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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: 8] [Impact Index Per Article: 8.0] [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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Abstract
Due to the growing number of chronic traumatic encephalopathy (CTE) cases in the military and contact sports, defining the cellular and molecular substrate of this disorder is crucial. Most classic neuropathological investigations describe cortical tau and, to a lesser extent, amyloid lesions, which may underlie the clinical sequela associated with CTE. The application of modern molecular biologic technology to postmortem human brain tissue has made it possible to evaluate the genetic signature of specific neuronal phenotypes at different stages of CTE pathology. Most recently, molecular pathobiology has been used in the field of CTE, with an emphasis on the cholinergic neurons located within the nucleus basalis of Meynert, which develop tau pathology and are associated with cognitive dysfunction similar to that found in Alzheimer's disease (AD). Quantitative findings derived from single-cell transcript investigations provide clues to our understanding of the selective vulnerability of neurons containing AD-like tau pathology at different stages of CTE. Since human tissue-based studies provide a gold standard for the field of CTE, continued molecular pathological studies are needed to reveal novel drug targets for the treatment of this disorder.
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Yavas E, Young AM. Repeated phencyclidine disrupts nicotinic acetylcholine regulation of dopamine release in nucleus accumbens: Implications for models of schizophrenia. Neurochem Int 2020; 140:104836. [DOI: 10.1016/j.neuint.2020.104836] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 08/11/2020] [Accepted: 08/13/2020] [Indexed: 01/02/2023]
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Relationship of common variants in CHRNA5 with early-onset schizophrenia and executive function. Schizophr Res 2019; 206:407-412. [PMID: 30366711 DOI: 10.1016/j.schres.2018.10.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 10/05/2018] [Accepted: 10/18/2018] [Indexed: 12/12/2022]
Abstract
Altered cholinergic neural transmission is hypothesized to increase susceptibility to cognitive deficits in psychotic disorders such as schizophrenia (SCZ). The nicotinic acetylcholine receptor α5 subunit gene (CHRNA5) is reported to be associated with cognitive function in nicotine-dependent populations and SCZ in non-smoking SCZ patients. Nevertheless, it is still not clear whether the CHRNA5 gene contributes to susceptibility to the cognitive deficits of SCZ without smoking. To further clarify the role of CHRNA5, we designed a two-stage, case-control study to examine the association between CHRNA5 and SCZ and its clinical features adjusted for smoking status in early-onset SCZ patients. A total of 15 tag single nucleotide polymorphisms (SNPs) on CHRNA5 were genotyped in the discovery stage, which included 485 early-onset SCZ patients and 1018 controls, and then, we replicated this association in a confirmatory population of 674 patients and 1886 controls. The rs16969968 SNP was identified as significantly associated with SCZ in both datasets. In addition, the severity of psychotic symptoms and cognitive deficits was assessed using the Positive and Negative Syndrome Scale (PANSS) and the Wisconsin Card Sorting Test (WCST). The rs16969968 SNP was associated with psychotic symptoms in patients and with cognitive function in patients and controls. Our results show that rs16969968 on CHRNA5 is tightly linked to genetic susceptibility, psychotic symptoms and cognitive deficits in SCZ in an early-onset Chinese population, suggesting that CHRNA5 may play an important role in the etiology of SCZ.
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Bozinoff N, Le Foll B. Understanding the implications of the biobehavioral basis of nicotine addiction and its impact on the efficacy of treatment. Expert Rev Respir Med 2018; 12:793-804. [PMID: 30092681 DOI: 10.1080/17476348.2018.1507736] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
INTRODUCTION Tobacco use remains the leading cause of preventable death in the United States. There are efficacious behavioral and pharmacological options for smoking cessation including three FDA approved therapies - nicotine replacement therapy, varenicline and bupropion. Nevertheless, uptake of smoking cessation treatments continues to be poor and there is a need for novel smoking cessation treatments. Areas covered: This article reviews the biobehavioral basis of nicotine addiction, its implications for smoking cessation treatments, the various neurotransmitter systems involved in nicotine addictive effects, and their potential therapeutic value. Included are discussions around the role of genetic factors in predicting response to pharmacotherapy and what we know about appropriate application of pharmacotherapy and behavioral interventions for tobacco use disorder. The evidence for harm reduction measures in individuals who are not willing or able to quit smoking is also reviewed. Expert commentary: Many neurotransmitter system targets have been investigated as a result of our understanding of the underlying neurobiology of tobacco use disorder, and there remain important targets that have yet to be fully explored. rTMS or combination therapies are proposed as possible novel strategies to improve smoking cessation.
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Affiliation(s)
- Nikki Bozinoff
- a Department of Family and Community Medicine , University of Toronto , Toronto , Canada.,b Addiction Medicine Service, Acute Care Program , Centre for Addiction and Mental Health , Toronto , Canada
| | - Bernard Le Foll
- a Department of Family and Community Medicine , University of Toronto , Toronto , Canada.,b Addiction Medicine Service, Acute Care Program , Centre for Addiction and Mental Health , Toronto , Canada.,c Department of Pharmacology and Toxicology, Psychiatry, Institute of Medical Sciences , University of Toronto , Toronto , Canada.,d Centre for Addiction and Mental Health , Campbell Family Mental Health Research Institute, CAMH , Toronto , Canada.,e Translational Addiction Research Laboratory, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health , Toronto , Canada
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Mufson EJ, He B, Ginsberg SD, Carper BA, Bieler GS, Crawford F, Alvarez VE, Huber BR, Stein TD, McKee AC, Perez SE. Gene Profiling of Nucleus Basalis Tau Containing Neurons in Chronic Traumatic Encephalopathy: A Chronic Effects of Neurotrauma Consortium Study. J Neurotrauma 2018; 35:1260-1271. [PMID: 29338612 PMCID: PMC5962931 DOI: 10.1089/neu.2017.5368] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Military personnel and athletes exposed to traumatic brain injury may develop chronic traumatic encephalopathy (CTE). Brain pathology in CTE includes intracellular accumulation of abnormally phosphorylated tau proteins (p-tau), the main constituent of neurofibrillary tangles (NFTs). Recently, we found that cholinergic basal forebrain (CBF) neurons within the nucleus basalis of Meynert (nbM), which provide the major cholinergic innervation to the cortex, display an increased number of NFTs across the pathological stages of CTE. However, molecular mechanisms underlying nbM neurodegeneration in the context of CTE pathology remain unknown. Here, we assessed the genetic signature of nbM neurons containing the p-tau pretangle maker pS422 from CTE subjects who came to autopsy and received a neuropathological CTE staging assessment (Stages II, III, and IV) using laser capture microdissection and custom-designed microarray analysis. Quantitative analysis revealed dysregulation of key genes in several gene ontology groups between CTE stages. Specifically, downregulation of the nicotinic cholinergic receptor subunit β-2 gene (CHRNB2), monoaminergic enzymes catechol-O-methyltransferase (COMT) and dopa decarboxylase (DDC), chloride channels CLCN4 and CLCN5, scaffolding protein caveolin 1 (CAV1), cortical development/cytoskeleton element lissencephaly 1 (LIS1), and intracellular signaling cascade member adenylate cyclase 3 (ADCY3) was observed in pS422-immunreactive nbM neurons in CTE patients. By contrast, upregulation of calpain 2 (CAPN2) and microtubule-associated protein 2 (MAP2) transcript levels was found in Stage IV CTE patients. These single-population data in vulnerable neurons indicate alterations in gene expression associated with neurotransmission, signal transduction, the cytoskeleton, cell survival/death signaling, and microtubule dynamics, suggesting novel molecular pathways to target for drug discovery in CTE.
