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Chaves-Coira I, García-Magro N, Zegarra-Valdivia J, Torres-Alemán I, Núñez Á. Cognitive Deficits in Aging Related to Changes in Basal Forebrain Neuronal Activity. Cells 2023; 12:1477. [PMID: 37296598 PMCID: PMC10252596 DOI: 10.3390/cells12111477] [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: 04/12/2023] [Revised: 05/22/2023] [Accepted: 05/24/2023] [Indexed: 06/12/2023] Open
Abstract
Aging is a physiological process accompanied by a decline in cognitive performance. The cholinergic neurons of the basal forebrain provide projections to the cortex that are directly engaged in many cognitive processes in mammals. In addition, basal forebrain neurons contribute to the generation of different rhythms in the EEG along the sleep/wakefulness cycle. The aim of this review is to provide an overview of recent advances grouped around the changes in basal forebrain activity during healthy aging. Elucidating the underlying mechanisms of brain function and their decline is especially relevant in today's society as an increasingly aged population faces higher risks of developing neurodegenerative diseases such as Alzheimer's disease. The profound age-related cognitive deficits and neurodegenerative diseases associated with basal forebrain dysfunction highlight the importance of investigating the aging of this brain region.
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Affiliation(s)
- Irene Chaves-Coira
- Department of Anatomy, Histology and Neurosciences, Universidad Autónoma de Madrid, 28029 Madrid, Spain;
| | - Nuria García-Magro
- Facultad de Ciencias de la Salud, Universidad Francisco de Vitoria, Pozuelo de Alarcón, 28223 Madrid, Spain;
| | - Jonathan Zegarra-Valdivia
- Achucarro Basque Center for Neuroscience, 48940 Leioa, Spain; (J.Z.-V.); (I.T.-A.)
- Facultad de Ciencias de la Salud, Universidad Señor de Sipán, Chiclayo 02001, Peru
| | - Ignacio Torres-Alemán
- Achucarro Basque Center for Neuroscience, 48940 Leioa, Spain; (J.Z.-V.); (I.T.-A.)
- Ikerbasque Science Foundation, 48009 Bilbao, Spain
| | - Ángel Núñez
- Department of Anatomy, Histology and Neurosciences, Universidad Autónoma de Madrid, 28029 Madrid, Spain;
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Dean B, Bakker G, Ueda HR, Tobin AB, Brown A, Kanaan RAA. A growing understanding of the role of muscarinic receptors in the molecular pathology and treatment of schizophrenia. Front Cell Neurosci 2023; 17:1124333. [PMID: 36909280 PMCID: PMC9992992 DOI: 10.3389/fncel.2023.1124333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 02/06/2023] [Indexed: 02/24/2023] Open
Abstract
Pre-clinical models, postmortem and neuroimaging studies all support a role for muscarinic receptors in the molecular pathology of schizophrenia. From these data it was proposed that activation of the muscarinic M1 and/or M4 receptor would reduce the severity of the symptoms of schizophrenia. This hypothesis is now supported by results from two clinical trials which indicate that activating central muscarinic M1 and M4 receptors can reduce the severity of positive, negative and cognitive symptoms of the disorder. This review will provide an update on a growing body of evidence that argues the muscarinic M1 and M4 receptors have critical roles in CNS functions that are dysregulated by the pathophysiology of schizophrenia. This realization has been made possible, in part, by the growing ability to visualize and quantify muscarinic M1 and M4 receptors in the human CNS using molecular neuroimaging. We will discuss how these advances have provided evidence to support the notion that there is a sub-group of patients within the syndrome of schizophrenia that have a unique molecular pathology driven by a marked loss of muscarinic M1 receptors. This review is timely, as drugs targeting muscarinic receptors approach clinical use for the treatment of schizophrenia and here we outline the background biology that supported development of such drugs to treat the disorder.
