1
|
Attarha M, de Figueiredo Pelegrino AC, Toussaint PJ, Grant SJ, Van Vleet T, de Villers-Sidani E. Improving Neurological Health in Aging Via Neuroplasticity-Based Computerized Exercise: Protocol for a Randomized Controlled Trial. JMIR Res Protoc 2024; 13:e59705. [PMID: 39116435 PMCID: PMC11342015 DOI: 10.2196/59705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 06/07/2024] [Accepted: 06/13/2024] [Indexed: 08/10/2024] Open
Abstract
BACKGROUND Our current understanding of how computerized brain training drives cognitive and functional benefits remains incomplete. This paper describes the protocol for Improving Neurological Health in Aging via Neuroplasticity-based Computerized Exercise (INHANCE), a randomized controlled trial in healthy older adults designed to evaluate whether brain training improves cholinergic signaling. OBJECTIVE INHANCE evaluates whether 2 computerized training programs alter acetylcholine binding using the vesicular acetylcholine transporter ligand [18F] fluoroethoxybenzovesamicol ([18F] FEOBV) and positron emission tomography (PET). METHODS In this phase IIb, prospective, double-blind, parallel-arm, active-controlled randomized trial, a minimum of 92 community-dwelling healthy adults aged 65 years and older are randomly assigned to a brain training program designed using the principles of neuroplasticity (BrainHQ by Posit Science) or to an active control program of computer games designed for entertainment (eg, Solitaire). Both programs consist of 30-minute sessions, 7 times per week for 10 weeks (35 total hours), completed remotely at home using either loaned or personal devices. The primary outcome is the change in FEOBV binding in the anterior cingulate cortex, assessed at baseline and posttest. Exploratory cognitive and behavioral outcomes sensitive to acetylcholine are evaluated before, immediately after, and 3 months following the intervention to assess the maintenance of observed effects. RESULTS The trial was funded in September 2019. The study received approval from the Western Institutional Review Board in October 2020 with Research Ethics Board of McGill University Health Centre and Health Canada approvals in June 2021. The trial is currently ongoing. The first participant was enrolled in July 2021, enrollment closed when 93 participants were randomized in December 2023, and the trial will conclude in June 2024. The study team will be unblinded to conduct analyses after the final participant exits the study. We expect to publish the results in the fourth quarter of 2024. CONCLUSIONS There remains a critical need to identify effective and scalable nonpharmaceutical interventions to enhance cognition in older adults. This trial contributes to our understanding of brain training by providing a potential neurochemical explanation of cognitive benefit. TRIAL REGISTRATION ClinicalTrials.gov NCT04149457; https://clinicaltrials.gov/ct2/show/NCT04149457. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID) DERR1-10.2196/59705.
Collapse
Affiliation(s)
- Mouna Attarha
- Posit Science Corporation, San Francisco, CA, United States
| | | | - Paule-Joanne Toussaint
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal, QC, Canada
| | | | | | - Etienne de Villers-Sidani
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal, QC, Canada
| |
Collapse
|
2
|
Okkels N, Grothe MJ, Taylor JP, Hasselbalch SG, Fedorova TD, Knudsen K, van der Zee S, van Laar T, Bohnen NI, Borghammer P, Horsager J. Cholinergic changes in Lewy body disease: implications for presentation, progression and subtypes. Brain 2024; 147:2308-2324. [PMID: 38437860 DOI: 10.1093/brain/awae069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/05/2024] [Accepted: 02/13/2024] [Indexed: 03/06/2024] Open
Abstract
Cholinergic degeneration is significant in Lewy body disease, including Parkinson's disease, dementia with Lewy bodies, and isolated REM sleep behaviour disorder. Extensive research has demonstrated cholinergic alterations in the CNS of these disorders. More recently, studies have revealed cholinergic denervation in organs that receive parasympathetic denervation. This enables a comprehensive review of cholinergic changes in Lewy body disease, encompassing both central and peripheral regions, various disease stages and diagnostic categories. Across studies, brain regions affected in Lewy body dementia show equal or greater levels of cholinergic impairment compared to the brain regions affected in Lewy body disease without dementia. This observation suggests a continuum of cholinergic alterations between these disorders. Patients without dementia exhibit relative sparing of limbic regions, whereas occipital and superior temporal regions appear to be affected to a similar extent in patients with and without dementia. This implies that posterior cholinergic cell groups in the basal forebrain are affected in the early stages of Lewy body disorders, while more anterior regions are typically affected later in the disease progression. The topographical changes observed in patients affected by comorbid Alzheimer pathology may reflect a combination of changes seen in pure forms of Lewy body disease and those seen in Alzheimer's disease. This suggests that Alzheimer co-pathology is important to understand cholinergic degeneration in Lewy body disease. Thalamic cholinergic innervation is more affected in Lewy body patients with dementia compared to those without dementia, and this may contribute to the distinct clinical presentations observed in these groups. In patients with Alzheimer's disease, the thalamus is variably affected, suggesting a different sequential involvement of cholinergic cell groups in Alzheimer's disease compared to Lewy body disease. Patients with isolated REM sleep behaviour disorder demonstrate cholinergic denervation in abdominal organs that receive parasympathetic innervation from the dorsal motor nucleus of the vagus, similar to patients who experienced this sleep disorder in their prodrome. This implies that REM sleep behaviour disorder is important for understanding peripheral cholinergic changes in both prodromal and manifest phases of Lewy body disease. In conclusion, cholinergic changes in Lewy body disease carry implications for understanding phenotypes and the influence of Alzheimer co-pathology, delineating subtypes and pathological spreading routes, and for developing tailored treatments targeting the cholinergic system.
