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Newman AH, Xi ZX, Heidbreder C. Current Perspectives on Selective Dopamine D 3 Receptor Antagonists/Partial Agonists as Pharmacotherapeutics for Opioid and Psychostimulant Use Disorders. Curr Top Behav Neurosci 2023; 60:157-201. [PMID: 35543868 PMCID: PMC9652482 DOI: 10.1007/7854_2022_347] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Over three decades of evidence indicate that dopamine (DA) D3 receptors (D3R) are involved in the control of drug-seeking behavior and may play an important role in the pathophysiology of substance use disorders (SUD). The expectation that a selective D3R antagonist/partial agonist would be efficacious for the treatment of SUD is based on the following key observations. First, D3R are distributed in strategic areas belonging to the mesolimbic DA system such as the ventral striatum, midbrain, and ventral pallidum, which have been associated with behaviors controlled by the presentation of drug-associated cues. Second, repeated exposure to drugs of abuse produces neuroadaptations in the D3R system. Third, the synthesis and characterization of highly potent and selective D3R antagonists/partial agonists have further strengthened the role of the D3R in SUD. Based on extensive preclinical and preliminary clinical evidence, the D3R shows promise as a target for the development of pharmacotherapies for SUD as reflected by their potential to (1) regulate the motivation to self-administer drugs and (2) disrupt the responsiveness to drug-associated stimuli that play a key role in reinstatement of drug-seeking behavior triggered by re-exposure to the drug itself, drug-associated environmental cues, or stress. The availability of PET ligands to assess clinically relevant receptor occupancy by selective D3R antagonists/partial agonists, the definition of reliable dosing, and the prospect of using human laboratory models may further guide the design of clinical proof of concept studies. Pivotal clinical trials for more rapid progression of this target toward regulatory approval are urgently required. Finally, the discovery that highly selective D3R antagonists, such as R-VK4-116 and R-VK4-40, do not adversely affect peripheral biometrics or cardiovascular effects alone or in the presence of oxycodone or cocaine suggests that this class of drugs has great potential in safely treating psychostimulant and/or opioid use disorders.
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Affiliation(s)
- Amy Hauck Newman
- Medicinal Chemistry Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse-Intramural Research Program, Baltimore, MD, USA.
| | - Zheng-Xiong Xi
- Medicinal Chemistry Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse-Intramural Research Program, Baltimore, MD, USA
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2
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Islam KUS, Meli N, Blaess S. The Development of the Mesoprefrontal Dopaminergic System in Health and Disease. Front Neural Circuits 2021; 15:746582. [PMID: 34712123 PMCID: PMC8546303 DOI: 10.3389/fncir.2021.746582] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 09/10/2021] [Indexed: 12/18/2022] Open
Abstract
Midbrain dopaminergic neurons located in the substantia nigra and the ventral tegmental area are the main source of dopamine in the brain. They send out projections to a variety of forebrain structures, including dorsal striatum, nucleus accumbens, and prefrontal cortex (PFC), establishing the nigrostriatal, mesolimbic, and mesoprefrontal pathways, respectively. The dopaminergic input to the PFC is essential for the performance of higher cognitive functions such as working memory, attention, planning, and decision making. The gradual maturation of these cognitive skills during postnatal development correlates with the maturation of PFC local circuits, which undergo a lengthy functional remodeling process during the neonatal and adolescence stage. During this period, the mesoprefrontal dopaminergic innervation also matures: the fibers are rather sparse at prenatal stages and slowly increase in density during postnatal development to finally reach a stable pattern in early adulthood. Despite the prominent role of dopamine in the regulation of PFC function, relatively little is known about how the dopaminergic innervation is established in the PFC, whether and how it influences the maturation of local circuits and how exactly it facilitates cognitive functions in the PFC. In this review, we provide an overview of the development of the mesoprefrontal dopaminergic system in rodents and primates and discuss the role of altered dopaminergic signaling in neuropsychiatric and neurodevelopmental disorders.
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Affiliation(s)
- K Ushna S Islam
- Neurodevelopmental Genetics, Institute of Reconstructive Neurobiology, Medical Faculty, University of Bonn, Bonn, Germany
| | - Norisa Meli
- Neurodevelopmental Genetics, Institute of Reconstructive Neurobiology, Medical Faculty, University of Bonn, Bonn, Germany.,Institute of Neuropathology, Section for Translational Epilepsy Research, Medical Faculty, University of Bonn, Bonn, Germany
| | - Sandra Blaess
- Neurodevelopmental Genetics, Institute of Reconstructive Neurobiology, Medical Faculty, University of Bonn, Bonn, Germany
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3
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Angarita GA, Hadizadeh H, Cerdena I, Potenza MN. Can pharmacotherapy improve treatment outcomes in people with co-occurring major depressive and cocaine use disorders? Expert Opin Pharmacother 2021; 22:1669-1683. [PMID: 34042556 DOI: 10.1080/14656566.2021.1931684] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Introduction: Major depressive disorder (MDD) and cocaine use disorder (CUD) are prevalent and frequently co-occur. When co-occurring, the presence of one disorder typically negatively impacts the prognosis for the other. Given the clinical relevance, we sought to examine pharmacotherapies for co-occurring CUD and MDD. While multiple treatment options have been examined in the treatment of each condition individually, studies exploring pharmacological options for their comorbidity are fewer and not conclusive.Areas Covered: For this review, the authors searched the literature in PubMed using clinical query options for therapies and keywords relating to each condition. Then, they described potentially promising pharmacologic therapeutic options based on shared mechanisms between the two conditions and/or results from individual clinical trials conducted to date.Expert opinion: Medications like stimulants, dopamine (D3) receptors partial agonists or antagonists, antagonists of kappa opioid receptors, topiramate, and ketamine could be promising as there is significant overlap relating to reward deficiency models, antireward pathways, and altered glutamatergic systems. However, the available clinical literature on any one of these types of agents is mixed. Additionally, for some agents there is possible concern related to abuse potential (e.g. ketamine and stimulants).
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Affiliation(s)
- Gustavo A Angarita
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.,Clinical Neuroscience Research Unit, Connecticut Mental Health Center, New Haven, CT, USA
| | - Hasti Hadizadeh
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.,Clinical Neuroscience Research Unit, Connecticut Mental Health Center, New Haven, CT, USA
| | - Ignacio Cerdena
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.,Connecticut Mental Health Center, New Haven, CT, USA
| | - Marc N Potenza
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.,Connecticut Mental Health Center, New Haven, CT, USA.,Child Study Center, Yale University School of Medicine, New Haven, CT, USA.,Department of Neuroscience, Yale University, New Haven, CT, USA.,Connecticut Council on Problem Gambling, Wethersfield, CT, USA
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Lanza K, Bishop C. Dopamine D3 Receptor Plasticity in Parkinson's Disease and L-DOPA-Induced Dyskinesia. Biomedicines 2021; 9:biomedicines9030314. [PMID: 33808538 PMCID: PMC8003204 DOI: 10.3390/biomedicines9030314] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/16/2021] [Accepted: 03/17/2021] [Indexed: 11/21/2022] Open
Abstract
Parkinson’s Disease (PD) is characterized by primary and secondary plasticity that occurs in response to progressive degeneration and long-term L-DOPA treatment. Some of this plasticity contributes to the detrimental side effects associated with chronic L-DOPA treatment, namely L-DOPA-induced dyskinesia (LID). The dopamine D3 receptor (D3R) has emerged as a promising target in LID management as it is upregulated in LID. This upregulation occurs primarily in the D1-receptor-bearing (D1R) cells of the striatum, which have been repeatedly implicated in LID manifestation. D3R undergoes dynamic changes both in PD and in LID, making it difficult to delineate D3R’s specific contributions, but recent genetic and pharmacologic tools have helped to clarify its role in LID. The following review will discuss these changes, recent advances to better clarify D3R in both PD and LID and potential steps for translating these findings.
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Affiliation(s)
- Kathryn Lanza
- Department of Physiology, Northwestern University, Chicago, IL 60201, USA;
| | - Christopher Bishop
- Department of Psychology, Binghamton University, Binghamton, NY 13902, USA
- Correspondence:
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Prasad K, de Vries EFJ, Elsinga PH, Dierckx RAJO, van Waarde A. Allosteric Interactions between Adenosine A 2A and Dopamine D 2 Receptors in Heteromeric Complexes: Biochemical and Pharmacological Characteristics, and Opportunities for PET Imaging. Int J Mol Sci 2021; 22:ijms22041719. [PMID: 33572077 PMCID: PMC7915359 DOI: 10.3390/ijms22041719] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 02/02/2021] [Accepted: 02/03/2021] [Indexed: 12/17/2022] Open
Abstract
Adenosine and dopamine interact antagonistically in living mammals. These interactions are mediated via adenosine A2A and dopamine D2 receptors (R). Stimulation of A2AR inhibits and blockade of A2AR enhances D2R-mediated locomotor activation and goal-directed behavior in rodents. In striatal membrane preparations, adenosine decreases both the affinity and the signal transduction of D2R via its interaction with A2AR. Reciprocal A2AR/D2R interactions occur mainly in striatopallidal GABAergic medium spiny neurons (MSNs) of the indirect pathway that are involved in motor control, and in striatal astrocytes. In the nucleus accumbens, they also take place in MSNs involved in reward-related behavior. A2AR and D2R co-aggregate, co-internalize, and co-desensitize. They are at very close distance in biomembranes and form heteromers. Antagonistic interactions between adenosine and dopamine are (at least partially) caused by allosteric receptor–receptor interactions within A2AR/D2R heteromeric complexes. Such interactions may be exploited in novel strategies for the treatment of Parkinson’s disease, schizophrenia, substance abuse, and perhaps also attention deficit-hyperactivity disorder. Little is known about shifting A2AR/D2R heteromer/homodimer equilibria in the brain. Positron emission tomography with suitable ligands may provide in vivo information about receptor crosstalk in the living organism. Some experimental approaches, and strategies for the design of novel imaging agents (e.g., heterobivalent ligands) are proposed in this review.
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Affiliation(s)
- Kavya Prasad
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713GZ Groningen, The Netherlands; (E.F.J.d.V.); (P.H.E.); (R.A.J.O.D.)
- Correspondence: (K.P.); (A.v.W.); Tel.: +31-50-3613215
| | - Erik F. J. de Vries
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713GZ Groningen, The Netherlands; (E.F.J.d.V.); (P.H.E.); (R.A.J.O.D.)
| | - Philip H. Elsinga
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713GZ Groningen, The Netherlands; (E.F.J.d.V.); (P.H.E.); (R.A.J.O.D.)
| | - Rudi A. J. O. Dierckx
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713GZ Groningen, The Netherlands; (E.F.J.d.V.); (P.H.E.); (R.A.J.O.D.)
- Department of Diagnostic Sciences, Ghent University Faculty of Medicine and Health Sciences, C.Heymanslaan 10, 9000 Gent, Belgium
| | - Aren van Waarde
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713GZ Groningen, The Netherlands; (E.F.J.d.V.); (P.H.E.); (R.A.J.O.D.)