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Affiliation(s)
- Brian Dean
- Synaptic Biology and Cognition Laboratory, The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
| | | | - Hiroki R Ueda
- Department of Systems Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Laboratory for Synthetic Biology, RIKEN Center for Biosystems Dynamics Research, Osaka, Japan
| | - Andrew B Tobin
- Advanced Research Centre (ARC), School of Molecular Bioscience, University of Glasgow, Glasgow, United Kingdom
| | | | - Richard A A Kanaan
- Department of Psychiatry, Austin Health, The University of Melbourne, Heidelberg, VIC, Australia
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3
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Mátyás A, Borbély E, Mihály A. Hippocampal Sclerosis in Pilocarpine Epilepsy: Survival of Peptide-Containing Neurons and Learning and Memory Disturbances in the Adult NMRI Strain Mouse. Int J Mol Sci 2021; 23:ijms23010204. [PMID: 35008630 PMCID: PMC8745054 DOI: 10.3390/ijms23010204] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 12/21/2021] [Accepted: 12/23/2021] [Indexed: 12/28/2022] Open
Abstract
The present experiments reveal the alterations of the hippocampal neuronal populations in chronic epilepsy. The mice were injected with a single dose of pilocarpine. They had status epilepticus and spontaneously recurrent motor seizures. Three months after pilocarpine treatment, the animals were investigated with the Barnes maze to determine their learning and memory capabilities. Their hippocampi were analyzed 2 weeks later (at 3.5 months) with standard immunohistochemical methods and cell counting. Every animal displayed hippocampal sclerosis. The neuronal loss was evaluated with neuronal-N immunostaining, and the activation of the microglia was measured with Iba1 immunohistochemistry. The neuropeptide Y, parvalbumin, and calretinin immunoreactive structures were qualitatively and quantitatively analyzed in the hippocampal formation. The results were compared statistically to the results of the control mice. We detected neuronal loss and strongly activated microglia populations. Neuropeptide Y was significantly upregulated in the sprouting axons. The number of parvalbumin- and calretinin-containing interneurons decreased significantly in the Ammon’s horn and dentate gyrus. The epileptic animals displayed significantly worse learning and memory functions. We concluded that degeneration of the principal neurons, a numerical decrease of PV-containing GABAergic neurons, and strong peptidergic axonal sprouting were responsible for the loss of the hippocampal learning and memory functions.
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Affiliation(s)
- Adrienne Mátyás
- Department of Anatomy, Albert Szent-Györgyi Faculty of Medicine, University of Szeged, Kossuth L. sgt. 38, H-6724 Szeged, Hungary;
| | - Emőke Borbély
- Department of Medical Chemistry, University of Szeged, Dóm tér. 8, H-6720 Szeged, Hungary;
- Professional Pedagogical Service of Csongrád-Csanád County, Űrhajós u. 4, H-6723 Szeged, Hungary
| | - András Mihály
- Department of Anatomy, Albert Szent-Györgyi Faculty of Medicine, University of Szeged, Kossuth L. sgt. 38, H-6724 Szeged, Hungary;
- Correspondence:
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Fernández de Sevilla D, Núñez A, Buño W. Muscarinic Receptors, from Synaptic Plasticity to its Role in Network Activity. Neuroscience 2020; 456:60-70. [PMID: 32278062 DOI: 10.1016/j.neuroscience.2020.04.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 03/27/2020] [Accepted: 04/01/2020] [Indexed: 12/13/2022]
Abstract
Acetylcholine acting via metabotropic receptors plays a key role in learning and memory by regulating synaptic plasticity and circuit activity. However, a recent overall view of the effects of muscarinic acetylcholine receptors (mAChRs) on excitatory and inhibitory long-term synaptic plasticity and on circuit activity is lacking. This review focusses on specific aspects of the regulation of synaptic plasticity and circuit activity by mAChRs in the hippocampus and cortex. Acetylcholine increases the excitability of pyramidal neurons, facilitating the generation of dendritic Ca2+-spikes, NMDA-spikes and action potential bursts which provide the main source of Ca2+ influx necessary to induce synaptic plasticity. The activation of mAChRs induced Ca2+ release from intracellular IP3-sensitive stores is a major player in the induction of a NMDA independent long-term potentiation (LTP) caused by an increased expression of AMPA receptors in hippocampal pyramidal neuron dendritic spines. In the neocortex, activation of mAChRs also induces a long-term enhancement of excitatory postsynaptic currents. In addition to effects on excitatory synapses, a single brief activation of mAChRs together with short repeated membrane depolarization can induce a long-term enhancement of GABA A type (GABAA) inhibition through an increased expression of GABAA receptors in hippocampal pyramidal neurons. By contrast, a long term depression of GABAA inhibition (iLTD) is induced by muscarinic receptor activation in the absence of postsynaptic depolarizations. This iLTD is caused by an endocannabinoid-mediated presynaptic inhibition that reduces the GABA release probability at the terminals of inhibitory interneurons. This bidirectional long-term plasticity of inhibition may dynamically regulate the excitatory/inhibitory balance depending on the quiescent or active state of the postsynaptic pyramidal neurons. Therefore, acetylcholine can induce varied effects on neuronal activity and circuit behavior that can enhance sensory detection and processing through the modification of circuit activity leading to learning, memory and behavior.