Collapse
Affiliation(s)
- Niels Okkels
- Department of Neurology, Aarhus University Hospital, 8200 Aarhus N, Denmark
- Department of Nuclear Medicine and PET, Aarhus University Hospital, 8200 Aarhus N, Denmark
| | - Michel J Grothe
- Unidad de Trastornos del Movimiento, Servicio de Neurología y Neurofisiología Clínica, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, 41013 Seville, Spain
- Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Reina Sofia Alzheimer's Centre, CIEN Foundation-ISCIII, 28031 Madrid, Spain
| | - John-Paul Taylor
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Steen Gregers Hasselbalch
- Danish Dementia Research Center, Department of Neurology, Copenhagen University Hospital, 2100 Copenhagen Ø, Denmark
- Department of Clinical Medicine, University of Copenhagen, 2100 Copenhagen Ø, Denmark
| | - Tatyana D Fedorova
- Department of Nuclear Medicine and PET, Aarhus University Hospital, 8200 Aarhus N, Denmark
| | - Karoline Knudsen
- Department of Nuclear Medicine and PET, Aarhus University Hospital, 8200 Aarhus N, Denmark
| | - Sygrid van der Zee
- Department of Neurology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
| | - Teus van Laar
- Department of Neurology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
| | - Nicolaas I Bohnen
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Radiology, University of Michigan, Ann Arbor, MI 48109, USA
- Neurology Service and GRECC, VA Ann Arbor Healthcare System, Ann Arbor, MI 48105, USA
- Morris K. Udall Center of Excellence for Parkinson's Disease Research, University of Michigan, Ann Arbor, MI 48109, USA
- Parkinson's Foundation Research Center of Excellence, University of Michigan, Ann Arbor, MI 48109, USA
| | - Per Borghammer
- Department of Nuclear Medicine and PET, Aarhus University Hospital, 8200 Aarhus N, Denmark
- Department of Clinical Medicine, Aarhus University, 8200 Aarhus N, Denmark
| | - Jacob Horsager
- Department of Nuclear Medicine and PET, Aarhus University Hospital, 8200 Aarhus N, Denmark
| |
Collapse
|
3
|
Albin RL, Kanel P, van Laar T, van der Zee S, Roytman S, Koeppe RA, Scott PJH, Bohnen NI. No Dopamine Agonist Modulation of Brain [ 18F]FEOBV Binding in Parkinson's Disease. Mol Pharm 2022; 19:1176-1182. [PMID: 35289620 PMCID: PMC8983523 DOI: 10.1021/acs.molpharmaceut.1c00961] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The [18F]fluoroethoxybenzovesamicol ([18F]FEOBV) positron emission tomography (PET) ligand targets the vesicular acetylcholine transporter. Recent [18F]FEOBV PET rodent studies suggest that regional brain [18F]FEOBV binding may be modulated by dopamine D2-like receptor agents. We examined associations of regional brain [18F]FEOBV PET binding in Parkinson's disease (PD) subjects without versus with dopamine D2-like receptor agonist drug treatment. PD subjects (n = 108; 84 males, 24 females; mean age 68.0 ± 7.6 [SD] years), mean disease duration of 6.0 ± 4.0 years, and mean Movement Disorder Society-revised Unified PD Rating Scale III 35.5 ± 14.2 completed [18F]FEOBV brain PET imaging. Thirty-eight subjects were taking dopamine D2-like agonists. Vesicular monoamine transporter type 2 [11C]dihydrotetrabenazine (DTBZ) PET was available in a subset of 54 patients. Subjects on dopamine D2-like agonists were younger, had a longer duration of disease, and were taking a higher levodopa equivalent dose (LED) compared to subjects not taking dopamine agonists. A group comparison between subjects with versus without dopamine D2-like agonist use did not yield significant differences in cortical, striatal, thalamic, or cerebellar gray matter [18F]FEOBV binding. Confounder analysis using age, duration of disease, LED, and striatal [11C]DTBZ binding also failed to show significant regional [18F]FEOBV binding differences between these two groups. Chronic D2-like dopamine agonist use in PD subjects is not associated with significant alterations of regional brain [18F]FEOBV binding.
Collapse
Affiliation(s)
- Roger L Albin
- Department of Neurology, University of Michigan, Ann Arbor, Michigan 48109, United States.,GRECC & Neurology Service, VAAAHS, Ann Arbor, Michigan 48105, United States.,University of Michigan Udall Center, Ann Arbor, Michigan 48109, United States.,University of Michigan Parkinson's Foundation Research Center of Excellence, Ann Arbor, Michigan 48109, United States
| | - Prabesh Kanel
- University of Michigan Udall Center, Ann Arbor, Michigan 48109, United States.,Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Teus van Laar
- University of Michigan Udall Center, Ann Arbor, Michigan 48109, United States.,Department of Neurology, University Medical Center Groningen, University of Groningen, 9713 AV Groningen, The Netherlands
| | - Sygrid van der Zee
- University of Michigan Udall Center, Ann Arbor, Michigan 48109, United States.,Department of Neurology, University Medical Center Groningen, University of Groningen, 9713 AV Groningen, The Netherlands
| | - Stiven Roytman
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Robert A Koeppe
- University of Michigan Udall Center, Ann Arbor, Michigan 48109, United States.,Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Peter J H Scott
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Nicolaas I Bohnen
- Department of Neurology, University of Michigan, Ann Arbor, Michigan 48109, United States.,GRECC & Neurology Service, VAAAHS, Ann Arbor, Michigan 48105, United States.,University of Michigan Udall Center, Ann Arbor, Michigan 48109, United States.,University of Michigan Parkinson's Foundation Research Center of Excellence, Ann Arbor, Michigan 48109, United States.,Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| |
Collapse
|
4
|
Abstract
The use of PET imaging agents in oncology, cardiovascular disease, and neurodegenerative disease shows the power of this technique in evaluating the molecular and biological characteristics of numerous diseases. These agents provide crucial information for designing therapeutic strategies for individual patients. Novel PET tracers are in continual development and many have potential use in clinical and research settings. This article discusses the potential applications of tracers in diagnostics, the biological characteristics of diseases, the ability to provide prognostic indicators, and using this information to guide treatment strategies including monitoring treatment efficacy in real time to improve outcomes and survival.
