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Schamiloglu S, Lewis E, Keeshen CM, Hergarden AC, Bender KJ, Whistler JL. Arrestin-3 Agonism at Dopamine D 3 Receptors Defines a Subclass of Second-Generation Antipsychotics That Promotes Drug Tolerance. Biol Psychiatry 2023; 94:531-542. [PMID: 36931452 PMCID: PMC10914650 DOI: 10.1016/j.biopsych.2023.03.006] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 02/09/2023] [Accepted: 03/02/2023] [Indexed: 03/19/2023]
Abstract
BACKGROUND Second-generation antipsychotics (SGAs) are frontline treatments for serious mental illness. Often, individual patients benefit only from some SGAs and not others. The mechanisms underlying this unpredictability in treatment efficacy remain unclear. All SGAs bind the dopamine D3 receptor (D3R) and are traditionally considered antagonists for dopamine receptor signaling. METHODS Here, we used a combination of two-photon calcium imaging, in vitro signaling assays, and mouse behavior to assess signaling by SGAs at D3R. RESULTS We report that some clinically important SGAs function as arrestin-3 agonists at D3R, resulting in modulation of calcium channels localized to the site of action potential initiation in prefrontal cortex pyramidal neurons. We further show that chronic treatment with an arrestin-3 agonist SGA, but not an antagonist SGA, abolishes D3R function through postendocytic receptor degradation by GASP1 (G protein-coupled receptor-associated sorting protein-1). CONCLUSIONS These results implicate D3R-arrestin-3 signaling as a source of SGA variability, highlighting the importance of including arrestin-3 signaling in characterizations of drug action. Furthermore, they suggest that postendocytic receptor trafficking that occurs during chronic SGA treatment may contribute to treatment efficacy.
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Affiliation(s)
- Selin Schamiloglu
- Neuroscience Graduate Program, University of California San Francisco, San Francisco, California
| | - Elinor Lewis
- Neuroscience Graduate Group, University of California Davis, Davis, California; Center for Neuroscience, University of California Davis, Davis, California
| | - Caroline M Keeshen
- Neuroscience Graduate Group, University of California Davis, Davis, California; Center for Neuroscience, University of California Davis, Davis, California
| | - Anne C Hergarden
- Center for Neuroscience, University of California Davis, Davis, California
| | - Kevin J Bender
- Neuroscience Graduate Program, University of California San Francisco, San Francisco, California; Department of Neurology, Kavli Institute for Fundamental Neuroscience, Weill Institute for Neurosciences, University of California San Francisco, San Francisco, California.
| | - Jennifer L Whistler
- Center for Neuroscience, University of California Davis, Davis, California; Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, California.
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2
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Kiss B, Krámos B, Laszlovszky I. Potential Mechanisms for Why Not All Antipsychotics Are Able to Occupy Dopamine D 3 Receptors in the Brain in vivo. Front Psychiatry 2022; 13:785592. [PMID: 35401257 PMCID: PMC8987915 DOI: 10.3389/fpsyt.2022.785592] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 02/25/2022] [Indexed: 11/29/2022] Open
Abstract
Dysfunctions of the dopaminergic system are believed to play a major role in the core symptoms of schizophrenia such as positive, negative, and cognitive symptoms. The first line of treatment of schizophrenia are antipsychotics, a class of medications that targets several neurotransmitter receptors in the brain, including dopaminergic, serotonergic, adrenergic and/or muscarinic receptors, depending on the given agent. Although the currently used antipsychotics display in vitro activity at several receptors, majority of them share the common property of having high/moderate in vitro affinity for dopamine D2 receptors (D2Rs) and D3 receptors (D3Rs). In terms of mode of action, these antipsychotics are either antagonist or partial agonist at the above-mentioned receptors. Although D2Rs and D3Rs possess high degree of homology in their molecular structure, have common signaling pathways and similar in vitro pharmacology, they have different in vivo pharmacology and therefore behavioral roles. The aim of this review, with summarizing preclinical and clinical evidence is to demonstrate that while currently used antipsychotics display substantial in vitro affinity for both D3Rs and D2Rs, only very few can significantly occupy D3Rs in vivo. The relative importance of the level of endogenous extracellular dopamine in the brain and the degree of in vitro D3Rs receptor affinity and selectivity as determinant factors for in vivo D3Rs occupancy by antipsychotics, are also discussed.
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Affiliation(s)
- Béla Kiss
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Balázs Krámos
- Spectroscopic Research Department, Gedeon Richter Plc., Budapest, Hungary
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3
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Adem A, Madjid N, Stiedl O, Bonito-Oliva A, Konradsson-Geuken Å, Holst S, Fisone G, Ögren SO. Atypical but not typical antipsychotic drugs ameliorate phencyclidine-induced emotional memory impairments in mice. Eur Neuropsychopharmacol 2019; 29:616-628. [PMID: 30910381 DOI: 10.1016/j.euroneuro.2019.03.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 02/28/2019] [Accepted: 03/07/2019] [Indexed: 01/09/2023]
Abstract
Schizophrenia is associated with cognitive impairments related to hypofunction in glutamatergic N-methyl-D-aspartate receptor (NMDAR) transmission. Phencyclidine (PCP), a non-competitive NMDAR antagonist, models schizophrenia-like behavioral symptoms including cognitive deficits in rodents. This study examined the effects of PCP on emotional memory function examined in the passive avoidance (PA) task in mice and the ability of typical and atypical antipsychotic drugs (APDs) to rectify the PCP-mediated impairment. Pre-training administration of PCP (0.5, 1, 2 or 3 mg/kg) dose-dependently interfered with memory consolidation in the PA task. In contrast, PCP was ineffective when administered after training, and immediately before the retention test indicating that NMDAR blockade interferes with memory encoding mechanisms. The typical APD haloperidol and the dopamine D2/3 receptor antagonist raclopride failed to block the PCP-induced PA impairment suggesting a negligible role of D2 receptors in the PCP impairment. In contrast, the memory impairment was blocked by the atypical APDs clozapine and olanzapine in a dose-dependent manner while risperidone was effective only at the highest dose tested (1 mg/kg). The PCP-induced impairment involves 5-HT1A receptor mechanisms since the antagonist NAD-299 blocked the memory impairment caused by PCP and the ability of clozapine to attenuate the impairment by PCP. These results indicate that atypical but not typical APDs can ameliorate NMDAR-mediated memory impairments and support the view that atypical APDs such as clozapine can modulate glutamatergic memory dysfunctions through 5-HT1A receptor mechanisms. These findings suggest that atypical APDs may improve cognitive impairments related to glutamatergic dysfunction relevant for emotional memories in schizophrenia.