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Affiliation(s)
- D Fernández de Sevilla
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid 28029, Spain.
| | - A Núñez
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid 28029, Spain
| | - W Buño
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid 28029, Spain
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5
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Ryan AE, Mowry BJ, Kesby JP, Scott JG, Greer JM. Is there a role for antibodies targeting muscarinic acetylcholine receptors in the pathogenesis of schizophrenia? Aust N Z J Psychiatry 2019; 53:1059-1069. [PMID: 31347380 DOI: 10.1177/0004867419864438] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE Muscarinic receptor dysfunction has been suggested to play an important role in the pathophysiology of schizophrenia. Recently, it has also become clear that immune reactivity directed against neurotransmitter receptors may play a pathogenic role in some cases of schizophrenia. The aim of this review is to summarize the case for muscarinic receptor dysfunction in schizophrenia and the evidence supporting the hypothesis that this dysfunction is related to the development of muscarinic receptor-targeting antibodies. METHOD The article reviews studies of muscarinic receptors and the presence and potential role(s) of anti-muscarinic acetylcholine receptor antibodies in people with schizophrenia. RESULTS There is accumulating evidence that altered or deficient muscarinic signalling underlies some of the key clinical features of schizophrenia. Although the number of studies investigating anti-muscarinic acetylcholine receptor antibodies in schizophrenia is relatively small, they consistently demonstrate that such antibodies are present in a proportion of patients. This evidence suggests that these antibodies could have pathogenic effects or exist as a biomarker to an unknown pathophysiological process in schizophrenia. CONCLUSION The presence of elevated levels of anti-muscarinic acetylcholine receptor antibodies may identify a subgroup of people with schizophrenia, potentially informing aetiopathogenesis, clinical presentation and treatment. To date, all studies have examined antibodies in participants with chronic schizophrenia, who have likely received antipsychotic medication for many years. As these medications modulate immune functions and regulate receptor densities, it is recommended that future studies screen for the presence of anti-muscarinic antibodies in people experiencing their first episode of psychosis.
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Affiliation(s)
- Alexander E Ryan
- UQ Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia.,Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Wacol, QLD, Australia
| | - Bryan J Mowry
- Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Wacol, QLD, Australia.,Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - James P Kesby
- UQ Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia.,Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - James G Scott
- UQ Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia.,Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Wacol, QLD, Australia.,School of Public Health, The University of Queensland, Brisbane, QLD, Australia.,Metro North Mental Health, Royal Brisbane and Women's Hospital, Herston, QLD, Australia
| | - Judith M Greer
- UQ Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia
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Erskine D, Taylor JP, Bakker G, Brown AJH, Tasker T, Nathan PJ. Cholinergic muscarinic M 1 and M 4 receptors as therapeutic targets for cognitive, behavioural, and psychological symptoms in psychiatric and neurological disorders. Drug Discov Today 2019; 24:2307-2314. [PMID: 31499186 DOI: 10.1016/j.drudis.2019.08.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 08/08/2019] [Accepted: 08/28/2019] [Indexed: 12/13/2022]
Abstract
Cholinergic dysfunction is involved in a range of neurological and psychiatric disorders, including schizophrenia, dementia and Lewy body disease (LBD), leading to widespread use of cholinergic therapies. However, such drugs have focused on increasing the availability of acetylcholine (ACh) generally, with relatively little work done on the muscarinic system and specific muscarinic receptor subtypes. In this review, we provide an overview of the major cholinergic pathways and cholinergic muscarinic receptors in the human brain and evidence for their dysfunction in several neurological and psychiatric disorders. We discuss how the selectivity of cholinergic system dysfunction suggests that targeted cholinergic therapeutics to the muscarinic receptor subtypes will be vital in treating several disorders associated with cognitive dysfunction and behavioural and psychological symptoms.