Collapse
|
5
|
Spatial topography of the basal forebrain cholinergic projections: Organization and vulnerability to degeneration. HANDBOOK OF CLINICAL NEUROLOGY 2021; 179:159-173. [PMID: 34225960 DOI: 10.1016/b978-0-12-819975-6.00008-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The basal forebrain (BF) cholinergic system constitutes a heterogeneous cluster of large projection neurons that innervate the entire cortical mantle and amygdala. Cholinergic neuromodulation plays a critical role in regulating cognition and behavior, as well as maintenance of cellular homeostasis. Decades of postmortem histology research have demonstrated that the BF cholinergic neurons are selectively vulnerable to aging and age-related neuropathology in degenerative diseases such as Alzheimer's and Parkinson's diseases. Emerging evidence from in vivo neuroimaging research, which permits longitudinal tracking of at-risk individuals, indicates that cholinergic neurodegeneration might play an earlier and more pivotal role in these diseases than was previously appreciated. Despite these advances, our understanding of the organization and functions of the BF cholinergic system mostly derives from nonhuman animal research. In this chapter, we begin with a review of the topographical organization of the BF cholinergic system in rodent and nonhuman primate models. We then discuss basic and clinical neuroscience research in humans, which has started to translate and extend the nonhuman animal research using novel noninvasive neuroimaging techniques. We focus on converging evidence indicating that the selective vulnerability of cholinergic neurons in Alzheimer's and Parkinson's diseases is expressed along a rostral-caudal topography in the BF. We close with a discussion of why this topography of vulnerability in the BF may occur and why it is relevant to the clinician.
Collapse
|
6
|
Cisneros-Franco JM, Voss P, Kang MS, Thomas ME, Côté J, Ross K, Gaudreau P, Rudko DA, Rosa-Neto P, de-Villers-Sidani É. PET Imaging of Perceptual Learning-Induced Changes in the Aged Rodent Cholinergic System. Front Neurosci 2020; 13:1438. [PMID: 32038142 PMCID: PMC6985428 DOI: 10.3389/fnins.2019.01438] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 12/20/2019] [Indexed: 12/14/2022] Open
Abstract
The cholinergic system enhances attention and gates plasticity, making it a major regulator of adult learning. With aging, however, progressive degeneration of the cholinergic system impairs both the acquisition of new skills and functional recovery following neurological injury. Although cognitive training and perceptual learning have been shown to enhance auditory cortical processing, their specific impact on the cholinergic system remains unknown. Here we used [18F]FEOBV, a positron emission tomography (PET) radioligand that selectively binds to the vesicular acetylcholine transporter (VAChT), as a proxy to assess whether training on a perceptual task results in increased cholinergic neurotransmission. We show for the first time that perceptual learning is associated with region-specific changes in cholinergic neurotransmission, as detected by [18F]FEOBV PET imaging and corroborated with immunohistochemistry.
Collapse
Affiliation(s)
- J Miguel Cisneros-Franco
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada.,Centre for Research on Brain, Language and Music, McGill University, Montreal, QC, Canada
| | - Patrice Voss
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada.,Centre for Research on Brain, Language and Music, McGill University, Montreal, QC, Canada
| | - Min Su Kang
- Douglas Mental Health University Institute, McGill University, Montreal, QC, Canada.,Research Centre for Studies in Aging, McGill University, Montreal, QC, Canada
| | - Maryse E Thomas
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada.,Centre for Research on Brain, Language and Music, McGill University, Montreal, QC, Canada
| | - Jonathan Côté
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada.,Centre for Research on Brain, Language and Music, McGill University, Montreal, QC, Canada
| | - Karen Ross
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Pierrette Gaudreau
- Réseau Québécois de Recherche sur le Vieillissement, Université de Montréal, Montreal, QC, Canada
| | - David A Rudko
- Department of Biomedical Engineering, McGill University, Montreal, QC, Canada
| | - Pedro Rosa-Neto
- Douglas Mental Health University Institute, McGill University, Montreal, QC, Canada.,Research Centre for Studies in Aging, McGill University, Montreal, QC, Canada
| | - Étienne de-Villers-Sidani
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada.,Centre for Research on Brain, Language and Music, McGill University, Montreal, QC, Canada
| |
Collapse
|
7
|
Bohnen NI, Kanel P, Zhou Z, Koeppe RA, Frey KA, Dauer WT, Albin RL, Müller MLTM. Cholinergic system changes of falls and freezing of gait in Parkinson's disease. Ann Neurol 2019; 85:538-549. [PMID: 30720884 PMCID: PMC6450746 DOI: 10.1002/ana.25430] [Citation(s) in RCA: 105] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Revised: 02/03/2019] [Accepted: 02/03/2019] [Indexed: 01/16/2023]
Abstract
