1
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Gronich N. Central Nervous System Medications: Pharmacokinetic and Pharmacodynamic Considerations for Older Adults. Drugs Aging 2024; 41:507-519. [PMID: 38814377 PMCID: PMC11193826 DOI: 10.1007/s40266-024-01117-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/16/2024] [Indexed: 05/31/2024]
Abstract
Most drugs have not been evaluated in the older population. Recognizing physiological alterations associated with changes in drug disposition and with the ultimate effect, especially in central nervous system-acting drugs, is fundamental. While considering pharmacokinetics, it should be noted that the absorption of most drugs from the gastrointestinal tract does not change in advanced age. There are only few data about the effect of age on the transdermal absorption of medications such as fentanyl. Absorption from an intramuscular injection may be similar in older adults as in younger patients. The distribution of lipophilic drugs (such as diazepam) is increased owing to a relative increase in the percentage of body fat, causing drug accumulation and prolonged drug elimination following cessation. Phase I drug biotransformation is variably decreased in aging, impacting elimination, and hepatic drug clearance has been shown to decrease in older individuals by 10-40% for most drugs studied. Lower doses of phenothiazines, butyrophenones, atypical antipsychotics, antidepressants (citalopram, mirtazapine, and tricyclic antidepressants), and benzodiazepines (such as diazepam) achieve the same extent of exposure. For renally cleared drugs with no prior metabolism (such as gabapentin), the glomerular filtration rate appropriately estimates drug clearance. Important pharmacodynamic changes in older adults include an increased sedative effect of benzodiazepines at a given drug exposure, and a higher sensitivity to mu opiate receptor agonists and to opioid adverse effects. Artificial intelligence, physiologically based pharmacokinetic modeling and simulation, and concentration-effect modeling enabling a differentiation between the pharmacokinetic and the pharmacodynamic effects of aging might help to close some of the gaps in knowledge.
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Affiliation(s)
- Naomi Gronich
- Department of Community Medicine and Epidemiology, Lady Davis Carmel Medical Center, Clalit Health Services, 7 Michal St, 3436212, Haifa, Israel.
- Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 3200003, Haifa, Israel.
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2
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Singh K, Ngo A, Keerthisinghe OV, Patel KK, Liang C, Mukherjee J. Synthesis and Evaluation of Compound Targeting α7 and β2 Subunits in Nicotinic Acetylcholinergic Receptor. Molecules 2023; 28:8128. [PMID: 38138615 PMCID: PMC10745926 DOI: 10.3390/molecules28248128] [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: 11/19/2023] [Revised: 12/07/2023] [Accepted: 12/14/2023] [Indexed: 12/24/2023] Open
Abstract
Nicotinic acetylcholine receptors (nAChRs) are involved in various central nervous system functions and have also been implicated in several neurodegenerative disorders. The heteromeric α4β2* and homomeric α7 are two major nAChR subtypes which have been studied in the brain using positron emission tomography (PET). Our comparative autoradiographic studies of the two receptor types in the mouse and rat brains show major differences in the thalamus (α4β2* >> α7), hippocampus (α7 >> α4β2*), and subiculum (α4β2* >> α7). A relatively newer heteromeric α7β2 nAChR subtype has been identified in the brain which may have a greater role in neurodegeneration. We report the development of KS7 (3-(2-(S)-azetidinylmethoxy)-5-(1,4-diaza-bicyclo[3.2.2]nonane)pyridine) which incorporates structural features of Nifzetidine (high affinity for α4β2* nAChR) and ASEM (high affinity for α7 nAChR) in an effort to target α7 and β2 subunits in α7β2 nAChR. KS7 exhibited higher affinities (IC50 = 50 to 172 nM) for [3H]cytisine radiolabeled sites and weaker affinities (IC50 = 10 μM) for [125I]-α-bungarotoxin radiolabeled rat brain sites in several brain regions. The weaker affinity of KS7 to α7 nAChR may suggest lack of binding at the α7 subunit of α7β2 nAChR. A radiolabeled derivative of KS7 may be required to identify any specific binding to brain regions suggested to contain α7β2 nAChR.
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Affiliation(s)
| | | | | | | | | | - Jogeshwar Mukherjee
- Preclinical Imaging, Department of Radiological Sciences, University of California-Irvine, Irvine, CA 92697, USA; (K.S.); (A.N.); (O.V.K.); (K.K.P.); (C.L.)
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3
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Zhang JJ, Fu H, Lin R, Zhou J, Haider A, Fang W, Elghazawy NH, Rong J, Chen J, Li Y, Ran C, Collier TL, Chen Z, Liang SH. Imaging Cholinergic Receptors in the Brain by Positron Emission Tomography. J Med Chem 2023; 66:10889-10916. [PMID: 37583063 PMCID: PMC10461233 DOI: 10.1021/acs.jmedchem.3c00573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Indexed: 08/17/2023]
Abstract
Cholinergic receptors represent a promising class of diagnostic and therapeutic targets due to their significant involvement in cognitive decline associated with neurological disorders and neurodegenerative diseases as well as cardiovascular impairment. Positron emission tomography (PET) is a noninvasive molecular imaging tool that has helped to shed light on the roles these receptors play in disease development and their diverse functions throughout the central nervous system (CNS). In recent years, there has been a notable advancement in the development of PET probes targeting cholinergic receptors. The purpose of this review is to provide a comprehensive overview of the recent progress in the development of these PET probes for cholinergic receptors with a specific focus on ligand structure, radiochemistry, and pharmacology as well as in vivo performance and applications in neuroimaging. The review covers the structural design, pharmacological properties, radiosynthesis approaches, and preclinical and clinical evaluations of current state-of-the-art PET probes for cholinergic receptors.