- Correspondence: (K.P.); (A.v.W.); Tel.: +31-50-3613215
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Neuronal Dopamine D3 Receptors: Translational Implications for Preclinical Research and CNS Disorders. Biomolecules 2021; 11:biom11010104. [PMID: 33466844 PMCID: PMC7830622 DOI: 10.3390/biom11010104] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 01/07/2021] [Accepted: 01/08/2021] [Indexed: 02/06/2023] Open
Abstract
Dopamine (DA), as one of the major neurotransmitters in the central nervous system (CNS) and periphery, exerts its actions through five types of receptors which belong to two major subfamilies such as D1-like (i.e., D1 and D5 receptors) and D2-like (i.e., D2, D3 and D4) receptors. Dopamine D3 receptor (D3R) was cloned 30 years ago, and its distribution in the CNS and in the periphery, molecular structure, cellular signaling mechanisms have been largely explored. Involvement of D3Rs has been recognized in several CNS functions such as movement control, cognition, learning, reward, emotional regulation and social behavior. D3Rs have become a promising target of drug research and great efforts have been made to obtain high affinity ligands (selective agonists, partial agonists and antagonists) in order to elucidate D3R functions. There has been a strong drive behind the efforts to find drug-like compounds with high affinity and selectivity and various functionality for D3Rs in the hope that they would have potential treatment options in CNS diseases such as schizophrenia, drug abuse, Parkinson’s disease, depression, and restless leg syndrome. In this review, we provide an overview and update of the major aspects of research related to D3Rs: distribution in the CNS and periphery, signaling and molecular properties, the status of ligands available for D3R research (agonists, antagonists and partial agonists), behavioral functions of D3Rs, the role in neural networks, and we provide a summary on how the D3R-related drug research has been translated to human therapy.
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Newman AH, Ku T, Jordan CJ, Bonifazi A, Xi ZX. New Drugs, Old Targets: Tweaking the Dopamine System to Treat Psychostimulant Use Disorders. Annu Rev Pharmacol Toxicol 2021; 61:609-628. [PMID: 33411583 DOI: 10.1146/annurev-pharmtox-030220-124205] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The abuse of illicit psychostimulants such as cocaine and methamphetamine continues to pose significant health and societal challenges. Despite considerable efforts to develop medications to treat psychostimulant use disorders, none have proven effective, leaving an underserved patient population and unanswered questions about what mechanism(s) of action should be targeted for developing pharmacotherapies. As both cocaine and methamphetamine rapidly increase dopamine (DA) levels in mesolimbic brain regions, leading to euphoria that in some can lead to addiction, targets in which this increased dopaminergic tone may be mitigated have been explored. Further, understanding and targeting mechanisms underlying relapse are fundamental to the success of discovering medications that reduce the reinforcing effects of the drug of abuse, decrease the negative reinforcement or withdrawal/negative affect that occurs during abstinence, or both. Atypical inhibitors of the DA transporter and partial agonists/antagonists at DA D3 receptors are described as two promising targets for future drug development.
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Affiliation(s)
- Amy Hauck Newman
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland 21224, USA;
| | - Therese Ku
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland 21224, USA;
| | - Chloe J Jordan
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland 21224, USA;
| | - Alessandro Bonifazi
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland 21224, USA;
| | - Zheng-Xiong Xi
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland 21224, USA;
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8
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Morales-Mulia S, Magdaleno-Madrigal VM, Nicolini H, Genis-Mendoza A, Morales-Mulia M. Orexin-A up-regulates dopamine D2 receptor and mRNA in the nucleus accumbens Shell. Mol Biol Rep 2020; 47:9689-9697. [PMID: 33170427 DOI: 10.1007/s11033-020-05979-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 11/03/2020] [Indexed: 01/11/2023]
Abstract
Orexins-A (OrxA) and -B (OrxB) neuropeptides are synthesized by a group of neurons located in the lateral hypothalamus and adjacent perifornical area, which send their projections to the mesolimbic dopaminergic (DAergic) system including ventral tegmental area and nucleus accumbens (NAc), where orexin receptors are expressed. NAc plays a central role in reward-seeking behavior and drug abuse. NAc-neurons express dopamine-1 (D1R) and dopamine-2 (D2R) receptors. Orexins bind to their two cognate G-protein-coupled receptors, orexin-receptor type-1 (Orx1R) and type-2 (Orx2R). Orexin receptor signaling is involved in behaviors such as motivation and addiction. Orexin-containing neurons modulate DAergic activity that is key in synaptic plasticity induced by addictive drugs. However, the effect of OrxA on expression and content of DAergic receptors in NAc is unknown. The purpose of this study was to investigate whether OrxA can alter gene expression and protein levels of D1R/D2R in NAc. Gene expression was evaluated by real-time PCR analysis and protein levels by western blot in rats. The results show that intracerebroventricular (i.c.v.) injection of OrxA increases both gene transcription and protein content of D2R but fails to modify D1R. This effect was also confirmed with OrxA infusion in NAc/Shell. Our results demonstrate for the first time that OrxA induces up-regulation of gene and protein of D2R in NAc. These findings support the hypothesis that OrxA modulates the DAergic transmission and this may serve to understand how orexin signaling enhances DA responses at baseline conditions and in response to psychostimulants.
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Affiliation(s)
- Sandra Morales-Mulia
- Departamento de Biología Celular, Facultad de Ciencias, UNAM, Mexico, DF, Mexico
| | | | - Humberto Nicolini
- Laboratory of Genomics of Psychiatric Diseases, Neurodegenerative and Addictions, National Institute of Genomic Medicine, Mexico, Mexico
| | - Alma Genis-Mendoza
- Laboratory of Genomics of Psychiatric Diseases, Neurodegenerative and Addictions, National Institute of Genomic Medicine, Mexico, Mexico.,Hospital Psiquiátrico Infantil "Dr. Juan N. Navarro" Psychiatric Attention Services, Mexico, Mexico
| | - Marcela Morales-Mulia
- Bases Moleculares de las Adicciones, Subdirección de Investigaciones Clínicas, INPRFM, Calzada México-Xochimilco 101, San Lorenzo Huipulco, Tlalpan, 14370, Mexico, DF, Mexico.
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9
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Castro DC, Bruchas MR. A Motivational and Neuropeptidergic Hub: Anatomical and Functional Diversity within the Nucleus Accumbens Shell. Neuron 2019; 102:529-552. [PMID: 31071288 PMCID: PMC6528838 DOI: 10.1016/j.neuron.2019.03.003] [Citation(s) in RCA: 125] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 02/22/2019] [Accepted: 03/01/2019] [Indexed: 01/14/2023]
Abstract
The mesocorticolimbic pathway is canonically known as the "reward pathway." Embedded within the center of this circuit is the striatum, a massive and complex network hub that synthesizes motivation, affect, learning, cognition, stress, and sensorimotor information. Although striatal subregions collectively share many anatomical and functional similarities, it has become increasingly clear that it is an extraordinarily heterogeneous region. In particular, the nucleus accumbens (NAc) medial shell has repeatedly demonstrated that the rules dictated by more dorsal aspects of the striatum do not apply or are even reversed in functional logic. These discrepancies are perhaps most easily captured when isolating the functions of various neuromodulatory peptide systems within the striatum. Endogenous peptides are thought to play a critical role in modulating striatal signals to either amplify or dampen evoked behaviors. Here we describe the anatomical-functional backdrop upon which several neuropeptides act within the NAc to modulate behavior, with a specific emphasis on nucleus accumbens medial shell and stress responsivity. Additionally, we propose that, as the field continues to dissect fast neurotransmitter systems within the NAc, we must also provide considerable contextual weight to the roles local peptides play in modulating these circuits to more comprehensively understand how this important subregion gates motivated behaviors.
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Affiliation(s)
- Daniel C Castro
- Center for Neurobiology of Addiction, Pain, and Emotion, University of Washington, Seattle, WA 98195, USA; Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA 98195, USA; Department of Pharmacology, University of Washington, Seattle, WA 98195, USA
| | - Michael R Bruchas
- Center for Neurobiology of Addiction, Pain, and Emotion, University of Washington, Seattle, WA 98195, USA; Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA 98195, USA; Department of Pharmacology, University of Washington, Seattle, WA 98195, USA.
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Genetic labeling reveals temporal and spatial expression pattern of D2 dopamine receptor in rat forebrain. Brain Struct Funct 2019; 224:1035-1049. [PMID: 30604007 PMCID: PMC6499762 DOI: 10.1007/s00429-018-01824-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 12/20/2018] [Indexed: 01/11/2023]
Abstract
The D2 dopamine receptor (Drd2) is implicated in several brain disorders such as schizophrenia, Parkinson’s disease, and drug addiction. Drd2 is also the primary target of both antipsychotics and Parkinson’s disease medications. Although the expression pattern of Drd2 is relatively well known in mouse brain, the temporal and spatial distribution of Drd2 is lesser clear in rat brain due to the lack of Drd2 reporter rat lines. Here, we used CRISPR/Cas9 techniques to generate two knockin rat lines: Drd2::Cre and Rosa26::loxp-stop-loxp-tdTomato. By crossing these two lines, we produced Drd2 reporter rats expressing the fluorescence protein tdTomato under the control of the endogenous Drd2 promoter. Using fluorescence imaging and unbiased stereology, we revealed the cellular expression pattern of Drd2 in adult and postnatal rat forebrain. Strikingly, the Drd2 expression pattern differs between Drd2 reporter rats and Drd2 reporter mice generated by BAC transgene in prefrontal cortex and hippocampus. These results provide fundamental information needed for the study of Drd2 function in rat forebrain. The Drd2::Cre rats generated here may represent a useful tool to study the function of neuronal populations expressing Drd2.
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Trace amine-associated receptor 1 agonists RO5263397 and RO5166017 attenuate quinpirole-induced yawning but not hypothermia in rats. Behav Pharmacol 2018; 28:590-593. [PMID: 28704278 DOI: 10.1097/fbp.0000000000000330] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Increasing evidence suggests that trace amine-associated receptor 1 (TAAR1) is an important modulator of the dopaminergic system. Existing molecular evidence indicates that TAAR1 regulates dopamine levels through interactions with dopamine transporters and D2 receptors. However, investigations to date have not been exhaustive and other pathways may be involved. In this study, we used a well-described set of behaviors, quinpirole-induced yawning and hypothermia, to explore the potential interaction of TAAR1 and D3 receptors, which are members of the 'D2-like' dopamine receptor subfamily. Previous studies have shown that for D2/D3 receptor agonists, the induction of yawning is a D3 receptor-mediated effect, whereas the inhibition of yawning and induction of hypothermia are D2 receptor-mediated effects. Quinpirole produced an inverted U-shaped dose-effect curve for yawning, which was shifted downward dose-dependently by each of the TAAR1 agonists RO5263397 and RO5166017. Quinpirole also produced dose-dependent hypothermia, which was not affected by either TAAR1 agonist. These results suggest that TAAR1 agonists may interact with D3 receptors and/or its downstream pathways, as opposed to D2 receptors. These findings may shed light on a previously unexplored possibility for the mechanism of TAAR1-mediated effects.