Objective Postural instability and gait difficulties (PIGDs) represent debilitating disturbances in Parkinson's disease (PD). Past acetylcholinesterase positron emission tomography (PET) imaging studies implicate cholinergic changes as significant contributors to PIGD features. These studies were limited in quantification of striatal cholinergic synapse integrity. Vesicular acetylcholine transporter (VAChT) PET ligands are better suited for evaluation of high binding areas. We examined associations between regional VAChT expression and freezing of gait (FoG) and falls. Methods Ninety‐four PD subjects underwent clinical assessment and VAChT ([18F]FEOBV) PET. Results Thirty‐five subjects (37.2%) reported a history of falls, and 15 (16%) had observed FoG. Univariate volume‐of‐interest analyses demonstrated significantly reduced thalamic (p = 0.0016) VAChT expression in fallers compared to nonfallers. VAChT expression was significantly reduced in the striatum (p = 0.0012) and limbic archicortex (p = 0.004) in freezers compared to nonfreezers. Whole‐brain voxel‐based analyses of FEOBV PET complemented these findings and showed more granular changes associated with falling history, including the right visual thalamus (especially the right lateral geniculate nucleus [LGN]), right caudate nucleus, and bilateral prefrontal regions. Freezers had prominent VAChT expression reductions in the bilateral striatum, temporal, and mesiofrontal limbic regions. Interpretation Our findings confirm and extend on previous PET findings of thalamic cholinergic deficits associated with falling history and now emphasize right visual thalamus complex changes, including the right LGN. FoG status is associated with reduced VAChT expression in striatal cholinergic interneurons and the limbic archicortex. These observations suggest different cholinergic systems changes underlying falls and FoG in PD. Ann Neurol 2019;85:538–549
Collapse
Affiliation(s)
- Nicolaas I Bohnen
- Radiology, University of Michigan, Ann Arbor, MI.,Neurology, University of Michigan, Ann Arbor, MI.,Neurology Service and GRECC, Veterans Administration Ann Arbor Healthcare System, Ann Arbor, MI.,Morris K. Udall Center of Excellence for Parkinson's Disease Research, University of Michigan, Ann Arbor, MI
| | - Prabesh Kanel
- Radiology, University of Michigan, Ann Arbor, MI.,Morris K. Udall Center of Excellence for Parkinson's Disease Research, University of Michigan, Ann Arbor, MI
| | - Zhi Zhou
- Radiology, University of Michigan, Ann Arbor, MI
| | - Robert A Koeppe
- Radiology, University of Michigan, Ann Arbor, MI.,Morris K. Udall Center of Excellence for Parkinson's Disease Research, University of Michigan, Ann Arbor, MI
| | - Kirk A Frey
- Radiology, University of Michigan, Ann Arbor, MI.,Neurology, University of Michigan, Ann Arbor, MI
| | - William T Dauer
- Neurology, University of Michigan, Ann Arbor, MI.,Neurology Service and GRECC, Veterans Administration Ann Arbor Healthcare System, Ann Arbor, MI.,Morris K. Udall Center of Excellence for Parkinson's Disease Research, University of Michigan, Ann Arbor, MI
| | - Roger L Albin
- Neurology, University of Michigan, Ann Arbor, MI.,Neurology Service and GRECC, Veterans Administration Ann Arbor Healthcare System, Ann Arbor, MI.,Morris K. Udall Center of Excellence for Parkinson's Disease Research, University of Michigan, Ann Arbor, MI
| | - Martijn L T M Müller
- Radiology, University of Michigan, Ann Arbor, MI.,Morris K. Udall Center of Excellence for Parkinson's Disease Research, University of Michigan, Ann Arbor, MI
| |
Collapse
|
8
|
Bedard MA, Aghourian M, Legault-Denis C, Postuma RB, Soucy JP, Gagnon JF, Pelletier A, Montplaisir J. Brain cholinergic alterations in idiopathic REM sleep behaviour disorder: a PET imaging study with 18F-FEOBV. Sleep Med 2019; 58:35-41. [PMID: 31078078 DOI: 10.1016/j.sleep.2018.12.020] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 12/19/2018] [Accepted: 12/27/2018] [Indexed: 01/29/2023]
Abstract
BACKGROUND REM sleep behaviour disorder (RBD) occurs frequently in patients with synucleinopathies such as Parkinson's disease, dementia with Lewy body, or multiple system atrophy, but may also occur as a prodromal stage of those diseases; and is termed idiopathic RBD (iRBD) when not accompanied by other symptoms. Cholinergic degeneration of the mesopontine nuclei have been described in synucleinopathies with or without RBD, but this has not yet been explored in iRBD. We sought to assess cholinergic neuronal integrity in iRBD using PET neuroimaging with the 18F-fluoroethoxybenzovesamicol (FEOBV). METHODS The sample included 10 participants evenly divided between healthy subjects and patients with iRBD. Polysomnography and PET imaging with FEOBV were performed in all participants. Standardized uptake value ratios (SUVRs) were compared between the two groups using voxel wise t-tests. Non-parametric correlations were also computed in patients with iRBD between FEOBV uptake and muscle tonic and phasic activity during REM sleep. RESULTS Compared with healthy participants, significantly higher FEOBV uptakes were observed in patients with iRBD. The largest differences were observed in specific brainstem areas corresponding to the bulbar reticular formation, pontine coeruleus/subcoeruleus complex, tegmental periacqueductal grey, and mesopontine cholinergic nuclei. FEOBV uptake in iRBD was also higher than in controls in the ventromedial area of the thalamus, deep cerebellar nuclei, and some cortical territories (including the paracentral lobule, anterior cingulate, and orbitofrontal cortex). Significant correlation was found between muscle activity during REM sleep, and SUVR increases in both the mesopontine area and paracentral cortex. CONCLUSION We showed here for the first time the brain cholinergic alterations in patients with iRBD. As opposed to the cholinergic depletion described previously in RBD associated with clinical Parkinson's disease, increased cholinergic innervation was found in multiple areas in iRBD. The most significant changes were observed in brainstem areas containing structures involved in the promotion of REM sleep and muscle atonia. This suggests that iRBD might be a clinical condition in which compensatory cholinergic upregulation in those areas occurs in association with the initial phases of a neurodegenerative process leading to a clinically observable synucleinopathy.