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Affiliation(s)
- Jing-Jing Zhang
- Jiangsu
Co-Innovation Center of Efficient Processing and Utilization of Forest
Resources, Jiangsu Provincial Key Lab for the Chemistry and Utilization
of Agro-Forest Biomass, Jiangsu Key Lab of Biomass-Based Green Fuels
and Chemicals, International Innovation Center for Forest Chemicals
and Materials, College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Hualong Fu
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Key
Laboratory of Radiopharmaceuticals, Ministry of Education, College
of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Ruofan Lin
- Jiangsu
Co-Innovation Center of Efficient Processing and Utilization of Forest
Resources, Jiangsu Provincial Key Lab for the Chemistry and Utilization
of Agro-Forest Biomass, Jiangsu Key Lab of Biomass-Based Green Fuels
and Chemicals, International Innovation Center for Forest Chemicals
and Materials, College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Jingyin Zhou
- Key
Laboratory of Radiopharmaceuticals, Ministry of Education, College
of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Ahmed Haider
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
| | - Weiwei Fang
- Jiangsu
Co-Innovation Center of Efficient Processing and Utilization of Forest
Resources, Jiangsu Provincial Key Lab for the Chemistry and Utilization
of Agro-Forest Biomass, Jiangsu Key Lab of Biomass-Based Green Fuels
and Chemicals, International Innovation Center for Forest Chemicals
and Materials, College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Nehal H. Elghazawy
- Department
of Pharmaceutical, Chemistry, Faculty of Pharmacy & Biotechnology, German University in Cairo, 11835 Cairo, Egypt
| | - Jian Rong
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
| | - Jiahui Chen
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
| | - Yinlong Li
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
| | - Chongzhao Ran
- Athinoula
A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02114, United States
| | - Thomas L. Collier
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
| | - Zhen Chen
- Jiangsu
Co-Innovation Center of Efficient Processing and Utilization of Forest
Resources, Jiangsu Provincial Key Lab for the Chemistry and Utilization
of Agro-Forest Biomass, Jiangsu Key Lab of Biomass-Based Green Fuels
and Chemicals, International Innovation Center for Forest Chemicals
and Materials, College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
| | - Steven H. Liang
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
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4
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Liang C, Nguyen GA, Danh TB, Sandhu AK, Melkonyan LL, Syed AU, Mukherjee J. Abnormal [ 18 F]NIFENE binding in transgenic 5xFAD mouse model of Alzheimer's disease: In vivo PET/CT imaging studies of α4β2* nicotinic acetylcholinergic receptors and in vitro correlations with Aβ plaques. Synapse 2023; 77:e22265. [PMID: 36749986 PMCID: PMC10148164 DOI: 10.1002/syn.22265] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 01/31/2023] [Accepted: 02/02/2023] [Indexed: 02/09/2023]
Abstract
Since cholinergic dysfunction has been implicated in Alzheimer's disease (AD), the effects of Aβ plaques on nicotinic acetylcholine receptors (nAChRs) α4β2* subtype were studied using the transgenic 5xFAD mouse model of AD. Using the PET radiotracer [18 F]nifene for α4β2* nAChRs, in vitro autoradiography and in vivo PET/CT studies in 5xFAD mice were carried out and compared with wild-type (C57BL/6) mice. Ratios of [18 F]nifene binding in brain regions versus cerebellum (CB) in 5xFAD mice brains were for thalamus (TH) = 17, hippocampus-subiculum = 7, frontal cortex (FC) = 5.5, and striatum = 4.7. [125 I]IBETA and immunohistochemistry (IHC) in 5xFAD brain slices confirmed Aβ plaques. Nicotine and acetylcholine displaced [18 F]nifene in 5xFAD mice (IC50 nicotine = 31-73 nM; ACh = 38-83 nM) and C57BL/6 (IC50 nicotine = 16-18 nM; ACh = 34-55 nM). Average [18 F]nifene SUVR (CB as reference) in 5xFAD mice was significantly higher in FC = 3.04 compared to C57BL/6 mice FC = 1.92 (p = .001), whereas TH difference between 5xFAD mice (SUVR = 2.58) and C57BL/6 mice (SUVR = 2.38) was not significant. Nicotine-induced dissociation half life (t1/2 ) of [18 F]nifene for TH were 37 min for 5xFAD mice and 26 min for C57BL/6 mice. Dissociation half life for FC in C57BL/6 mice was 77 min , while no dissociation of [18 F]nifene occurred in the medial prefrontal cortex (mFC) of 5xFAD mice. Coregistration of [18 F]nifene PET with MR suggested that the mPFC, and anterior cingulate (AC) regions exhibited high uptake in 5xFAD mice compared to C57BL/6 mice. Ex vivo [18 F]nifene and in vitro [125 I]IBETA Aβ plaque autoradiography after in vivo PET/CT scan of 5xFAD mouse brain were moderately correlated (r2 = 0.68). In conclusion, 5xFAD mice showed increased non-displaceable [18 F]nifene binding in mPFC.
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Affiliation(s)
- Christopher Liang
- Preclinical Imaging, Department of Radiological Sciences, University of California-Irvine, Irvine, California, USA
| | - Grace A Nguyen
- Preclinical Imaging, Department of Radiological Sciences, University of California-Irvine, Irvine, California, USA
| | - Tram B Danh
- Preclinical Imaging, Department of Radiological Sciences, University of California-Irvine, Irvine, California, USA
| | - Anoopraj K Sandhu
- Preclinical Imaging, Department of Radiological Sciences, University of California-Irvine, Irvine, California, USA
| | - Lusine L Melkonyan
- Preclinical Imaging, Department of Radiological Sciences, University of California-Irvine, Irvine, California, USA
| | - Amina U Syed
- Preclinical Imaging, Department of Radiological Sciences, University of California-Irvine, Irvine, California, USA
| | - Jogeshwar Mukherjee
- Preclinical Imaging, Department of Radiological Sciences, University of California-Irvine, Irvine, California, USA
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5
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Terry AV, Jones K, Bertrand D. Nicotinic acetylcholine receptors in neurological and psychiatric diseases. Pharmacol Res 2023; 191:106764. [PMID: 37044234 DOI: 10.1016/j.phrs.2023.106764] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 03/30/2023] [Accepted: 04/07/2023] [Indexed: 04/14/2023]
Abstract
Neuronal nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels that are widely distributed both pre- and post-synaptically in the mammalian brain. By modulating cation flux across cell membranes, neuronal nAChRs regulate neuronal excitability and the release of a variety of neurotransmitters to influence multiple physiologic and behavioral processes including synaptic plasticity, motor function, attention, learning and memory. Abnormalities of neuronal nAChRs have been implicated in the pathophysiology of neurologic disorders including Alzheimer's disease, Parkinson's disease, epilepsy, and Tourette´s syndrome, as well as psychiatric disorders including schizophrenia, depression, and anxiety. The potential role of nAChRs in a particular illness may be indicated by alterations in the expression of nAChRs in relevant brain regions, genetic variability in the genes encoding for nAChR subunit proteins, and/or clinical or preclinical observations where specific ligands showed a therapeutic effect. Over the past 25 years, extensive preclinical and some early clinical evidence suggested that ligands at nAChRs might have therapeutic potential for neurologic and psychiatric disorders. However, to date the only approved indications for nAChR ligands are smoking cessation and the treatment of dry eye disease. It has been argued that progress in nAChR drug discovery has been limited by translational gaps between the preclinical models and the human disease as well as unresolved questions regarding the pharmacological goal (i.e., agonism, antagonism or receptor desensitization) depending on the disease.
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Affiliation(s)
- Alvin V Terry
- Department of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, Georgia, 30912.
| | - Keri Jones
- Educational Innovation Institute, Medical College of Georgia at Augusta University, Augusta, Georgia, 30912
| | - Daniel Bertrand
- HiQScreen Sàrl, 6, rte de Compois, 1222 Vésenaz, Geneva, Switzerland
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6
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Yarns BC, Holiday KA, Carlson DM, Cosgrove CK, Melrose RJ. Pathophysiology of Alzheimer's Disease. Psychiatr Clin North Am 2022; 45:663-676. [PMID: 36396271 DOI: 10.1016/j.psc.2022.07.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disease leading to dementia worldwide. While neuritic plaques consisting of aggregated amyloid-beta proteins and neurofibrillary tangles of accumulated tau proteins represent the pathophysiologic hallmarks of AD, numerous processes likely interact with risk and protective factors and one's culture to produce the cognitive loss, neuropsychiatric symptoms, and functional impairments that characterize AD dementia. Recent biomarker and neuroimaging research has revealed how the pathophysiology of AD may lead to symptoms, and as the pathophysiology of AD gains clarity, more potential treatments are emerging that aim to modify the disease and relieve its burden.
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Affiliation(s)
- Brandon C Yarns
- Psychiatry/Mental Health Service, VA Greater Los Angeles Healthcare System, 11301 Wilshire Boulevard, Building 401, Mail Code 116AE, Los Angeles, CA 90073, USA; Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, 757 Westwood Plaza #4, Los Angeles, CA 90095, USA.