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Affiliation(s)
- Abdu Adem
- Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, United Arab Emirates University, United Arab Emirates.
| | - Nather Madjid
- Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, United Arab Emirates University, United Arab Emirates; Department of Neuroscience, Karolinska Institutet, Solnavägen 9, S-171 77 Stockholm, Sweden
| | - Oliver Stiedl
- Center for Neurogenomics and Cognitive Research, VU University Amsterdam, the Netherlands
| | | | - Åsa Konradsson-Geuken
- Department of Neuroscience, Karolinska Institutet, Solnavägen 9, S-171 77 Stockholm, Sweden
| | - Sarah Holst
- Department of Neuroscience, Karolinska Institutet, Solnavägen 9, S-171 77 Stockholm, Sweden
| | - Gilberto Fisone
- Department of Neuroscience, Karolinska Institutet, Solnavägen 9, S-171 77 Stockholm, Sweden
| | - Sven Ove Ögren
- Department of Neuroscience, Karolinska Institutet, Solnavägen 9, S-171 77 Stockholm, Sweden.
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Hashimoto T, Baba S, Ikeda H, Oda Y, Hashimoto K, Shimizu I. Lack of dopamine supersensitivity in rats after chronic administration of blonanserin: Comparison with haloperidol. Eur J Pharmacol 2018; 830:26-32. [DOI: 10.1016/j.ejphar.2018.04.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 04/05/2018] [Accepted: 04/13/2018] [Indexed: 10/17/2022]
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Sun X, Gou HY, Li F, Lu GY, Song R, Yang RF, Wu N, Su RB, Cong B, Li J. Y-QA31, a novel dopamine D3 receptor antagonist, exhibits antipsychotic-like properties in preclinical animal models of schizophrenia. Acta Pharmacol Sin 2016; 37:322-33. [PMID: 26775662 PMCID: PMC4775839 DOI: 10.1038/aps.2015.105] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 09/29/2015] [Indexed: 11/09/2022] Open
Abstract
AIM To investigate the potential effects of Y-QA31, a novel dopamine D3 receptor antagonist, as an antipsychotic drug. METHODS A panel of radioligand-receptor binding assays was performed to identify the affinities of Y-QA31 for different G protein-coupled receptors. [(35)S]GTPγS-binding assays and Ca(2+) imaging were used to assess its intrinsic activities. The antipsychotic profile of Y-QA31 was characterized in mouse models for the positive symptoms and cognitive deficits of schizophrenia and extrapyramidal side effects with haloperidol and clozapine as positive controls. RESULTS In vitro, Y-QA31 is a dopamine D3 receptor antagonist that is 186-fold more potent at the D3 receptor than at the D2 receptor. Y-QA31 also exhibits 5-HT1A receptor partial agonist and α1A adrenoceptor antagonist activities with medium affinity, whereas it exhibits very little affinity for other receptors (100-fold lower than for the D3 receptor). In vivo, Y-QA31 (10-40 mg/kg, po) significantly inhibited MK-801-induced hyperlocomotion and methamphetamine-induced prepulse inhibition disruption in a dose-dependent manner. Y-QA31 also inhibited the avoidance response and methamphetamine-induced hyperlocomotion with potency lower than haloperidol. Y-QA31 was effective in alleviating the MK-801-induced disruption of novel object recognition at a low dose (1 mg/kg, po). Moreover, Y-QA31 itself did not affect spontaneous locomotion or induce cataleptic response until its dose reached 120 mg/kg. CONCLUSION Y-QA31 is a selective D3R antagonist that exhibits antipsychotic effects in some animal models with positive symptoms and cognitive disorder and less extrapyramidal side effects.
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Affiliation(s)
- Xue Sun
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China
| | - Hong-yan Gou
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China
- Hebei Key Laboratory of Forensic Medicine, Department of Forensic Medicine, Hebei Medical University, Shijiazhuang 050017, China
| | - Fei Li
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China
| | - Guan-yi Lu
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China
| | - Rui Song
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China
| | - Ri-fang Yang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China
| | - Ning Wu
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China
| | - Rui-bin Su
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China
| | - Bin Cong
- Hebei Key Laboratory of Forensic Medicine, Department of Forensic Medicine, Hebei Medical University, Shijiazhuang 050017, China
| | - Jin Li
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China
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Nakamura T, Kubota T, Iwakaji A, Imada M, Kapás M, Morio Y. Clinical pharmacology study of cariprazine (MP-214) in patients with schizophrenia (12-week treatment). Drug Des Devel Ther 2016; 10:327-38. [PMID: 26834462 PMCID: PMC4716719 DOI: 10.2147/dddt.s95100] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
PURPOSE Cariprazine is a potent dopamine D3-preferring D3/D2 receptor partial agonist in development for the treatment of schizophrenia, bipolar mania, and depression. Pharmacokinetics of cariprazine and the two clinically relevant metabolites (desmethyl- and didesmethyl-cariprazine) was evaluated in a clinical pharmacology study. METHODS This was a multicenter, randomized, open-label, parallel-group, fixed-dose (3, 6, or 9 mg/day) study of 28-week duration (≤4-week observation, 12-week open-label treatment, and 12-week follow-up). Once-daily cariprazine was administered to 38 adult patients with schizophrenia. The pharmacokinetics of cariprazine, metabolites, and total active moieties (sum of cariprazine and two metabolites) was evaluated; efficacy and safety were also assessed. RESULTS Steady state was reached within 1-2 weeks for cariprazine and desmethyl-cariprazine, 4 weeks for didesmethyl-cariprazine, and 3 weeks for total active moieties. Cariprazine and desmethyl-cariprazine levels decreased >90% within 1 week after the last dose, didesmethyl-cariprazine decreased ~50% at 1 week, and total active moieties decreased ~90% within 4 weeks. Terminal half-lives of cariprazine, desmethyl-cariprazine, and didesmethyl-cariprazine ranged from 31.6 to 68.4, 29.7 to 37.5, and 314 to 446 hours, respectively. Effective half-life (calculated from time to steady state) of total active moieties was ~1 week. Incidence of treatment-emergent adverse events was 97.4%; 15.8% of patients discontinued due to adverse events. No abnormal laboratory values or major differences from baseline in extrapyramidal symptoms were observed. CONCLUSION Cariprazine and its active metabolites reached steady state within 4 weeks, and exposure was dose proportional over the range of 3-9 mg/day. Once-daily cariprazine was generally well tolerated in adult patients with schizophrenia.