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Affiliation(s)
- Daniel Erskine
- Institute of Neuroscience, Newcastle University, Newcastle, UK.
| | | | | | | | | | - Pradeep J Nathan
- Sosei Heptares, Cambridge, UK; Department of Psychiatry, University of Cambridge, Cambridge, UK; School of Psychological Sciences, Monash University, Melbourne, VIC, Australia.
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Hopper S, Pavey GM, Gogos A, Dean B. Widespread Changes in Positive Allosteric Modulation of the Muscarinic M1 Receptor in Some Participants With Schizophrenia. Int J Neuropsychopharmacol 2019; 22:640-650. [PMID: 31428788 PMCID: PMC6822142 DOI: 10.1093/ijnp/pyz045] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/22/2019] [Accepted: 08/15/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Preclinical and some human data suggest allosteric modulation of the muscarinic M1 receptor (CHRM1) is a promising approach for the treatment of schizophrenia. However, it is suggested there is a subgroup of participants with schizophrenia who have profound loss of cortical CHRM1 (MRDS). This raises the possibility that some participants with schizophrenia may not respond optimally to CHRM1 allosteric modulation. Here we describe a novel methodology to measure positive allosteric modulation of CHRM1 in human CNS and the measurement of that response in the cortex, hippocampus, and striatum from participants with MRDS, non-MRDS and controls. METHODS The cortex (Brodmann's area 6), hippocampus, and striatum from 40 participants with schizophrenia (20 MRDS and 20 non-MRDS) and 20 controls were used to measure benzyl quinolone carboxylic acid-mediated shift in acetylcholine displacement of [3H]N-methylscopolamine using a novel in situ radioligand binding with autoradiography methodology. RESULTS Compared with controls, participants with schizophrenia had lower levels of specific [3H]N-methylscopolamine binding in all CNS regions, whilst benzyl quinolone carboxylic acid-modulated binding was less in the striatum, Brodmann's area 6, dentate gyrus, and subiculum. When divided by subgroup, only in MRDS was there lower specific [3H]N-methylscopolamine binding and less benzyl quinolone carboxylic acid-modulated binding in all cortical and subcortical regions studied. CONCLUSIONS In a subgroup of participants with schizophrenia, there is a widespread decreased responsiveness to a positive allosteric modulator at the CHRM1. This finding may have ramifications it positive allosteric modulators of the CHRM1 are used in clinical trials to treat schizophrenia as some participants may not have an optimal response.
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Affiliation(s)
- Shaun Hopper
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia,Cooperative Research Centre for Mental Health, Parkville, Victoria, Australia
| | - Geoffrey Mark Pavey
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Andrea Gogos
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Brian Dean
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia,Cooperative Research Centre for Mental Health, Parkville, Victoria, Australia,The Centre for Mental Health, Swinburne University, Hawthorn, Victoria, Australia,Correspondence: Professor Brian Dean, Head, The Molecular Psychiatry Laboratories, The Florey Institute for Neuroscience and Mental Health, 30 Royal Parade, Parkville, VIC 3010, Australia ()
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8
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Maksymetz J, Joffe ME, Moran SP, Stansley BJ, Li B, Temple K, Engers DW, Lawrence JJ, Lindsley CW, Conn PJ. M 1 Muscarinic Receptors Modulate Fear-Related Inputs to the Prefrontal Cortex: Implications for Novel Treatments of Posttraumatic Stress Disorder. Biol Psychiatry 2019; 85:989-1000. [PMID: 31003787 PMCID: PMC6555658 DOI: 10.1016/j.biopsych.2019.02.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/15/2019] [Accepted: 02/18/2019] [Indexed: 12/20/2022]
Abstract
BACKGROUND The prefrontal cortex (PFC) integrates information from multiple inputs to exert top-down control allowing for appropriate responses in a given context. In psychiatric disorders such as posttraumatic stress disorder, PFC hyperactivity is associated with inappropriate fear in safe situations. We previously reported a form of muscarinic acetylcholine receptor (mAChR)-dependent long-term depression in the PFC that we hypothesize is involved in appropriate fear responding and could serve to reduce cortical hyperactivity following stress. However, it is unknown whether this long-term depression occurs at fear-related inputs. METHODS Using optogenetics with extracellular and whole-cell electrophysiology, we assessed the effect of mAChR activation on the synaptic strength of specific PFC inputs. We used selective pharmacological tools to assess the involvement of M1 mAChRs in conditioned fear extinction in control mice and in the stress-enhanced fear-learning model. RESULTS M1 mAChR activation induced long-term depression at inputs from the ventral hippocampus and basolateral amygdala but not from the mediodorsal nucleus of the thalamus. We found that systemic M1 mAChR antagonism impaired contextual fear extinction. Treatment with an M1 positive allosteric modulator enhanced contextual fear extinction consolidation in stress-enhanced fear learning-conditioned mice. CONCLUSIONS M1 mAChRs dynamically modulate synaptic transmission at two PFC inputs whose activity is necessary for fear extinction, and M1 mAChR function is required for proper contextual fear extinction. Furthermore, an M1 positive allosteric modulator enhanced the consolidation of fear extinction in the stress-enhanced fear-learning model, suggesting that M1 positive allosteric modulators may provide a novel treatment strategy to facilitate exposure therapy in the clinic for the treatment of posttraumatic stress disorder.