| | - Kelsey A Holiday
- Psychiatry/Mental Health Service, VA Greater Los Angeles Healthcare System, 11301 Wilshire Boulevard, Building 401, Mail Code 116AE, Los Angeles, CA 90073, USA
| | - David M Carlson
- Psychiatry/Mental Health Service, VA Greater Los Angeles Healthcare System, 11301 Wilshire Boulevard, Building 401, Mail Code 116AE, Los Angeles, CA 90073, USA; Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, 757 Westwood Plaza #4, Los Angeles, CA 90095, USA
| | - Coleman K Cosgrove
- Department of Psychiatry, University at Buffalo, 462 Grider Street, Buffalo, NY 14215, USA
| | - Rebecca J Melrose
- Psychiatry/Mental Health Service, VA Greater Los Angeles Healthcare System, 11301 Wilshire Boulevard, Building 401, Mail Code 116AE, Los Angeles, CA 90073, USA; Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, 757 Westwood Plaza #4, Los Angeles, CA 90095, USA
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7
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Cummings J, Kinney J. Biomarkers for Alzheimer's Disease: Context of Use, Qualification, and Roadmap for Clinical Implementation. MEDICINA (KAUNAS, LITHUANIA) 2022; 58:952. [PMID: 35888671 PMCID: PMC9318582 DOI: 10.3390/medicina58070952] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/13/2022] [Accepted: 07/15/2022] [Indexed: 12/30/2022]
Abstract
Background and Objectives: The US Food and Drug Administration (FDA) defines a biomarker as a characteristic that is measured as an indicator of normal biological processes, pathogenic processes, or responses to an exposure or intervention. Biomarkers may be used in clinical care or as drug development tools (DDTs) in clinical trials. The goal of this review and perspective is to provide insight into the regulatory guidance for the use of biomarkers in clinical trials and clinical care. Materials and Methods: We reviewed FDA guidances relevant to biomarker use in clinical trials and their transition to use in clinical care. We identified instructive examples of these biomarkers in Alzheimer's disease (AD) drug development and their application in clinical practice. Results: For use in clinical trials, biomarkers must have a defined context of use (COU) as a risk/susceptibility, diagnostic, monitoring, predictive, prognostic, pharmacodynamic, or safety biomarker. A four-stage process defines the pathway to establish the regulatory acceptance of the COU for a biomarker including submission of a letter of intent, description of the qualification plan, submission of a full qualification package, and acceptance through a qualification recommendation. Biomarkers used in clinical care may be companion biomarkers, in vitro diagnostic devices (IVDs), or laboratory developed tests (LDTs). A five-phase biomarker development process has been proposed to structure the biomarker development process. Conclusions: Biomarkers are increasingly important in drug development and clinical care. Adherence to regulatory guidance for biomarkers used in clinical trials and patient care is required to advance these important drug development and clinical tools.
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Affiliation(s)
- Jeffrey Cummings
- Pam Quirk Brain Health and Biomarker Laboratory, Chambers-Grundy Center for Transformative Neuroscience, Department of Brain Health, School of Integrated Health Sciences, University of Nevada Las Vegas, Las Vegas, NV 89154, USA;
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Tiepolt S, Meyer PM, Patt M, Deuther-Conrad W, Hesse S, Barthel H, Sabri O. PET Imaging of Cholinergic Neurotransmission in Neurodegenerative Disorders. J Nucl Med 2022; 63:33S-44S. [PMID: 35649648 DOI: 10.2967/jnumed.121.263198] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 05/06/2022] [Indexed: 12/13/2022] Open
Abstract
As a neuromodulator, the neurotransmitter acetylcholine plays an important role in cognitive, mood, locomotor, sleep/wake, and olfactory functions. In the pathophysiology of most neurodegenerative diseases, such as Alzheimer disease (AD) or Lewy body disorder (LBD), cholinergic receptors, transporters, or enzymes are involved and relevant as imaging targets. The aim of this review is to summarize current knowledge on PET imaging of cholinergic neurotransmission in neurodegenerative diseases. For PET imaging of presynaptic vesicular acetylcholine transporters (VAChT), (-)-18F-fluoroethoxybenzovesamicol (18F-FEOBV) was the first PET ligand that could be successfully translated to clinical application. Since then, the number of 18F-FEOBV PET investigations on patients with AD or LBD has grown rapidly and provided novel, important findings concerning the pathophysiology of AD and LBD. Regarding the α4β2 nicotinic acetylcholine receptors (nAChRs), various second-generation PET ligands, such as 18F-nifene, 18F-AZAN, 18F-XTRA, (-)-18F-flubatine, and (+)-18F-flubatine, were developed and successfully translated to human application. In neurodegenerative diseases such as AD and LBD, PET imaging of α4β2 nAChRs is of special value for monitoring disease progression and drugs directed to α4β2 nAChRs. For PET of α7 nAChR, 18F-ASEM and 11C-MeQAA were successfully applied in mild cognitive impairment and AD, respectively. The highest potential for α7 nAChR PET is seen in staging, in evaluating disease progression, and in therapy monitoring. PET of selective muscarinic acetylcholine receptors (mAChRs) is still in an early stage, as the development of subtype-selective radioligands is complicated. Promising radioligands to image mAChR subtypes M1 (11C-LSN3172176), M2 (18F-FP-TZTP), and M4 (11C-MK-6884) were developed and successfully translated to humans. PET imaging of mAChRs is relevant for the assessment and monitoring of therapies in AD and LBD. PET of acetylcholine esterase activity has been investigated since the 1990s. Many PET studies with 11C-PMP and 11C-MP4A demonstrated cortical cholinergic dysfunction in dementia associated with AD and LBD. Recent studies indicated a solid relationship between subcortical and cortical cholinergic dysfunction and noncognitive dysfunctions such as balance and gait in LBD. Taken together, PET of distinct components of cholinergic neurotransmission is of great interest for diagnosis, disease monitoring, and therapy monitoring and to gain insight into the pathophysiology of different neurodegenerative disorders.
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Affiliation(s)
- Solveig Tiepolt
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
| | - Philipp M Meyer
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
| | - Marianne Patt
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
| | | | - Swen Hesse
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
| | - Henryk Barthel
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
| | - Osama Sabri
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
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Sultzer DL, Lim AC, Gordon HL, Yarns BC, Melrose RJ. Cholinergic receptor binding in unimpaired older adults, mild cognitive impairment, and Alzheimer's disease dementia. Alzheimers Res Ther 2022; 14:25. [PMID: 35130968 PMCID: PMC8819935 DOI: 10.1186/s13195-021-00954-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 12/21/2021] [Indexed: 01/07/2023]
Abstract
BACKGROUND Cholinergic neurotransmitter system dysfunction contributes to cognitive impairment in Alzheimer's disease and other syndromes. However, the specific cholinergic mechanisms and brain structures involved, time course of alterations, and relationships with specific cognitive deficits are not well understood. METHODS This study included 102 older adults: 42 cognitively unimpaired (CU), 28 with mild cognitive impairment (MCI), and 32 with Alzheimer's disease (AD) dementia. Each participant underwent a neuropsychological assessment. Regional brain α4β2 nicotinic cholinergic receptor binding (VT/fp) was measured using 2-[18F]fluoro-3-(2(S)azetidinylmethoxy)pyridine (2FA) and PET imaging. Voxel-wise analyses of group differences were performed. Relationships between receptor binding and cognition, age, and cholinesterase inhibitor medication use were assessed using binding values in six prespecified regions of interest. RESULTS SPM analysis showed the group VT/fp binding differences in the bilateral entorhinal cortex, hippocampus, insula, anterior cingulate, thalamus, and basal ganglia (p < .05, FWE-corrected). Pairwise comparisons revealed lower binding in the AD group compared to the CU group in similar regions. Binding in the entorhinal cortex was lower in the MCI group than in the CU group; binding in the hippocampus was lower in the AD group than in the MCI group. AD participants taking cholinesterase inhibitor medication had lower 2FA binding in the bilateral hippocampus and thalamus compared to those not taking medication. In the CU group, age was negatively associated with 2FA binding in each region of interest (rs = - .33 to - .59, p < .05 for each, uncorrected). Attention, immediate recall, and delayed recall scores were inversely associated with 2FA binding in most regions across the full sample. In the combined group of CU and MCI participants, attention was inversely associated with 2FA binding in most regions, beyond the effect of hippocampal volume. CONCLUSIONS Nicotinic cholinergic receptor binding in specific limbic and subcortical regions is lower in MCI and further reduced in AD dementia, compared to CU older adults, and is related to cognitive deficits. Cognitive decline with age may be a consequence of reduced cholinergic receptor density or binding affinity that may also promote vulnerability to other Alzheimer's processes. Contemporary modification of the "cholinergic deficit" of aging and AD may reveal opportunities to prevent or improve clinical symptoms.