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Affiliation(s)
- Elliott J. Mufson
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, Arizona
| | - Bin He
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, Arizona
| | - Stephen D. Ginsberg
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, New York and NYU Medical Center, New York, New York
| | | | | | | | - Victor E. Alvarez
- VA Boston HealthCare System, Boston University School of Medicine, Boston, Massachusetts
- Alzheimer Disease Center and CTE Center Program, Boston University School of Medicine, Boston, Massachusetts
- Department of Neurology, Boston University School of Medicine, Boston, Massachusetts
| | - Bertrand R. Huber
- VA Boston HealthCare System, Boston University School of Medicine, Boston, Massachusetts
- Alzheimer Disease Center and CTE Center Program, Boston University School of Medicine, Boston, Massachusetts
- Department of Neurology, Boston University School of Medicine, Boston, Massachusetts
| | - Thor D. Stein
- VA Boston HealthCare System, Boston University School of Medicine, Boston, Massachusetts
- Alzheimer Disease Center and CTE Center Program, Boston University School of Medicine, Boston, Massachusetts
- Department of Pathology, Boston University School of Medicine, Boston, Massachusetts
| | - Ann C. McKee
- VA Boston HealthCare System, Boston University School of Medicine, Boston, Massachusetts
- Alzheimer Disease Center and CTE Center Program, Boston University School of Medicine, Boston, Massachusetts
- Department of Neurology, Boston University School of Medicine, Boston, Massachusetts
- Department of Pathology, Boston University School of Medicine, Boston, Massachusetts
| | - Sylvia E. Perez
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, Arizona
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Smucny J, Tregellas JR. Targeting neuronal dysfunction in schizophrenia with nicotine: Evidence from neurophysiology to neuroimaging. J Psychopharmacol 2017; 31:801-811. [PMID: 28441884 PMCID: PMC5963521 DOI: 10.1177/0269881117705071] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Patients with schizophrenia self-administer nicotine at rates higher than is self-administered for any other psychiatric illness. Although the reasons are unclear, one hypothesis suggests that nicotine is a form of 'self-medication' in order to restore normal levels of nicotinic signaling and target abnormalities in neuronal function associated with cognitive processes. This brief review discusses evidence from neurophysiological and neuroimaging studies in schizophrenia patients that nicotinic agonists may effectively target dysfunctional neuronal circuits in the illness. Evidence suggests that nicotine significantly modulates a number of these circuits, although relatively few studies have used modern neuroimaging techniques (e.g. functional magnetic resonance imaging (fMRI)) to examine the effects of nicotinic drugs on disease-related neurobiology. The neuronal effects of nicotine and other nicotinic agonists in schizophrenia remain a priority for psychiatry research.
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Affiliation(s)
- Jason Smucny
- Department of Psychiatry, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Jason R Tregellas
- Department of Psychiatry, University of Colorado Anschutz Medical Campus, Aurora, CO, USA,Research Service, Denver VA Medical Center, Denver, CO, USA
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Shi J, Wang Z, Tan Y, Fan H, An H, Zuo L, Yang F, Tan S, Li J, Zhang X, Zhou D, Luo X. CHRNA4 was associated with prepulse inhibition of schizophrenia in Chinese: a pilot study. Cogn Neuropsychiatry 2016; 21:156-67. [PMID: 26982087 DOI: 10.1080/13546805.2016.1155437] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
INTRODUCTION Prepulse inhibition (PPI) of the auditory startle reflex, as an operational measurement used to evaluate the function of brain sensorimotor gating, appears to be a sensitive potential endophenotype for schizophrenia. CHRNA4 is highly expressed in the central nervous system and has been demonstrated to be significantly associated with schizophrenia by previous studies. The purpose of the current study was to evaluate the effect of CHRNA4 on PPI and acoustic startle parameters in schizophrenia. METHODS 77 patients with schizophrenia and 62 controls were administered the test PPI, and 3 single nucleotide polymorphisms (SNPs) (rs3746372, rs1044396, and rs3787140) of CHRNA4 were genotyped in these subjects. RESULTS Patients with schizophrenia showed significantly lower levels of PPI at the 120 ms prepulse intervals and longer peak latency than controls, and the GG genotype of rs3746372 and the TT genotype of rs1044396 were associated with decreased PPI levels in schizophrenia but not in controls. CONCLUSION PPI may be influenced by the polymorphisms of the CHRNA4 in schizophrenia and it may be a potential endophenotype of schizophrenia. An independent replication would greatly increase the value of this study.
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Affiliation(s)
- Jing Shi
- a Beijing HuiLongGuan Hospital , Beijing , People's Republic of China
| | - Zhiren Wang
- a Beijing HuiLongGuan Hospital , Beijing , People's Republic of China
| | - Yunlong Tan
- a Beijing HuiLongGuan Hospital , Beijing , People's Republic of China
| | - Hongzhen Fan
- a Beijing HuiLongGuan Hospital , Beijing , People's Republic of China
| | - Huimei An
- a Beijing HuiLongGuan Hospital , Beijing , People's Republic of China
| | - Lingjun Zuo
- a Beijing HuiLongGuan Hospital , Beijing , People's Republic of China
| | - Fude Yang
- a Beijing HuiLongGuan Hospital , Beijing , People's Republic of China
| | - Shuping Tan
- a Beijing HuiLongGuan Hospital , Beijing , People's Republic of China
| | - Jia Li
- a Beijing HuiLongGuan Hospital , Beijing , People's Republic of China
| | - Xiangyang Zhang
- a Beijing HuiLongGuan Hospital , Beijing , People's Republic of China
| | - Dongfeng Zhou
- b Institute of Mental Health , Peking University , Beijing , People's Republic of China
| | - Xingguang Luo
- a Beijing HuiLongGuan Hospital , Beijing , People's Republic of China
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Imaging α4β2 Nicotinic Acetylcholine Receptors (nAChRs) in Baboons with [18F]XTRA, a Radioligand with Improved Specific Binding in Extra-Thalamic Regions. Mol Imaging Biol 2016; 19:280-288. [DOI: 10.1007/s11307-016-0999-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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10
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Featherstone RE, Siegel SJ. The Role of Nicotine in Schizophrenia. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2015; 124:23-78. [PMID: 26472525 DOI: 10.1016/bs.irn.2015.07.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Schizophrenia is associated with by severe disruptions in thought, cognition, emotion, and behavior. Patients show a marked increase in rates of smoking and nicotine dependence relative to nonaffected individuals, a finding commonly ascribed to the potential ameliorative effects of nicotine on symptom severity and cognitive impairment. Indeed, many studies have demonstrated improvement in patients following the administration of nicotine. Such findings have led to an increased emphasis on the development of therapeutic agents to target the nicotinic system as well as increasing the impetus to understand the genetic basis for nicotinic dysfunction in schizophrenia. The goal of this review article is to provide a critical summary of evidence for the role of the nicotinic system in schizophrenia. The first part will review the role of nicotine in normalization of primary dysfunctions and endophenotypical changes found in schizophrenia. The second part will provide a summary of genetic evidence linking polymorphisms in nicotinic receptor genes to smoking and schizophrenia. The third part will summarize attempts to treat schizophrenia using agents specifically targeting nicotinic and nicotinic receptor subtypes. Although currently available antipsychotic treatments are generally able to manage some aspects of schizophrenia (e.g., positive symptoms) they fail to address several other critically effected aspects of the disease. As such, the search for novel mechanisms to treat this disease is necessary.