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Triarhou LC, Solà C, Mengod G, García-Ladona FJ, Landwehrmeyer B, Ghetti B, Palacios JM. Ventral Mesencephalic Grafts in the Neostriatum of the Weaver Mutant Mouse: Structural Molecule and Receptor Studies. Cell Transplant 2017; 4:39-48. [PMID: 7728332 DOI: 10.1177/096368979500400107] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Mesencephalic cell suspensions were prepared from E12 wild-type (+/+) mouse embryos and stereotaxically implanted into the dorsal neostriatum of weaver mutant mice (wv/wv), which have a genetic mesostriatal dopamine (DA) deficiency. Survival of DA neurons in the grafts was documented by tyrosine hydroxylase (TH) immunocytochemistry. Axon growth was monitored by immunocytochemistry using a battery of antibody markers, and the cellular localization of structural protein and receptor RNA transcripts was studied by in situ hybridization histochemistry using [32P]oigo-nucleotide probes. The cellw suspension grafts exhibited strong immunoreactivity for neural cell adhesion molecule (N-CAM), growth-associated phosphoprotein GAP-43, micro-tubule-associated protein 2 (MAP2), β-amyloid protein precursor (βAPP), and phosphorylated neurofilament epitopes (clone SMI-31); intermediate-to-high levels of immunoreactivity were seen for synaptophysin. High levels of hybridization were found in the grafts for the RNA transcripts of GAP-43, MAP2, and isoforms βAPP695, βAPP714 and βAPP751 of the βAPP. No hybridization signal was detected in the grafts for DA D2 or neurotensin receptor mRNAs, both of which are normally expressed by nigral DA neurons. DA receptor autoradiography using the D2/D3 agonist [3H]CV 205-502 as a ligand showed no binding in the transplants, indicating an apparent abnormality of grafted cells; neurotensin binding sites, labeled with [125I]neurotensin, were visualized in the suspensions, indicating the possibility that receptors could be present but that RNA message levels might be too low to allow detection. These findings offer a molecular correlate of axonal, dendritic and structural protein expression by transplanted mesencephalic neurons; further, they suggest that specific functional properties of grafted nigral cells are maintained after transplantation, while other aspects of their cellular biology may be compromised.
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Affiliation(s)
- L C Triarhou
- Department of Pathology, Indiana University School of Medicine, Indianapolis 46202, USA
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13
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Leggio GM, Bucolo C, Platania CBM, Salomone S, Drago F. Current drug treatments targeting dopamine D3 receptor. Pharmacol Ther 2016; 165:164-77. [DOI: 10.1016/j.pharmthera.2016.06.007] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 06/08/2016] [Indexed: 12/29/2022]
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Huang M, Kwon S, Oyamada Y, Rajagopal L, Miyauchi M, Meltzer HY. Dopamine D3 receptor antagonism contributes to blonanserin-induced cortical dopamine and acetylcholine efflux and cognitive improvement. Pharmacol Biochem Behav 2015; 138:49-57. [DOI: 10.1016/j.pbb.2015.09.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 09/09/2015] [Accepted: 09/11/2015] [Indexed: 12/01/2022]
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15
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Villalba RM, Mathai A, Smith Y. Morphological changes of glutamatergic synapses in animal models of Parkinson's disease. Front Neuroanat 2015; 9:117. [PMID: 26441550 PMCID: PMC4585113 DOI: 10.3389/fnana.2015.00117] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 08/17/2015] [Indexed: 02/05/2023] Open
Abstract
The striatum and the subthalamic nucleus (STN) are the main entry doors for extrinsic inputs to reach the basal ganglia (BG) circuitry. The cerebral cortex, thalamus and brainstem are the key sources of glutamatergic inputs to these nuclei. There is anatomical, functional and neurochemical evidence that glutamatergic neurotransmission is altered in the striatum and STN of animal models of Parkinson’s disease (PD) and that these changes may contribute to aberrant network neuronal activity in the BG-thalamocortical circuitry. Postmortem studies of animal models and PD patients have revealed significant pathology of glutamatergic synapses, dendritic spines and microcircuits in the striatum of parkinsonians. More recent findings have also demonstrated a significant breakdown of the glutamatergic corticosubthalamic system in parkinsonian monkeys. In this review, we will discuss evidence for synaptic glutamatergic dysfunction and pathology of cortical and thalamic inputs to the striatum and STN in models of PD. The potential functional implication of these alterations on synaptic integration, processing and transmission of extrinsic information through the BG circuits will be considered. Finally, the significance of these pathological changes in the pathophysiology of motor and non-motor symptoms in PD will be examined.
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Affiliation(s)
- Rosa M Villalba
- Yerkes National Primate Research Center, Emory University Atlanta, GA, USA ; UDALL Center of Excellence for Parkinson's Disease, Emory University Atlanta, GA, USA
| | - Abraham Mathai
- Yerkes National Primate Research Center, Emory University Atlanta, GA, USA ; UDALL Center of Excellence for Parkinson's Disease, Emory University Atlanta, GA, USA
| | - Yoland Smith
- Yerkes National Primate Research Center, Emory University Atlanta, GA, USA ; UDALL Center of Excellence for Parkinson's Disease, Emory University Atlanta, GA, USA ; Department of Neurology, Emory University Atlanta, GA, USA
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Gonzales KK, Smith Y. Cholinergic interneurons in the dorsal and ventral striatum: anatomical and functional considerations in normal and diseased conditions. Ann N Y Acad Sci 2015; 1349:1-45. [PMID: 25876458 DOI: 10.1111/nyas.12762] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Striatal cholinergic interneurons (ChIs) are central for the processing and reinforcement of reward-related behaviors that are negatively affected in states of altered dopamine transmission, such as in Parkinson's disease or drug addiction. Nevertheless, the development of therapeutic interventions directed at ChIs has been hampered by our limited knowledge of the diverse anatomical and functional characteristics of these neurons in the dorsal and ventral striatum, combined with the lack of pharmacological tools to modulate specific cholinergic receptor subtypes. This review highlights some of the key morphological, synaptic, and functional differences between ChIs of different striatal regions and across species. It also provides an overview of our current knowledge of the cellular localization and function of cholinergic receptor subtypes. The future use of high-resolution anatomical and functional tools to study the synaptic microcircuitry of brain networks, along with the development of specific cholinergic receptor drugs, should help further elucidate the role of striatal ChIs and permit efficient targeting of cholinergic systems in various brain disorders, including Parkinson's disease and addiction.
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Affiliation(s)
- Kalynda K Gonzales
- Yerkes National Primate Research Center, Department of Neurology and Udall Center of Excellence for Parkinson's Disease Research, Emory University, Atlanta, Georgia.,Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York
| | - Yoland Smith
- Yerkes National Primate Research Center, Department of Neurology and Udall Center of Excellence for Parkinson's Disease Research, Emory University, Atlanta, Georgia
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Davoodi N, te Riele P, Langlois X. Examining dopamine D3 receptor occupancy by antipsychotic drugs via [3H]7-OH-DPAT ex vivo autoradiography and its cross-validation via c-fos immunohistochemistry in the rat brain. Eur J Pharmacol 2014; 740:669-75. [DOI: 10.1016/j.ejphar.2014.06.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 06/06/2014] [Accepted: 06/16/2014] [Indexed: 11/16/2022]
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Schmouth JF, Dion PA, Rouleau GA. Genetics of essential tremor: From phenotype to genes, insights from both human and mouse studies. Prog Neurobiol 2014; 119-120:1-19. [DOI: 10.1016/j.pneurobio.2014.05.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 04/16/2014] [Accepted: 05/02/2014] [Indexed: 11/30/2022]
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Prante O, Maschauer S, Banerjee A. Radioligands for the dopamine receptor subtypes. J Labelled Comp Radiopharm 2014; 56:130-48. [PMID: 24285319 DOI: 10.1002/jlcr.3000] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 10/11/2012] [Accepted: 11/06/2012] [Indexed: 12/29/2022]
Abstract
The actions of the predominant neurotransmitter in the brain, dopamine, are mediated by the postsynaptic dopamine receptors. The five dopamine receptor subtypes and their regulation have been associated with a large variety of psychiatric diseases. Therefore, positron emission tomography (PET) imaging studies using suitable and selective (18) F-labeled and (11) C-labeled dopamine receptor radioligands could provide valuable knowledge on the impact of receptor density on the pathogenesis and evolvement of neuropsychiatric and neurological diseases. This special issue subchapter provides a summary of the most important (18) F-labeled and (11) C-labeled radioligands for PET imaging of the dopamine receptor subtypes, their radiochemistry, and characteristics from in vitro and in vivo applications, considering not only the already established PET ligands but also the recently published preclinical work.
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Affiliation(s)
- Olaf Prante
- Laboratory of Molecular Imaging and Radiochemistry, Friedrich-Alexander University, Schwabachanlage 6, D-91054, Erlangen, Germany
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Leggio GM, Salomone S, Bucolo C, Platania C, Micale V, Caraci F, Drago F. Dopamine D3 receptor as a new pharmacological target for the treatment of depression. Eur J Pharmacol 2013; 719:25-33. [DOI: 10.1016/j.ejphar.2013.07.022] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2013] [Revised: 06/05/2013] [Accepted: 07/01/2013] [Indexed: 12/12/2022]
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Wheeler TL, Smith LN, Bachus SE, McDonald CG, Fryxell KJ, Smith RF. Low-dose adolescent nicotine and methylphenidate have additive effects on adult behavior and neurochemistry. Pharmacol Biochem Behav 2012; 103:723-34. [PMID: 23262400 DOI: 10.1016/j.pbb.2012.12.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2012] [Revised: 12/01/2012] [Accepted: 12/06/2012] [Indexed: 12/30/2022]
Abstract
Adolescents with Attention Deficit Hyperactivity Disorder (ADHD) have higher rates of smoking than adolescents without ADHD. Since methylphenidate is the primary drug used to treat ADHD, it is likely that many adolescents are exposed to both methylphenidate and nicotine. Recent studies have established that adolescent nicotine induces long-term changes in several neurobehavioral variables. Limited data also suggest that adolescent methylphenidate may affect neural development. Nicotine tolerance is a well-established behavioral phenomenon in rodents, yet the underlying mechanism remains elusive. Recent theories suggest that changes in ventral striatal dopamine indices may relate to nicotine tolerance. As an initial determination of whether nicotine and methylphenidate have additive effects on neurobehavioral development, the present study investigated the combined effects of adolescent nicotine [2mg/kg/d] alone or in conjunction with methylphenidate [1.5mg/kg, 2× daily] following a one-month drug free period on adult behavioral tolerance to nicotine [0.5mg/kg s.c.] and its relation to dopamine receptor mRNA expression in the ventral striatum. Animals with chronic combined (nicotine+methylphenidate) adolescent exposure displayed stronger tolerance as adults to the nicotine-induced locomotor effects in comparison to animals with adolescent exposure to nicotine alone, methylphenidate alone, or controls. Combined chronic adolescent exposure significantly elevated adult D3nf mRNA expression levels in the nucleus accumbens, however a single nicotine injection in adults increased D3nf mRNA levels in naïve animals and decreased D3nf mRNA levels in those that had been previously exposed to combined stimulants during adolescence. Conversely, a single adult nicotine injection increased D1 mRNA levels in the adult nucleus accumbens, particularly in the shell, but only in rats previously exposed to nicotine or methylphenidate as adolescents. To our knowledge this is the first study that has shown long-term behavioral and neurochemical changes stemming from low chronic exposure of these two commonly co-consumed stimulants during adolescence.
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Affiliation(s)
- Tracey L Wheeler
- Department of Psychology, Biopsychology, George Mason University, David King Hall Room 2086, 4400 University Drive MSN 3F5, Fairfax, VA 22030, United States.