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Affiliation(s)
- David L. Sultzer
- grid.417119.b0000 0001 0384 5381Psychiatry/Mental Health Service, VA Greater Los Angeles Healthcare System, Los Angeles, CA USA ,grid.266093.80000 0001 0668 7243Department of Psychiatry and Human Behavior, School of Medicine, and Institute for Memory Impairments and Neurological Disorders (UCI MIND), University of California, Irvine, Irvine, CA USA
| | - Aaron C. Lim
- grid.417119.b0000 0001 0384 5381Psychiatry/Mental Health Service, VA Greater Los Angeles Healthcare System, Los Angeles, CA USA ,grid.42505.360000 0001 2156 6853Department of Family Medicine, USC Keck School of Medicine, Alhambra, CA USA
| | - Hailey L. Gordon
- grid.417119.b0000 0001 0384 5381Psychiatry/Mental Health Service, VA Greater Los Angeles Healthcare System, Los Angeles, CA USA ,grid.147455.60000 0001 2097 0344Biomedical Engineering Department, Carnegie Mellon University, Pittsburgh, PA USA
| | - Brandon C. Yarns
- grid.417119.b0000 0001 0384 5381Psychiatry/Mental Health Service, VA Greater Los Angeles Healthcare System, Los Angeles, CA USA ,grid.19006.3e0000 0000 9632 6718Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA USA
| | - Rebecca J. Melrose
- grid.417119.b0000 0001 0384 5381Psychiatry/Mental Health Service, VA Greater Los Angeles Healthcare System, Los Angeles, CA USA ,grid.19006.3e0000 0000 9632 6718Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA USA
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10
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Apathy as a Treatment Target in Alzheimer's Disease: Implications for Clinical Trials. Am J Geriatr Psychiatry 2022; 30:119-147. [PMID: 34315645 DOI: 10.1016/j.jagp.2021.06.016] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 06/25/2021] [Accepted: 06/25/2021] [Indexed: 12/11/2022]
Abstract
Apathy is one of the most prevalent, stable and persistent neuropsychiatric symptom across the neurocognitive disorders spectrum. Recent advances in understanding of phenomenology, neurobiology and intervention trials highlight apathy as an important target for clinical intervention. We conducted a comprehensive review and critical evaluation of recent advances to determine the evidence-based suggestions for future trial designs. This review focused on 4 key areas: 1) pre-dementia states; 2) assessment; 3) mechanisms/biomarkers and 4) treatment/intervention efficacy. Considerable progress has been made in understanding apathy as a treatment target and appreciating pharmacological and non-pharmacological apathy treatment interventions. Areas requiring greater investigation include: diagnostic procedures, symptom measurement, understanding the biological mechanisms/biomarkers of apathy, and a well-formed approach to the development of treatment strategies. A better understanding of the subdomains and biological mechanisms of apathy will advance apathy as a treatment target for clinical trials.
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Gasiorowska A, Wydrych M, Drapich P, Zadrozny M, Steczkowska M, Niewiadomski W, Niewiadomska G. The Biology and Pathobiology of Glutamatergic, Cholinergic, and Dopaminergic Signaling in the Aging Brain. Front Aging Neurosci 2021; 13:654931. [PMID: 34326765 PMCID: PMC8315271 DOI: 10.3389/fnagi.2021.654931] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 06/14/2021] [Indexed: 12/12/2022] Open
Abstract
The elderly population is growing worldwide, with important health and socioeconomic implications. Clinical and experimental studies on aging have uncovered numerous changes in the brain, such as decreased neurogenesis, increased synaptic defects, greater metabolic stress, and enhanced inflammation. These changes are associated with cognitive decline and neurobehavioral deficits. Although aging is not a disease, it is a significant risk factor for functional worsening, affective impairment, disease exaggeration, dementia, and general disease susceptibility. Conversely, life events related to mental stress and trauma can also lead to accelerated age-associated disorders and dementia. Here, we review human studies and studies on mice and rats, such as those modeling human neurodegenerative diseases, that have helped elucidate (1) the dynamics and mechanisms underlying the biological and pathological aging of the main projecting systems in the brain (glutamatergic, cholinergic, and dopaminergic) and (2) the effect of defective glutamatergic, cholinergic, and dopaminergic projection on disabilities associated with aging and neurodegenerative disorders, such as Alzheimer's and Parkinson's diseases. Detailed knowledge of the mechanisms of age-related diseases can be an important element in the development of effective ways of treatment. In this context, we briefly analyze which adverse changes associated with neurodegenerative diseases in the cholinergic, glutaminergic and dopaminergic systems could be targeted by therapeutic strategies developed as a result of our better understanding of these damaging mechanisms.
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Affiliation(s)
- Anna Gasiorowska
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Malgorzata Wydrych
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Patrycja Drapich
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Maciej Zadrozny
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Marta Steczkowska
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Wiktor Niewiadomski
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Grazyna Niewiadomska
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
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Nop O, Senft Miller A, Culver H, Makarewicz J, Dumas JA. Nicotine and Cognition in Cognitively Normal Older Adults. Front Aging Neurosci 2021; 13:640674. [PMID: 34025390 PMCID: PMC8131527 DOI: 10.3389/fnagi.2021.640674] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 04/12/2021] [Indexed: 11/13/2022] Open
Abstract
The cholinergic system has been shown to be the primary neurotransmitter system which is responsible for the cognitive symptoms associated with dementia; its role in healthy non-demented older adults remains a gap in the literature. Understanding the effects of age-related functional changes on the nicotinic system will address this knowledge gap. As the older adult population grows and hence the importance of understanding cognitive changes that impact functional abilities and everyday life. In this article we examine the benefits of using nicotine as a method for improving cognition in non-demented healthy older adults which may have the potential for slowing neurodegeneration in aging. Furthermore, we discuss how nicotine can play a crucial role in maintaining cognitive abilities throughout normal cognitive aging.