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Affiliation(s)
- Robert E Featherstone
- Translational Neuroscience Program, Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
| | - Steven J Siegel
- Translational Neuroscience Program, Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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11
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Scarr E, Dean B. Role of the cholinergic system in the pathology and treatment of schizophrenia. Expert Rev Neurother 2014; 9:73-86. [DOI: 10.1586/14737175.9.1.73] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Lewis AS, Picciotto MR. High-affinity nicotinic acetylcholine receptor expression and trafficking abnormalities in psychiatric illness. Psychopharmacology (Berl) 2013; 229:477-85. [PMID: 23624811 PMCID: PMC3766461 DOI: 10.1007/s00213-013-3126-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 04/15/2013] [Indexed: 12/22/2022]
Abstract
RATIONALE Nicotinic acetylcholine receptors (nAChRs) are a critical component of the cholinergic system of neurotransmission in the brain that modulates important physiological processes such as reward, cognition, and mood. Abnormalities in this system are accordingly implicated in multiple psychiatric illnesses, including addiction, schizophrenia, and mood disorders. There is significantly increased tobacco use, and therefore nicotine intake, in patient populations, and pharmacological agents that act on various nicotinic receptor subtypes ameliorate clinical features of these disorders. Better understanding of the molecular mechanisms underlying cholinergic dysfunction in psychiatric disease will permit more targeted design of novel therapeutic agents. RESULTS The objective of this review is to describe the multiple cellular pathways through which chronic nicotine exposure regulates nAChR expression, and to juxtapose these mechanisms with evidence for altered expression of high-affinity nAChRs in human psychiatric illness. Here, we summarize multiple studies from pre-clinical animal models to human in vivo imaging and post-mortem experiments demonstrating changes in nAChR regulation and expression in psychiatric illness. CONCLUSIONS We conclude that a mechanistic explanation of nAChR abnormalities in psychiatric illness will arise from a fuller understanding of normal nAChR trafficking, along with the detailed study of human tissue, perhaps using novel biotechnological advances, such as induced pluripotent stem cells.
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Affiliation(s)
| | - Marina R. Picciotto
- Correspondence Dr. Marina R. Picciotto, Department of Psychiatry, Yale University School of Medicine, 34 Park Street, 3rd Floor Research, New Haven, CT, 06508, USA, , Phone: (203) 737-2041
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D’Souza DC, Esterlis I, Carbuto M, Krasenics M, Seibyl J, Bois F, Pittman B, Ranganathan M, Cosgrove K, Staley J. Lower ß2*-nicotinic acetylcholine receptor availability in smokers with schizophrenia. Am J Psychiatry 2012; 169:326-34. [PMID: 22193533 PMCID: PMC3881431 DOI: 10.1176/appi.ajp.2011.11020189] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE There is a strong association between cigarette smoking and schizophrenia. Nicotine's actions in the brain are mediated through nicotinic acetylcholine receptors. Those containing α(4) and β(2) subunits are the most abundant ones in the brain, have the highest affinity for nicotine, and are critical in mediating nicotine's reinforcing properties. Healthy tobacco smokers have significantly higher levels of β(2)*-nicotinic acetylcholine receptors than do nonsmokers. However, in postmortem studies, smokers with schizophrenia do not show these higher levels. The purpose of this study was to measure β(2)*-nicotinic acetylcholine receptors in vivo and to relate levels to concurrent behavioral measures of smoking and schizophrenia. METHOD By using single-photon emission computed tomography with the β(2)*-nicotinic acetylcholine receptor agonist radiotracer [(123)I]5-IA-85380, the availability of receptors was measured in smokers with schizophrenia (11 men) and matched comparison smokers after 1 week of confirmed smoking abstinence. RESULTS Smokers with schizophrenia showed significantly lower (21%-26%) β(2)*-nicotinic acetylcholine receptor availability relative to comparison smokers in the frontal cortex, parietal cortex, and thalamus (in descending order). There was a specific and robust negative correlation between regional β(2)*-nicotinic acetylcholine receptor availability and negative symptoms. CONCLUSIONS These are the first in vivo findings of lower β(2)*-nicotinic acetylcholine receptor availability in smokers with schizophrenia. The relationship between β(2)*-nicotinic acetylcholine receptor availability and negative symptoms may explain the high rates of smoking in schizophrenia and the relationship between smoking and negative symptoms. Findings support the development of medications targeting the β(2)*-nicotinic acetylcholine receptor system for the treatment of negative symptoms.
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Affiliation(s)
- Deepak Cyril D’Souza
- Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA
,Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, USA
,Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Irina Esterlis
- Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA
,Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Michelle Carbuto
- Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA
,Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, USA
,Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Maegan Krasenics
- Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA
,Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, USA
,Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - John Seibyl
- Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA
,Institute for Neurodegenerative Disorders, New Haven, T 06510, USA
| | - Frederic Bois
- Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA
,Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Brian Pittman
- Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, USA
,Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Mohini Ranganathan
- Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA
,Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, USA
,Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Kelly Cosgrove
- Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA
,Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Julie Staley
- Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA
,Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT, USA
,Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
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Muscarinic and nicotinic acetylcholine receptor agonists and allosteric modulators for the treatment of schizophrenia. Neuropsychopharmacology 2012; 37:16-42. [PMID: 21956443 PMCID: PMC3238081 DOI: 10.1038/npp.2011.199] [Citation(s) in RCA: 155] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Muscarinic and nicotinic acetylcholine (ACh) receptors (mAChRs and nAChRs) are emerging as important targets for the development of novel treatments for the symptoms associated with schizophrenia. Preclinical and early proof-of-concept clinical studies have provided strong evidence that activators of specific mAChR (M(1) and M(4)) and nAChR (α(7) and α(2)β(4)) subtypes are effective in animal models of antipsychotic-like activity and/or cognitive enhancement, and in the treatment of positive and cognitive symptoms in patients with schizophrenia. While early attempts to develop selective mAChR and nAChR agonists provided important preliminary findings, these compounds have ultimately failed in clinical development due to a lack of true subtype selectivity and subsequent dose-limiting adverse effects. In recent years, there have been major advances in the discovery of highly selective activators for the different mAChR and nAChR subtypes with suitable properties for optimization as potential candidates for clinical trials. One novel strategy has been to identify ligands that activate a specific receptor subtype through actions at sites that are distinct from the highly conserved ACh-binding site, termed allosteric sites. These allosteric activators, both allosteric agonists and positive allosteric modulators, of mAChR and nAChR subtypes demonstrate unique mechanisms of action and high selectivity in vivo, and may provide innovative treatment strategies for schizophrenia.
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Chen J, Brunzell DH, Jackson K, van der Vaart A, Ma JZ, Payne TJ, Sherva R, Farrer LA, Gejman P, Levinson DF, Holmans P, Aggen SH, Damaj I, Kuo PH, Webb BT, Anton R, Kranzler HR, Gelernter J, Li MD, Kendler KS, Chen X. ACSL6 is associated with the number of cigarettes smoked and its expression is altered by chronic nicotine exposure. PLoS One 2011; 6:e28790. [PMID: 22205969 PMCID: PMC3243669 DOI: 10.1371/journal.pone.0028790] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Accepted: 11/15/2011] [Indexed: 11/19/2022] Open
Abstract
Individuals with schizophrenia tend to be heavy smokers and are at high risk for tobacco dependence. However, the nature of the comorbidity is not entirely clear. We previously reported evidence for association of schizophrenia with SNPs and SNP haplotypes in a region of chromosome 5q containing the SPEC2, PDZ-GEF2 and ACSL6 genes. In this current study, analysis of the control subjects of the Molecular Genetics of Schizophrenia (MGS) sample showed similar pattern of association with number of cigarettes smoked per day (numCIG) for the same region. To further test if this locus is associated with tobacco smoking as measured by numCIG and FTND, we conducted replication and meta-analysis in 12 independent samples (n>16,000) for two markers in ACSL6 reported in our previous schizophrenia study. In the meta-analysis of the replication samples, we found that rs667437 and rs477084 were significantly associated with numCIG (p = 0.00038 and 0.00136 respectively) but not with FTND scores. We then used in vitro and in vivo techniques to test if nicotine exposure influences the expression of ACSL6 in brain. Primary cortical culture studies showed that chronic (5-day) exposure to nicotine stimulated ACSL6 mRNA expression. Fourteen days of nicotine administration via osmotic mini pump also increased ACSL6 protein levels in the prefrontal cortex and hippocampus of mice. These increases were suppressed by injection of the nicotinic receptor antagonist mecamylamine, suggesting that elevated expression of ACSL6 requires nicotinic receptor activation. These findings suggest that variations in the ACSL6 gene may contribute to the quantity of cigarettes smoked. The independent associations of this locus with schizophrenia and with numCIG in non-schizophrenic subjects suggest that this locus may be a common liability to both conditions.