Collapse
Affiliation(s)
- Marc-Andre Bedard
- NeuroQAM Centre, Université du Québec à Montréal (UQAM), Canada; McConnell Brain Imaging Centre, Montreal Neurological Institute, Canada
| | - Meghmik Aghourian
- NeuroQAM Centre, Université du Québec à Montréal (UQAM), Canada; McConnell Brain Imaging Centre, Montreal Neurological Institute, Canada
| | - Camille Legault-Denis
- NeuroQAM Centre, Université du Québec à Montréal (UQAM), Canada; McConnell Brain Imaging Centre, Montreal Neurological Institute, Canada
| | - Ronald B Postuma
- Centre for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Canada; Department of Neurology and Neurosurgery, McGill University, Canada
| | - Jean-Paul Soucy
- McConnell Brain Imaging Centre, Montreal Neurological Institute, Canada; Department of Radiology and Nuclear Medicine, Université de Montréal, Canada; PERFORM Centre, Concordia University, Canada
| | - Jean-François Gagnon
- NeuroQAM Centre, Université du Québec à Montréal (UQAM), Canada; Centre for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Canada
| | - Amélie Pelletier
- Centre for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Canada
| | - Jacques Montplaisir
- Centre for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Canada; Department of Psychiatry, Université de Montréal, Canada.
| |
Collapse
|
9
|
Longitudinal Alzheimer’s Degeneration Reflects the Spatial Topography of Cholinergic Basal Forebrain Projections. Cell Rep 2018; 24:38-46. [DOI: 10.1016/j.celrep.2018.06.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 04/09/2018] [Accepted: 05/30/2018] [Indexed: 10/28/2022] Open
|
10
|
Jin H, Yue X, Liu H, Han J, Flores H, Su Y, Parsons SM, Perlmutter JS, Tu Z. Kinetic modeling of [ 18 F]VAT, a novel radioligand for positron emission tomography imaging vesicular acetylcholine transporter in non-human primate brain. J Neurochem 2018; 144:791-804. [PMID: 29315563 DOI: 10.1111/jnc.14291] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 12/16/2017] [Accepted: 12/19/2017] [Indexed: 01/06/2023]
Abstract
Molecular imaging of vesicular acetylcholine transporter (VAChT) in the brain provides an important cholinergic biomarker for the pathophysiology and treatment of dementias including Alzheimer's disease. In this study, kinetics modeling methods were applied and compared for quantifying regional brain uptake of the VAChT-specific positron emission tomography radiotracer, ((-)-(1-(-8-(2-fluoroethoxy)-3-hydroxy-1,2,3,4-tetrahydronaphthalen-2-yl)piperidin-4-yl)(4-fluorophenyl)-methanone) ([18 F]VAT) in macaques. Total volume distribution (VT ) estimates were compared for one-tissue compartment model (1TCM), two-tissue compartment model (2TCM), Logan graphic analysis (LoganAIF) and multiple linear analysis (MA1) with arterial blood input function using data from three macaques. Using the cerebellum-hemispheres as the reference region with data from seven macaques, three additional models were compared: reference tissue model (RTM), simplified RTM (SRTM), and Logan graphic analysis (LoganREF). Model selection criterion indicated that a) 2TCM and SRTM were the most appropriate kinetics models for [18 F]VAT; and b) SRTM was strongly correlated with 2TCM (Pearson's coefficients r > 0.93, p < 0.05). Test-retest studies demonstrated that [18 F]VAT has good reproducibility and reliability (TRV < 10%, ICC > 0.72). These studies demonstrate [18 F]VAT is a promising VAChT positron emission tomography tracer for quantitative assessment of VAChT levels in the brain of living subjects.