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Affiliation(s)
- Olivia Nop
- Department of Psychiatry, University of Vermont, Burlington, VT, United States
| | - Anna Senft Miller
- Department of Psychiatry, University of Vermont, Burlington, VT, United States
| | - Hannah Culver
- Department of Psychiatry, University of Vermont, Burlington, VT, United States
| | - Jenna Makarewicz
- Department of Psychiatry, University of Vermont, Burlington, VT, United States
| | - Julie A Dumas
- Department of Psychiatry, University of Vermont, Burlington, VT, United States
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Chaney AM, Lopez-Picon FR, Serrière S, Wang R, Bochicchio D, Webb SD, Vandesquille M, Harte MK, Georgiadou C, Lawrence C, Busson J, Vercouillie J, Tauber C, Buron F, Routier S, Reekie T, Snellman A, Kassiou M, Rokka J, Davies KE, Rinne JO, Salih DA, Edwards FA, Orton LD, Williams SR, Chalon S, Boutin H. Prodromal neuroinflammatory, cholinergic and metabolite dysfunction detected by PET and MRS in the TgF344-AD transgenic rat model of AD: a collaborative multi-modal study. Am J Cancer Res 2021; 11:6644-6667. [PMID: 34093845 PMCID: PMC8171096 DOI: 10.7150/thno.56059] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 02/15/2021] [Indexed: 12/25/2022] Open
Abstract
Mouse models of Alzheimer's disease (AD) are valuable but do not fully recapitulate human AD pathology, such as spontaneous Tau fibril accumulation and neuronal loss, necessitating the development of new AD models. The transgenic (TG) TgF344-AD rat has been reported to develop age-dependent AD features including neuronal loss and neurofibrillary tangles, despite only expressing APP and PSEN1 mutations, suggesting an improved modelling of AD hallmarks. Alterations in neuronal networks as well as learning performance and cognition tasks have been reported in this model, but none have combined a longitudinal, multimodal approach across multiple centres, which mimics the approaches commonly taken in clinical studies. We therefore aimed to further characterise the progression of AD-like pathology and cognition in the TgF344-AD rat from young-adults (6 months (m)) to mid- (12 m) and advanced-stage (18 m, 25 m) of the disease. Methods: TgF344-AD rats and wild-type (WT) littermates were imaged at 6 m, 12 m and 18 m with [18F]DPA-714 (TSPO, neuroinflammation), [18F]Florbetaben (Aβ) and [18F]ASEM (α7-nicotinic acetylcholine receptor) and with magnetic resonance spectroscopy (MRS) and with (S)-[18F]THK5117 (Tau) at 15 and 25 m. Behaviour tests were also performed at 6 m, 12 m and 18 m. Immunohistochemistry (CD11b, GFAP, Aβ, NeuN, NeuroChrom) and Tau (S)-[18F]THK5117 autoradiography, immunohistochemistry and Western blot were also performed. Results: [18F]DPA-714 positron emission tomography (PET) showed an increase in neuroinflammation in TG vs wildtype animals from 12 m in the hippocampus (+11%), and at the advanced-stage AD in the hippocampus (+12%), the thalamus (+11%) and frontal cortex (+14%). This finding coincided with strong increases in brain microgliosis (CD11b) and astrogliosis (GFAP) at these time-points as assessed by immunohistochemistry. In vivo [18F]ASEM PET revealed an age-dependent increase uptake in the striatum and pallidum/nucleus basalis of Meynert in WT only, similar to that observed with this tracer in humans, resulting in TG being significantly lower than WT by 18 m. In vivo [18F]Florbetaben PET scanning detected Aβ accumulation at 18 m, and (S)-[18F]THK5117 PET revealed subsequent Tau accumulation at 25m in hippocampal and cortical regions. Aβ plaques were low but detectable by immunohistochemistry from 6 m, increasing further at 12 and 18 m with Tau-positive neurons adjacent to Aβ plaques at 18 m. NeuroChrom (a pan neuronal marker) immunohistochemistry revealed a loss of neuronal staining at the Aβ plaques locations, while NeuN labelling revealed an age-dependent decrease in hippocampal neuron number in both genotypes. Behavioural assessment using the novel object recognition task revealed that both WT & TgF344-AD animals discriminated the novel from familiar object at 3 m and 6 m of age. However, low levels of exploration observed in both genotypes at later time-points resulted in neither genotype successfully completing the task. Deficits in social interaction were only observed at 3 m in the TgF344-AD animals. By in vivo MRS, we showed a decrease in neuronal marker N-acetyl-aspartate in the hippocampus at 18 m (-18% vs age-matched WT, and -31% vs 6 m TG) and increased Taurine in the cortex of TG (+35% vs age-matched WT, and +55% vs 6 m TG). Conclusions: This multi-centre multi-modal study demonstrates, for the first time, alterations in brain metabolites, cholinergic receptors and neuroinflammation in vivo in this model, validated by robust ex vivo approaches. Our data confirm that, unlike mouse models, the TgF344-AD express Tau pathology that can be detected via PET, albeit later than by ex vivo techniques, and is a useful model to assess and longitudinally monitor early neurotransmission dysfunction and neuroinflammation in AD.
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14
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Tiepolt S, Becker GA, Wilke S, Cecchin D, Rullmann M, Meyer PM, Barthel H, Hesse S, Patt M, Luthardt J, Wagenknecht G, Sattler B, Deuther-Conrad W, Ludwig FA, Fischer S, Gertz HJ, Smits R, Hoepping A, Steinbach J, Brust P, Sabri O. (+)-[ 18F]Flubatine as a novel α4β2 nicotinic acetylcholine receptor PET ligand-results of the first-in-human brain imaging application in patients with β-amyloid PET-confirmed Alzheimer's disease and healthy controls. Eur J Nucl Med Mol Imaging 2021; 48:731-746. [PMID: 32935187 PMCID: PMC8036219 DOI: 10.1007/s00259-020-05029-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 09/07/2020] [Indexed: 11/25/2022]
Abstract
PURPOSES We present the first in-human brain PET imaging data of the new α4β2 nicotinic acetylcholine receptor (nAChR)-targeting radioligand (+)-[18F]Flubatine. Aims were to develop a kinetic modeling-based approach to quantify (+)-[18F]Flubatine and compare the data of healthy controls (HCs) and patients with Alzheimer's disease (AD); to investigate the partial volume effect (PVE) on regional (+)-[18F]Flubatine binding; and whether (+)-[18F]Flubatine binding and cognitive test data respective β-amyloid radiotracer accumulation were correlated. METHODS We examined 11 HCs and 9 mild AD patients. All subjects underwent neuropsychological testing and [11C]PiB PET/MRI examination. (+)-[18F]Flubatine PET data were evaluated using full kinetic modeling and regional as well as voxel-based analyses. RESULTS With 270-min p.i., the unchanged parent compound amounted to 97 ± 2%. Adequate fits of the time-activity curves were obtained with the 1 tissue compartment model (1TCM). (+)-[18F]Flubatine distribution volume (binding) was significantly reduced in bilateral mesial temporal cortex in AD patients compared with HCs (right 10.6 ± 1.1 vs 11.6 ± 1.4, p = 0.049; left 11.0 ± 1.1 vs 12.2 ± 1.8, p = 0.046; one-sided t tests each). PVE correction increased not only (+)-[18F]Flubatine binding of approximately 15% but also standard deviation of 0.4-70%. Cognitive test data and (+)-[18F]Flubatine binding were significantly correlated in the left anterior cingulate, right posterior cingulate, and right parietal cortex (r > 0.5, p < 0.05 each). In AD patients, (+)-[18F]Flubatine binding and [11C]PiB standardized uptake value ratios were negatively correlated in several regions; whereas in HCs, a positive correlation between cortical (+)-[18F]Flubatine binding and [11C]PiB accumulation in the white matter was found. No adverse event related to (+)-[18F]Flubatine occurred. CONCLUSION (+)-[18F]Flubatine is a safe and stable PET ligand. Full kinetic modeling can be realized by 1TCM without metabolite correction. (+)-[18F]Flubatine binding affinity was high enough to detect group differences. Of interest, correlation between white matter β-amyloid PET uptake and (+)-[18F]Flubatine binding indicated an association between white matter integrity and availability of α4β2 nAChRs. Overall, (+)-[18F]Flubatine showed favorable characteristics and has therefore the potential to serve as α4β2 nAChR-targeting PET ligand in further clinical trials.