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Affiliation(s)
- Tadakatsu Nakamura
- Sohyaku. Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, Tokyo, Japan
| | - Tomoko Kubota
- Sohyaku. Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, Tokyo, Japan
| | - Atsushi Iwakaji
- Sohyaku. Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, Tokyo, Japan
| | - Masayoshi Imada
- Sohyaku. Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, Tokyo, Japan
| | - Margit Kapás
- Developmental Drug Metabolism and Pharmacokinetics, Gedeon Richter Plc, Budapest, Hungary
| | - Yasunori Morio
- Sohyaku. Innovative Research Division, Mitsubishi Tanabe Pharma Corporation, Tokyo, Japan
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7
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Tatara A, Shimizu S, Masui A, Tamura M, Minamimoto S, Mizuguchi Y, Ochiai M, Mizobe Y, Ohno Y. Atypical antipsychotic properties of AD-6048, a primary metabolite of blonanserin. Pharmacol Biochem Behav 2015; 138:14-9. [DOI: 10.1016/j.pbb.2015.09.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 08/22/2015] [Accepted: 09/02/2015] [Indexed: 11/30/2022]
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8
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Klenotich SJ, Ho EV, McMurray MS, Server CH, Dulawa SC. Dopamine D2/3 receptor antagonism reduces activity-based anorexia. Transl Psychiatry 2015; 5:e613. [PMID: 26241351 PMCID: PMC4564564 DOI: 10.1038/tp.2015.109] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 05/18/2015] [Accepted: 06/14/2015] [Indexed: 01/04/2023] Open
Abstract
Anorexia nervosa (AN) is an eating disorder characterized by severe hypophagia and weight loss, and an intense fear of weight gain. Activity-based anorexia (ABA) refers to the weight loss, hypophagia and paradoxical hyperactivity that develops in rodents exposed to running wheels and restricted food access, and provides a model for aspects of AN. The atypical antipsychotic olanzapine was recently shown to reduce both AN symptoms and ABA. We examined which component of the complex pharmacological profile of olanzapine reduces ABA. Mice received 5-HT(2A/2C), 5-HT3, dopamine D1-like, D2, D3 or D2/3 antagonist treatment, and were assessed for food intake, body weight, wheel running and survival in ABA. D2/3 receptor antagonists eticlopride and amisulpride reduced weight loss and hypophagia, and increased survival during ABA. Furthermore, amisulpride produced larger reductions in weight loss and hypophagia than olanzapine. Treatment with either D3 receptor antagonist SB277011A or D2 receptor antagonist L-741,626 also increased survival. All the other treatments either had no effect or worsened ABA. Overall, selective antagonism of D2 and/or D3 receptors robustly reduces ABA. Studies investigating the mechanisms by which D2 and/or D3 receptors regulate ABA, and the efficacy for D2/3 and/or D3 antagonists to treat AN, are warranted.
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Affiliation(s)
- S J Klenotich
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, IL, USA
| | - E V Ho
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, IL, USA
| | - M S McMurray
- Department of Psychology, University of Illinois at Chicago, Chicago, IL, USA
| | - C H Server
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, IL, USA
| | - S C Dulawa
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, IL, USA,Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 924 E. 57th Street Room R022, MC3077, Chicago, IL 60637, USA. E-mail:
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9
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Kusumi I, Boku S, Takahashi Y. Psychopharmacology of atypical antipsychotic drugs: From the receptor binding profile to neuroprotection and neurogenesis. Psychiatry Clin Neurosci 2015; 69:243-58. [PMID: 25296946 DOI: 10.1111/pcn.12242] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/06/2014] [Indexed: 12/12/2022]
Abstract
The original definition of atypical antipsychotic drugs (APD) was drugs that are effective against positive symptoms in schizophrenia with no or little extrapyramidal symptoms (EPS). However, atypical APD have been reported to be more effective for cognitive dysfunction and negative symptoms in schizophrenia than typical APD, which expands the definition of 'atypicality'. This article provides a critical review of the pharmacology of atypical APD, especially from the viewpoint of receptor binding profiles and neurotransmitter regulations as well as neuroprotection and neurogenesis. A variety of serotonin (5-HT) receptors, such as 5-HT2A / 2C , 5-HT1A , 5-HT6 and 5-HT7 receptors, may contribute to the mechanisms of action of 'atypicality'. The dopaminergic modulations, including a low affinity for dopamine D2 receptors and a partial D2 receptor agonistic action, and glutamatergic regulations may also be involved in the pharmacological backgrounds of 'atypicality'. Atypical APD, but not typical APD, may facilitate cortical neuroprotection and hippocampal neurogenesis, which might be a part of the action mechanisms of atypical APD. The facilitation of cortical neuroprotection and hippocampal neurogenesis induced by atypical APD might be mediated by an increase in the Ser9 phosphorylation of glycogen synthase kinase-3β (GSK-3β). The stimulation of 5-HT1A receptors and/or the blockade of 5-HT2 receptors, which is characteristic of atypical APD, might increase Ser9 phosphorylation of GSK-3β. Moreover, atypical APD increase brain-derived neurotrophic factor (BDNF) levels. BDNF increases Ser9 phosphorylation of GSK-3β and has neuroprotective and neurogenic effects, as in the case of atypical APD. These findings suggest that GSK-3β might play a role in the action mechanisms of atypical APD, in both the 5-HT-dependent and BDNF-dependent mechanisms.
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Affiliation(s)
- Ichiro Kusumi
- Department of Psychiatry, Hokkaido University Graduate School of Medicine, Sapporo, Japan
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10
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Hida H, Mouri A, Mori K, Matsumoto Y, Seki T, Taniguchi M, Yamada K, Iwamoto K, Ozaki N, Nabeshima T, Noda Y. Blonanserin ameliorates phencyclidine-induced visual-recognition memory deficits: the complex mechanism of blonanserin action involving D₃-5-HT₂A and D₁-NMDA receptors in the mPFC. Neuropsychopharmacology 2015; 40:601-13. [PMID: 25120077 PMCID: PMC4289947 DOI: 10.1038/npp.2014.207] [Citation(s) in RCA: 191] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 06/21/2014] [Accepted: 07/21/2014] [Indexed: 11/09/2022]
Abstract
Blonanserin differs from currently used serotonin 5-HT₂A/dopamine-D₂ receptor antagonists in that it exhibits higher affinity for dopamine-D₂/₃ receptors than for serotonin 5-HT₂A receptors. We investigated the involvement of dopamine-D₃ receptors in the effects of blonanserin on cognitive impairment in an animal model of schizophrenia. We also sought to elucidate the molecular mechanism underlying this involvement. Blonanserin, as well as olanzapine, significantly ameliorated phencyclidine (PCP)-induced impairment of visual-recognition memory, as demonstrated by the novel-object recognition test (NORT) and increased extracellular dopamine levels in the medial prefrontal cortex (mPFC). With blonanserin, both of these effects were antagonized by DOI (a serotonin 5-HT₂A receptor agonist) and 7-OH-DPAT (a dopamine-D₃ receptor agonist), whereas the effects of olanzapine were antagonized by DOI but not by 7-OH-DPAT. The ameliorating effect was also antagonized by SCH23390 (a dopamine-D₁ receptor antagonist) and H-89 (a protein kinase A (PKA) inhibitor). Blonanserin significantly remediated the decrease in phosphorylation levels of PKA at Thr(197) and of NR1 (an essential subunit of N-methyl-D-aspartate (NMDA) receptors) at Ser(897) by PKA in the mPFC after a NORT training session in the PCP-administered mice. There were no differences in the levels of NR1 phosphorylated at Ser(896) by PKC in any group. These results suggest that the ameliorating effect of blonanserin on PCP-induced cognitive impairment is associated with indirect functional stimulation of the dopamine-D₁-PKA-NMDA receptor pathway following augmentation of dopaminergic neurotransmission due to inhibition of both dopamine-D₃ and serotonin 5-HT₂A receptors in the mPFC.