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Beauvais G, Atwell K, Jayanthi S, Ladenheim B, Cadet JL. Involvement of dopamine receptors in binge methamphetamine-induced activation of endoplasmic reticulum and mitochondrial stress pathways. PLoS One 2011; 6:e28946. [PMID: 22174933 PMCID: PMC3236770 DOI: 10.1371/journal.pone.0028946] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Accepted: 11/17/2011] [Indexed: 01/11/2023] Open
Abstract
Single large doses of methamphetamine (METH) cause endoplasmic reticulum (ER) stress and mitochondrial dysfunctions in rodent striata. The dopamine D1 receptor appears to be involved in these METH-mediated stresses. The purpose of this study was to investigate if dopamine D1 and D2 receptors are involved in ER and mitochondrial stresses caused by single-day METH binges in the rat striatum. Male Sprague-Dawley rats received 4 injections of 10 mg/kg of METH alone or in combination with a putative D1 or D2 receptor antagonist, SCH23390 or raclopride, respectively, given 30 min prior to each METH injection. Rats were euthanized at various timepoints afterwards. Striatal tissues were used in quantitative RT-PCR and western blot analyses. We found that binge METH injections caused increased expression of the pro-survival genes, BiP/GRP-78 and P58IPK, in a SCH23390-sensitive manner. METH also caused up-regulation of ER-stress genes, Atf2, Atf3, Atf4, CHOP/Gadd153 and Gadd34. The expression of heat shock proteins (HSPs) was increased after METH injections. SCH23390 completely blocked induction in all analyzed ER stress-related proteins that included ATF3, ATF4, CHOP/Gadd153, HSPs and caspase-12. The dopamine D2-like antagonist, raclopride, exerted small to moderate inhibitory influence on some METH-induced changes in ER stress proteins. Importantly, METH caused decreases in the mitochondrial anti-apoptotic protein, Bcl-2, but increases in the pro-apoptotic proteins, Bax, Bad and cytochrome c, in a SCH23390-sensitive fashion. In contrast, raclopride provided only small inhibition of METH-induced changes in mitochondrial proteins. These findings indicate that METH-induced activation of striatal ER and mitochondrial stress pathways might be more related to activation of SCH23390-sensitive receptors.
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Affiliation(s)
- Genevieve Beauvais
- Molecular Neuropsychiatry Research Branch, National Institute on Drug Abuse, Intramural Research Program, Baltimore, Maryland, United States of America
- Faculté de Pharmacie, Université Paris Descartes, Paris, France
| | - Kenisha Atwell
- Molecular Neuropsychiatry Research Branch, National Institute on Drug Abuse, Intramural Research Program, Baltimore, Maryland, United States of America
| | - Subramaniam Jayanthi
- Molecular Neuropsychiatry Research Branch, National Institute on Drug Abuse, Intramural Research Program, Baltimore, Maryland, United States of America
| | - Bruce Ladenheim
- Molecular Neuropsychiatry Research Branch, National Institute on Drug Abuse, Intramural Research Program, Baltimore, Maryland, United States of America
| | - Jean Lud Cadet
- Molecular Neuropsychiatry Research Branch, National Institute on Drug Abuse, Intramural Research Program, Baltimore, Maryland, United States of America
- * E-mail:
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McCormick PN, Ginovart N, Wilson AA. Isoflurane anaesthesia differentially affects the amphetamine sensitivity of agonist and antagonist D2/D3 positron emission tomography radiotracers: implications for in vivo imaging of dopamine release. Mol Imaging Biol 2011; 13:737-46. [PMID: 20680481 DOI: 10.1007/s11307-010-0380-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
PURPOSE Using positron emission tomography in isoflurane-anaesthetised cat, we recently demonstrated that the effect of D-amphetamine (AMPH) was greater on the binding potential (BP(ND)) of the agonist dopamine D2/D3 radiotracer (+)-4-[(11)C]propyl-3,4,4a,5,6,10b-hexahydro-2H-naphtho[1,2-b][1, 4]oxazin-9-ol ([(11)C]-(+)-PHNO) than on that of the antagonist [(11)C]-raclopride, a finding that we were unable to replicate in conscious rat. Herein we tested whether isoflurane differentially affects the AMPH sensitivity of [(11)C]-(+)-PHNO and [(3)H]-raclopride. PROCEDURES Conscious or isoflurane-anaesthetised rats pretreated intravenously (i.v.) with saline or 4 mg/kg AMPH were co-injected i.v. with [(11)C]-(+)-PHNO/[(3)H]-raclopride or [(3)H]-(+)-PHNO/[(11)C]-(-)-N-propyl-norapomorphine ([(11)C]-(-)-NPA) and euthanised 2, 10, 20, 30, 40 or 60 min following [(11)C]-(+)-PHNO/[(3)H]-raclopride or 60 min following [(3)H]-(+)-PHNO/[(11)C]-(-)-NPA. Striatal binding at 60 min, estimated by the specific binding ratio (SBR) and the binding potential with respect to non-displaceable binding (BP(ND)) for pseudodynamic data, was calculated using the simplified reference tissue model. RESULTS Isoflurane increased [(11)C]-(+)-PHNO, [(3)H]-(+)-PHNO and [(11)C]-(-)-NPA SBR (mean ± SD) by 80 ± 30%, 170 ± 50% and 120 ± 40%, and doubled the effect of AMPH on the SBR of these radiotracers to -61 ± 9%, -69 ± 12% and -60 ± 12%, respectively. Neither effect was seen for [(3)H]-raclopride SBR. Similar results were observed for [(11)C]-(+)-PHNO and [(3)H]-raclopride BP(ND). CONCLUSIONS Isoflurane differentially increases the binding and AMPH sensitivity of [(11)C]-(+)-PHNO and [(11)C]-(-)-NPA relative to [(3)H]-raclopride, suggesting that agonist radiotracers will prove no more effective for imaging dopaminergic activity in human than antagonist radiotracers.
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Yamamoto K, Vernier P. The evolution of dopamine systems in chordates. Front Neuroanat 2011; 5:21. [PMID: 21483723 PMCID: PMC3070214 DOI: 10.3389/fnana.2011.00021] [Citation(s) in RCA: 157] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2010] [Accepted: 03/15/2011] [Indexed: 12/24/2022] Open
Abstract
Dopamine (DA) neurotransmission in the central nervous system (CNS) is found throughout chordates, and its emergence predates the divergence of chordates. Many of the molecular components of DA systems, such as biosynthetic enzymes, transporters, and receptors, are shared with those of other monoamine systems, suggesting the common origin of these systems. In the mammalian CNS, the DA neurotransmitter systems are diversified and serve for visual and olfactory perception, sensory–motor programming, motivation, memory, emotion, and endocrine regulations. Some of the functions are conserved among different vertebrate groups, while others are not, and this is reflected in the anatomical aspects of DA systems in the forebrain and midbrain. Recent findings concerning a second tyrosine hydroxylase gene (TH2) revealed new populations of DA-synthesizing cells, as evidenced in the periventricular hypothalamic zones of teleost fish. It is likely that the ancestor of vertebrates possessed TH2 DA-synthesizing cells, and the TH2 gene has been lost secondarily in placental mammals. All the vertebrates possess DA cells in the olfactory bulb, retina, and in the diencephalon. Midbrain DA cells are abundant in amniotes while absent in some groups, e.g., teleosts. Studies of protochordate DA cells suggest that the diencephalic DA cells were present before the divergence of the chordate lineage. In contrast, the midbrain cell populations have probably emerged in the vertebrate lineage following the development of the midbrain–hindbrain boundary. The functional flexibility of the DA systems, and the evolvability provided by duplication of the corresponding genes permitted a large diversification of these systems. These features were instrumental in the adaptation of brain functions to the very variable way of life of vertebrates.
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Affiliation(s)
- Kei Yamamoto
- Neurobiology and Development (UPR3294), Institute of Neurobiology Alfred Fessard, CNRS Gif-sur-Yvette, France
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McCormick PN, Kapur S, Graff-Guerrero A, Raymond R, Nobrega JN, Wilson AA. The antipsychotics olanzapine, risperidone, clozapine, and haloperidol are D2-selective ex vivo but not in vitro. Neuropsychopharmacology 2010; 35:1826-35. [PMID: 20410873 PMCID: PMC3055486 DOI: 10.1038/npp.2010.50] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Revised: 03/16/2010] [Accepted: 03/21/2010] [Indexed: 11/09/2022]
Abstract
In a recent human [(11)C]-(+)-PHNO positron emission tomography study, olanzapine, clozapine, and risperidone occupied D2 receptors in striatum (STR), but, despite their similar in vitro D2 and D3 affinities, failed to occupy D3 receptors in globus pallidus. This study had two aims: (1) to characterize the regional D2/D3 pharmacology of in vitro and ex vivo [(3)H]-(+)-PHNO binding sites in rat brain and (2) to compare, using [(3)H]-(+)-PHNO autoradiography, the ex vivo and in vitro pharmacology of olanzapine, clozapine, risperidone, and haloperidol. Using the D3-selective drug SB277011, we found that ex vivo and in vitro [(3)H]-(+)-PHNO binding in STR is exclusively due to D2, whereas that in cerebellar lobes 9 and 10 is exclusively due to D3. Surprisingly, the D3 contribution to [(3)H]-(+)-PHNO binding in the islands of Calleja, ventral pallidum, substantia nigra, and nucleus accumbens was greater ex vivo than in vitro. Ex vivo, systemically administered olanzapine, risperidone, and haloperidol, at doses occupying approximately 80% D2, did not occupy D3 receptors. Clozapine, which also occupied approximately 80% of D2 receptors ex vivo, occupied a smaller percentage of D3 receptors than predicted by its in vitro pharmacology. Across brain regions, ex vivo occupancy by antipsychotics was inversely related to the D3 contribution to [(3)H]-(+)-PHNO binding. In contrast, in vitro occupancy was similar across brain regions, independent of the regional D3 contribution. These data indicate that at clinically relevant doses, olanzapine, clozapine, risperidone, and haloperidol are D2-selective ex vivo. This unforeseen finding suggests that their clinical effects cannot be attributed to D3 receptor blockade.
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Abstract
Dopamine is a key neuromodulatory transmitter in the brain. It acts through
dopamine receptors to affect changes in neural activity, gene expression, and
behavior. In songbirds, dopamine is released into the striatal song nucleus Area
X, and the levels depend on social contexts of undirected and directed singing.
This differential release is associated with differential expression of
activity-dependent genes, such as egr1 (avian zenk), which in mammalian brain
are modulated by dopamine receptors. Here we cloned from zebra finch brain cDNAs
of all avian dopamine receptors: the D1 (D1A, D1B, D1D) and D2 (D2, D3, D4)
families. Comparative sequence analyses of predicted proteins revealed expected
phylogenetic relationships, in which the D1 family exists as single exon and the
D2 family exists as spliced exon genes. In both zebra finch and chicken, the
D1A, D1B, and D2 receptors were highly expressed in the striatum, the D1D and D3
throughout the pallium and within the mesopallium, respectively, and the D4
mainly in the cerebellum. Furthermore, within the zebra finch, all receptors,
except for D4, showed differential expression in song nuclei relative to the
surrounding regions and developmentally regulated expression that decreased for
most receptors during the sensory acquisition and sensorimotor phases of song
learning. Within Area X, half of the cells expressed both D1A and D2 receptors,
and a higher proportion of the D1A-only-containing neurons expressed egr1 during
undirected but not during directed singing. Our findings are consistent with
hypotheses that dopamine receptors may be involved in song development and
social context-dependent behaviors. J. Comp. Neurol. 518:741–769, 2010.