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Affiliation(s)
- James Maksymetz
- Department of Pharmacology,Vanderbilt Center for Neuroscience Drug Discovery
| | - Max E. Joffe
- Department of Pharmacology,Vanderbilt Center for Neuroscience Drug Discovery
| | - Sean P. Moran
- Department of Pharmacology,Vanderbilt Center for Neuroscience Drug Discovery,Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN
| | - Branden J. Stansley
- Department of Pharmacology,Vanderbilt Center for Neuroscience Drug Discovery
| | | | - Kayla Temple
- Vanderbilt Center for Neuroscience Drug Discovery
| | - Darren W. Engers
- Department of Pharmacology,Vanderbilt Center for Neuroscience Drug Discovery
| | - J. Josh Lawrence
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX
| | - Craig W. Lindsley
- Department of Pharmacology,Vanderbilt Center for Neuroscience Drug Discovery,Department of Chemistry, Vanderbilt University, Nashville, TN
| | - P. Jeffrey Conn
- Department of Pharmacology,Vanderbilt Center for Neuroscience Drug Discovery,Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN,Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN,Corresponding Author: P. Jeffrey Conn, Ph.D., Lee E. Limbird Professor of Pharmacology, Director, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, 1205 Light Hall, Nashville, TN 37232-0697, Tel: 615-936-2189, Fax: 615-343-3088,
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9
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Broad LM, Sanger HE, Mogg AJ, Colvin EM, Zwart R, Evans DA, Pasqui F, Sher E, Wishart GN, Barth VN, Felder CC, Goldsmith PJ. Identification and pharmacological profile of SPP1, a potent, functionally selective and brain penetrant agonist at muscarinic M 1 receptors. Br J Pharmacol 2019; 176:110-126. [PMID: 30276808 PMCID: PMC6284335 DOI: 10.1111/bph.14510] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 09/14/2018] [Accepted: 09/18/2018] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE We aimed to identify and develop novel, selective muscarinic M1 receptor agonists as potential therapeutic agents for the symptomatic treatment of Alzheimer's disease. EXPERIMENTAL APPROACH We developed and utilized a novel M1 receptor occupancy assay to drive a structure activity relationship in a relevant brain region while simultaneously tracking drug levels in plasma and brain to optimize for central penetration. Functional activity was tracked in relevant native in vitro assays allowing translational (rat-human) benchmarking of structure-activity relationship molecules to clinical comparators. KEY RESULTS Using this paradigm, we identified a series of M1 receptor selective molecules displaying desirable in vitro and in vivo properties and optimized key features, such as central penetration while maintaining selectivity and a partial agonist profile. From these compounds, we selected spiropiperidine 1 (SPP1). In vitro, SPP1 is a potent, partial agonist of cortical and hippocampal M1 receptors with activity conserved across species. SPP1 displays high functional selectivity for M1 receptors over native M2 and M3 receptor anti-targets and over a panel of other targets. Assessment of central target engagement by receptor occupancy reveals SPP1 significantly and dose-dependently occupies rodent cortical M1 receptors. CONCLUSIONS AND IMPLICATIONS We report the discovery of SPP1, a novel, functionally selective, brain penetrant partial orthosteric agonist at M1 receptors, identified by a novel receptor occupancy assay. SPP1 is amenable to in vitro and in vivo study and provides a valuable research tool to further probe the role of M1 receptors in physiology and disease.