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Affiliation(s)
- Jingchun Chen
- Department of Psychiatry and Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Darlene H. Brunzell
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, United States of America
- Institute for Drug and Alcohol Studies, Virginia Commonwealth University, Richmond, Virginia, United States of America
- Interdisciplinary Neuroscience Program, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Kia Jackson
- Department of Psychiatry and Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Andrew van der Vaart
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, Virginia, United States of America
| | - Jennie Z. Ma
- Department of Public Health Sciences, University of Virginia, Charlottesville, Virginia, United States of America
| | - Thomas J. Payne
- Department of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, Mississippi, United States of America
| | - Richard Sherva
- Department of Medicine (Biomedical Genetics), Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Lindsay A. Farrer
- Department of Medicine (Biomedical Genetics), Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Pablo Gejman
- Center for Psychiatric Genetics, NorthShore University HealthSystem Research Institute, Evanston, Illinois, United States of America
| | - Douglas F. Levinson
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, California, United States of America
| | - Peter Holmans
- Biostatistics and Bioinformatics Unit, Medical Resource Council Centre for Neuropsychiatric Genetics and Genomics, Department of Psychological Medicine and Neurology, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom
| | - Steven H. Aggen
- Department of Psychiatry and Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Imad Damaj
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Po-Hsiu Kuo
- Institute of Epidemiology and Preventive Medicine, National Taiwan University, Taipei, Taiwan
| | - Bradley T. Webb
- Department of Psychiatry and Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Raymond Anton
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Henry R. Kranzler
- Department of Psychiatry, Treatment Research Center, University of Pennsylvania School of Medicine 3900 and Philadelphia Veterans Affairs Medical Center, Philadelphia, Pennsylvania, United States of America
| | - Joel Gelernter
- Departments of Psychiatry, Genetics, and Neurobiology, Yale University School of Medicine, New Haven, Connecticut, and Veterans Affairs Connecticut Healthcare Center, West Haven, Connecticut, United States of America
| | - Ming D. Li
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, Virginia, United States of America
| | - Kenneth S. Kendler
- Department of Psychiatry and Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, Virginia, United States of America
- Institute for Drug and Alcohol Studies, Virginia Commonwealth University, Richmond, Virginia, United States of America
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Xiangning Chen
- Department of Psychiatry and Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, Virginia, United States of America
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, Virginia, United States of America
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16
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Wing VC, Wass CE, Soh DW, George TP. A review of neurobiological vulnerability factors and treatment implications for comorbid tobacco dependence in schizophrenia. Ann N Y Acad Sci 2011; 1248:89-106. [DOI: 10.1111/j.1749-6632.2011.06261.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Papaleo F, Lipska BK, Weinberger DR. Mouse models of genetic effects on cognition: relevance to schizophrenia. Neuropharmacology 2011; 62:1204-20. [PMID: 21557953 DOI: 10.1016/j.neuropharm.2011.04.025] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2010] [Revised: 04/08/2011] [Accepted: 04/20/2011] [Indexed: 01/27/2023]
Abstract
Cognitive dysfunction is a core feature of schizophrenia. Growing evidence indicates that a wide variety of genetic mutations and polymorphisms impact cognition and may thus be implicated in various aspects of this mental disorder. Despite differences between human and rodent brain structure and function, genetic mouse models have contributed critical information about brain mechanisms involved in cognitive processes. Here, we summarize discoveries of genetic modifications in mice that impact cognition. Based on functional hypotheses, gene modifications within five model systems are described: 1) dopamine (D1, D2, D3, D4, D5, DAT, COMT, MAO); 2) glutamate (GluR-A, NR1, NR2A, NR2B, GRM2, GRM3, GLAST); 3) GABA (α(5), γ(2), α(4), δGABA(A), GABA(B(1)), GAT1); 4) acetylcholine (nAChRβ2, α7, CHRM1); and 5) calcium (CaMKII-α, neurogranin, CaMKKβ, CaMKIV). We also consider other risk-associated genes for schizophrenia such as dysbindin (DTNBP1), neuregulin (NRG1), disrupted-in-schizophrenia1 (DISC1), reelin and proline dehydrogenase (PRODH). Because of the presumed importance of environmental factors, we further consider genetic modifications within the stress-sensitive systems of corticotropin-releasing factor (CRF), brain-derived neurotrophic factor (BDNF) and the endocannabinoid systems. We highlight the missing information and limitations of cognitive assays in genetically modified mice models relevant to schizophrenia pathology.
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Affiliation(s)
- Francesco Papaleo
- Department of Neuroscience and Brain Technologies, The Italian Institute of Technology, Via Morego 30, 16163 Genova, Italy.
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18
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Hong LE, Yang X, Wonodi I, Hodgkinson CA, Goldman D, Stine OC, Stein ES, Thaker GK. A CHRNA5 allele related to nicotine addiction and schizophrenia. GENES BRAIN AND BEHAVIOR 2011; 10:530-5. [PMID: 21418140 DOI: 10.1111/j.1601-183x.2011.00689.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Schizophrenia and nicotine addiction are both highly heritable phenotypes. Because individuals with schizophrenia have a higher rate of smoking than those in the general population, one could hypothesize that genes associated with smoking might be overrepresented in schizophrenia and thus help explain their increased smoking incidence. Although a number of genes have been proposed to explain the increased smoking risk in schizophrenia, none of them have been consistently linked to smoking and schizophrenia, and thus difficult to explain the increased smoking in schizophrenia. A functional smoking-related nicotinic acetylcholine receptor α5 subunit gene (CHRNA5) nonsynonymous single nucleotide polymorphism (SNP) rs16969968 (Asp398Asn) has recently been discovered and replicated. As such, we tested whether this variant contributes to smoking in schizophrenia in a sample of 313 schizophrenia patients and 525 controls. The Asp398Asn risk allele is significantly associated with smoking severity independently in schizophrenia patient smokers (P = 0.001) and control smokers (P = 0.029). Furthermore, the same risk allele is significantly associated with schizophrenia in both Caucasian (P = 0.022) and African-American (P = 0.006) nonsmoker schizophrenia patients compared with control nonsmokers. Intriguingly, this SNP was not significantly associated with smoking status (smokers vs. nonsmokers) in either schizophrenia patients or controls. Therefore, our study identifies a genetic variant that is simultaneously linked to smoking and schizophrenia in the same cohort, but whether this SNP contributes to the increased smoking prevalence in schizophrenia patients requires additional studies.
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Affiliation(s)
- L E Hong
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21228, USA.
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19
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Sarter M, Lustig C, Taylor SF. Cholinergic contributions to the cognitive symptoms of schizophrenia and the viability of cholinergic treatments. Neuropharmacology 2010; 62:1544-53. [PMID: 21156184 DOI: 10.1016/j.neuropharm.2010.12.001] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2010] [Revised: 10/31/2010] [Accepted: 12/01/2010] [Indexed: 12/27/2022]
Abstract
Effective treatment of the cognitive symptoms of schizophrenia has remained an elusive goal. Despite the intense focus on treatments acting at or via cholinergic mechanisms, little remains known about the dynamic cholinergic abnormalities that contribute to the manifestation of the cognitive symptoms in patients. Evidence from basic neuroscientific and psychopharmacological investigations assists in proposing detailed cholinergic mechanisms and treatment targets for enhancement of attentional performance. Dynamic, cognitive performance-dependent abnormalities in cholinergic activity have been observed in animal models of the disorder and serve to further refine such proposals. Finally, the potential usefulness of individual groups of cholinergic drugs and important issues concerning the interactions between pro-cholinergic and antipsychotic treatments are addressed. The limited evidence available from patient studies and animal models indicates pressing research needs in order to guide the development of cholinergic treatments of the cognitive symptoms of schizophrenia.