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Affiliation(s)
- Hirotake Hida
- Division of Clinical Sciences and Neuropsychopharmacology, Graduate School of Pharmacy, Meijo University, Nagoya, Japan
| | - Akihiro Mouri
- Division of Clinical Sciences and Neuropsychopharmacology, Graduate School of Pharmacy, Meijo University, Nagoya, Japan
| | - Kentaro Mori
- Division of Clinical Sciences and Neuropsychopharmacology, Graduate School of Pharmacy, Meijo University, Nagoya, Japan
| | - Yurie Matsumoto
- Division of Clinical Sciences and Neuropsychopharmacology, Graduate School of Pharmacy, Meijo University, Nagoya, Japan,Department of Psychiatry, Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Takeshi Seki
- Department of Regional Pharmaceutical Care and Science, Faculty of Pharmacy, Meijo University, Nagoya, Japan
| | - Masayuki Taniguchi
- Division of Clinical Sciences and Neuropsychopharmacology, Graduate School of Pharmacy, Meijo University, Nagoya, Japan
| | - Kiyofumi Yamada
- Department of Neuropsychopharmacology and Hospital Pharmacy, Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Kunihiro Iwamoto
- Department of Psychiatry, Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Norio Ozaki
- Department of Psychiatry, Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Toshitaka Nabeshima
- Department of Regional Pharmaceutical Care and Science, Faculty of Pharmacy, Meijo University, Nagoya, Japan
| | - Yukihiro Noda
- Division of Clinical Sciences and Neuropsychopharmacology, Graduate School of Pharmacy, Meijo University, Nagoya, Japan,Division of Clinical Sciences and Neuropsychopharmacology, Graduate School of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan, Tel: +81 52 741 6021, Fax: +81 52 741 6023, E-mail:
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11
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Gross G, Drescher K. The role of dopamine D(3) receptors in antipsychotic activity and cognitive functions. Handb Exp Pharmacol 2013:167-210. [PMID: 23027416 DOI: 10.1007/978-3-642-25758-2_7] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Dopamine D(3) receptors have a pre- and postsynaptic localization in brain stem nuclei, limbic parts of the striatum, and cortex. Their widespread influence on dopamine release, on dopaminergic function, and on several other neurotransmitters makes them attractive targets for therapeutic intervention. The signaling pathways of D(3) receptors are distinct from those of other members of the D(2)-like receptor family. There is increasing evidence that D(3) receptors can form heteromers with dopamine D(1), D(2), and probably other G-protein-coupled receptors. The functional consequences remain to be characterized in more detail but might open new interesting pharmacological insight and opportunities. In terms of behavioral function, D(3) receptors are involved in cognitive, social, and motor functions, as well as in filtering and sensitization processes. Although the role of D(3) receptor blockade for alleviating positive symptoms is still unsettled, selective D(3) receptor antagonism has therapeutic features for schizophrenia and beyond as demonstrated by several animal models: improved cognitive function, emotional processing, executive function, flexibility, and social behavior. D(3) receptor antagonism seems to contribute to atypicality of clinically used antipsychotics by reducing extrapyramidal motor symptoms; has no direct influence on prolactin release; and does not cause anhedonia, weight gain, or metabolic dysfunctions. Unfortunately, clinical data with new, selective D(3) antagonists are still incomplete; their cognitive effects have only been communicated in part. In vitro, virtually all clinically used antipsychotics are not D(2)-selective but also have affinity for D(3) receptors. The exact D(3) receptor occupancies achieved in patients, particularly in cortical areas, are largely unknown, mainly because only nonselective or agonist PET tracers are currently available. It is unlikely that a degree of D(3) receptor antagonism optimal for antipsychotic and cognitive function can be achieved with existing antipsychotics. Therefore, selective D(3) antagonism represents a promising mechanism still to be fully exploited for the treatment of schizophrenia, cognitive deficits in schizophrenia, and comorbid conditions such as substance abuse.
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Affiliation(s)
- Gerhard Gross
- Abbott, Neuroscience Research, Ludwigshafen, Germany.
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12
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Dopamine D3 receptor antagonism—still a therapeutic option for the treatment of schizophrenia. Naunyn Schmiedebergs Arch Pharmacol 2012; 386:155-66. [DOI: 10.1007/s00210-012-0806-3] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 10/19/2012] [Indexed: 10/27/2022]
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Banasikowski TJ, Beninger RJ. Reduced expression of haloperidol conditioned catalepsy in rats by the dopamine D3 receptor antagonists nafadotride and NGB 2904. Eur Neuropsychopharmacol 2012; 22:761-8. [PMID: 22410316 DOI: 10.1016/j.euroneuro.2012.02.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2011] [Revised: 01/30/2012] [Accepted: 02/16/2012] [Indexed: 10/28/2022]
Abstract
Haloperidol, a dopamine (DA) D2 receptor-preferring antagonist, produces catalepsy whereby animals maintain awkward posture for a period of time. Sub-threshold doses of haloperidol fail to produce catalepsy initially, however, when the drug is given repeatedly in the same test environment, gradual day-to-day increases in catalepsy are observed. More importantly, if sensitized rats are injected with saline instead of haloperidol they continue to be cataleptic in the test environment suggesting that environment-drug associations may play a role. DA D3 receptors have been implicated in a number of conditioned behaviors. We were interested if DA D3 receptors contribute to catalepsy sensitization and conditioning in rats. We tested this hypothesis using the DA D3 receptor-selective antagonist NGB 2904 (0.5, 1.8 mg/kg) and the DA D3 receptor-preferring antagonist nafadotride (0.1, 0.5 mg/kg). For 10 consecutive conditioning days rats were treated with one of the D3 receptor antagonists alone or in combination with haloperidol (0.25 mg/kg) and tested for catalepsy, quantified by the time a rat remained with its forepaws on a horizontal bar. On test day (day 11), rats were injected with saline or the D3 receptor antagonist and tested for conditioned catalepsy in the previously drug-paired environment. Rats treated with NGB 2904 or nafadotride alone did not develop catalepsy. Rats treated with haloperidol or haloperidol plus NGB 2904 or nafadotride developed catalepsy sensitization with repeated conditioning. When injected with saline they continued to exhibit catalepsy in the test environment--now conditioned. On the other hand, NGB 2904 (1.8 mg/kg) or nafadotride (0.5 mg/kg) given on the test day (after sensitization to haloperidol) significantly attenuated the expression of conditioned catalepsy. Our data suggest that the D3 receptor antagonist NGB 2904 (1.8 mg/kg) and nafadotride (0.5 mg/kg) significantly attenuate conditioned catalepsy in rats when given in test but not when given during sensitization. Results implicate DA D3 receptors in regulating the expression of conditioned catalepsy.