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Affiliation(s)
- Solveig Tiepolt
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Georg-Alexander Becker
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Stephan Wilke
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Diego Cecchin
- Department of Medicine, University-Hospital of Padova, Via Giustiniani 2, 35128 Padova, Italy
| | - Michael Rullmann
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Philipp M. Meyer
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Henryk Barthel
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Swen Hesse
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Marianne Patt
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Julia Luthardt
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Gudrun Wagenknecht
- Electronic Systems (ZEA-2), Central Institute for Engineering, Electronics and Analytics, Research Centre Juelich, Wilhelm-Johnen-Straße, 52428 Juelich, Germany
| | - Bernhard Sattler
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Winnie Deuther-Conrad
- Helmholtz-Zentrum Dresden-Rossendorf, Research Site Leipzig, Permoserstraße 15, 04318 Leipzig, Germany
| | | | - Steffen Fischer
- Helmholtz-Zentrum Dresden-Rossendorf, Research Site Leipzig, Permoserstraße 15, 04318 Leipzig, Germany
| | - Hermann-Josef Gertz
- Department of Psychiatry, University of Leipzig, Semmelweisstraße 10, 04103 Leipzig, Germany
| | - René Smits
- ABX advanced biochemical compounds GmbH, Heinrich-Gläser-Straße 10, 01454 Radeberg, Germany
| | - Alexander Hoepping
- ABX advanced biochemical compounds GmbH, Heinrich-Gläser-Straße 10, 01454 Radeberg, Germany
| | - Jörg Steinbach
- Helmholtz-Zentrum Dresden-Rossendorf, Bautzener Landstr. 400, 01328 Dresden, Germany
| | - Peter Brust
- Helmholtz-Zentrum Dresden-Rossendorf, Research Site Leipzig, Permoserstraße 15, 04318 Leipzig, Germany
| | - Osama Sabri
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
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Abstract
This article presents an overview of imaging agents for PET that have been applied for research and diagnostic purposes in patients affected by dementia. Classified by the target which the agents visualize, seven groups of tracers can be distinguished, namely radiopharmaceuticals for: (1) Misfolded proteins (ß-amyloid, tau, α-synuclein), (2) Neuroinflammation (overexpression of translocator protein), (3) Elements of the cholinergic system, (4) Elements of monoamine neurotransmitter systems, (5) Synaptic density, (6) Cerebral energy metabolism (glucose transport/ hexokinase), and (7) Various other proteins. This last category contains proteins involved in mechanisms underlying neuroinflammation or cognitive impairment, which may also be potential therapeutic targets. Many receptors belong to this category: AMPA, cannabinoid, colony stimulating factor 1, metabotropic glutamate receptor 1 and 5 (mGluR1, mGluR5), opioid (kappa, mu), purinergic (P2X7, P2Y12), sigma-1, sigma-2, receptor for advanced glycation endproducts, and triggering receptor expressed on myeloid cells-1, besides several enzymes: cyclooxygenase-1 and 2 (COX-1, COX-2), phosphodiesterase-5 and 10 (PDE5, PDE10), and tropomyosin receptor kinase. Significant advances in neuroimaging have been made in the last 15 years. The use of 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) for quantification of regional cerebral glucose metabolism is well-established. Three tracers for ß-amyloid plaques have been approved by the Food and Drug Administration and European Medicines Agency. Several tracers for tau neurofibrillary tangles are already applied in clinical research. Since many novel agents are in the preclinical or experimental stage of development, further advances in nuclear medicine imaging can be expected in the near future. PET studies with established tracers and tracers for novel targets may result in early diagnosis and better classification of neurodegenerative disorders and in accurate monitoring of therapy trials which involve these targets. PET data have prognostic value and may be used to assess the response of the human brain to interventions, or to select the appropriate treatment strategy for an individual patient.
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Affiliation(s)
- Aren van Waarde
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen, the Netherlands.
| | - Sofia Marcolini
- University of Groningen, University Medical Center Groningen, Department of Neurology, Groningen, the Netherlands
| | - Peter Paul de Deyn
- University of Groningen, University Medical Center Groningen, Department of Neurology, Groningen, the Netherlands; University of Antwerp, Born-Bunge Institute, Neurochemistry and Behavior, Campus Drie Eiken, Wilrijk, Belgium
| | - Rudi A J O Dierckx
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen, the Netherlands; Ghent University, Ghent, Belgium
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Bateman DR, Gill S, Hu S, Foster ED, Ruthirakuhan MT, Sellek AF, Mortby ME, Matušková V, Ng KP, Tarawneh RM, Freund-Levi Y, Kumar S, Gauthier S, Rosenberg PB, Ferreira de Oliveira F, Devanand DP, Ballard C, Ismail Z. Agitation and impulsivity in mid and late life as possible risk markers for incident dementia. ALZHEIMER'S & DEMENTIA (NEW YORK, N. Y.) 2020; 6:e12016. [PMID: 32995467 PMCID: PMC7507499 DOI: 10.1002/trc2.12016] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Accepted: 02/17/2020] [Indexed: 12/14/2022]
Abstract
To identify knowledge gaps regarding new-onset agitation and impulsivity prior to onset of cognitive impairment or dementia the International Society to Advance Alzheimer's Research and Treatment Neuropsychiatric Syndromes (NPS) Professional Interest Area conducted a scoping review. Extending a series of reviews exploring the pre-dementia risk syndrome Mild Behavioral Impairment (MBI), we focused on late-onset agitation and impulsivity (the MBI impulse dyscontrol domain) and risk of incident cognitive decline and dementia. This scoping review of agitation and impulsivity pre-dementia syndromes summarizes the current biomedical literature in terms of epidemiology, diagnosis and measurement, neurobiology, neuroimaging, biomarkers, course and prognosis, treatment, and ongoing clinical trials. Validations for pre-dementia scales such as the MBI Checklist, and incorporation into longitudinal and intervention trials, are needed to better understand impulse dyscontrol as a risk factor for mild cognitive impairment and dementia.
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Affiliation(s)
- Daniel R Bateman
- Department of Psychiatry Indiana University School of Medicine Indianapolis Indiana
- Indiana University Center for Aging Research Regenstrief Institute Indianapolis Indiana
| | - Sascha Gill
- Department of Clinical Neurosciences; and the Ron and Rene Ward Centre for Healthy Brain Aging Research; Hotchkiss Brain Institute University of Calgary Calgary Alberta Canada
| | - Sophie Hu
- Community Health Sciences, and O'Brien Institute for Public Health University of Calgary Calgary Alberta Canada
| | - Erin D Foster
- Ruth Lilly Medical Library Indiana University School of Medicine Indianapolis Indiana
- University of California Berkeley Berkeley CA
| | - Myuri T Ruthirakuhan
- Hurvitz Brain Sciences Research Program Sunnybrook Research Institute Toronto Ontario Canada
- Department of Pharmacology and Toxicology University of Toronto Ontario Canada
| | | | - Moyra E Mortby
- School of Psychology University of New South Wales Sydney New South Wales Australia
- Neuroscience Research Australia University of New South Wales Sydney New South Wales Australia
| | - Veronika Matušková
- International Clinical Research Center St. Anne's University Hospital Brno Brno Czech Republic
- Memory Disorders Clinic, Department of Neurology, 2nd Faculty of Medicine Charles University in Prague and Motol University Hospital Prague Czech Republic
| | - Kok Pin Ng
- Department of Neurology National Neuroscience Institute Singapore Singapore
| | - Rawan M Tarawneh
- Department of Neurology, College of Medicine The Ohio State University Columbus Ohio USA
| | - Yvonne Freund-Levi
- Center for Alzheimer Research, Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society Karolinska Institute Stockholm Sweden
- School of Medical Sciences Örebro University Örebro Sweden
| | - Sanjeev Kumar
- Centre for Addiction and Mental Health Toronto Ontario Canada
- Department of Psychiatry University of Toronto Ontario Canada
| | - Serge Gauthier
- McGill Center for Studies in Aging McGill University Montreal Quebec Canada
| | - Paul B Rosenberg
- Division of Geriatric Psychiatry and Neuropsychiatry, Department of Psychiatry and Behavioral, Sciences Johns Hopkins University School of Medicine Baltimore Maryland
| | - Fabricio Ferreira de Oliveira
- Department of Neurology and Neurosurgery, Escola Paulista de Medicina Federal University of São Paulo (UNIFESP), São Paulo São Paulo Brazil
| | - D P Devanand
- New York State Psychiatric Institute and Department of Psychiatry and Department of Psychiatry, College of Physicians and Surgeons Columbia University New York New York
| | - Clive Ballard
- College of Medicine and Health The University of Exeter Exeter UK
| | - Zahinoor Ismail
- Department of Clinical Neurosciences; and the Ron and Rene Ward Centre for Healthy Brain Aging Research; Hotchkiss Brain Institute University of Calgary Calgary Alberta Canada
- Community Health Sciences, and O'Brien Institute for Public Health University of Calgary Calgary Alberta Canada
- Department of Psychiatry, and the Mathison Centre for Mental Health Research & Education Cumming School of Medicine, University of Calgary Calgary Alberta Canada
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Tiepolt S, Patt M, Aghakhanyan G, Meyer PM, Hesse S, Barthel H, Sabri O. Current radiotracers to image neurodegenerative diseases. EJNMMI Radiopharm Chem 2019; 4:17. [PMID: 31659510 PMCID: PMC6660543 DOI: 10.1186/s41181-019-0070-7] [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: 03/27/2019] [Accepted: 07/16/2019] [Indexed: 12/11/2022] Open
Abstract
The term of neurodegenerative diseases covers a heterogeneous group of disorders that are distinguished by progressive degeneration of the structure and function of the nervous system such as dementias, movement disorders, motor neuron disorders, as well as some prion disorders. In recent years, a paradigm shift started for the diagnosis of neurodegenerative diseases, for which successively clinical testing is supplemented by biomarker information. In research scenarios, it was even proposed recently to substitute the current syndromic by a biological definition of Alzheimer's diseases. PET examinations with various radiotracers play an important role in providing non-invasive biomarkers and co-morbidity information in neurodegeneration. Information on co-morbidity, e.g. Aβ plaques and Lewy-bodies or Aβ plaques in patients with aphasia or the absence of Aβ plaques in clinical AD patients are of interest to expand our knowledge about the pathogenesis of different phenotypically defined neurodegenerative diseases. Moreover, this information is also important in therapeutic trials targeting histopathological abnormalities.The aim of this review is to present an overview of the currently available radiotracers for imaging neurodegenerative diseases in research and in routine clinical settings. In this context, we also provide a short summary of the most frequent neurodegenerative diseases from a nuclear medicine point of view, their clinical and pathophysiological as well as nuclear imaging characteristics, and the resulting need for new radiotracers.