© 2009 Wiley-Liss, Inc.
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Affiliation(s)
- Lubica Kubikova
- Department of Neurobiology, Howard Hughes Medical Institute, Duke University Medical Center, Durham, North Carolina 27710, USA.
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McCormick PN, Kapur S, Reckless G, Wilson AA. Ex vivo [11C]-(+)-PHNO binding is unchanged in animal models displaying increased high-affinity states of the D2 receptor in vitro. Synapse 2009; 63:998-1009. [PMID: 19598174 DOI: 10.1002/syn.20671] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Dopamine (DA) D2 receptor supersensitivity has been linked to an increase in the density of the D2 high-affinity state as measured in vitro. The two- affinity-state model of the D2 receptor predicts that the ex vivo specific binding of [11C]-(+)-PHNO, an agonist radiotracer thought to bind selectively to the high-affinity state in vivo, should be increased in animal models that display in vitro increases in the proportion of receptors in the D2 high-affinity state. Here, we test this hypotheses by comparing the ex vivo SBR of [11C]-(+)-PHNO with that of the antagonist radiotracer [3H]-raclopride in three dopaminergically supersensitive rat models-AMPH-sensitized rats, rats withdrawn from chronic ethanol, and unilaterally 6-OHDA-lesioned rats-using ex vivo dual-radiotracer biodistribution studies. We find that in AMPH-sensitized rats and rats withdrawn from chronic ethanol treatment, models that exhibited approximately 4-fold increases in the D2 high-affinity state in vitro, the SBRs of [11C]-(+)-PHNO and [3H]-raclopride are unchanged relative to control rats. In unilaterally 6-OHDA-lesioned rats, we find that the increase in [11C]-(+)-PHNO SBR is no different than that observed for the antagonist radiotracer [3H]-raclopride (54% +/- 16% and 52% +/- 14%, respectively). In addition, the effect of acute AMPH pretreatment (4 mg/kg, i.v.) on the SBRs of [11C]-(+)-PHNO and [3H]-raclopride is equivalent in AMPH-sensitized (-38% +/- 12% and -36% +/- 8%, respectively) and in control rats (-40% +/- 11% and -38% +/- 7%). These data emphasize a significant discrepancy between in vitro and in vivo measures of D2 agonist binding, indicating that the two-affinity-state model of the D2 receptor may not apply veridically to living systems. The potential implications of this discrepancy are discussed.
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Affiliation(s)
- Patrick N McCormick
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada M5S1A8.
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Choy KHC, de Visser YP, van den Buuse M. The effect of 'two hit' neonatal and young-adult stress on dopaminergic modulation of prepulse inhibition and dopamine receptor density. Br J Pharmacol 2009; 156:388-96. [PMID: 19154431 PMCID: PMC2697842 DOI: 10.1111/j.1476-5381.2008.00008.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2008] [Revised: 07/31/2008] [Accepted: 08/29/2008] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND AND PURPOSE A combination of early neurodevelopmental insult(s) and young-adult stress exposure may be involved in the development of schizophrenia. We studied prepulse inhibition (PPI) regulation in rats after an early stress, maternal deprivation, combined with a later stress, simulated by chronic corticosterone treatment, and also determined whether changes in brain dopamine receptor density were involved. EXPERIMENTAL APPROACH Rats were subjected to either 24 h maternal deprivation on postnatal day 9, corticosterone treatment from 8 to 10 weeks of age, or both. At 12 weeks of age, the rats were injected with 0.1, 0.3 or 1.0 mg.kg(-1) of apomorphine or 0.5 or 2.5 mg.kg(-1) of amphetamine and PPI was determined using automated startle boxes. Dopamine D(1) and D(2) receptor levels were assessed in the nucleus accumbens and caudate nucleus using receptor autoradiography. KEY RESULTS Young-adult treatment with corticosterone resulted in attenuated disruption of PPI by apomorphine and amphetamine. In some rats, maternal deprivation resulted in reduced baseline PPI which added to the effect of corticosterone treatment. There was no down-regulation of dopamine D(1) or D(2) receptors. CONCLUSIONS AND IMPLICATIONS These results confirm and extend our finding of an inhibitory interaction of developmental stress on dopaminergic regulation of PPI. No corresponding changes in dopamine receptor density were observed in brain regions with a major involvement in PPI regulation, suggesting long-lasting desensitization of dopamine receptor signalling or indirect changes in PPI regulation.
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Affiliation(s)
- Kwok Ho Christopher Choy
- Behavioural Neuroscience Laboratory, Mental Health Research Institute of Victoria, 155 Oak Street, Parkville, Victoria 3052, Australia
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Hocke C, Prante O, Salama I, Hübner H, Löber S, Kuwert T, Gmeiner P. 18F-Labeled FAUC 346 and BP 897 derivatives as subtype-selective potential PET radioligands for the dopamine D3 receptor. ChemMedChem 2008; 3:788-93. [PMID: 18306190 DOI: 10.1002/cmdc.200700327] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Disturbances of neutrotransmission at the dopamine D3 receptor are related to several neuropsychiatric diseases and in particular to drug addiction. Herein, we report the computer-assisted prediction of D3 selectivities of new fluoroalkoxy-substituted receptor ligands by means of 3D-QSAR analysis. As close analogues of the D3-selective lead compound FAUC 346 and BP 879, the (19)F-substituted test compounds 4 a-d were synthesized and evaluated. In vitro investigation of their binding characteristics in transfected Chinese Hamster Ovary (CHO) cells led to excellent K(i) values between 0.12 and 0.69 nM at the dopamine D3 subtype. The benzothiophene-substituted carboxamide 4 a (K(i)=0.12 nM) displayed 133 and 283-fold selectivity over the structurally related D2(Long) and D4 subtypes, respectively. Mitogenesis assays showed the behavior of partial agonists. Based on these data, we synthesized the [(18)F]fluoroethoxy-substituted radioligands [(18)F]4 a-d. The N-[4-[4-(2-hydroxyphenyl)piperazin-1-yl]butyl]-2-carboxamides 3 a-d were prepared and labeled with 2-[(18)F]fluoroethyltosylate in a two-step procedure. Optimization of the (18)F-labeling conditions led to radiochemical yields between 24 and 65 %.
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Affiliation(s)
- Carsten Hocke
- Clinic of Nuclear Medicine, Friedrich-Alexander University, Krankenhausstrasse 12, 91054 Erlangen, Germany.
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McCormick PN, Kapur S, Seeman P, Wilson AA. Dopamine D2 receptor radiotracers [(11)C](+)-PHNO and [(3)H]raclopride are indistinguishably inhibited by D2 agonists and antagonists ex vivo. Nucl Med Biol 2007; 35:11-7. [PMID: 18158938 DOI: 10.1016/j.nucmedbio.2007.08.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2007] [Revised: 08/17/2007] [Accepted: 08/17/2007] [Indexed: 11/25/2022]
Abstract
INTRODUCTION In vitro, the dopamine D2 receptor exists in two states, with high and low affinity for agonists. The high-affinity state is the physiologically active state thought to be involved in dopaminergic illnesses such as schizophrenia. The positron emission tomography radiotracer [(11)C](+)-PHNO ([(11)C](+)-4-propyl-3,4,4a,5,6,10b-hexahydro-2H-naphtho[1,2-b][1,4]oxazin-9-ol), being a D2 agonist, should selectively label the high-affinity state at tracer dose and therefore be more susceptible to competition by agonist as compared to the antagonist [(3)H]raclopride, which binds to both affinity states. METHODS We tested this prediction using ex vivo dual-radiotracer experiments in conscious rats. D2 antagonists (haloperidol or clozapine), a partial agonist (aripiprazole), a full agonist [(-)-NPA] or the dopamine-releasing drug amphetamine (AMPH) were administered to rats prior to an intravenous coinjection of [(11)C](+)-PHNO and [(3)H]raclopride. Rats were sacrificed 60 min after radiotracer injection. Striatum, cerebellum and plasma samples were counted for (11)C and (3)H. The specific binding ratio {SBR, i.e., [%ID/g (striatum)-%ID/g (cerebellum)]/(%ID/g (cerebellum)} was used as the outcome measure. RESULTS In response to D2 antagonists, partial agonist or full agonist, [(11)C](+)-PHNO and [(3)H]raclopride SBRs responded indistinguishably in terms of both ED(50) and Hill slope (e.g., (-)-NPA ED(50) values are 0.027 and 0.023 mg/kg for [(11)C](+)-PHNO and [(3)H]raclopride, respectively). In response to AMPH challenge, [(11)C](+)-PHNO and [(3)H]raclopride SBRs were inhibited to the same degree. CONCLUSIONS We have shown that the SBRs of [(11)C](+)-PHNO- and [(3)H]raclopride do not differ in their response to agonist challenge. These results do not support predictions of the in vivo binding behavior of a D2 agonist radiotracer and cast some doubt on the in vivo applicability of the D2 two-state model, as described by in vitro binding experiments.
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Affiliation(s)
- Patrick N McCormick
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada M5S 1A8.
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Millan MJ, Svenningsson P, Ashby CR, Hill M, Egeland M, Dekeyne A, Brocco M, Di Cara B, Lejeune F, Thomasson N, Muńoz C, Mocaër E, Crossman A, Cistarelli L, Girardon S, Iob L, Veiga S, Gobert A. S33138 [N-[4-[2-[(3aS,9bR)-8-Cyano-1,3a,4,9b-tetrahydro[1]-benzopyrano[3,4-c]pyrrol-2(3H)-yl)-ethyl]phenylacetamide], a Preferential Dopamine D3 versus D2 Receptor Antagonist and Potential Antipsychotic Agent. II. A Neurochemical, Electrophysiological and Behavioral Characterization in Vivo. J Pharmacol Exp Ther 2007; 324:600-11. [DOI: 10.1124/jpet.107.132563] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Chagas-Martinich L, Carey RJ, Carrera MP. 7-OH-DPAT effects on latent inhibition: low dose facilitation but high dose blockade: Implications for dopamine receptor involvement in attentional processes. Pharmacol Biochem Behav 2007; 86:441-8. [PMID: 17291574 DOI: 10.1016/j.pbb.2007.01.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2006] [Revised: 12/23/2006] [Accepted: 01/03/2007] [Indexed: 11/30/2022]
Abstract
7-OH-DPAT is a dopamine D2/D3 agonist, which at low doses acts preferentially on D3 receptors but at high doses it acts on D2 and D3 receptors. The present study investigated the contribution of D3 and D2 receptors on latent inhibition (LI) by using two dose levels of 7-OH-DPAT: a low dose, 0.1 mg/kg (D3 receptor activation) and a high dose, 1.0 mg/kg, (D2/D3 receptor activation) in a conditioned emotional response (CER) paradigm. The LI Protocols included CS pre-exposure (10 or 40 CS alone trials), CER induction and a non-drug CER test phase. Additionally, the drug effects upon CER acquisition without LI were assessed using the same treatments and test environment pre-exposure protocols but without the tone CS. The effects of 7-OH-DPAT on crossing, rearing and grooming were also measured in an open field 1 day after the CER test phase. The results showed that the low dose 7-OH-DPAT treatment potentiated LI at 10 but not at 40 CS pre-exposures. The high dose 7-OH-DPAT treatment blocked LI at both the 10 and 40 stimulus pre-exposures; and it also induced hyperactivity. Thus, D3 stimulation induced by a low dose of 7-OH-DPAT can facilitate LI but these effects are contingent upon and are specific to the number of stimulus presentations. Altogether, these findings indicate that D3 stimulation can enhance attentional processes, but D2 stimulation can impair attentional processes.