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Affiliation(s)
- Martin Sarter
- Department of Psychology and Neuroscience Program, University of Michigan, 530 Church Street, 4032 East Hall, Ann Arbor, MI 48109, USA.
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20
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Li Q, Fallin MD, Louis TA, Lasseter VK, McGrath JA, Avramopoulos D, Wolyniec PS, Valle D, Liang KY, Pulver AE, Ruczinski I. Detection of SNP-SNP interactions in trios of parents with schizophrenic children. Genet Epidemiol 2010; 34:396-406. [PMID: 20568257 DOI: 10.1002/gepi.20488] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Schizophrenia (SZ) is a heritable and complex psychiatric disorder with an estimated worldwide prevalence of about 1%. Research on the risk factors for SZ has thus far yielded few clues to causes, but has pointed to a heterogeneous etiology that likely involves multiple genes and gene-environment interactions. In this manuscript, we apply a novel method (trio logic regression, Li et al., 2009) to case-parent trio data from a SZ candidate gene study conducted on families of Ashkenazi Jewish descent, and demonstrate the method's ability to detect multi-gene models for SZ risk in the family-based design. In particular, we demonstrate how this method revealed a genotype-phenotype association that includes an allele without marginal effect.
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Affiliation(s)
- Qing Li
- Department of Biostatistics, Bloomberg School of Public Health, Baltimore, Maryland 21205, USA
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21
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Dome P, Lazary J, Kalapos MP, Rihmer Z. Smoking, nicotine and neuropsychiatric disorders. Neurosci Biobehav Rev 2009; 34:295-342. [PMID: 19665479 DOI: 10.1016/j.neubiorev.2009.07.013] [Citation(s) in RCA: 149] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 07/23/2009] [Accepted: 07/30/2009] [Indexed: 12/20/2022]
Abstract
Tobacco smoking is an extremely addictive and harmful form of nicotine (NIC) consumption, but unfortunately also the most prevalent. Although disproportionately high frequencies of smoking and its health consequences among psychiatric patients are widely known, the neurobiological background of this epidemiological association is still obscure. The diverse neuroactive effects of NIC and some other major tobacco smoke constituents in the central nervous system may underlie this association. This present paper summarizes the pharmacology of NIC and its receptors (nAChR) based on a systematic review of the literature. The role of the brain's reward system(s) in NIC addiction and the results of functional and structural neuroimaging studies on smoking-related states and behaviors (i.e. dependence, craving, withdrawal) are also discussed. In addition, the epidemiological, neurobiological, and genetic aspects of smoking in several specific neuropsychiatric disorders are reviewed and the clinical relevance of smoking in these disease states addressed.
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Affiliation(s)
- Peter Dome
- Department of Clinical and Theoretical Mental Health, Kutvolgyi Clinical Center, Semmelweis University, Faculty of Medicine, Kutvolgyi ut 4, 1125 Budapest, Hungary.
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22
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Brasić JR, Zhou Y, Musachio JL, Hilton J, Fan H, Crabb A, Endres CJ, Reinhardt MJ, Dogan AS, Alexander M, Rousset O, Maris MA, Galecki J, Nandi A, Wong DF. Single photon emission computed tomography experience with (S)-5-[(123)I]iodo-3-(2-azetidinylmethoxy)pyridine in the living human brain of smokers and nonsmokers. Synapse 2009; 63:339-58. [PMID: 19140167 PMCID: PMC2766259 DOI: 10.1002/syn.20611] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
(S)-5-[(123)I]iodo-3-(2-azetidinylmethoxy)pyridine (5-[(123)I]IA), a novel potent radioligand for high-affinity alpha4beta2* neuronal nicotinic acetylcholine receptors (nAChRs), provides a means to evaluate the density and the distribution of nAChRs in the living human brain. We sought in healthy adult smokers and nonsmokers to (1) evaluate the safety, tolerability, and efficacy of 5-[(123)I]IA in an open nonblind trial and (2) to estimate the density and the distribution of alpha(4)beta(2)* nAChRs in the brain. Single photon emission computed tomography (SPECT) was performed for 5 h after the i.v. administration of approximately 0.001 microg/kg ( approximately 10 mCi) 5-[(123)I]IA. Blood pressure, heart rate, and neurobehavioral status were monitored before, during, and after the administration of 5-[(123)I]IA to 12 healthy adults (8 men and 4 women) (6 smokers and 6 nonsmokers) ranging in age from 19 to 46 years (mean = 28.25, standard deviation = 8.20). High plasma-nicotine level was significantly associated with low 5-[(123)I]IA binding in: (1) the caudate head, the cerebellum, the cortex, and the putamen, utilizing both the Sign and Mann-Whitney U-tests; (2) the fusiform gyrus, the hippocampus, the parahippocampus, and the pons utilizing the Mann-Whitney U-test; and (3) the thalamus utilizing the Sign test. We conclude that 5-[(123)I]IA is a safe, well-tolerated, and effective pharmacologic agent for human subjects to estimate high-affinity alpha4/beta2 nAChRs in the living human brain.
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Affiliation(s)
- James Robert Brasić
- Division of Nuclear Medicine, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.
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A neurocognitive animal model dissociating between acute illness and remission periods of schizophrenia. Psychopharmacology (Berl) 2009; 202:237-58. [PMID: 18618100 PMCID: PMC2719245 DOI: 10.1007/s00213-008-1216-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2007] [Accepted: 05/26/2008] [Indexed: 12/11/2022]
Abstract
RATIONALE The development and validation of animal models of the cognitive impairments of schizophrenia have remained challenging subjects. OBJECTIVE We review evidence from a series of experiments concerning an animal model that dissociates between the disruption of attentional capacities during acute illness periods and the cognitive load-dependent impairments that characterize periods of remission. The model focuses on the long-term attentional consequences of an escalating-dosing pretreatment regimen with amphetamine (AMPH). RESULTS Acute illness periods are modeled by the administration of AMPH challenges. Such challenges result in extensive impairments in attentional performance and the "freezing" of performance-associated cortical acetylcholine (ACh) release at pretask levels. During periods of remission (in the absence of AMPH challenges), AMPH-pretreated animals' attentional performance is associated with abnormally high levels of performance-associated cortical ACh release, indicative of the elevated attentional effort required to maintain performance. Furthermore, and corresponding with clinical evidence, attentional performance during remission periods is exquisitely vulnerable to distractors, reflecting impaired top-down control and abnormalities in fronto-mesolimbic-basal forebrain circuitry. Finally, this animal model detects the moderately beneficial cognitive effects of low-dose treatment with haloperidol and clozapine that were observed in clinical studies. CONCLUSIONS The usefulness and limitations of this model for research on the neuronal mechanisms underlying the cognitive impairments in schizophrenia and for drug-finding efforts are discussed.