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Affiliation(s)
- Tomek J Banasikowski
- Center Neurosci Studies, Department Psychology, Queen's University, Kingston, ON, Canada K7L 3 N6
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Cariprazine (RGH-188), a potent D3/D2 dopamine receptor partial agonist, binds to dopamine D3 receptors in vivo and shows antipsychotic-like and procognitive effects in rodents. Neurochem Int 2011; 59:925-35. [PMID: 21767587 DOI: 10.1016/j.neuint.2011.07.002] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Revised: 06/24/2011] [Accepted: 07/01/2011] [Indexed: 11/22/2022]
Abstract
We investigated the in vivo effects of orally administered cariprazine (RGH-188; trans-N-{4-[2-[4-(2,3-dichlorophenyl)-piperazin-1-yl]-ethyl]-cyclohexyl}-N',N'-dimethyl-urea), a D(3)/D(2) dopamine receptor partial agonist with ∼10-fold preference for the D(3) receptor. Oral bioavailability of cariprazine at a dose of 1mg/kg in rats was 52% with peak plasma concentrations of 91ng/mL. Cariprazine 10mg/kg had good blood-brain barrier penetration, with a brain/plasma AUC ratio of 7.6:1. In rats, cariprazine showed dose-dependent in vivo displacement of [(3)H](+)-PHNO, a dopamine D(3) receptor-preferring radiotracer, in the D(3) receptor-rich region of cerebellar lobules 9 and 10. Its potent inhibition of apomorphine-induced climbing in mice (ED(50)=0.27mg/kg) was sustained for 8h. Cariprazine blocked amphetamine-induced hyperactivity (ED(50)=0.12mg/kg) and conditioned avoidance response (CAR) (ED(50)=0.84mg/kg) in rats, and inhibited the locomotor-stimulating effects of the noncompetitive NMDA antagonists MK-801 (ED(50)=0.049mg/kg) and phencyclidine (ED(50)=0.09mg/kg) in mice and rats, respectively. It reduced novelty-induced motor activity of mice (ED(50)=0.11mg/kg) and rats (ED(50)=0.18mg/kg) with a maximal effect of 70% in both species. Cariprazine produced no catalepsy in rats at up to 100-fold dose of its CAR inhibitory ED(50) value. Cariprazine 0.02-0.08mg/kg significantly improved the learning performance of scopolamine-treated rats in a water-labyrinth learning paradigm. Though risperidone, olanzapine, and aripiprazole showed antipsychotic-like activity in many of these assays, they were less active against phencyclidine and more cataleptogenic than cariprazine, and had no significant effect in the learning task. The distinct in vivo profile of cariprazine may be due to its higher affinity and in vivo binding to D(3) receptors versus currently marketed typical and atypical antipsychotics.
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Ohno Y, Okano M, Imaki J, Tatara A, Okumura T, Shimizu S. Atypical antipsychotic properties of blonanserin, a novel dopamine D2 and 5-HT2A antagonist. Pharmacol Biochem Behav 2010; 96:175-80. [DOI: 10.1016/j.pbb.2010.04.027] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Revised: 04/26/2010] [Accepted: 04/30/2010] [Indexed: 11/27/2022]
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Subnanomolar dopamine D3 receptor antagonism coupled to moderate D2 affinity results in favourable antipsychotic-like activity in rodent models: I. neurochemical characterisation of RG-15. Naunyn Schmiedebergs Arch Pharmacol 2008; 378:515-28. [PMID: 18551280 DOI: 10.1007/s00210-008-0308-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Accepted: 05/01/2008] [Indexed: 10/22/2022]
Abstract
RG-15 (trans-N-[4-[2-[4-(3-cyano-5-trifluoromethyl-phenyl)-piperazine-1-yl]-ethyl]-cyclohexyl]-3-pyridinesulfonic amide dihydrochloride) displayed subnanomolar affinity to human and rat dopamine D3 receptors (pKi 10.49 and 9.42, respectively) and nanomolar affinity to human and rat D2 receptors (pKi 8.23 and 7.62, respectively). No apparent interactions were found with the other 44 receptors and four channel sites tested in this study. RG-15 inhibited dopamine-stimulated [35S]GTPgammaS binding in membranes from rat striatum, in murine A9 cells expressing human D2L receptors and in CHO cells expressing human D3 receptors (IC50 values were 21.2, 36.7 and 7.2 nM, respectively). In these tests RG-15 showed the highest affinity toward D3 receptors when compared to amisulpride, haloperidol and SB-277011. RG-15, similar to haloperidol and amisulpride, dose-dependently inhibited in vivo [3H]raclopride binding in mouse striatum, enhanced dopamine turnover and synthesis rate in mouse and rat striatum and olfactory tubercle. SB-277011 did not change [3H]raclopride binding in mouse striatum nor biosynthesis or turnover rates in either region in mice or rats. RG-15 and haloperidol, but not SB-277011, antagonised dopamine synthesis inhibition induced by the D3/D2 full agonist 7-OH-DPAT in GBL-treated mice. RG-15, but not SB-277011, elevated plasma prolactin levels. In vitro receptor binding and functional experiments demonstrated that RG-15 had an antagonist profile on both D3 and D2 receptors. with high selectivity for dopamine D3 receptors over D2 receptors. However, in vivo, its neurochemical actions were similar to those of D2 receptor antagonists. Neurochemical comparison of RG-15 with antagonists having a different affinity and selectivity toward D3 and D2 receptors indicate that D3 receptors have little, if any, role in the control of presynaptic dopamine biosynthesis/release in dopaminergic terminal regions.