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MESH Headings
- Animals
- Attention/drug effects
- Attention/physiology
- Behavior, Animal/drug effects
- Behavior, Animal/physiology
- Conditioning, Psychological/drug effects
- Conditioning, Psychological/physiology
- Dopamine Agonists/administration & dosage
- Dopamine Agonists/pharmacology
- Dose-Response Relationship, Drug
- Inhibition, Psychological
- Male
- Rats
- Rats, Wistar
- Receptors, Dopamine/drug effects
- Receptors, Dopamine/physiology
- Receptors, Dopamine D2/agonists
- Receptors, Dopamine D2/drug effects
- Receptors, Dopamine D2/physiology
- Receptors, Dopamine D3/agonists
- Receptors, Dopamine D3/drug effects
- Receptors, Dopamine D3/physiology
- Tetrahydronaphthalenes/administration & dosage
- Tetrahydronaphthalenes/pharmacology
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Affiliation(s)
- Ligia Chagas-Martinich
- Behavioral Pharmacology Group, Laboratory of Animal Health, State University of North Fluminense, Avenida Alberto Lamego, 2000, Campos dos Goytacazes, 28013-600, RJ, Brazil
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Mizuno T, Schmauss C, Rayport S. Distinct roles of presynaptic dopamine receptors in the differential modulation of the intrinsic synapses of medium-spiny neurons in the nucleus accumbens. BMC Neurosci 2007; 8:8. [PMID: 17239247 PMCID: PMC1783657 DOI: 10.1186/1471-2202-8-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2006] [Accepted: 01/19/2007] [Indexed: 11/21/2022] Open
Abstract
Background In both schizophrenia and addiction, pathological changes in dopamine release appear to induce alterations in the circuitry of the nucleus accumbens that affect coordinated thought and motivation. Dopamine acts principally on medium-spiny GABA neurons, which comprise 95% of accumbens neurons and give rise to the majority of inhibitory synapses in the nucleus. To examine dopamine action at single medium-spiny neuron synapses, we imaged Ca2+ levels in their presynaptic varicosities in the acute brain slice using two-photon microscopy. Results Presynaptic Ca2+ rises were differentially modulated by dopamine. The D1/D5 selective agonist SKF81297 was exclusively facilitatory. The D2/D3 selective agonist quinpirole was predominantly inhibitory, but in some instances it was facilitatory. Studies using D2 and D3 receptor knockout mice revealed that quinpirole inhibition was either D2 or D3 receptor-mediated, while facilitation was mainly D3 receptor-mediated. Subsets of varicosities responded to both D1 and D2 agonists, showing that there was significant co-expression of these receptor families in single medium-spiny neurons. Neighboring presynaptic varicosities showed strikingly heterogeneous responses to DA agonists, suggesting that DA receptors may be differentially trafficked to individual varicosities on the same medium-spiny neuron axon. Conclusion Dopamine receptors are present on the presynaptic varicosities of medium-spiny neurons, where they potently control GABAergic synaptic transmission. While there is significant coexpression of D1 and D2 family dopamine receptors in individual neurons, at the subcellular level, these receptors appear to be heterogeneously distributed, potentially explaining the considerable controversy regarding dopamine action in the striatum, and in particular the degree of dopamine receptor segregation on these neurons. Assuming that post-receptor signaling is restricted to the microdomains of medium-spiny neuron varicosities, the heterogeneous distribution of dopamine receptors on individual varicosities is likely to encode patterns in striatal information processing.
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Affiliation(s)
- Takeo Mizuno
- Department of Psychiatry, Columbia University, 1051 Riverside Drive, Unit 62, New York, NY 10032, USA
- Department of Neuroscience, New York State Psychiatric Institute, 1051 Riverside Drive, Unit 62, New York, NY 10032, USA
| | - Claudia Schmauss
- Department of Psychiatry, Columbia University, 1051 Riverside Drive, Unit 62, New York, NY 10032, USA
- Department of Neuroscience, New York State Psychiatric Institute, 1051 Riverside Drive, Unit 62, New York, NY 10032, USA
| | - Stephen Rayport
- Department of Psychiatry, Columbia University, 1051 Riverside Drive, Unit 62, New York, NY 10032, USA
- Department of Neuroscience, New York State Psychiatric Institute, 1051 Riverside Drive, Unit 62, New York, NY 10032, USA
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Richtand NM. Behavioral sensitization, alternative splicing, and d3 dopamine receptor-mediated inhibitory function. Neuropsychopharmacology 2006; 31:2368-75. [PMID: 16855531 PMCID: PMC1815380 DOI: 10.1038/sj.npp.1301163] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Behavioral sensitization, the progressive and enduring augmentation of certain behaviors following repetitive drug use, alters rodent locomotion in a long-standing manner. The same dopamine pathways playing an important role in drug dependence and psychosis also play a critical role in sensitization. Individual dopamine receptor subtypes have markedly different functional responses to stimulation, with D3 dopamine receptor stimulation inhibiting rodent locomotion. The D3 receptor has highest affinity of the dopamine receptor subtypes for dopamine, and is occupied to a greater degree following stimulant drug administration. D3 receptor activity may be regulated through the expression of an alternatively spliced, truncated receptor isoform (termed 'D3nf') altering receptor localization and function via dimerization with the full-length subunit. The expected physiological response to repetitive drug administration is tolerance. Tolerance of D3 receptor inhibition of locomotion would contribute to sensitization to stimulant drugs. We hypothesize that repetitive D3 receptor stimulation contributes to the development of behavioral sensitization through decreased responsivity of D3-receptor-mediated locomotor inhibition. Increased D3nf expression may direct altered receptor localization and subsequent release of D3-receptor-mediated inhibition, contributing to the expression of sensitization. These hypotheses follow directly from the affinities of the receptor subtypes for dopamine; dopamine concentrations following stimulant administration; the effects of individual dopamine receptor subtype stimulation on locomotion; and the expected homeostatic response of the system to perturbation by drug. Clarifying these mechanisms underlying sensitization may suggest new interventions for neuropsychiatric conditions in which dopamine plays an important role, including psychosis, drug dependence, and Parkinson's disease. This information may also elucidate a previously unrecognized mechanism regulating receptor trafficking and desensitization.
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Affiliation(s)
- Neil M Richtand
- Psychiatry Service (V116A), Cincinnati Veterans Affairs Medical Center, Cincinnati, OH, USA.
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Guitart-Masip M, Johansson B, Fernández-Teruel A, Cañete T, Tobeña A, Terenius L, Giménez-Llort L. Divergent anatomical pattern of D1 and D3 binding and dopamine- and cyclic AMP-regulated phosphoprotein of 32 kDa mRNA expression in the Roman rat strains: Implications for drug addiction. Neuroscience 2006; 142:1231-43. [PMID: 17008016 DOI: 10.1016/j.neuroscience.2006.07.041] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2005] [Revised: 07/06/2006] [Accepted: 07/11/2006] [Indexed: 11/24/2022]
Abstract
Autoradiography analysis of D1, D2 and D3 dopamine receptors and in situ hybridization analysis of mRNA for dopamine and cAMP regulated phosphoprotein of 32 kDa (DARPP-32) were performed in brains of naïve Roman high avoidance (RHA) and Roman low avoidance (RLA) inbred rats. These strains, genetically selected for high (RHA) or extremely low (RLA) active avoidance acquisition in the two-way shuttle box, differ in indices of dopaminergic activity along with sensation/novelty and substance-seeking behavioral profiles. The present study shows no differences in D2 receptor binding between the two strains. In contrast, the D1 and D3 receptor binding in the nucleus accumbens was higher in RHA-I rats, whereas RLA-I rats show higher D3 binding in the Calleja islands. Together with previous evidence showing behavioral and presynaptic differences related to the dopamine system, the present results suggest a higher dopaminergic tone at the nucleus accumbens shell in RHA-I rats. Besides, the comparison of the expression pattern of DARPP-32 mRNA with that of dopamine receptor binding revealed a mismatch in some amygdala nuclei. In some cortical structures (prelimbic and cingulate cortices, the dentate gyrus) as well as in the central amygdala, RHA-I rats showed higher DARPP-32 mRNA expression than RLA-I rats. Hence, RHA-I and RLA-I rats may be a useful tool to identify dopamine-related mechanisms that predispose to drug and alcohol dependence.
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Affiliation(s)
- M Guitart-Masip
- Medical Psychology Unit, Department of Psychiatry and Forensic Medicine, Institute of Neuroscience, Autonomous University of Barcelona, 08193 Bellaterra, Barcelona, Spain
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Anderson SM, Schmidt HD, Pierce RC. Administration of the D2 dopamine receptor antagonist sulpiride into the shell, but not the core, of the nucleus accumbens attenuates cocaine priming-induced reinstatement of drug seeking. Neuropsychopharmacology 2006; 31:1452-61. [PMID: 16205775 DOI: 10.1038/sj.npp.1300922] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Enhanced dopamine transmission in the nucleus accumbens plays an important role in cocaine priming-induced reinstatement of drug-seeking behavior. However, the contribution of each dopamine receptor subtype to this behavior remains unclear. The present experiments were designed to assess the role of D2-like dopamine receptors in the nucleus accumbens core and shell subregions in cocaine priming-induced reinstatement of drug seeking. Rats were trained to lever press for cocaine using a fixed ratio (FR) 5 schedule of reinforcement. After approximately 18 days of cocaine self-administration, the animals underwent an extinction phase during which cocaine was replaced with saline. Daily extinction sessions were conducted until responding was less than 10% of the response rate maintained by cocaine self-administration. Following the extinction phase, priming-induced reinstatement of cocaine-seeking behavior was assessed. A range of doses of antagonists selective for D2- (sulpiride, 0.2 or 2.0 microg), D3- (U99194A, 3.9 or 7.8 microg), or D4- (L-750,667, 5.5 or 11 microg) dopamine receptors were microinjected into either the nucleus accumbens core, shell or lateral septum prior to a priming injection of cocaine (10 mg/kg, i.p.). Following administration into the shell, but not core or lateral septum, sulpiride dose-dependently attenuated reinstatement induced by a cocaine priming injection. In contrast, U99194A and L-750,667 failed to influence cocaine seeking at any of the doses tested in either accumbal subregion. Collectively, these findings indicate that activation of D2 dopamine receptors mediates cocaine priming-induced reinstatement of cocaine seeking in a region-specific manner within the nucleus accumbens.