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24
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Grucza RA, Wang JC, Stitzel JA, Hinrichs AL, Saccone SF, Saccone NL, Bucholz KK, Cloninger CR, Neuman RJ, Budde JP, Fox L, Bertelsen S, Kramer J, Hesselbrock V, Tischfield J, Nurnberger JI, Almasy L, Porjesz B, Kuperman S, Schuckit MA, Edenberg HJ, Rice JP, Goate AM, Bierut LJ. A risk allele for nicotine dependence in CHRNA5 is a protective allele for cocaine dependence. Biol Psychiatry 2008; 64:922-9. [PMID: 18519132 PMCID: PMC2582594 DOI: 10.1016/j.biopsych.2008.04.018] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2007] [Revised: 03/19/2008] [Accepted: 04/05/2008] [Indexed: 10/22/2022]
Abstract
BACKGROUND A nonsynonymous coding polymorphism, rs16969968, of the CHRNA5 gene that encodes the alpha-5 subunit of the nicotinic acetylcholine receptor (nAChR) has been found to be associated with nicotine dependence. The goal of this study was to examine the association of this variant with cocaine dependence. METHODS Genetic association analysis was performed in two independent samples of unrelated case and control subjects: 1) 504 European Americans participating in the Family Study on Cocaine Dependence (FSCD) and 2) 814 European Americans participating in the Collaborative Study on the Genetics of Alcoholism (COGA). RESULTS In the FSCD, there was a significant association between the CHRNA5 variant and cocaine dependence (odds ratio = .67 per allele, p = .0045, assuming an additive genetic model), but in the reverse direction compared with that previously observed for nicotine dependence. In multivariate analyses that controlled for the effects of nicotine dependence, both the protective effect for cocaine dependence and the previously documented risk effect for nicotine dependence were statistically significant. The protective effect for cocaine dependence was replicated in the COGA sample. In COGA, effect sizes for habitual smoking, a proxy phenotype for nicotine dependence, were consistent with those observed in FSCD. CONCLUSIONS The minor (A) allele of rs16969968, relative to the major G allele, appears to be both a risk factor for nicotine dependence and a protective factor for cocaine dependence. The biological plausibility of such a bidirectional association stems from the involvement of nAChRs with both excitatory and inhibitory modulation of dopamine-mediated reward pathways.
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Affiliation(s)
- Richard A Grucza
- Department of Psychiatry, Washington University School of Medicine, 660 South Euclid Avenue, Box 8134, St. Louis, Missouri 63110, USA.
| | - Jen C. Wang
- Department of Psychiatry, Washington University, Saint Louis, Missouri, 63117
| | - Jerry A. Stitzel
- Department of Integrative Physiology, Institute for Behavioral Genetics, University of Colorado, Boulder, Colorado, 80309
| | - Anthony L. Hinrichs
- Department of Psychiatry, Washington University, Saint Louis, Missouri, 63117
| | - Scott F. Saccone
- Department of Psychiatry, Washington University, Saint Louis, Missouri, 63117
| | - Nancy L. Saccone
- Department of Genetics, Washington University, Saint Louis, Missouri, 63117
| | - Kathleen K. Bucholz
- Department of Psychiatry, Washington University, Saint Louis, Missouri, 63117
| | - C. Robert Cloninger
- Department of Psychiatry, Washington University, Saint Louis, Missouri, 63117, Department of Genetics, Washington University, Saint Louis, Missouri, 63117
| | - Rosalind J. Neuman
- Department of Psychiatry, Washington University, Saint Louis, Missouri, 63117
| | - John P. Budde
- Department of Psychiatry, Washington University, Saint Louis, Missouri, 63117
| | - Louis Fox
- Department of Psychiatry, Washington University, Saint Louis, Missouri, 63117
| | - Sarah Bertelsen
- Department of Psychiatry, Washington University, Saint Louis, Missouri, 63117
| | - John Kramer
- Department of Psychiatry, University of Iowa College of Medicine, Iowa City, Iowa, 52242
| | - Victor Hesselbrock
- Department of Psychiatry, University of Connecticut Health Center, 263 Farmington Ave, Farmington, Connecticut, 06030
| | - Jay Tischfield
- Department of Genetics, Rutgers, New Brunswick, New Jersey, 08901
| | - John. I. Nurnberger
- Department of Psychiatry, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, Indiana, 46202
| | - Laura Almasy
- Department of Genetics, Southwest Foundation for Biomedical Research, San Antonio, Texas, 78245
| | - Bernice Porjesz
- Department of Psychiatry, SUNY Health Science Center at Brooklyn, Brooklyn, New York, 11203
| | - Samuel Kuperman
- Department of Psychiatry, University of Iowa College of Medicine, Iowa City, Iowa, 52242
| | - Marc A. Schuckit
- Department of Psychiatry, University of California at San Diego, La Jolla, CA 92093
| | - Howard J. Edenberg
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, Indiana, 46202
| | - John P. Rice
- Department of Psychiatry, Washington University, Saint Louis, Missouri, 63117
| | - Alison M. Goate
- Department of Psychiatry, Washington University, Saint Louis, Missouri, 63117, Department of Genetics, Washington University, Saint Louis, Missouri, 63117, Department of Neurology, Washington University, Saint Louis, Missouri, 63117
| | - Laura J. Bierut
- Department of Psychiatry, Washington University, Saint Louis, Missouri, 63117
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25
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Zhao CJ, Noack C, Brackmann M, Gloveli T, Maelicke A, Heinemann U, Anand R, Braunewell KH. Neuronal Ca2+ sensor VILIP-1 leads to the upregulation of functional alpha4beta2 nicotinic acetylcholine receptors in hippocampal neurons. Mol Cell Neurosci 2008; 40:280-92. [PMID: 19063970 DOI: 10.1016/j.mcn.2008.11.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Revised: 10/23/2008] [Accepted: 11/03/2008] [Indexed: 01/17/2023] Open
Abstract
The neuronal Ca2+-sensor protein VILIP-1, known to affect clathrin-dependent receptor trafficking, has been shown to interact with the cytoplasmic loop of the alpha4-subunit of the alpha4beta2 nicotinic acetylcholine receptor (nAChR), which is the most abundant nAChR subtype with high-affinity for nicotine in the brain. The alpha4beta2 nAChR is crucial for nicotine addiction and the beneficial effects of nicotine on cognition. Its dysfunction has been implicated in frontal lobe epilepsy, Alzheimer's disease and schizophrenia. Here we report that overexpression of VILIP-1 enhances ACh responsiveness, whereas siRNA against VILIP-1 reduces alpha4beta2 nAChR currents of hippocampal neurons. The underlying molecular mechanism likely involves enhanced constitutive exocytosis of alpha4beta2 nAChRs mediated by VILIP-1. The two interaction partners co-localize in a Ca2+-dependent manner with syntaxin-6, a Golgi-SNARE protein involved in trans-Golgi membrane trafficking. Thus, we speculate that regulation of VILIP-1-expression might modulate surface expression of ligand-gated ion channels, such as the alpha4beta2 nAChRs, possibly comprising a novel form of physiological up-regulation of ligand-gated ion channels.
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Affiliation(s)
- C J Zhao
- Signal Transduction Research Group, Neuroscience Research Center, Charité, Universitaetsmedizin Berlin, Germany
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26
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Genetic association analysis of tagging SNPs in alpha4 and beta2 subunits of neuronal nicotinic acetylcholine receptor genes (CHRNA4 and CHRNB2) with schizophrenia in the Japanese population. J Neural Transm (Vienna) 2008; 115:1457-61. [PMID: 18762859 DOI: 10.1007/s00702-008-0114-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2008] [Accepted: 08/15/2008] [Indexed: 10/21/2022]
Abstract
Several lines of evidence suggest that nicotinic cholinergic dysfunction may contribute to the cognitive impairments in schizophrenia. The majority of high affinity nicotine binding sites in the human brain have been implicated in heteropentameric alpha4 and beta2 subunits of neuronal nicotinic acetylcholine receptors; therefore, these two neuronal nicotinic acetylcholine receptors genes (CHRNA4 and CHRNB2) are considered to be attractive candidate genes for the pathophysiology of schizophrenia. To represent these two genes in a gene-wide manner, we first evaluated the linkage disequilibrium structure using our own control samples. Thirteen SNPs (7 SNPs for CHRNA4 and 5 SNPs for CHRNB2) were selected as tagging SNPs. Using these tagging SNPs, we then conducted genetic association analysis of case-control samples (738 schizophrenia and 753 controls) in the Japanese population. No significant association was detected in the allele/genotype-wise or haplotype-wise analysis. Our results suggest that CHRNA4 and CHRNB2 do not play a major role in Japanese schizophrenia.