Collapse
Affiliation(s)
- Hongjun Jin
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Xuyi Yue
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Hui Liu
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Junbin Han
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Hubert Flores
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Yi Su
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA.,Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Stanley M Parsons
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California, USA
| | - Joel S Perlmutter
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA.,Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, USA.,Department of Neuroscience, Physical Therapy and Occupational Therapy, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Zhude Tu
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA
| |
Collapse
|
11
|
Aghourian M, Legault-Denis C, Soucy JP, Rosa-Neto P, Gauthier S, Kostikov A, Gravel P, Bédard MA. Quantification of brain cholinergic denervation in Alzheimer's disease using PET imaging with [ 18F]-FEOBV. Mol Psychiatry 2017; 22:1531-1538. [PMID: 28894304 DOI: 10.1038/mp.2017.183] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 07/17/2017] [Accepted: 07/20/2017] [Indexed: 01/08/2023]
Abstract
18F-fluoroethoxybenzovesamicol (FEOBV) is a new PET radiotracer that binds to the vesicular acetylcholine transporter. In both animals and healthy humans, FEOBV was found sensitive and reliable to characterize presynaptic cholinergic nerve terminals in the brain. It has been used here for we believe the first time in patients with Alzheimer's disease (AD) to quantify brain cholinergic losses. The sample included 12 participants evenly divided in healthy subjects and patients with AD, all assessed with the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) cognitive scales. Every participant underwent three consecutive PET imaging sessions with (1) the FEOBV as a tracer of the cholinergic terminals, (2) the 18F-NAV4694 (NAV) as an amyloid-beta tracer, and (3) the 18F-Fluorodeoxyglucose (FDG) as a brain metabolism agent. Standardized uptake value ratios (SUVRs) were computed for each tracer, and compared between the two groups using voxel wise t-tests. Correlations were also computed between each tracer and the cognitive scales, as well as between FEOBV and the two other radiotracers. Results showed major reductions of FEOBV uptake in multiple cortical areas that were evident in each AD subject, and in the AD group as a whole when compared to the control group. FDG and NAV were also able to distinguish the two groups, but with lower sensitivity than FEOBV. FEOBV uptake values were positively correlated with FDG in numerous cortical areas, and negatively correlated with NAV in some restricted areas. The MMSE and MoCA cognitive scales were found to correlate significantly with FEOBV and with FDG, but not with NAV. We concluded that PET imaging with FEOBV is more sensitive than either FDG or NAV to distinguish AD patients from control subjects, and may be useful to quantify disease severity. FEOBV can be used to assess cholinergic degeneration in human, and may represent an excellent biomarker for AD.
Collapse
Affiliation(s)
- M Aghourian
- Université du Québec à Montréal (UQAM), Cognitive Pharmacology Research Unit, Montreal, QC, Canada.,McConnell Brain Imaging Centre, Montreal Neurological Institute, Montreal, QC, Canada.,McGill Centre for Studies in Aging, Douglas Mental Health University Institute, Verdun, QC, Canada
| | - C Legault-Denis
- Université du Québec à Montréal (UQAM), Cognitive Pharmacology Research Unit, Montreal, QC, Canada.,McConnell Brain Imaging Centre, Montreal Neurological Institute, Montreal, QC, Canada.,McGill Centre for Studies in Aging, Douglas Mental Health University Institute, Verdun, QC, Canada
| | - J-P Soucy
- McConnell Brain Imaging Centre, Montreal Neurological Institute, Montreal, QC, Canada.,Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada.,PERFORM Centre, Concordia University, Montreal, QC, Canada
| | - P Rosa-Neto
- McConnell Brain Imaging Centre, Montreal Neurological Institute, Montreal, QC, Canada.,McGill Centre for Studies in Aging, Douglas Mental Health University Institute, Verdun, QC, Canada.,Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - S Gauthier
- McGill Centre for Studies in Aging, Douglas Mental Health University Institute, Verdun, QC, Canada.,Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - A Kostikov
- McConnell Brain Imaging Centre, Montreal Neurological Institute, Montreal, QC, Canada.,Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - P Gravel
- McConnell Brain Imaging Centre, Montreal Neurological Institute, Montreal, QC, Canada
| | - M-A Bédard
- Université du Québec à Montréal (UQAM), Cognitive Pharmacology Research Unit, Montreal, QC, Canada.,McConnell Brain Imaging Centre, Montreal Neurological Institute, Montreal, QC, Canada.,McGill Centre for Studies in Aging, Douglas Mental Health University Institute, Verdun, QC, Canada
| |
Collapse
|
12
|
Barthel C, Sorger D, Deuther-Conrad W, Scheunemann M, Schweiger S, Jäckel P, Roghani A, Steinbach J, Schüürmann G, Sabri O, Brust P, Wenzel B. New systematically modified vesamicol analogs and their affinity and selectivity for the vesicular acetylcholine transporter – A critical examination of the lead structure. Eur J Med Chem 2015; 100:50-67. [DOI: 10.1016/j.ejmech.2015.05.033] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 05/20/2015] [Accepted: 05/21/2015] [Indexed: 12/14/2022]
|
13
|
Liu H, Jin H, Li J, Zhang X, Kaneshige K, Parsons SM, Perlmutter JS, Tu Z. In vitro and ex vivo characterization of (-)-TZ659 as a ligand for imaging the vesicular acetylcholine transporter. Eur J Pharmacol 2015; 752:18-25. [PMID: 25678250 PMCID: PMC4369186 DOI: 10.1016/j.ejphar.2015.02.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 01/30/2015] [Accepted: 02/03/2015] [Indexed: 12/30/2022]
Abstract
The loss of cholinergic neurons and synapses relates to the severity of dementia in several neurodegenerative pathologies; and the vesicular acetylcholine transporter (VAChT) provides a reliable biomarker of cholinergic function. We recently characterized and (11)C-labeled a new VAChT inhibitor, (-)-TZ659. Here we report the in vitro and ex vivo characterization of (-)-TZ659. A stably transfected PC12(A123.7) cell line which expresses human VAChT (hVAChT) was used for the in vitro binding characterization of (-)-[(3)H]TZ659. A saturated binding curve was obtained with Kd=1.97±0.30nM and Bmax=3240±145.9fmol/mg protein. In comparison, a PC12(A123.7) cell line that expresses mutant hVAChT showed decreased binding affinity (Kd=15.94±0.28nM). Competitive binding assays using a panel of other CNS ligands showed no inhibition of (-)-[(3)H]TZ659 binding. On the other hand, binding inhibitions were observed only using VAChT inhibitors (Ki=0.20-31.35nM). An in vitro assay using rat brain homogenates showed that (-)-[(3)H]TZ659 had higher binding in striatum than in cerebellum, with a target: non-target ratio>3.46. Even higher ex vivo striatum-to-cerebellum ratios (9.56±1.11) were observed using filtered homogenates of brain tissue after rats were injected intravenously with (-)-[(11)C]TZ659. Ex vivo autoradiography of (-)-[(11)C]TZ659 confirmed high striatal uptake, with a consistently high striatum-to-cerebellum ratio (2.99±0.44). In conclusion, (-)-TZ659 demonstrated high potency and good specificity for VAChT in vitro and in vivo. These data suggest that (-)-[(11)C]TZ659 may be a promising PET tracer to image VAChT in the brain.