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Affiliation(s)
- Solveig Tiepolt
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Marianne Patt
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Gayane Aghakhanyan
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Philipp M. Meyer
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Swen Hesse
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Henryk Barthel
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
| | - Osama Sabri
- Department of Nuclear Medicine, University of Leipzig, Liebigstraße 18, 04103 Leipzig, Germany
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18
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Knopman DS, Haeberlein SB, Carrillo MC, Hendrix JA, Kerchner G, Margolin R, Maruff P, Miller DS, Tong G, Tome MB, Murray ME, Nelson PT, Sano M, Mattsson N, Sultzer DL, Montine TJ, Jack CR, Kolb H, Petersen RC, Vemuri P, Canniere MZ, Schneider JA, Resnick SM, Romano G, van Harten AC, Wolk DA, Bain LJ, Siemers E. The National Institute on Aging and the Alzheimer's Association Research Framework for Alzheimer's disease: Perspectives from the Research Roundtable. Alzheimers Dement 2019; 14:563-575. [PMID: 29653607 DOI: 10.1016/j.jalz.2018.03.002] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 03/07/2018] [Accepted: 03/08/2018] [Indexed: 12/14/2022]
Abstract
The Alzheimer's Association's Research Roundtable met in November 2017 to explore the new National Institute on Aging and the Alzheimer's Association Research Framework for Alzheimer's disease. The meeting allowed experts in the field from academia, industry, and government to provide perspectives on the new National Institute on Aging and the Alzheimer's Association Research Framework. This review will summarize the "A, T, N System" (Amyloid, Tau, and Neurodegeneration) using biomarkers and how this may be applied to clinical research and drug development. In addition, challenges and barriers to the potential adoption of this new framework will be discussed. Finally, future directions for research will be proposed.
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Affiliation(s)
| | | | | | | | | | | | - Paul Maruff
- Cogstate Ltd, Melbourne, Victoria, Australia
| | | | | | | | | | | | - Mary Sano
- Mount Sinai School of Medicine, New York, NY, USA
| | - Niklas Mattsson
- Clinical Memory Research Unit, Lund University, Lund, Sweden
| | - David L Sultzer
- David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | | | | | - Hartmuth Kolb
- Janssen Research and Development, San Diego, CA, USA
| | | | | | | | | | | | | | | | - David A Wolk
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
| | - Lisa J Bain
- Independent Science Writer, Elverson, PA, USA
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Newhouse PA. Therapeutic Applications of Nicotinic Stimulation: Successes, Failures, and Future Prospects. Nicotine Tob Res 2019; 21:345-348. [PMID: 30203054 DOI: 10.1093/ntr/nty189] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Paul A Newhouse
- Center for Cognitive Medicine, Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN.,US Department of Veterans Affairs, Tennessee Valley Health Systems, Geriatric Research Education and Clinical Center, Nashville, TN
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Utkin YN. Aging Affects Nicotinic Acetylcholine Receptors in Brain. Cent Nerv Syst Agents Med Chem 2019; 19:119-124. [PMID: 30894113 DOI: 10.2174/1871524919666190320102834] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 02/28/2019] [Accepted: 03/08/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Aging is a common and inevitable stage in the life cycle of higher organisms. Different organs, including the central nervous system, are affected by aging in different ways. Many processes are involved in aging, and neurodegeneration is one of the aging processes in which the central nervous system is engaged. Brain degeneration during normal aging underlies cognitive disorders experienced by older people. Not all molecular mechanisms associated with age-related neurodegeneration are fully understood; however, there is a whole range of data on the participation of nicotinic acetylcholine receptors in the processes of aging and neurodegeneration. Two main subtypes of nicotinic acetylcholine receptor α7 and α4β2 present in the central nervous system are affected by these processes. The loss of these receptor subtypes during normal aging is one of the reasons for the cognitive impairments. The decrease in nicotinic acetylcholine receptors is also very important for the pathogenesis of age-related neurodegenerative diseases. Thus, the drugs enhancing receptor functions may be considered promising for the treatment of cognitive dysfunction in the aged people. CONCLUSION To achieve healthy longevity, the molecular processes that occur during aging should be established. In this regard, the participation and role of nicotinic acetylcholine receptors in the brain aging and degeneration are considered in this review.
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Affiliation(s)
- Yuri N Utkin
- Laboratory of Molecular Toxinology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow, Russian Federation
- National University of Science and Technology MISIS, 119049 Moscow, Russian Federation
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21
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Ruthirakuhan M, Lanctôt KL, Di Scipio M, Ahmed M, Herrmann N. Biomarkers of agitation and aggression in Alzheimer's disease: A systematic review. Alzheimers Dement 2018; 14:1344-1376. [DOI: 10.1016/j.jalz.2018.04.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Revised: 04/12/2018] [Accepted: 04/26/2018] [Indexed: 01/24/2023]
Affiliation(s)
- Myuri Ruthirakuhan
- Hurvitz Brain Sciences ProgramSunnybrook Research InstituteTorontoONCanada
- Department of Pharmacology and ToxicologyUniversity of TorontoTorontoONCanada
| | - Krista L. Lanctôt
- Hurvitz Brain Sciences ProgramSunnybrook Research InstituteTorontoONCanada
- Department of Pharmacology and ToxicologyUniversity of TorontoTorontoONCanada
- Geriatric PsychiatrySunnybrook Health Sciences CentreTorontoONCanada
- Department of PsychiatryUniversity of TorontoTorontoONCanada
| | - Matteo Di Scipio
- Hurvitz Brain Sciences ProgramSunnybrook Research InstituteTorontoONCanada
| | - Mehnaz Ahmed
- Hurvitz Brain Sciences ProgramSunnybrook Research InstituteTorontoONCanada
- Department of Pharmacology and ToxicologyUniversity of TorontoTorontoONCanada
| | - Nathan Herrmann
- Hurvitz Brain Sciences ProgramSunnybrook Research InstituteTorontoONCanada
- Geriatric PsychiatrySunnybrook Health Sciences CentreTorontoONCanada
- Department of PsychiatryUniversity of TorontoTorontoONCanada
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22
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Liu KY, Stringer AE, Reeves SJ, Howard RJ. The neurochemistry of agitation in Alzheimer's disease: a systematic review. Ageing Res Rev 2018. [PMID: 29524596 DOI: 10.1016/j.arr.2018.03.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECTIVE To provide an up-to-date systematic review of the characteristics, methodology and findings of studies that have investigated the neurochemistry of agitation in Alzheimer's disease (AD). METHODS Electronic databases were searched for published peer-reviewed articles which provided data on any neurotransmitter system in relation to agitation in AD. Screening of titles and abstracts and data extraction from full texts were conducted in duplicate. RESULTS Forty-five studies were included. Monoamines (serotonin, dopamine and noradrenaline) were most commonly investigated. A variety of methods were used to investigate the neurochemistry underlying agitation in AD and, although there were several conflicting findings, there was evidence of serotonergic deficit, relatively preserved dopaminergic function and compensatory overactivity of postsynaptic noradrenergic neurons in agitation in AD. CONCLUSIONS Disruption of the dynamic balance between multiple neurotransmitter systems could impair functional neural networks involved in affective regulation and executive function. Differences in study design and methodology may have contributed to conflicting findings. Future studies that overcome these limitations (e.g. using standardized criteria to define agitation) and employ neuroimaging methods such as MRI/PET to investigate specific neural networks are needed to clarify the role of neurotransmitter alterations in these patients.