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27
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Fowler CD, Arends MA, Kenny PJ. Subtypes of nicotinic acetylcholine receptors in nicotine reward, dependence, and withdrawal: evidence from genetically modified mice. Behav Pharmacol 2008; 19:461-84. [PMID: 18690103 PMCID: PMC2669417 DOI: 10.1097/fbp.0b013e32830c360e] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Neuronal nicotinic acetylcholine receptors (nAChRs) can regulate the activity of many neurotransmitter pathways throughout the central nervous system and are considered to be important modulators of cognition and emotion. nAChRs are also the primary site of action in the brain for nicotine, the major addictive component of tobacco smoke. nAChRs consist of five membrane-spanning subunits (alpha and beta isoforms) that can associate in various combinations to form functional nAChR ion channels. Owing to a dearth of nAChR subtype-selective ligands, the precise subunit composition of the nAChRs that regulate the rewarding effects of nicotine and the development of nicotine dependence are unknown. The advent of mice with genetic nAChR subunit modifications, however, has provided a useful experimental approach to assess the contribution of individual subunits in vivo. Here, we review data generated from nAChR subunit knockout and genetically modified mice supporting a role for discrete nAChR subunits in nicotine reinforcement and dependence processes. Importantly, the rates of tobacco dependence are far higher in patients suffering from comorbid psychiatric illnesses compared with the general population, which may at least partly reflect disease-associated alterations in nAChR signaling. An understanding of the role of nAChRs in psychiatric disorders associated with high rates of tobacco addiction, therefore, may reveal novel insights into mechanisms of nicotine dependence. Thus, we also briefly review data generated from genetically modified mice to support a role for discrete nAChR subunits in anxiety disorders, depression, and schizophrenia.
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Affiliation(s)
- Christie D. Fowler
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Michael A. Arends
- Committee on the Neurobiology of Addictive Disorders, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Paul J. Kenny
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA
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Rasmussen BA, Perry DC, O’Neil J, Manaye KF, Tizabi Y. Effects of nicotine on sensorimotor gating impairment induced by long-term treatment with neurotoxic NMDA antagonism. Neurotox Res 2008; 13:151-61. [DOI: 10.1007/bf03033499] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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29
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Hong LE, Wonodi I, Lewis J, Thaker GK. Nicotine effect on prepulse inhibition and prepulse facilitation in schizophrenia patients. Neuropsychopharmacology 2008; 33:2167-74. [PMID: 17957213 PMCID: PMC4241357 DOI: 10.1038/sj.npp.1301601] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Acoustic prepulse inhibition (PPI) is considered an important biomarker in animal studies of psychosis and a number of psychiatric conditions. Nicotine has been shown to improve acoustic PPI in some animal strains and in humans. However, there is little data on effects of nicotine on acoustic PPI in schizophrenia patients using a double-blind, placebo-controlled study design. The primary aim of the current study was to test the effect of nicotine nasal spray on acoustic PPI in schizophrenia patients. The secondary aim was to test nicotine effect on prepulse facilitation (PPF). The study included 18 schizophrenia patient smokers and 12 healthy control smokers, tested in a double-blind, placebo-controlled, crossover, randomized design immediately after nicotine or saline placebo nasal sprays. PPI was tested using 120 ms prepulse-pulse interval. PPF was tested using 4500 ms prepulse-pulse interval. The results showed a significant main effect of drug on PPI in that nicotine improved PPI compared to placebo (p=0.008) with no drug by diagnosis interaction (p=0.90). Improvement in PPI in response to nicotine was significantly correlated with the baseline severity of clinical symptoms (r=0.59, p=0.02) in patients. There was no significant drug or drug by diagnosis interaction for the 4500 ms prepulse-pulse interval condition. However, nicotine improved inhibition in a subgroup of subjects exhibiting PPF (p=0.002). In conclusion, the findings confirmed that nicotine transiently improves acoustic PPI in schizophrenia patients. Additionally, schizophrenia patients with more clinical symptoms may have benefited more from nicotinic effect on PPI.
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Affiliation(s)
- L Elliot Hong
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21228, USA.
| | - Ikwunga Wonodi
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Jada Lewis
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Gunvant K Thaker
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
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Gierke P, Zhao C, Bernstein HG, Noack C, Anand R, Heinemann U, Braunewell KH. Implication of neuronal Ca2+ -sensor protein VILIP-1 in the glutamate hypothesis of schizophrenia. Neurobiol Dis 2008; 32:162-75. [PMID: 18691652 DOI: 10.1016/j.nbd.2008.07.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2008] [Revised: 06/12/2008] [Accepted: 07/08/2008] [Indexed: 11/29/2022] Open
Abstract
Post mortem studies in the hippocampus of schizophrenia patients revealed increased expression of neuronal Ca(2+)-sensor VILIP-1 (visinin-like protein) and enhanced co-localization with alpha4beta2 nAChR in interneurons. To study the pathological role of VILIP-1, particularly in interneurons, in the context of the glutamate hypothesis of schizophrenia, we have used ketamine-treated rats, a NMDA receptor hypofunction model, and hippocampal cultures as model systems for schizophrenia. Treatment with ketamine leads to enhanced VILIP-1 expression in interneurons in rat hippocampal CA1 region. In cultures glutamate treatment led to an increase in VILIP-1-positive interneurons, which is not dependent on NMDA receptor but metabotropic glutamate receptor activation. VILIP-1 mainly co-localizes with the interneuron marker calretinin, mGluR1alpha and the VILIP-1 interaction partner alpha4beta2 nAChR in hippocampal slices. Overexpression of VILIP-1 leads to enhanced nAChR-dependent inhibitory postsynaptic current (IPSC) generation by interneurons. This novel molecular link between the pathological role of mGluRs, VILIP-1 and its interaction partner alpha4beta2 nAChR by converging pathological glutamatergic and nicotinergic transmission may underlie cognitive impairments in schizophrenia.
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Affiliation(s)
- Paul Gierke
- Signal Transduction Research Group, Neuroscience Research Center, Charité, Universitaetsmedizin Berlin, Germany
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31
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Wildeboer KM, Stevens KE. Stimulation of the alpha4beta2 nicotinic receptor by 5-I A-85380 improves auditory gating in DBA/2 mice. Brain Res 2008; 1224:29-36. [PMID: 18582447 DOI: 10.1016/j.brainres.2008.06.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Revised: 06/03/2008] [Accepted: 06/04/2008] [Indexed: 11/17/2022]
Abstract
Abnormal auditory gating is a symptom of schizophrenia which has been proposed to be mediated through the alpha7 nicotinic acetylcholine receptor (nAChR). It has been shown that the non-selective nicotinic agonist nicotine has an influence on auditory gating in part by acting on the alpha4beta2 nAChR. The goal of this study was to determine the effect of 5-I A-85380, an agonist for the alpha4beta2 nAChR, in an inbred mouse model with a deficiency for auditory gating. Anesthetized DBA/2 mice were administered 5-I A-85380 alone and in combination with the alpha4beta2 nAChR antagonist, dihydro-beta-erythroidine, or the alpha7 nAChR antagonist, alpha-bungarotoxin. A recording electrode in the CA3 region of the hippocampus recorded P20-N40 waveforms in response to two auditory stimuli. The amplitudes of the response to the first and second clicks were used to determine TC ratios, the measure of auditory gating. 5-I A-85380 significantly decreased the TC ratios by selectively increasing the response amplitudes to the first click with no significant influence on the response amplitudes to the second click. The effect was blocked by dihydro-beta-erythroidine whereas alpha-bungarotoxin had no effect on response amplitude to either click. Although the alpha7 nAChR may mediate the hippocampal response of DBA/2 mice to the second click, the alpha4beta2 nAChR appears to modulate the response to the first click. Thus, the present study implicates the involvement of more than one subtype of nAChR in the auditory gating of DBA/2 mice, specifically the alpha4beta2 nAChR, and its role in the response amplitude to the first stimulus.