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Gyertyán I, Sághy K, Laszy J, Elekes O, Kedves R, Gémesi LI, Pásztor G, Zájer-Balázs M, Kapás M, Agai Csongor E, Domány G, Kiss B, Szombathelyi Z. Subnanomolar dopamine D3 receptor antagonism coupled to moderate D2 affinity results in favourable antipsychotic-like activity in rodent models: II. behavioural characterisation of RG-15. Naunyn Schmiedebergs Arch Pharmacol 2008; 378:529-39. [PMID: 18548231 DOI: 10.1007/s00210-008-0311-x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Accepted: 05/01/2008] [Indexed: 11/25/2022]
Abstract
RG-15 (trans-N-[4-[2-[4-(3-cyano-5-trifluoromethyl -phenyl) -piperazine -1 -yl] -ethyl] -cyclohexyl] -3 -pyridinesulfonic amide dihydro-chloride), is a highly selective dopamine D3/D2 receptor antagonist with subnanomolar affinity for the D3 receptor and nanomolar affinity for the D2 receptor. We found that RG-15 showed a good oral bioavailability (54%) and high brain levels (approx. 900 ng/g) in rats and demonstrated antipsychotic efficacy in amphetamine-induced hyperactivity and conditioned avoidance response tests in rats, yielding ED50 (median effective dose) values of 8.6 and 12 mg/kg orally, respectively. At six- to eightfold higher doses, RG-15 blocked spontaneous motor activity, while a 30 mg/kg dose of the compound caused an increase in the home-cage motility of rats. The drug did not produce catalepsy up to 160 mg/kg oral dose; moreover, it inhibited haloperidol-induced catalepsy in the range 15-60 mg/kg. RG-15 (10 mg/kg orally) restored the impaired learning performance of scopolamine- or diazepam-treated rats in a water-labyrinth paradigm. It is assumed that the motor activating, anticataleptic and cognitive-enhancing properties of RG-15 result from its potent D3 antagonism. In this regard, RG 15 clearly differs from other antipsychotics. Olanzapine, clozapine and amisulpride all showed efficacy against amphetamine-induced hyperactivity and on conditioned avoidance, but compared to RG-15, they proved to be more cataleptogenic and depressed or did not change the home-cage activity of animals. Olanzapine was also inactive in the learning paradigm. Our results suggest that subnanomolar dopamine D3 receptor antagonism coupled to moderate D2 affinity may result in an antipsychotic profile characterised by a lack of extrapyramidal side effects and secondary negative symptoms with simultaneous efficacy on positive and cognitive symptoms of schizophrenia.
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Affiliation(s)
- István Gyertyán
- Research Division, Gedeon Richter Plc., Budapest 1475, Hungary.
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Gyertyán I, Sághy K. The selective dopamine D3 receptor antagonists, SB 277011-A and S 33084 block haloperidol-induced catalepsy in rats. Eur J Pharmacol 2007; 572:171-4. [PMID: 17628535 DOI: 10.1016/j.ejphar.2007.06.035] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2007] [Revised: 06/08/2007] [Accepted: 06/12/2007] [Indexed: 11/20/2022]
Abstract
SB 277011-A (trans-N-[4-[2-(6-cyano-1,2,3,4-tetrahydroisoquinolin-2-yl)ethyl]cyclohexyl]-4-quinolinecarboxamide) and S 33084 [(3aR,9bS)-N[4-(8-cyano-1,3a,4,9b-tetrahydro-3H-benzopyrano[3,4-c]pyrrole-2-yl)-butyl](4-phenyl)benzamide] were already shown to lack cataleptogenic actions. Further to that, we report that SB 277011 exerted a dose-dependent dampening on the development of haloperidol-induced catalepsy in the dose-range of 13.5-30 mg/kg p.o. while S 33084, at the dose of 0.625 mg/kg sc. significantly inhibited catalepsy induced by haloperidol; had no effect at 1.25 mg/kg, and further augmented the effect of haloperidol after 2.5 mg/kg. The compounds also produced effective inhibition when administered 2 hours after haloperidol. The results underline that dopamine D3 receptor antagonist action may have therapeutic value in the treatment of schizophrenia.
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Affiliation(s)
- István Gyertyán
- Department of Behavioural Pharmacology, Gedeon Richter Plc., Budapest, Hungary.
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Flores-Tochihuitl J, Vargas G, Morales-Medina JC, Rivera G, De La Cruz F, Zamudio S, Flores G. Enhanced apomorphine sensitivity and increased binding of dopamine D2 receptors in nucleus accumbens in prepubertal rats after neonatal blockade of the dopamine D3 receptors by (+)-S14297. Synapse 2007; 62:40-9. [DOI: 10.1002/syn.20463] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Heidbreder CA, Gardner EL, Xi ZX, Thanos PK, Mugnaini M, Hagan JJ, Ashby CR. The role of central dopamine D3 receptors in drug addiction: a review of pharmacological evidence. ACTA ACUST UNITED AC 2005; 49:77-105. [PMID: 15960988 PMCID: PMC3732040 DOI: 10.1016/j.brainresrev.2004.12.033] [Citation(s) in RCA: 212] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2004] [Revised: 10/21/2004] [Accepted: 12/06/2004] [Indexed: 10/25/2022]
Abstract
The cDNA for the dopamine D3 receptor was isolated and characterized in 1990. Subsequent studies have indicated that D3 receptors, as well as D3 receptor mRNA, are primarily localized in limbic regions in mammals. This finding led to the postulate that D3 receptors may be involved in drug dependence and addiction. However, this hypothesis has been difficult to test due to the lack of compounds with high selectivity for central D3 receptors. The interpretation of results from studies using mixed D2/D3 agonists and/or antagonists is problematic because these agents have low selectivity for D3 over D2 receptors and it is likely that their actions are primarily related to D2 receptor antagonism and possibly interaction with other neurotransmitter receptors. Currently, with the synthesis and characterization of new highly selective D3 receptor antagonists such as SB-277011-A this difficulty has been surmounted. The purpose of the present article is to review, for the first time, the effects of various putative D3 receptor selective compounds in animal models of drug dependence and addiction. The results obtained with highly selective D3 receptor antagonists such as SB-277011-A, SB-414796, and NGB-2904 indicate that central D3 receptors may play an important role in drug-induced reward, drug-taking, and cue-, drug-, and stress-induced reinstatement of drug-seeking behavior. Provided these results can be extrapolated to human drug addicts, they suggest that selective DA D3 receptor antagonists may prove effective as potential pharmacotherapeutic agents to manage drug dependence and addiction.