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Affiliation(s)
- Lisa M Broad
- Eli Lilly and Company, Lilly Research CentreWindleshamSurreyUK
| | - Helen E Sanger
- Eli Lilly and Company, Lilly Research CentreWindleshamSurreyUK
| | - Adrian J Mogg
- Eli Lilly and Company, Lilly Research CentreWindleshamSurreyUK
| | - Ellen M Colvin
- Eli Lilly and Company, Lilly Research CentreWindleshamSurreyUK
| | - Ruud Zwart
- Eli Lilly and Company, Lilly Research CentreWindleshamSurreyUK
| | - David A Evans
- Eli Lilly and Company, Lilly Research CentreWindleshamSurreyUK
| | | | - Emanuele Sher
- Eli Lilly and Company, Lilly Research CentreWindleshamSurreyUK
| | | | - Vanessa N Barth
- Eli Lilly and Company, Lilly Corporate CenterIndianapolisINUSA
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10
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Scarr E, Hopper S, Vos V, Seo MS, Everall IP, Aumann TD, Chana G, Dean B. Low levels of muscarinic M1 receptor-positive neurons in cortical layers III and V in Brodmann areas 9 and 17 from individuals with schizophrenia. J Psychiatry Neurosci 2018; 43:170202. [PMID: 29848411 PMCID: PMC6158028 DOI: 10.1503/jpn.170202] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 11/28/2017] [Accepted: 01/04/2018] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Results of neuroimaging and postmortem studies suggest that people with schizophrenia may have lower levels of muscarinic M1 receptors (CHRM1) in the cortex, but not in the hippocampus or thalamus. Here, we use a novel immunohistochemical approach to better understand the likely cause of these low receptor levels. METHODS We determined the distribution and number of CHRM1-positive (CHRM1+) neurons in the cortex, medial dorsal nucleus of the thalamus and regions of the hippocampus from controls (n = 12, 12 and 5, respectively) and people with schizophrenia (n = 24, 24 and 13, respectively). RESULTS Compared with controls, levels of CHRM1+ neurons in people with schizophrenia were lower on pyramidal cells in layer III of Brodmann areas 9 (-44%) and 17 (-45%), and in layer V in Brodmann areas 9 (-45%) and 17 (-62%). We found no significant differences in the number of CHRM1+ neurons in the medial dorsal nucleus of the thalamus or in the hippocampus. LIMITATIONS Although diagnostic cohort sizes were typical for this type of study, they were relatively small. As well, people with schizophrenia were treated with antipsychotic drugs before death. CONCLUSION The loss of CHRM1+ pyramidal cells in the cortex of people with schizophrenia may underpin derangements in the cholinergic regulation of GABAergic activity in cortical layer III and in cortical/subcortical communication via pyramidal cells in layer V.
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Affiliation(s)
- Elizabeth Scarr
- From the Molecular Psychiatry Laboratory, University of Melbourne, Victoria, Australia (Scarr, Hopper, Vos, Suk Seo, Dean); the Midbrain Dopamine Plasticity Laboratory, the Florey Institute of Neuroscience and Mental Health, University of Melbourne, Victoria, Australia (Aumann); the Centre for Mental Health, Faculty of Health, Arts and Design, Swinburne University, Victoria, Australia (Dean); the Department of Psychiatry, University of Melbourne, Victoria, Australia (Everall); the Integrative Biological Psychiatry Laboratory, Centre for Neural Engineering, University of Melbourne, Victoria, Australia (Chunam); and the Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Victoria, Australia (Scarr)
| | - Shaun Hopper
- From the Molecular Psychiatry Laboratory, University of Melbourne, Victoria, Australia (Scarr, Hopper, Vos, Suk Seo, Dean); the Midbrain Dopamine Plasticity Laboratory, the Florey Institute of Neuroscience and Mental Health, University of Melbourne, Victoria, Australia (Aumann); the Centre for Mental Health, Faculty of Health, Arts and Design, Swinburne University, Victoria, Australia (Dean); the Department of Psychiatry, University of Melbourne, Victoria, Australia (Everall); the Integrative Biological Psychiatry Laboratory, Centre for Neural Engineering, University of Melbourne, Victoria, Australia (Chunam); and the Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Victoria, Australia (Scarr)
| | - Valentina Vos