Collapse
Affiliation(s)
- Hui Liu
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Hongjun Jin
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Junfeng Li
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Xiang Zhang
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Kota Kaneshige
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106, USA
| | - Stanley M Parsons
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106, USA
| | - Joel S Perlmutter
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Zhude Tu
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
| |
Collapse
|
14
|
Schilling LP, Leuzy A, Zimmer ER, Gauthier S, Rosa-Neto P. Nonamyloid PET biomarkers and Alzheimer's disease: current and future perspectives. FUTURE NEUROLOGY 2014. [DOI: 10.2217/fnl.14.40] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
ABSTRACT Recent advances in neurobiology and PET have helped redefine Alzheimer's disease (AD) as a dynamic pathophysiological process, clinically characterized by preclinical, mild cognitive impairment due to AD and dementia stages. Though a majority of PET studies conducted within these populations have to date focused on β-amyloid, various ‘nonamyloid’ radiopharmaceuticals exist for evaluating neurodegeneration, neuroinflammation and perturbations in neurotransmission across the spectrum of AD. Importantly, findings using such tracers have been shown to correlate with various clinical, cognitive and behavioral measures. In the context of a growing shift toward early diagnosis and symptomatic and disease-modifying clinical trials, nonamyloid PET radiotracers will prove of use, and, potentially, contribute to improved therapeutic prospects for AD.
Collapse
Affiliation(s)
- Lucas Porcello Schilling
- Translational Neuroimaging Laboratory (TNL), McGill Center for Studies in Aging (MCSA), Douglas Mental Health Research Institute, Montreal, Canada
- Alzheimer's Disease Research Unit, McGill Center for Studies in Aging (MCSA), Douglas Mental Health Research Institute, Montreal, Canada
- Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
| | - Antoine Leuzy
- Translational Neuroimaging Laboratory (TNL), McGill Center for Studies in Aging (MCSA), Douglas Mental Health Research Institute, Montreal, Canada
- Alzheimer's Disease Research Unit, McGill Center for Studies in Aging (MCSA), Douglas Mental Health Research Institute, Montreal, Canada
| | - Eduardo Rigon Zimmer
- Translational Neuroimaging Laboratory (TNL), McGill Center for Studies in Aging (MCSA), Douglas Mental Health Research Institute, Montreal, Canada
- Alzheimer's Disease Research Unit, McGill Center for Studies in Aging (MCSA), Douglas Mental Health Research Institute, Montreal, Canada
- Department of Biochemistry, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Serge Gauthier
- Alzheimer's Disease Research Unit, McGill Center for Studies in Aging (MCSA), Douglas Mental Health Research Institute, Montreal, Canada
| | - Pedro Rosa-Neto
- Translational Neuroimaging Laboratory (TNL), McGill Center for Studies in Aging (MCSA), Douglas Mental Health Research Institute, Montreal, Canada
- Alzheimer's Disease Research Unit, McGill Center for Studies in Aging (MCSA), Douglas Mental Health Research Institute, Montreal, Canada
| |
Collapse
|
15
|
Enhanced consumption of salient solutions following pedunculopontine tegmental lesions. Neuroscience 2014; 284:381-399. [PMID: 25305665 DOI: 10.1016/j.neuroscience.2014.09.075] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 09/26/2014] [Accepted: 09/30/2014] [Indexed: 12/19/2022]
Abstract
Rats with lesions of the pedunculopontine tegmental nucleus (PPTg) reliably overconsume high concentration sucrose solution. This effect is thought to be indicative of response-perseveration or loss of behavioral control in conditions of high excitement. While these theories have anatomical and behavioral support, they have never been explicitly tested. Here, we used a contact lickometer to examine the microstructure of drinking behavior to gain insight into the behavioral changes during overconsumption. Rats received either excitotoxic (ibotenic acid) damage to all PPTg neuronal subpopulations or selective depletion of the cholinergic neuronal sub-population (diphtheria toxin-urotensin II (Dtx-UII) lesions). We offered rats a variety of pleasant, neutral and aversive tastants to assess the generalizability and specificity of the overconsumption effect. Ibotenic-lesioned rats consumed significantly more 20% sucrose than sham controls, and did so through licking significantly more times. However, the behavioral microstructure during overconsumption was unaffected by the lesion and showed no indications of response-perseveration. Furthermore, the overconsumption effect did not generalize to highly consumed saccharin. In contrast, while only consuming small amounts of quinine solution, ibotenic-lesioned rats had significantly more licks and bursts for this tastant. Selective depletion of cholinergic PPTg neurons had no effect on consumption of any tastant. We then assessed whether it is the salience of the solution which determines overconsumption by ibotenic-lesioned rats. While maintained on free-food, ibotenic-lesioned rats had normal consumption of sucrose and hypertonic saline. After mild food deprivation ibotenic PPTg-lesioned rats overconsumed 20% sucrose. Subsequently, after dietary-induced sodium deficiency, lesioned rats consumed significantly more saline than controls. These results establish that it is the salience of the solution which is the determining factor leading to overconsumption following excitotoxic PPTg lesion. They also find no support for response-perseveration contributing to this effect. Results are discussed in terms of altered dopamine (DA) and salience signaling.
