015] [Indexed: 12/23/2022]
Abstract
Previous studies demonstrated that patients with schizophrenia show greater sensitivity to psychostimulants than healthy subjects. Sensitization to psychostimulants and resultant alteration of dopaminergic neurotransmission in rodents have been suggested as a useful model of schizophrenia. This study was aimed to examine the use of methylphenidate as a psychostimulant to induce dopamine release and that of [18F]fallypride as a radioligand to estimate the release in a rat model of schizophrenia. Six rats were scanned by positron emission tomography (PET) twice before and after methylphenidate challenge to evaluate dopamine release. After the scans, these rats were sensitized by using repeated methamphetamine (MAP) administration. Then, they were re-scanned twice again before and after methylphenidate challenge to evaluate whether MAP-sensitized rats show greater sensitivity to methylphenidate. We revealed a main effect of MAP-pretreatment and that of metylphenidate challenge. We found that % change of distribution volume ratio after repeated administration of MAP was greater than that before sensitization. These results suggest that methylphenidate-induced striatal dopamine release increased after sensitization to MAP. PET scan using [18F]fallypride at methylphenidate-challenge may provide a biological marker for schizophrenia and be useful to diagnose schizophrenia.
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Affiliation(s)
- Miho Ota
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry4-1-1 Ogawa-Higashi, KodairaTokyo187-8502, Japan.
| | - Shintaro Ogawa
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry4-1-1 Ogawa-Higashi, KodairaTokyo187-8502, Japan
| | - Koichi Kato
- Organic Radiochemistry Section, Department of Advanced Neuroimaging, Integrative Brain Imaging Center, National Center Hospital of Neurology and Psychiatry, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan
| | - Chisato Wakabayashi
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry4-1-1 Ogawa-Higashi, KodairaTokyo187-8502, Japan
| | - Hiroshi Kunugi
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry4-1-1 Ogawa-Higashi, KodairaTokyo187-8502, Japan
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9
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Lee DE, Reid WC, Ibrahim WG, Peterson KL, Lentz MR, Maric D, Choyke PL, Jagoda EM, Hammoud DA. Imaging dopaminergic dysfunction as a surrogate marker of neuropathology in a small-animal model of HIV. Mol Imaging 2015; 13. [PMID: 25248756 DOI: 10.2310/7290.2014.00031] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The dopaminergic system is especially vulnerable to the effects of human immunodeficiency virus (HIV) infection, rendering dopaminergic deficits early surrogate markers of HIV-associated neuropathology. We quantified dopamine D2/3 receptors in young HIV-1 transgenic (Tg) (n = 6) and age-matched control rats (n = 7) and adult Tg (n = 5) and age-matched control rats (n = 5) using [18F]fallypride positron emission tomography (PET). Regional uptake was quantified as binding potential (BPND) using the two-tissue reference model with the cerebellum as the reference. Time-activity curves were generated for the ventral striatum, dorsal striatum, thalamus, and cerebellum. Whereas BPND values were significantly lower in the ventral striatum (p < .001) and dorsal striatum (p = .001) in the adult Tg rats compared to controls rats, they were significantly lower only in the dorsal striatum (p < .05) in the young rats. Tg rats had smaller striatal volumes on magnetic resonance imaging. We also found lower expression levels of tyrosine hydroxylase on immunohistochemistry in the Tg animals. Our findings suggest that progressive striatal D2/3 receptor deficits occur in Tg rats as they age and can be detected using small-animal PET imaging. The effectiveness of various approaches in preventing or halting this dopaminergic loss in the Tg rat can thus be measured preclinically using [18F]fallypride PET as a molecular imaging biomarker of HIV-associated neuropathology.
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10
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Bruns A, Mueggler T, Künnecke B, Risterucci C, Prinssen EP, Wettstein JG, von Kienlin M. "Domain gauges": A reference system for multivariate profiling of brain fMRI activation patterns induced by psychoactive drugs in rats. Neuroimage 2015; 112:70-85. [PMID: 25724758 DOI: 10.1016/j.neuroimage.2015.02.032] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 02/06/2015] [Accepted: 02/16/2015] [Indexed: 01/01/2023] Open
Abstract
Pharmacological magnetic resonance imaging (phMRI) of the brain has become a widely used tool in both preclinical and clinical drug research. One of its challenges is to condense the observed complex drug-induced brain-activation patterns into semantically meaningful metrics that can then serve as a basis for informed decision making. To aid interpretation of spatially distributed activation patterns, we propose here a set of multivariate metrics termed "domain gauges", which have been calibrated based on different classes of marketed or validated reference drugs. Each class represents a particular "domain" of interest, i.e., a specific therapeutic indication or mode of action. The drug class is empirically characterized by the unique activation pattern it evokes in the brain-the "domain profile". A domain gauge provides, for any tested intervention, a "classifier" as a measure of response strength with respect to the domain in question, and a "differentiator" as a measure of deviation from the domain profile, both along with error ranges. Capitalizing on our in-house database with an unprecedented wealth of standardized perfusion-based phMRI data obtained from rats subjected to various validated treatments, we exemplarily focused on 3 domains based on therapeutic indications: an antipsychotic, an antidepressant and an anxiolytic domain. The domain profiles identified as part of the gauge definition process, as well as the outputs of the gauges when applied to both reference and validation data, were evaluated for their reconcilability with prior biological knowledge and for their performance in drug characterization. The domain profiles provided quantitative activation patterns with high biological plausibility. The antipsychotic profile, for instance, comprised key areas (e.g., cingulate cortex, nucleus accumbens, ventral tegmental area, substantia nigra) which are believed to be strongly involved in mediating an antipsychotic effect, and which are in line with network-level dysfunctions observed in schizophrenia. The domain gauges plausibly positioned the vast majority of the pharmacological and even non-pharmacological treatments. The results also suggest the segregation of sub-domains based on, e.g., the mode of action. Upon judicious selection of domains and careful calibration of the gauges, our approach represents a valuable analytical tool for biological interpretation and decision making in drug discovery.