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Affiliation(s)
- Sharon M Anderson
- Department of Pharmacology, Boston University School of Medicine, Boston, MA 02118, USA
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Ginovart N, Galineau L, Willeit M, Mizrahi R, Bloomfield PM, Seeman P, Houle S, Kapur S, Wilson AA. Binding characteristics and sensitivity to endogenous dopamine of [11C]-(+)-PHNO, a new agonist radiotracer for imaging the high-affinity state of D2 receptors in vivo using positron emission tomography. J Neurochem 2006; 97:1089-103. [PMID: 16606355 DOI: 10.1111/j.1471-4159.2006.03840.x] [Citation(s) in RCA: 129] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[11C]-(+)-PHNO (4-propyl-9-hydroxynaphthoxazine) is a new agonist radioligand that provides a unique opportunity to measure the high-affinity states of the D2 receptors (D2-high) using positron emission tomography (PET). Here we report on the distribution, displaceablity, specificity and modeling of [11C]-(+)-PHNO and compare it with the well characterized antagonist D2 radioligand, [11C]raclopride, in cat. [11C]-(+)-PHNO displayed high uptake in striatum with a mean striatal binding potential (BP) of 3.95 +/- 0.85. Pre-treatment with specific D1 (SCH23390), D2 (raclopride, haloperidol) and D3 receptor (SB-277011) antagonists indicated that [11C]-(+)-PHNO binding in striatum is specific to D2 receptors. Within-subject comparisons showed that [11C]-(+)-PHNO BP in striatum was almost 2.5-fold higher than that measured with [11C]-(-)-NPA ([11C]-(-)-N-propyl-norapomorphine). Comparison of the dose-effect of amphetamine (0.1, 0.5 and 2 mg/kg; i.v.) showed that [11C]-(+)-PHNO was more sensitive to the dopamine releasing effect of amphetamine than [11C]raclopride. Amphetamine induced up to 83 +/- 4% inhibition of [11C]-(+)-PHNO BP and only up to 56 +/- 8% inhibition of [11C]raclopride BP. Scatchard analyses of [11C]-(+)-PHNO and [11C]raclopride bindings in two cats showed that the Bmax obtained with the agonist (29.6 and 32.9 pmol/mL) equalled that obtained with the antagonist (30.6 and 33.4 pmol/mL). The high penetration of [11C]-(+)-PHNO in brain, its high signal-to-noise ratio, its favorable in vivo kinetics and its high sensitivity to amphetamine shows that [11C]-(+)-PHNO has highly suitable characteristics for probing the D2-high with PET.
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Affiliation(s)
- Nathalie Ginovart
- The Vivian Rakoff Positron Emission Tomography Unit, Center for Addiction and Mental Health, Toronto, Canada.
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Le Saux M, Morissette M, Di Paolo T. ERbeta mediates the estradiol increase of D2 receptors in rat striatum and nucleus accumbens. Neuropharmacology 2005; 50:451-7. [PMID: 16309717 DOI: 10.1016/j.neuropharm.2005.10.004] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2004] [Revised: 10/04/2005] [Accepted: 10/08/2005] [Indexed: 11/26/2022]
Abstract
Estradiol was previously reported to increase striatal D(2) receptor density. The following experiments investigated the contribution of each estrogen receptor in estradiol modulation of D(2) receptors. Ovariectomized Sprague-Dawley rats were treated for 2 weeks with an agonist for ERalpha, 4,4',4''-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol (PPT), an agonist for ERbeta, 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN) and compared to estradiol treatment. Ovariectomy decreased D(2) agonist and antagonist striatal binding sites, specific binding was measured using [(3)H]quinpirole and [(3)H]spiperone. Estradiol prevented this decrease, while DPN but not PPT mimicked the estradiol increase of D(2) receptor specific binding. In the nucleus accumbens, ovariectomy decreased [(3)H]quinpirole specific binding in the core and left the shell unchanged. Similarly, estradiol and DPN but not PPT prevented this decrease. Neither ovariectomy nor treatments affected [(3)H]spiperone specific binding in this area. In the olfactory tubercle, neither ovariectomy nor treatments changed D(2) receptor binding. Finally, both ovariectomy and treatments did not affect D(2L), D(2S) mRNA and D(2L)/D(2S) ratios measured by semi-quantitative RT-PCR. The present results show, for the first time, that an ERbeta agonist treatment modulates D(2) receptors and suggest that ERbeta is involved in the estradiol modulation of D(2) receptors.
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Affiliation(s)
- Maryvonne Le Saux
- Molecular Endocrinology and Oncology Research Center, Laval University Medical Center (CHUL), Laval University, Québec, Canada
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David HN, Ansseau M, Abraini JH. Dopamine-glutamate reciprocal modulation of release and motor responses in the rat caudate-putamen and nucleus accumbens of "intact" animals. ACTA ACUST UNITED AC 2005; 50:336-60. [PMID: 16278019 DOI: 10.1016/j.brainresrev.2005.09.002] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2004] [Revised: 09/10/2005] [Accepted: 09/16/2005] [Indexed: 10/25/2022]
Abstract
Functional interactions between dopaminergic neurotransmission and glutamatergic neurotransmission are well known to play a crucial integrative role in the striatum, the major input structure of the basal ganglia now widely recognized to contribute to the control of motor activity and movements but also to the processing of cognitive and limbic functions. However, the nature of these interactions is still a matter of debate and controversy. This review (1) summarizes anatomical data on the distribution of dopaminergic and glutamatergic receptors in the striatum-accumbens complex, (2) focuses on the dopamine-glutamate interactions in the modulation of each other's release in the striatum-accumbens complex, and (3) examines the dopamine-glutamate interactions in the entire striatum involved in the control of locomotor activity. The effects of dopaminergic and glutamatergic receptor selective agonists and antagonists on dopamine and glutamate release as well on motor responses are analyzed in the entire striatum, by reviewing both in vitro and in vivo data. Regarding in vivo data, only findings from focal injections studies in the nucleus accumbens or the caudate-putamen of "intact" animals are reviewed. Altogether, the available data demonstrate that dopamine and glutamate do not uniformly interact to modulate each others' release and postsynaptic modulation of striatal output neurons. Depending on the receptor subtypes involved, interactions between dopaminergic and glutamatergic transmission vary as a multiple and complex combination of tonic, phasic, facilitatory, and inhibitory properties.
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Affiliation(s)
- Hélène N David
- Unité de Psychologie Médicale, CHU Sart-Tilman, B 4000 Liège, Belgium.
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Reyes-Irisarri E, Pérez-Torres S, Mengod G. Neuronal expression of cAMP-specific phosphodiesterase 7B mRNA in the rat brain. Neuroscience 2005; 132:1173-85. [PMID: 15857719 DOI: 10.1016/j.neuroscience.2005.01.050] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2004] [Revised: 01/27/2005] [Accepted: 01/28/2005] [Indexed: 11/30/2022]
Abstract
cAMP plays an important role as second messenger molecule controlling multiple cellular processes in the brain. cAMP levels depend critically on the phosphodiesterases (PDE) activity, enzymes responsible for the clearance of intracellular cAMP. We have examined the regional distribution and cellular localization of mRNA coding for the cAMP-specific phosphodiesterase 7B (PDE7B) in rat brain by in situ hybridization histochemistry. PDE7B mRNA is specifically distributed in rat brain, preferentially in neuronal cell populations. The highest levels of hybridization are observed in olfactory tubercle, islands of Calleja, dentate gyrus, caudate-putamen and some thalamic nuclei. Positive hybridization signals are also detected in other areas, such as cerebral cortex, Purkinje cells of the cerebellum and area postrema. By double in situ hybridization histochemistry, we found that 74% and 79% of the cells expressing PDE7B mRNA in striatum and olfactory tubercle, respectively, were GABAergic cells (expressing glutamic acid decarboxylase mRNA), in contrast with the lack of expression in the few cholinergic cells (expressing choline acetyltransferase mRNA) present in those two areas (around 0.4% in olfactory tubercle). In the thalamic nuclei, a majority of cells containing PDE7B mRNA also expresses a glutamatergic marker (76.7% express vesicular glutamate transporter vGluT1 and 76% express vGluT2 mRNAs). Almost all PDE7B expressing cells in dentate gyrus (93%) were glutamatergic. These results offer a neuroanatomical and neurochemical base that will support the search for specific functions for cAMP dependent PDEs and for the development of specific PDE7 inhibitors.
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Affiliation(s)
- E Reyes-Irisarri
- Department of Neurochemistry, Institut d'Investigacions, Biomèdiques de Barcelona, Consejo Superior de Investigaciones Científicas, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IIBB-CSIC, IDIBAPS), Spain
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Bahi A, Boyer F, Bussard G, Dreyer JL. Silencing dopamine D3-receptors in the nucleus accumbens shellin vivoinduces changes in cocaine-induced hyperlocomotion. Eur J Neurosci 2005; 21:3415-26. [PMID: 16026479 DOI: 10.1111/j.1460-9568.2005.04157.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The dopamine D(3) receptor (D(3)R) is an important pharmacotherapeutic target for its potential role in psychiatric disorders and drug dependence. To further explore its function in rats, a regulatable lentivirus, Lenti-D3, holding the rat D(3)R cDNA, has been constructed as well as three nonregulatable lentiviruses, Lenti-D3-siRNA1, Lenti-D3-siRNA2 and Lenti-D3-siRNA3, expressing small hairpin RNAs, aimed at silencing D(3)R expression and specifically targeted against different regions of the D(3)R mRNA. In vitro, Lenti-D3 expressed D(3)R and could efficiently be blocked with Lenti-D3-Sils. These viruses were stereotaxically injected into the shell part of the nucleus accumbens (NAcc) and effects of passive cocaine delivery on locomotor activity were assessed. Manipulations of D(3)R levels induced changes in the locomotor stimulant effects of cocaine as compared to control treatment. Suppression of dopamine (DA) D(3)R in the NAcc by means of local knockdown (with Lenti-D3-Sils) increased locomotor stimulant effects, whereas its overexpression with Lenti-D3 drastically reduced them. The latter effects could be reversed when animals were fed doxycycline, which prevented lentiviral-mediated DA D(3)R overexpression in the NAcc. Gene expression assessed by quantitative RT-PCR confirmed very efficient gene knockdown in vivo in animals treated with Lenti-D3-Sils (> 93% silencing of D(3)R gene). Thus D(3)R expression significantly contributes to behavioural changes associated with chronic cocaine delivery.