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Affiliation(s)
- Kristin M Wildeboer
- Department of Psychiatry, University of Colorado Denver, Aurora, CO 80045, USA.
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Tizabi Y. Nicotine and nicotinic system in hypoglutamatergic models of schizophrenia. Neurotox Res 2008; 12:233-46. [PMID: 18201951 DOI: 10.1007/bf03033907] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Schizophrenia is a complex neuropsychiatric disorder with devastating consequences. It is characterized by thought fragmentation, hallucination and delusion, collectively referred to as positive symptoms. In addition, mood changes or affective disorders, referred to as negative symptoms, as well as cognitive impairments can be manifested in these patients. Arguably, modeling such a disorder in its entirety in animals might not be feasible. Despite this limitation, various models with significant construct, predictive and some face validity have been developed. One such model, based on hypoglutamatergic hypothesis of schizophrenia, makes use of administering NMDA receptor antagonists and evaluating behavioral paradigms such as sensorimotor gating. Because of very high incidence of smoking among schizophrenic patients, it has been postulated that some of these patients may actually be self medicating with tobacco's nicotine. Research on nicotinic-glutamatergic interactions using various animal models has yielded conflicting results. In this review, some of these models and possible confounding factors are discussed. Overall, a therapeutic potential for nicotinic agonists in schizophrenia can be suggested. Moreover, it is evident that various experimental paradigms or models of schizophrenia symptoms need to be combined to provide a wider spectrum of the behavioral phenotype, as each model has its inherent limitations.
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Affiliation(s)
- Yousef Tizabi
- Department of Pharmacology, College of Medicine, Howard University, Washington, DC 20059, USA.
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Ochoa ELM, Lasalde-Dominicci J. Cognitive deficits in schizophrenia: focus on neuronal nicotinic acetylcholine receptors and smoking. Cell Mol Neurobiol 2008; 27:609-39. [PMID: 17554626 PMCID: PMC4676572 DOI: 10.1007/s10571-007-9149-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2006] [Accepted: 04/13/2007] [Indexed: 02/08/2023]
Abstract
Patients with schizophrenia present with deficits in specific areas of cognition. These are quantifiable by neuropsychological testing and can be clinically observable as negative signs. Concomitantly, they self-administer nicotine in the form of cigarette smoking. Nicotine dependence is more prevalent in this patient population when compared to other psychiatric conditions or to non-mentally ill people. The target for nicotine is the neuronal nicotinic acetylcholine receptor (nAChR). There is ample evidence that these receptors are involved in normal cognitive operations within the brain. This review describes neuronal nAChR structure and function, focusing on both cholinergic agonist-induced nAChR desensitization and nAChR up-regulation. The several mechanisms proposed for the nAChR up-regulation are examined in detail. Desensitization and up-regulation of nAChRs may be relevant to the physiopathology of schizophrenia. The participation of several subtypes of neuronal nAChRs in the cognitive processing of non-mentally ill persons and schizophrenic patients is reviewed. The role of smoking is then examined as a possible cognitive remediator in this psychiatric condition. Finally, pharmacological strategies focused on neuronal nAChRs are discussed as possible therapeutic avenues that may ameliorate the cognitive deficits of schizophrenia.
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Affiliation(s)
- Enrique L. M. Ochoa
- Department of Psychiatry, University of California at Davis, 2230 Stockton Boulevard, Sacramento, CA 95817, USA
| | - Jose Lasalde-Dominicci
- Department of Biology, University of Puerto Rico, Río Piedras Campus, P.O. Box 23360, San Juan 00931-3360, Puerto Rico
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The role of cortical inhibition in the pathophysiology and treatment of schizophrenia. ACTA ACUST UNITED AC 2007; 56:427-42. [DOI: 10.1016/j.brainresrev.2007.09.006] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2007] [Revised: 08/27/2007] [Accepted: 09/17/2007] [Indexed: 11/18/2022]
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Abstract
Schizophrenia is a common mental illness with a high prevalence of smoking. More than 80% of schizophrenics smoke compared to 25% of the general population. Both schizophrenia and tobacco use have strong genetic components, which may overlap. It has been suggested that smoking in schizophrenia may be a form of self-medication in an attempt to treat an underlying biological pathology. Smoking normalizes auditory evoked potential and eye tracking deficits in schizophrenia, as well as improving cognitive function. Nicotine acts through a family of nicotinic receptors with either high or low affinity for nicotine. The loci for several of these receptors have been genetically linked to both smoking and to schizophrenia. Smoking changes gene expression for more than 200 genes in human hippocampus, and differentially normalizes aberrant gene expression in schizophrenia. The α7* nicotinic receptor, linked to schizophrenia and smoking, has been implicated in sensory processing deficits and is important for cognition and protection from neurotoxicity. Nicotine, however, has multiple health risks and desensitizes the receptor. A Phase I trial of DMXB-A, an α7* agonist, shows improvement in both P50 gating and in cognition, suggesting that further development of nicotinic cholinergic drugs is a promising direction in schizophrenia research.
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Affiliation(s)
- Sherry Leonard
- Department of Psychiatry, University of Colorado at Denver
- Department of Pharmacology, University of Colorado at Denver
- Health Sciences Center, the Veterans Affairs Medical Research Service, Denver, Colorado
| | - Sharon Mexal
- The Institute for Behavioral Genetics, Boulder, Colorado
| | - Robert Freedman
- Department of Psychiatry, University of Colorado at Denver
- Department of Pharmacology, University of Colorado at Denver
- Health Sciences Center, the Veterans Affairs Medical Research Service, Denver, Colorado
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Nicodemus KK, Kolachana BS, Vakkalanka R, Straub RE, Giegling I, Egan MF, Rujescu D, Weinberger DR. Evidence for statistical epistasis between catechol-O-methyltransferase (COMT) and polymorphisms in RGS4, G72 (DAOA), GRM3, and DISC1: influence on risk of schizophrenia. Hum Genet 2006; 120:889-906. [PMID: 17006672 DOI: 10.1007/s00439-006-0257-3] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2006] [Accepted: 08/31/2006] [Indexed: 10/24/2022]
Abstract
Catechol-O-methyltransferase (COMT) regulates dopamine degradation and is located in a genomic region that is deleted in a syndrome associated with psychosis, making it a promising candidate gene for schizophrenia. COMT also has been shown to influence prefrontal cortex processing efficiency. Prefrontal processing dysfunction is a common finding in schizophrenia, and a background of inefficient processing may modulate the effect of other candidate genes. Using the NIMH sibling study (SS), a non-independent case-control set, and an independent German (G) case-control set, we performed conditional/unconditional logistic regression to test for epistasis between SNPs in COMT (rs2097603, Val158Met (rs4680), rs165599) and polymorphisms in other schizophrenia susceptibility genes. Evidence for interaction was evaluated using a likelihood ratio test (LRT) between nested models. SNPs in RGS4, G72, GRM3, and DISC1 showed evidence for significant statistical epistasis with COMT. A striking result was found in RGS4: three of five SNPs showed a significant increase in risk [LRT P-values: 90387 = 0.05 (SS); SNP4 = 0.02 (SS), 0.02 (G); SNP18 = 0.04 (SS), 0.008 (G)] in interaction with COMT; main effects for RGS4 SNPs were null. Significant results for SNP4 and SNP18 were also found in the German study. We were able to detect statistical interaction between COMT and polymorphisms in candidate genes for schizophrenia, many of which had no significant main effect. In addition, we were able to replicate other studies, including allelic directionality. The use of epistatic models may improve replication of psychiatric candidate gene studies.
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Affiliation(s)
- Kristin K Nicodemus
- Clinical Brain Disorders Branch, National Institute of Mental Health, National Institute of Health, Bethesda, MD 20892, USA
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