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Affiliation(s)
- Andreas Bruns
- Roche Pharmaceutical Research & Early Development, Neuroscience Discovery, Roche Innovation Center Basel, Switzerland.
| | - Thomas Mueggler
- Roche Pharmaceutical Research & Early Development, Neuroscience Discovery, Roche Innovation Center Basel, Switzerland
| | - Basil Künnecke
- Roche Pharmaceutical Research & Early Development, Neuroscience Discovery, Roche Innovation Center Basel, Switzerland
| | - Céline Risterucci
- Roche Pharmaceutical Research & Early Development, Neuroscience Discovery, Roche Innovation Center Basel, Switzerland
| | - Eric P Prinssen
- Roche Pharmaceutical Research & Early Development, Neuroscience Discovery, Roche Innovation Center Basel, Switzerland
| | - Joseph G Wettstein
- Roche Pharmaceutical Research & Early Development, Neuroscience Discovery, Roche Innovation Center Basel, Switzerland
| | - Markus von Kienlin
- Roche Pharmaceutical Research & Early Development, Neuroscience Discovery, Roche Innovation Center Basel, Switzerland
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Tsartsalis S, Moulin-Sallanon M, Dumas N, Tournier BB, Ginovart N, Millet P. A Modified Simplified Reference Tissue Model for the Quantification of Dopamine D2/3Receptors with [18F]Fallypride Images. Mol Imaging 2014; 13. [DOI: 10.2310/7290.2014.00028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Stergios Tsartsalis
- From the Vulnerability Biomarkers Unit, Division of General Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland; Department of Psychiatry, University of Geneva, Geneva, Switzerland; and INSERM Unit 1039, J. Fourier University, La Tronche, France
| | - Marcelle Moulin-Sallanon
- From the Vulnerability Biomarkers Unit, Division of General Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland; Department of Psychiatry, University of Geneva, Geneva, Switzerland; and INSERM Unit 1039, J. Fourier University, La Tronche, France
| | - Noé Dumas
- From the Vulnerability Biomarkers Unit, Division of General Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland; Department of Psychiatry, University of Geneva, Geneva, Switzerland; and INSERM Unit 1039, J. Fourier University, La Tronche, France
| | - Benjamin B. Tournier
- From the Vulnerability Biomarkers Unit, Division of General Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland; Department of Psychiatry, University of Geneva, Geneva, Switzerland; and INSERM Unit 1039, J. Fourier University, La Tronche, France
| | - Nathalie Ginovart
- From the Vulnerability Biomarkers Unit, Division of General Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland; Department of Psychiatry, University of Geneva, Geneva, Switzerland; and INSERM Unit 1039, J. Fourier University, La Tronche, France
| | - Philippe Millet
- From the Vulnerability Biomarkers Unit, Division of General Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland; Department of Psychiatry, University of Geneva, Geneva, Switzerland; and INSERM Unit 1039, J. Fourier University, La Tronche, France
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Johnson KA, Jones CK, Tantawy MN, Bubser M, Marvanova M, Ansari MS, Baldwin RM, Conn PJ, Niswender CM. The metabotropic glutamate receptor 8 agonist (S)-3,4-DCPG reverses motor deficits in prolonged but not acute models of Parkinson's disease. Neuropharmacology 2012; 66:187-95. [PMID: 22546615 DOI: 10.1016/j.neuropharm.2012.03.029] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Revised: 03/27/2012] [Accepted: 03/29/2012] [Indexed: 10/28/2022]
Abstract
Metabotropic glutamate receptors (mGlus) are 7 Transmembrane Spanning Receptors (7TMs) that are differentially expressed throughout the brain and modulate synaptic transmission at both excitatory and inhibitory synapses. Recently, mGlus have been implicated as therapeutic targets for many disorders of the central nervous system, including Parkinson's disease (PD). Previous studies have shown that nonselective agonists of group III mGlus have antiparkinsonian effects in several animal models of PD, suggesting that these receptors represent promising targets for treating the motor symptoms of PD. However, the relative contributions of different group III mGlu subtypes to these effects have not been fully elucidated. Here we report that intracerebroventricular (icv) administration of the mGlu(8)-selective agonist (S)-3,4-dicarboxyphenylglycine (DCPG [ 2.5, 10, or 30 nmol]) does not alleviate motor deficits caused by acute (2 h) treatment with haloperidol or reserpine. However, following prolonged pretreatment with haloperidol (three doses evenly spaced over 18-20 h) or reserpine (18-20 h), DCPG robustly reverses haloperidol-induced catalepsy and reserpine-induced akinesia. Furthermore, DCPG (10 nmol, icv) reverses the long-lasting catalepsy induced by 20 h pretreatment with the decanoate salt of haloperidol. Finally, icv administration of DCPG ameliorates forelimb use asymmetry caused by unilateral 6-hydroxydopamine lesion of substantia nigra dopamine neurons. These findings suggest that mGlu(8) may partially mediate the antiparkinsonian effects of group III mGlu agonists in animal models of PD in which dopamine depletion or blockade of D(2)-like dopamine receptors is prolonged and indicate that selective activation of mGlu(8) may represent a novel therapeutic strategy for alleviating the motor symptoms of PD. This article is part of a Special Issue entitled 'Metabotropic Glutamate Receptors'.
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Affiliation(s)
- Kari A Johnson
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
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