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Affiliation(s)
- Christian A. Heidbreder
- Centre of Excellence for Drug Discovery in Psychiatry, GlaxoSmithKline Pharmaceuticals, 37135 Verona, Italy
| | - Eliot L. Gardner
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Baltimore, Maryland 21224-6823, USA
| | - Zheng-Xiong Xi
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Baltimore, Maryland 21224-6823, USA
| | - Panayotis K. Thanos
- Medical Department, Brookhaven National Laboratory, Upton, NY 11973-5000, USA
| | - Manolo Mugnaini
- Centre of Excellence for Drug Discovery in Psychiatry, GlaxoSmithKline Pharmaceuticals, 37135 Verona, Italy
| | - Jim J. Hagan
- Centre of Excellence for Drug Discovery in Psychiatry, GlaxoSmithKline Pharmaceuticals, 37135 Verona, Italy
| | - Charles R. Ashby
- Pharmaceutical Sciences Department, Saint John’s University, 8000 Utopia Parkway, Jamaica, NY 11439-0001, USA
- Corresponding author. Fax: +1 718 990 1877. (C.R. Ashby)
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Abstract
Schizophrenia is a common and debilitating illness, characterized by chronic psychotic symptoms and psychosocial impairment that exact considerable human and economic costs. The literature in electronic databases as well as citations and major articles are reviewed with respect to the phenomenology, pathology, treatment, genetics and neurobiology of schizophrenia. Although studied extensively from a clinical, psychological, biological and genetic perspective, our expanding knowledge of schizophrenia provides only an incomplete understanding of this complex disorder. Recent advances in neuroscience have allowed the confirmation or refutation of earlier findings in schizophrenia, and permit useful comparisons between the different levels of organization from which the illness has been studied. Schizophrenia is defined as a clinical syndrome that may include a collection of diseases that share a common presentation. Genetic factors are the most important in the etiology of the disease, with unknown environmental factors potentially modulating the expression of symptoms. Schizophrenia is a complex genetic disorder in which many genes may be implicated, with the possibility of gene-gene interactions and a diversity of genetic causes in different families or populations. A neurodevelopmental rather than degenerative process has received more empirical support as a general explanation of the pathophysiology, although simple dichotomies are not particularly helpful in such a complicated disease. Structural brain changes are present in vivo and post-mortem, with both histopathological and imaging studies in overall agreement that the temporal and frontal lobes of the cerebral cortex are the most affected. Functional imaging, neuropsychological testing and clinical observation are also generally consistent in demonstrating deficits in cognitive ability that correlate with abnormalities in the areas of the brain with structural abnormalities. The dopamine and other neurotransmitter systems are certainly involved in the treatment or modulation of psychotic symptoms. These broad findings represent the distillation of a large body of disparate data, but firm and specific findings are sparse, and much about schizophrenia remains unknown.
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Affiliation(s)
- Albert Hung Choy Wong
- Centre for Addiction and Mental Health, 250 College Street, M5T 1R8, Toronto, Ont., Canada.
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Abstract
The cloning of the gene for the D3 receptor and subsequent identification of its distribution in brain and pharmacology allowed for serious consideration of the possibility that it might be a target for drugs used to treat schizophrenia and Parkinson's disease (PD). That is because it is highly expressed in limbic regions of the brain, exhibits low expression in motor divisions, and has pharmacologic similarity to the D2 receptor. Thus, antipsychotics that were presumed to block D2 receptors also had high affinity for the D3 receptor. Dopamine agonists used to treat the clinical symptoms of PD also have high affinity for the D3 receptor, and two D3 receptor-preferring agonists were found to be effective for treatment of PD. Many compounds achieving high potency and selectivity are now available, but few have reached clinical testing. Recent findings with respect to the anatomy of this receptor in human brain, altered expression in schizophrenia and PD, and biological models to study its function support the proposal that it is a target for development of drugs to alleviate symptoms in neuropsychiatric and neurologic disorders. Because of distinct aspects of regulation of the D3 receptor, it represents a unique target for therapeutic intervention in schizophrenia without high potential for unintended side effects such as tardive dyskinesia. It may also be that D3 receptor agonists can provide neuroprotective effects in PD and can modify clinical symptoms that D2 receptor-preferring agonists cannot provide.
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Affiliation(s)
- J N Joyce
- Thomas H. Christopher Center for Parkinson's Disease Research, Sun Health Research Institute, 10515 West Santa Fe Drive, Sun City, AZ 85351, USA.
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Abstract
The recent enthusiasm among clinicians for the so-called 'atypical antipsychotics' has both improved treatment for schizophrenic patients and provided a welcome stimulus for basic research on antipsychotic mechanisms. Even the newer drugs have shortcomings, and research is underway aimed at identifying novel agents with greater efficacy and safety. Much of this effort is directed towards compounds which, in addition to blocking dopamine receptors, also act on other neurotransmitter receptors such as 5-HT2, 5-HT1A and alpha2-adrenergic receptors. However, there is also a large amount of scientific activity seeking to discover and develop selective dopamine receptor subtype antagonists (including compounds which specifically block D3 or D4 receptors) or drugs that specifically target the dopamine autoreceptor. Finally, a number of drug development programmes are searching for non-dopaminergic antipsychotics. Drugs that do not have affinity for dopamine receptors but act through neurotensin, sigma or cannabinoid CB1 receptors or glutamatergic mechanisms are currently being evaluated. If any of these agents prove to have clinical efficacy this may lead to a third generation of antipsychotics. It is likely, however, that the mechanisms of action of such drugs will nevertheless imply the intimate involvement of dopaminergic pathways.
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Affiliation(s)
- B Scatton
- Discovery Research, Sanofi-Synthelabo Research, Bagneux, France.
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Boulay D, Depoortere R, Oblin A, Sanger DJ, Schoemaker H, Perrault G. Haloperidol-induced catalepsy is absent in dopamine D(2), but maintained in dopamine D(3) receptor knock-out mice. Eur J Pharmacol 2000; 391:63-73. [PMID: 10720636 DOI: 10.1016/s0014-2999(99)00916-4] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
We have previously found that mice homozygous for the deletion of the dopamine D(2) receptor gene (D(2)(-/-) mice) do not present spontaneous catalepsy when tested in a "bar test". In the present study, we sought to analyse the reactivity of D(2) receptor mutant mice to the cataleptogenic effects of dopamine D(2)-like or D(1)-like receptor antagonists. In parallel, we assessed the cataleptogenic effects of these antagonists in dopamine D(3) receptor mutant mice. D(2)(-/-) mice were totally unresponsive to the cataleptogenic effects of the dopamine D(2)-like receptor antagonist haloperidol (0.125-2 mg/kg i.p.), while D(2)(+/-) mice, at the highest haloperidol doses tested, showed a level of catalepsy about half that of wild-type controls. The degree of haloperidol-induced catalepsy was thus proportional to the level of striatal dopamine D(2) receptor expression (0.50, 0.30 and 0.08 pmol/mg protein as measured at 0.25 nM [3H]spiperone for D(2)(+/+), D(2)(+/-) and D(2)(-/-) mice, respectively). However, D(2)(-/-) and D(2)(+/-) mice were as sensitive as their wild-type counterparts to the cataleptogenic effects of the dopamine D(1)-like receptor antagonist R-(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4, 5-tetrahydro-1H-3-benzazepine hydrochloride (SCH 23390: 0.03-0.6 mg/kg s.c.). Striatal dopamine D(1) receptor expression (as measured using [3H]SCH 23390 binding) was not significantly affected by the genotype. The ability of SCH 23390 to induce catalepsy in D(2)(-/-) mice suggests that their resistance to haloperidol-induced catalepsy is due to the absence of dopamine D(2) receptors, and not to the abnormal striatal synaptic plasticity that has been shown by others to occur in these mice. In agreement with the observation that dopamine D(2) and dopamine D(1) receptor expression was essentially identical in D(3)(+/+), D(3)(+/-) and D(3)(-/-) mice, dopamine D(3) receptor homozygous and heterozygous mutant mice, on the whole, did not differ from their controls in the time spent in a cataleptic position following administration of either haloperidol (0.5-2 mg/kg i.p.) or SCH 23390 (0.03-0.6 mg/kg s.c.). Also, dopamine D(3) receptor mutant mice were no more responsive than wild-type controls when co-administered subthreshold doses of haloperidol (0.125 mg/kg) and SCH 23390 (0.03 mg/kg), suggesting that dopamine D(3) receptor knock-out mice are not more sensitive than wild-types to the synergistic effects of concurrent blockade of dopamine D(2) and dopamine D(1) receptors in this model. These results suggest that the dopamine D(2) receptor subtype is necessary for haloperidol to produce catalepsy, and that the dopamine D(3) receptor subtype appears to exert no observable control over the catalepsy produced by dopamine D(2)-like, D(1)-like and the combination of D(1)-like and D(2)-like receptor antagonists.