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Affiliation(s)
- Amine Bahi
- Institute of Biochemistry, University of Fribourg, Rue du Musée 5, CH-1700 Fribourg, Switzerland
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Bentivoglio M, Morelli M. Chapter I The organization and circuits of mesencephalic dopaminergic neurons and the distribution of dopamine receptors in the brain. HANDBOOK OF CHEMICAL NEUROANATOMY 2005. [DOI: 10.1016/s0924-8196(05)80005-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Ireland MD, Lowe AS, Reavill C, James MF, Leslie RA, Williams SCR. Mapping the effects of the selective dopamine D2/D3 receptor agonist quinelorane using pharmacological magnetic resonance imaging. Neuroscience 2005; 133:315-26. [PMID: 15893653 DOI: 10.1016/j.neuroscience.2005.02.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2004] [Revised: 01/18/2005] [Accepted: 02/03/2005] [Indexed: 11/18/2022]
Abstract
Dopamine agonists with a high affinity for D2 and D3 receptors have a biphasic effect on rodent locomotion, inducing hypolocomotion at low doses and hyperlocomotion at higher doses. Controversy surrounds the role of the D3 receptor in mediating the hypolocomotor response to low agonist doses. This study examines patterns of neuronal activation induced by varying doses of the D2/D3 receptor agonist quinelorane using blood oxygen level dependent (BOLD) pharmacological magnetic resonance imaging (phMRI), and compares them with corresponding behavioural responses. Quinelorane (3 microg/kg) induced hypolocomotion in rats naive to the testing environment, and in phMRI experiments increased neuronal activity within the anterior olfactory nuclei, nucleus accumbens and islets of Calleja, regions containing a high density of D3 receptors. A 30 microg/kg dose of quinelorane resulted in biphasic locomotor effects, with initial hypolocomotion followed by sustained hyperlocomotion. phMRI indicated that this higher dose increased cerebral activity within limbic and olfactory regions, as did the lower drug dose, but induced additional activation in the caudate-putamen and globus pallidus, areas dense in D2 receptors but containing few D3 receptors. The more restricted pattern of activation at low agonist doses and close temporal relationship between behavioural and BOLD signal responses to quinelorane suggest that those nuclei most dense in D3 receptors play a key role in mediating the hypolocomotor effects of quinelorane. However, the presence of D3 receptors in activated brain regions may be coincidental, and further studies are required to show definitively which class of receptors mediates agonist-induced hypolocomotion. In contrast, the activation of D2 receptors within the striatum appears necessary for quinelorane-induced hyperlocomotion.
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Affiliation(s)
- M D Ireland
- Neuroimaging Research Group, Institute of Psychiatry, Denmark Hill, London SE5 8AF, UK.
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Xi ZX, Gilbert J, Campos AC, Kline N, Ashby CR, Hagan JJ, Heidbreder CA, Gardner EL. Blockade of mesolimbic dopamine D3 receptors inhibits stress-induced reinstatement of cocaine-seeking in rats. Psychopharmacology (Berl) 2004; 176:57-65. [PMID: 15083257 PMCID: PMC3726040 DOI: 10.1007/s00213-004-1858-y] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2003] [Accepted: 02/24/2004] [Indexed: 02/03/2023]
Abstract
RATIONALE The dopamine (DA) D3 receptor is preferentially expressed in the mesolimbic system. We have previously shown that selective D3 receptor blockade by the novel D3 antagonist SB-277011A inhibits cocaine's reinforcing action and cocaine-induced reinstatement of cocaine-seeking behavior. OBJECTIVE In the present study, we investigated whether SB-277011A similarly inhibits stress-induced reinstatement of cocaine-seeking behavior. METHODS Rats were allowed to self-administer cocaine (0.5 mg/kg per infusion, 3 h per session) for 10-14 days, followed by a once-daily extinction session for 7-14 days during which saline was substituted for cocaine. Extinction criteria were fewer than ten lever-presses per 3-h session for at least 3 consecutive days. After cocaine-seeking behavior was extinguished, each animal was tested twice for footshock-stress-induced reinstatement, once with vehicle (25% hydroxypropyl-beta-cyclodextrin) and once with one of three doses of SB-277011A in counterbalanced fashion. RESULTS During the last 3 days of cocaine self-administration (SA), active lever-presses were approximately 100 per session under fixed-ratio 2 reinforcement (approximately 25 mg/kg cocaine per session). After extinction, intermittent footshock (10 min, 0.5 mA, 0.5 s on with a mean inter-shock interval of 40 s) robustly reinstated the cocaine-seeking behavior (8.4+/-3.6 active lever-presses in last extinction session to 35.3+/-5.2 in animals after footshock stress). Intraperitoneal (i.p.) injections of SB-277011A (3, 6, and 12 mg/kg) dose-dependently blocked stress-induced reinstatement of cocaine-seeking. Reinstatement was also blocked by microinjections of SB-277011A (1.5 microg/0.5 microl per side) bilaterally into the nucleus accumbens, but not into the dorsal striatum. CONCLUSIONS The mesolimic DA D3 receptor plays an important role in mediating stress-induced reinstatement.
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MESH Headings
- Animals
- Cocaine/administration & dosage
- Cocaine/pharmacokinetics
- Cocaine-Related Disorders/complications
- Cocaine-Related Disorders/physiopathology
- Cocaine-Related Disorders/prevention & control
- Conditioning, Operant/drug effects
- Conditioning, Operant/physiology
- Corpus Striatum/drug effects
- Dopamine D2 Receptor Antagonists
- Extinction, Psychological/drug effects
- Extinction, Psychological/physiology
- Infusions, Intravenous
- Male
- Microinjections
- Nitriles/pharmacology
- Nitriles/therapeutic use
- Nucleus Accumbens/drug effects
- Nucleus Accumbens/physiology
- Nucleus Accumbens/ultrastructure
- Rats
- Rats, Long-Evans
- Receptors, Dopamine D2/drug effects
- Receptors, Dopamine D2/physiology
- Receptors, Dopamine D3
- Reinforcement, Psychology
- Secondary Prevention
- Self Administration/methods
- Stress, Psychological/complications
- Stress, Psychological/physiopathology
- Stress, Psychological/prevention & control
- Substance Withdrawal Syndrome/complications
- Substance Withdrawal Syndrome/prevention & control
- Tetrahydroisoquinolines/pharmacology
- Tetrahydroisoquinolines/therapeutic use
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Affiliation(s)
- Zheng-Xiong Xi
- Neuropsychopharmacology Section, Intramural Research Program, Department of Health and Human Services, National Institute on Drug Abuse, National Institutes of Health, 5500 Nathan Shock Drive, Baltimore, MD 21224, USA.
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47
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Chu E, Socci R, Chu TC. PD128,907 induces ocular hypotension in rabbits: involvement of D2/D3 dopamine receptors and brain natriuretic peptide. J Ocul Pharmacol Ther 2004; 20:15-23. [PMID: 15006155 DOI: 10.1089/108076804772745428] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The purpose of this study was to determine the potential role of brain natriuretic peptide (BNP) in the PD128,907 (a dopamine D2/D3 receptor agonist)-induced ocular hypotension in rabbits. The effects of topical application of PD128,907 (75, 250, 750 microg) on intraocular pressure (IOP) were investigated. The lowest dose (75 microg) did not alter IOP; while the higher doses (250 and 750 microg) reduced IOP bilaterally. The PD128,907 (250 microg)-induced ocular hypotension, which lasted 3 hours, could be blocked by raclopride (1000 microg), a dopamine D2/D3 receptor antagonist, as well as by sympathetic denervation. Aqueous humor inflow was reduced by intravitreal injection of PD128,907 (10 microg) by 67% at 1 and 2 hours, which then returned to baseline at 3 hours. Furthermore, topical application of PD128,907 (250 microg) elevated aqueous BNP levels by 3-fold at 30 minutes, 6-fold at 1 hour and 5-fold at 2 hours, which could be blocked by pretreatment with raclopride (250 microg). Taken together, PD128,907-induced ocular hypotension by activation of dopamine D2/D3 receptors. This action was associated with reduced aqueous humor inflow and increased aqueous BNP levels.
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48
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Mizuo K, Narita M, Miyatake M, Suzuki T. Enhancement of dopamine-induced signaling responses in the forebrain of mice lacking dopamine D3 receptor. Neurosci Lett 2004; 358:13-6. [PMID: 15016423 DOI: 10.1016/j.neulet.2003.12.119] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2003] [Revised: 12/12/2003] [Accepted: 12/15/2003] [Indexed: 11/18/2022]
Abstract
It is well known that the dopamine D(3) receptor plays a critical role in several psychological disorders, such as drug dependence. The present study was designed to investigate the influence of lacking dopamine D(3) receptors in dopamine-induced G-protein activation and Ca(2+) influx in the mouse forebrain. The deletion of dopamine D(3) receptor gene caused the enhancement of dopamine-induced G-protein activation in the limbic forebrain of dopamine D(3) receptor knockout (D(3)KO) mice. Furthermore, the dopamine-induced Ca(2+) influx was enhanced in the coculture of neuron/glia cells obtained from the forebrain of D(3)KO mice. The present data provide direct evidence that a deletion of central dopamine D(3) receptor enhances the dopamine D(1)/D(2) receptor-mediated intracellular signaling.
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Affiliation(s)
- Keisuke Mizuo
- Department of Toxicology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
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Schwarz A, Gozzi A, Reese T, Bertani S, Crestan V, Hagan J, Heidbreder C, Bifone A. Selective dopamine D3 receptor antagonist SB-277011-A potentiates phMRI response to acute amphetamine challenge in the rat brain. Synapse 2004; 54:1-10. [PMID: 15300879 DOI: 10.1002/syn.20055] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Dopamine (DA) receptors are a major target for drugs employed in the treatment of neuropsychiatric disorders such as schizophrenia and drug dependence. The D(3) subtype of the D(2) DA receptor family presents a particularly focal distribution in limbic brain areas known to be associated with cognitive and emotional functions. This study examined the modulation of brain activation induced by acute administration of amphetamine in the rat by the highly selective DA D(3) receptor antagonist SB-277011-A using relative cerebral blood volume (rCBV) pharmacological MRI (phMRI). The acute administration of D-amphetamine (1 mg/kg i.v.) produced a widespread rCBV response that was strongest in cortical regions. SB-277011-A (20 mg/kg i.p.) itself did not produce significant changes in rCBV, but potentiated the phMRI response to 1 mg/kg i.v. D-amphetamine in a regionally specific manner, involving a number of structures outside the focal distribution of the D(3) receptor. Potentiated regions included the accumbens, dorsal caudate putamen, islands of Calleja, thalamus, cingulate cortex, ventral tegmental area, dorsal Raphe nucleus, and ventral subiculum. The increased response following D(3) receptor antagonism is consistent with this receptor mediating an inhibitory action on brain activity following a dopaminergic stimulus.
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Affiliation(s)
- Adam Schwarz
- Department of Neuroimaging, Centre of Excellence for Drug Discovery, Psychiatry, GlaxoSmithKline Medicines Research Centre, 37135 Verona, Italy.
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50
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Leriche L, Diaz J, Sokoloff P. Dopamine and glutamate dysfunctions in schizophrenia: role of the dopamine D3 receptor. Neurotox Res 2004; 6:63-71. [PMID: 15184107 DOI: 10.1007/bf03033298] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Symptoms of schizophrenia are improved by dopamine antagonists and exacerbated by dopamine-releasing agents, suggesting hyperactivity of dopamine. However, chronic blockade of glutamate neurotransmission by antagonists at the N-methyl-D-aspartate (NMDA) receptor subtype produces a pathophysiological state resembling schizophrenia. A link between cortical glutamate/NMDA deficiency and subcortical dopamine hyperactivity, particularly in the mesolimbic pathway, has been hypothesized in schizophrenia. Here we show that hyperactivity produced by NMDA receptor blockade is dependent upon stimulation of the dopamine D3 receptor subtype. Since D3 receptor antagonists and antipsychotics produced very similar effects, our results add to the growing evidence suggesting that D3 receptor blockade might produce antipsychotic effects.
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Affiliation(s)
- L Leriche
- Unité de Neurobiologie et Pharmacologie Moléculaire, INSERM U 573, Centre Paul Broca, 2 ter rue d'Alésia, 75014 Paris, France
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