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Affiliation(s)
- Kathy Y Liu
- Division of Psychiatry, University College London, UK.
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23
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Coughlin JM, Slania S, Du Y, Rosenthal HB, Lesniak WG, Minn I, Smith GS, Dannals RF, Kuwabara H, Wong DF, Wang Y, Horti AG, Pomper MG. 18F-XTRA PET for Enhanced Imaging of the Extrathalamic α4β2 Nicotinic Acetylcholine Receptor. J Nucl Med 2018; 59:1603-1608. [PMID: 29496987 DOI: 10.2967/jnumed.117.205492] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Accepted: 02/03/2018] [Indexed: 11/16/2022] Open
Abstract
Reduced density of the α4β2 nicotinic acetylcholine receptor (α4β2-nAChR) in the cortex and hippocampus of the human brain has been reported in aging and patients with neurodegenerative disease. This study assessed the pharmacokinetic behavior of 18F-(-)-JHU86428 (18F-XTRA), a new radiotracer for in vivo PET imaging of the α4β2-nAChR, particularly in extrathalamic regions of interest in which the α4β2-nAChR is less densely expressed than in thalamus. 18F-XTRA was also used to evaluate the α4β2-nAChR in the hippocampus in human aging. Methods: Seventeen healthy nonsmoker adults (11 men, 6 women; age, 30-82 y) underwent PET neuroimaging over 90 or 180 min in a high-resolution research tomograph after bolus injection of 18F-XTRA. Methods to quantify binding of 18F-XTRA to the α4β2-nAChR in the human brain were compared, and the relationship between age and binding in the hippocampus was tested. Results: 18F-XTRA rapidly entered the brain, and time-activity curves peaked within 10 min after injection for extrathalamic regions and at approximately 70 min in the thalamus. The 2-tissue-compartment model (2TCM) predicted the regional time-activity curves better than the 1-tissue-compartment model, and total distribution volume (VT) was well identified by the 2TCM in all ROIs. VT values estimated using Logan analysis with metabolite-corrected arterial input were highly correlated with those from the 2TCM in all regions, and values from 90-min scan duration were on average within 5% of those values from 180 min of data. Parametric images of VT were consistent with the known distribution of the α4β2-nAChR across the brain. Finally, an inverse correlation between VT in the hippocampus and age was observed. Conclusion: Our results extend support for use of 18F-XTRA with 90 min of emission scanning in quantitative human neuroimaging of the extrathalamic α4β2-nAChR, including in studies of aging.
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Affiliation(s)
- Jennifer M Coughlin
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland.,Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Stephanie Slania
- Department of Biomedical Engineering, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Yong Du
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Hailey B Rosenthal
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Wojciech G Lesniak
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Il Minn
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Gwenn S Smith
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland.,Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Robert F Dannals
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Hiroto Kuwabara
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Dean F Wong
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland.,Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland.,Department of Neuroscience, Johns Hopkins Medical Institutions, Baltimore, Maryland; and.,Department of Neurology, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Yuchuan Wang
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Andrew G Horti
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Martin G Pomper
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland .,Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland.,Department of Biomedical Engineering, Johns Hopkins Medical Institutions, Baltimore, Maryland
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24
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Mukherjee J, Lao PJ, Betthauser TJ, Samra GK, Pan ML, Patel IH, Liang C, Metherate R, Christian BT. Human brain imaging of nicotinic acetylcholine α4β2* receptors using [ 18 F]Nifene: Selectivity, functional activity, toxicity, aging effects, gender effects, and extrathalamic pathways. J Comp Neurol 2017; 526:80-95. [PMID: 28875553 DOI: 10.1002/cne.24320] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 08/22/2017] [Accepted: 08/23/2017] [Indexed: 02/06/2023]
Abstract
Nicotinic acetylcholinergic receptors (nAChR's) have been implicated in several brain disorders, including addiction, Parkinson's disease, Alzheimer's disease and schizophrenia. Here we report in vitro selectivity and functional properties, toxicity in rats, in vivo evaluation in humans, and comparison across species of [18 F]Nifene, a fast acting PET imaging agent for α4β2* nAChRs. Nifene had subnanomolar affinities for hα2β2 (0.34 nM), hα3β2 (0.80 nM) and hα4β2 (0.83 nM) nAChR but weaker (27-219 nM) for hβ4 nAChR subtypes and 169 nM for hα7 nAChR. In functional assays, Nifene (100 μM) exhibited 14% agonist and >50% antagonist characteristics. In 14-day acute toxicity in rats, the maximum tolerated dose (MTD) and the no observed adverse effect level (NOAEL) were estimated to exceed 40 μg/kg/day (278 μg/m2 /day). In human PET studies, [18 F]Nifene (185 MBq; <0.10 μg) was well tolerated with no adverse effects. Distribution volume ratios (DVR) of [18 F]Nifene in white matter thalamic radiations were ∼1.6 (anterior) and ∼1.5 (superior longitudinal fasciculus). Habenula known to contain α3β2 nAChR exhibited low levels of [18 F]Nifene binding while the red nucleus with α2β2 nAChR had DVR ∼1.6-1.7. Females had higher [18 F]Nifene binding in all brain regions, with thalamus showing >15% than males. No significant aging effect was observed in [18 F]Nifene binding over 5 decades. In all species (mice, rats, monkeys, and humans) thalamus showed highest [18 F]Nifene binding with reference region ratios >2 compared to extrathalamic regions. Our findings suggest that [18 F]Nifene PET may be used to study α4β2* nAChRs in various CNS disorders and for translational research.
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Affiliation(s)
- Jogeshwar Mukherjee
- Preclinical Imaging, Department of Radiological Sciences, University of California, Irvine, California
| | - Patrick J Lao
- Department of Medical Physics and Waisman Center, University of Wisconsin, Madison, Wisconsin
| | - Tobey J Betthauser
- Department of Medical Physics and Waisman Center, University of Wisconsin, Madison, Wisconsin
| | - Gurleen K Samra
- Preclinical Imaging, Department of Radiological Sciences, University of California, Irvine, California
| | - Min-Liang Pan
- Preclinical Imaging, Department of Radiological Sciences, University of California, Irvine, California
| | - Ishani H Patel
- Preclinical Imaging, Department of Radiological Sciences, University of California, Irvine, California
| | | | - Raju Metherate
- Department of Neurobiology and Behavior, University of California, Irvine, California
| | - Bradley T Christian
- Department of Medical Physics and Waisman Center, University of Wisconsin, Madison, Wisconsin
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25
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Smith GS. Molecular Imaging of the Nicotinic Cholinergic Receptor in Alzheimer Disease. Am J Geriatr Psychiatry 2017; 25:354-356. [PMID: 28209287 PMCID: PMC5646276 DOI: 10.1016/j.jagp.2017.01.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Accepted: 01/04/2017] [Indexed: 10/20/2022]
Affiliation(s)
- Gwenn S Smith
- Department of Psychiatry and Behavioral Sciences, Division of Geriatric Psychiatry and Neuropsychiatry, Johns Hopkins University School of Medicine, Johns Hopkins Bayview Medical Center, Baltimore, MD; Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Johns Hopkins Bayview Medical Center, Baltimore, MD.
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