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Affiliation(s)
- D Boulay
- Department of Psychopharmacology, Sanofi-Synthélabo, 31 ave P. Vaillant-Couturier, 92220, Bagneux, France.
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Perachon S, Betancur C, Pilon C, Rostène W, Schwartz JC, Sokoloff P. Role of dopamine D3 receptors in thermoregulation: a reappraisal. Neuroreport 2000; 11:221-5. [PMID: 10683862 DOI: 10.1097/00001756-200001170-00044] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Dopamine agonist-induced hypothermia has been proposed to be mediated by the D3 receptor (D3R), as it is elicited by (+)7-OH-DPAT and antagonized by S 14297, two putative D3R-preferential ligands. Here we show, however, that S 14297 is a full and partial agonist at D3R and D2R, respectively. Hypothermia was induced in rats by agonists with potencies correlated with their D3R and D2R functional potencies, and was reversed by antagonists, with a rank order of potency typical of the D2R. Moreover, BP 897, a highly potent and selective but partial D3R agonist was inactive in producing hypothermia or reversing (+)7-OH-DPAT-induced hypothermia. (+)7-OH-DPAT was as potent and efficient in inducing hypothermia in wild-type as in D3R-deficient mice. Hence, our results suggest that hypothermia does not result from a selective stimulation of the D3R.
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Affiliation(s)
- S Perachon
- Unité de Neurobiologie et Pharmacologie Moléculaire (INSERM U 109), Centre Paul Broca, Paris, France
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Newman-Tancredi A, Gavaudan S, Conte C, Chaput C, Touzard M, Verrièle L, Audinot V, Millan MJ. Agonist and antagonist actions of antipsychotic agents at 5-HT1A receptors: a [35S]GTPgammaS binding study. Eur J Pharmacol 1998; 355:245-56. [PMID: 9760039 DOI: 10.1016/s0014-2999(98)00483-x] [Citation(s) in RCA: 180] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Recombinant human (h) 5-HT1A receptor-mediated G-protein activation was characterised in membranes of transfected Chinese hamster ovary (CHO) cells by use of guanosine-5'-O-(3-[35S]thio)-triphosphate ([35S]GTPgammaS binding). The potency and efficacy of 21 5-HT receptor agonists and antagonists was determined. The agonists, 5-CT (carboxamidotryptamine) and flesinoxan displayed high affinity (subnanomolar Ki values) and high efficacy (Emax > 90%, relative to 5-HT = 100%). In contrast, ipsapirone, zalospirone and buspirone displayed partial agonist activity. EC50s for agonist stimulation of [35S]GTPgammaS binding correlated well with Ki values from competition binding (r = +0.99). Among the compounds tested for antagonist activity, methiothepin and (+)butaclamol exhibited 'inverse agonist' behaviour, inhibiting basal [35S]GTPgammaS binding. The actions of 17 antipsychotic agents were investigated. Clozapine and several putatively 'atypical' antipsychotic agents, including ziprasidone, quetiapine and tiospirone, exhibited partial agonist activity and marked affinity at h5-HT1A receptors, similar to their affinity at hD2 dopamine receptors. In contrast, risperidone and sertindole displayed low affinity at h5-HT1A receptors and behaved as 'neutral' antagonists, inhibiting 5-HT-stimulated [35S]GTPgammaS binding. Likewise the 'typical' neuroleptics, haloperidol, pimozide, raclopride and chlorpromazine exhibited relatively low affinity and 'neutral' antagonist activity at h5-HT1A receptors with Ki values which correlated with their respective Kb values. The present data show that (i) [35S]GTPgammaS binding is an effective method to evaluate the efficacy and potency of agonists and antagonists at recombinant human 5-HT1A receptors. (ii) Like clozapine, several putatively 'atypical' antipsychotic drugs display balanced serotonin h5-HT1A/dopamine hD2 receptor affinity and partial agonist activity at h5-HT1A receptors. (iii) Several 'typical' and some putatively 'atypical' antipsychotic agents displayed antagonist properties at h5-HT1A sites with generally much lower affinity than at hD2 dopamine receptors. It is suggested that agonist activity at 5-HT1A receptors may be of utility for certain antipsychotic agents.
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Affiliation(s)
- A Newman-Tancredi
- Department of Psychopharmacology, Institut de Recherches Servier, Paris, France.
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Wilson JM, Sanyal S, Van Tol HH. Dopamine D2 and D4 receptor ligands: relation to antipsychotic action. Eur J Pharmacol 1998; 351:273-86. [PMID: 9721018 DOI: 10.1016/s0014-2999(98)00312-4] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Since the discovery that the antipsychotic action of phenothiazines was mediated by dopamine D2 receptors, the dopamine system has been scrutinized for schizophrenia related abnormalities. The focus has been to create neuroleptics with improved antipsychotic profiles and reduced side effects. With the identification of multiple dopamine receptor subtypes, the hypotheses regarding the role of dopamine in schizophrenia and antipsychotic action of neuroleptics have been refined. Even after the molecular identification of newer dopamine D2-like receptor subtypes (D3 and D4), the dopamine D2 receptor is still considered the predominant site for antipsychotic action. However, there has been much debate concerning the modulatory role of other dopamine receptor sites in the mechanism of action of antipsychotic drugs. Specifically, the dopamine D4 receptor has received much attention in this regard, since the atypical antipsychotic agent, clozapine, preferentially blocks this receptor subtype as compared with dopamine D2 and D3 receptors. In this review we will highlight some of the observations and arguments regarding the involvement of the dopamine D2 and D4 receptor sites in the therapeutic efficacy of antipsychotic medication.
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Affiliation(s)
- J M Wilson
- Laboratory for Molecular Neurobiology,3 Clarke Institute of Psychiatry, Toronto, Ontario, Canada
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