Collapse
|
16
|
Cyr M, Parent MJ, Mechawar N, Rosa-Neto P, Soucy JP, Clark SD, Aghourian M, Bedard MA. Deficit in sustained attention following selective cholinergic lesion of the pedunculopontine tegmental nucleus in rat, as measured with both post-mortem immunocytochemistry and in vivo PET imaging with [¹⁸F]fluoroethoxybenzovesamicol. Behav Brain Res 2014; 278:107-14. [PMID: 25257103 DOI: 10.1016/j.bbr.2014.09.021] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2014] [Revised: 09/12/2014] [Accepted: 09/15/2014] [Indexed: 12/28/2022]
Abstract
Cholinergic neurons of the pedunculopontine tegmental nucleus (PPTg) are thought to be involved in cognitive functions such as sustained attention, and lesions of these cells have been documented in patients showing fluctuations of attention such as in Parkinson's disease or dementia with Lewy Body. Animal studies have been conducted to support the role of these cells in attention, but the lesions induced in these animals were not specific to the cholinergic PPTg system, and were assessed by post-mortem methods remotely performed from the in vivo behavioral assessments. Moreover, sustained attention have not been directly assessed in these studies, but rather deduced from indirect measurements. In the present study, rats were assessed on the 5-Choice Serial Reaction Time Task (5-CSRTT), and a specific measure of variability in response latency was created. Animals were observed both before and after selective lesion of the PPTg cholinergic neurons. Brain cholinergic denervation was assessed both in vivo and ex vivo, using PET imaging with [(18)F]fluoroethoxybenzovesamicol ([(18)F]FEOBV) and immunocytochemistry respectively. Results showed that the number of correct responses and variability in response latency in the 5-CSRTT were the only behavioral measures affected following the lesions. These measures were found to correlate significantly with the number of PPTg cholinergic cells, as measured with both [(18)F]FEOBV and immunocytochemistry. This suggests the primary role of the PPTg cholinergic cells in sustained attention. It also allows to reliably use the PET imaging with [(18)F]FEOBV for the purpose of assessing the relationship between behavior and cholinergic innervation in living animals.
Collapse
Affiliation(s)
- Marilyn Cyr
- Université du Québec à Montréal (UQAM), Canada; Douglas Mental Health University Institute, Canada
| | - Maxime J Parent
- Université du Québec à Montréal (UQAM), Canada; Douglas Mental Health University Institute, Canada
| | | | - Pedro Rosa-Neto
- Douglas Mental Health University Institute, Canada; Montreal Neurological Institute (MNI), Canada
| | | | | | | | - Marc-Andre Bedard
- Université du Québec à Montréal (UQAM), Canada; Douglas Mental Health University Institute, Canada; Montreal Neurological Institute (MNI), Canada.
| |
Collapse
|
17
|
Bergman S, Estrada S, Hall H, Rahman R, Blomgren A, Larhed M, Svedberg M, Thibblin A, Wångsell F, Antoni G. Synthesis and labeling of a piperazine-based library of11C-labeled ligands for imaging of the vesicular acetylcholine transporter. J Labelled Comp Radiopharm 2014; 57:525-32. [DOI: 10.1002/jlcr.3208] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 04/24/2014] [Accepted: 04/25/2014] [Indexed: 01/08/2023]
Affiliation(s)
- Sara Bergman
- Preclinical PET Platform, Department of Medicinal Chemistry; Uppsala University; Box 574 SE-751 23 Uppsala Sweden
| | - Sergio Estrada
- Preclinical PET Platform, Department of Medicinal Chemistry; Uppsala University; Box 574 SE-751 23 Uppsala Sweden
| | - Håkan Hall
- Preclinical PET Platform, Department of Medicinal Chemistry; Uppsala University; Box 574 SE-751 23 Uppsala Sweden
| | - Rashidur Rahman
- Preclinical PET Platform, Department of Medicinal Chemistry; Uppsala University; Box 574 SE-751 23 Uppsala Sweden
| | - Andreas Blomgren
- Organic Pharmaceutical Chemistry, Department of Medicinal Chemistry; Uppsala University; BMC Box 574 SE-751 23 Uppsala Sweden
| | - Mats Larhed
- Science for Life Laboratory, Department of Medicinal Chemistry; Uppsala University; BMC Box 574 SE-751 23 Uppsala Sweden
| | - Marie Svedberg
- Preclinical PET Platform, Department of Medicinal Chemistry; Uppsala University; Box 574 SE-751 23 Uppsala Sweden
| | - Alf Thibblin
- Preclinical PET Platform, Department of Medicinal Chemistry; Uppsala University; Box 574 SE-751 23 Uppsala Sweden
| | - Fredrik Wångsell
- Organic Pharmaceutical Chemistry, Department of Medicinal Chemistry; Uppsala University; BMC Box 574 SE-751 23 Uppsala Sweden
| | - Gunnar Antoni
- Preclinical PET Platform, Department of Medicinal Chemistry; Uppsala University; Box 574 SE-751 23 Uppsala Sweden
| |
Collapse
|