- From the Molecular Psychiatry Laboratory, University of Melbourne, Victoria, Australia (Scarr, Hopper, Vos, Suk Seo, Dean); the Midbrain Dopamine Plasticity Laboratory, the Florey Institute of Neuroscience and Mental Health, University of Melbourne, Victoria, Australia (Aumann); the Centre for Mental Health, Faculty of Health, Arts and Design, Swinburne University, Victoria, Australia (Dean); the Department of Psychiatry, University of Melbourne, Victoria, Australia (Everall); the Integrative Biological Psychiatry Laboratory, Centre for Neural Engineering, University of Melbourne, Victoria, Australia (Chunam); and the Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Victoria, Australia (Scarr)
| | - Myoung Suk Seo
- From the Molecular Psychiatry Laboratory, University of Melbourne, Victoria, Australia (Scarr, Hopper, Vos, Suk Seo, Dean); the Midbrain Dopamine Plasticity Laboratory, the Florey Institute of Neuroscience and Mental Health, University of Melbourne, Victoria, Australia (Aumann); the Centre for Mental Health, Faculty of Health, Arts and Design, Swinburne University, Victoria, Australia (Dean); the Department of Psychiatry, University of Melbourne, Victoria, Australia (Everall); the Integrative Biological Psychiatry Laboratory, Centre for Neural Engineering, University of Melbourne, Victoria, Australia (Chunam); and the Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Victoria, Australia (Scarr)
| | - Ian Paul Everall
- From the Molecular Psychiatry Laboratory, University of Melbourne, Victoria, Australia (Scarr, Hopper, Vos, Suk Seo, Dean); the Midbrain Dopamine Plasticity Laboratory, the Florey Institute of Neuroscience and Mental Health, University of Melbourne, Victoria, Australia (Aumann); the Centre for Mental Health, Faculty of Health, Arts and Design, Swinburne University, Victoria, Australia (Dean); the Department of Psychiatry, University of Melbourne, Victoria, Australia (Everall); the Integrative Biological Psychiatry Laboratory, Centre for Neural Engineering, University of Melbourne, Victoria, Australia (Chunam); and the Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Victoria, Australia (Scarr)
| | - Timothy Douglas Aumann
- From the Molecular Psychiatry Laboratory, University of Melbourne, Victoria, Australia (Scarr, Hopper, Vos, Suk Seo, Dean); the Midbrain Dopamine Plasticity Laboratory, the Florey Institute of Neuroscience and Mental Health, University of Melbourne, Victoria, Australia (Aumann); the Centre for Mental Health, Faculty of Health, Arts and Design, Swinburne University, Victoria, Australia (Dean); the Department of Psychiatry, University of Melbourne, Victoria, Australia (Everall); the Integrative Biological Psychiatry Laboratory, Centre for Neural Engineering, University of Melbourne, Victoria, Australia (Chunam); and the Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Victoria, Australia (Scarr)
| | - Gursharan Chana
- From the Molecular Psychiatry Laboratory, University of Melbourne, Victoria, Australia (Scarr, Hopper, Vos, Suk Seo, Dean); the Midbrain Dopamine Plasticity Laboratory, the Florey Institute of Neuroscience and Mental Health, University of Melbourne, Victoria, Australia (Aumann); the Centre for Mental Health, Faculty of Health, Arts and Design, Swinburne University, Victoria, Australia (Dean); the Department of Psychiatry, University of Melbourne, Victoria, Australia (Everall); the Integrative Biological Psychiatry Laboratory, Centre for Neural Engineering, University of Melbourne, Victoria, Australia (Chunam); and the Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Victoria, Australia (Scarr)
| | - Brian Dean
- From the Molecular Psychiatry Laboratory, University of Melbourne, Victoria, Australia (Scarr, Hopper, Vos, Suk Seo, Dean); the Midbrain Dopamine Plasticity Laboratory, the Florey Institute of Neuroscience and Mental Health, University of Melbourne, Victoria, Australia (Aumann); the Centre for Mental Health, Faculty of Health, Arts and Design, Swinburne University, Victoria, Australia (Dean); the Department of Psychiatry, University of Melbourne, Victoria, Australia (Everall); the Integrative Biological Psychiatry Laboratory, Centre for Neural Engineering, University of Melbourne, Victoria, Australia (Chunam); and the Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Victoria, Australia (Scarr)
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