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Livingston NR, Kiemes A, Devenyi GA, Knight S, Lukow PB, Jelen LA, Reilly T, Dima A, Nettis MA, Casetta C, Agyekum T, Zelaya F, Spencer T, De Micheli A, Fusar-Poli P, Grace AA, Williams SCR, McGuire P, Egerton A, Chakravarty MM, Modinos G. Effects of diazepam on hippocampal blood flow in people at clinical high risk for psychosis. Neuropsychopharmacology 2024; 49:1448-1458. [PMID: 38658738 PMCID: PMC11250854 DOI: 10.1038/s41386-024-01864-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 03/11/2024] [Accepted: 04/08/2024] [Indexed: 04/26/2024]
Abstract
Elevated hippocampal perfusion has been observed in people at clinical high risk for psychosis (CHR-P). Preclinical evidence suggests that hippocampal hyperactivity is central to the pathophysiology of psychosis, and that peripubertal treatment with diazepam can prevent the development of psychosis-relevant phenotypes. The present experimental medicine study examined whether diazepam can normalize hippocampal perfusion in CHR-P individuals. Using a randomized, double-blind, placebo-controlled, crossover design, 24 CHR-P individuals were assessed with magnetic resonance imaging (MRI) on two occasions, once following a single oral dose of diazepam (5 mg) and once following placebo. Regional cerebral blood flow (rCBF) was measured using 3D pseudo-continuous arterial spin labeling and sampled in native space using participant-specific hippocampus and subfield masks (CA1, subiculum, CA4/dentate gyrus). Twenty-two healthy controls (HC) were scanned using the same MRI acquisition sequence, but without administration of diazepam or placebo. Mixed-design ANCOVAs and linear mixed-effects models were used to examine the effects of group (CHR-P placebo/diazepam vs. HC) and condition (CHR-P diazepam vs. placebo) on rCBF in the hippocampus as a whole and by subfield. Under the placebo condition, CHR-P individuals (mean [±SD] age: 24.1 [±4.8] years, 15 F) showed significantly elevated rCBF compared to HC (mean [±SD] age: 26.5 [±5.1] years, 11 F) in the hippocampus (F(1,41) = 24.7, pFDR < 0.001) and across its subfields (all pFDR < 0.001). Following diazepam, rCBF in the hippocampus (and subfields, all pFDR < 0.001) was significantly reduced (t(69) = -5.1, pFDR < 0.001) and normalized to HC levels (F(1,41) = 0.4, pFDR = 0.204). In conclusion, diazepam normalized hippocampal hyperperfusion in CHR-P individuals, consistent with evidence implicating medial temporal GABAergic dysfunction in increased vulnerability for psychosis.
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Affiliation(s)
- Nicholas R Livingston
- Department of Psychological Medicine, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, UK.
| | - Amanda Kiemes
- Department of Psychological Medicine, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, UK
| | - Gabriel A Devenyi
- Department of Psychiatry, McGill University, Montreal, QC, Canada
- Cerebral Imaging Centre, Douglas Mental Health University Institute, Montreal, QC, Canada
| | - Samuel Knight
- Department of Psychological Medicine, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, UK
| | - Paulina B Lukow
- Institute of Cognitive Neuroscience, University College London, London, UK
- Department of Psychosis Studies, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, UK
| | - Luke A Jelen
- Department of Psychological Medicine, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, UK
| | - Thomas Reilly
- Department of Psychiatry, University of Oxford, Oxford, UK
| | - Aikaterini Dima
- Department of Psychosis Studies, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, UK
| | - Maria Antonietta Nettis
- Department of Psychosis Studies, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, UK
| | - Cecilia Casetta
- Department of Psychosis Studies, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, UK
| | - Tyler Agyekum
- Department of Psychiatry, McGill University, Montreal, QC, Canada
- Cerebral Imaging Centre, Douglas Mental Health University Institute, Montreal, QC, Canada
| | - Fernando Zelaya
- Department of Neuroimaging, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, UK
| | - Thomas Spencer
- Department of Psychosis Studies, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, UK
- Outreach and Support in South-London (OASIS) service, South London and Maudsley (SLaM) NHS Foundation Trust, London, UK
| | - Andrea De Micheli
- Department of Psychosis Studies, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, UK
- Outreach and Support in South-London (OASIS) service, South London and Maudsley (SLaM) NHS Foundation Trust, London, UK
| | - Paolo Fusar-Poli
- Department of Psychosis Studies, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, UK
- Outreach and Support in South-London (OASIS) service, South London and Maudsley (SLaM) NHS Foundation Trust, London, UK
- Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy
| | - Anthony A Grace
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Steve C R Williams
- Department of Neuroimaging, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, UK
| | - Philip McGuire
- Department of Psychiatry, University of Oxford, Oxford, UK
| | - Alice Egerton
- Department of Psychosis Studies, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, UK
| | - M Mallar Chakravarty
- Department of Psychiatry, McGill University, Montreal, QC, Canada
- Cerebral Imaging Centre, Douglas Mental Health University Institute, Montreal, QC, Canada
| | - Gemma Modinos
- Department of Psychological Medicine, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, UK
- MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
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Uliana DL, Lisboa JRF, Gomes FV, Grace AA. The excitatory-inhibitory balance as a target for the development of novel drugs to treat schizophrenia. Biochem Pharmacol 2024:116298. [PMID: 38782077 DOI: 10.1016/j.bcp.2024.116298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 05/13/2024] [Accepted: 05/16/2024] [Indexed: 05/25/2024]
Abstract
The intricate balance between excitation and inhibition (E/I) in the brain plays a crucial role in normative information processing. Dysfunctions in the E/I balance have been implicated in various psychiatric disorders, including schizophrenia (SCZ). In particular, abnormalities in GABAergic signaling, specifically in parvalbumin (PV)-containing interneurons, have been consistently observed in SCZ pathophysiology. PV interneuron function is vital for maintaining an ideal E/I balance, and alterations in PV interneuron-mediated inhibition contribute to circuit deficits observed in SCZ, including hippocampus hyperactivity and midbrain dopamine system overdrive. While current antipsychotic medications primarily target D2 dopamine receptors and are effective primarily in treating positive symptoms, novel therapeutic strategies aiming to restore the E/I balance could potentially mitigate not only positive symptoms but also negative symptoms and cognitive deficits. This could involve, for instance, increasing the inhibitory drive onto excitatory neurons or decreasing the putative enhanced pyramidal neuron activity due to functional loss of PV interneurons. Compounds targeting the glycine site at glutamate NMDA receptors and muscarinic acetylcholine receptors on PV interneurons that can increase PV interneuron drive, as well as drugs that increase the postsynaptic action of GABA, such as positive allosteric modulators of α5-GABA-A receptors, and decrease glutamatergic output, such as mGluR2/3 agonists, represent promising approaches. Preventive strategies aiming at E/I balance also represent a path to reduce the risk of transitioning to SCZ in high-risk individuals. Therefore, compounds with novel mechanisms targeting E/I balance provide optimism for more effective and tailored interventions in the management of SCZ.
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Affiliation(s)
- Daniela L Uliana
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Joao Roberto F Lisboa
- Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Felipe V Gomes
- Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Anthony A Grace
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA, USA.
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Livingston NR, De Micheli A, McCutcheon RA, Butler E, Hamdan M, Grace AA, McGuire P, Egerton A, Fusar-Poli P, Modinos G. Effects of Benzodiazepine Exposure on Real-World Clinical Outcomes in Individuals at Clinical High Risk for Psychosis. Schizophr Bull 2024:sbae036. [PMID: 38567823 DOI: 10.1093/schbul/sbae036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
BACKGROUND AND HYPOTHESIS Animal models indicate GABAergic dysfunction in the development of psychosis, and that benzodiazepine (BDZ) exposure can prevent the emergence of psychosis-relevant phenotypes. However, whether BDZ exposure influences real-world clinical outcomes in individuals at clinical high risk for psychosis (CHR-P) is unknown. STUDY DESIGN This observational cohort study used electronic health record data from CHR-P individuals to investigate whether BDZ exposure (including hypnotics, eg, zopiclone) reduces the risk of developing psychosis and adverse clinical outcomes. Cox proportional-hazards models were employed in both the whole-unmatched sample, and a propensity score matched (PSM) subsample. STUDY RESULTS 567 CHR-P individuals (306 male, mean[±SD] age = 22.3[±4.9] years) were included after data cleaning. The BDZ-exposed (n = 105) and BDZ-unexposed (n = 462) groups differed on several demographic and clinical characteristics, including psychotic symptom severity. In the whole-unmatched sample, BDZ exposure was associated with increased risk of transition to psychosis (HR = 1.61; 95% CI: 1.03-2.52; P = .037), psychiatric hospital admission (HR = 1.93; 95% CI: 1.13-3.29; P = .017), home visit (HR = 1.64; 95% CI: 1.18-2.28; P = .004), and Accident and Emergency department attendance (HR = 1.88; 95% CI: 1.31-2.72; P < .001). However, after controlling for confounding-by-indication through PSM, BDZ exposure did not modulate the risk of any outcomes (all P > .05). In an analysis restricted to antipsychotic-naïve individuals, BDZ exposure reduced the risk of transition to psychosis numerically, although this was not statistically significant (HR = 0.59; 95% CI: 0.32-1.08; P = .089). CONCLUSIONS BDZ exposure in CHR-P individuals was not associated with a reduction in the risk of psychosis transition or adverse clinical outcomes. Results in the whole-unmatched sample suggest BDZ prescription may be more likely in CHR-P individuals with higher symptom severity.
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Affiliation(s)
- Nicholas R Livingston
- Department of Psychological Medicine, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Andrea De Micheli
- Early Psychosis: Interventions & Clinical-detection (EPIC) Lab, Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- Outreach And Support in South London (OASIS) Service, South London and Maudsley NHS Foundation Trust, London, UK
| | - Robert A McCutcheon
- Department of Psychiatry, University of Oxford, Oxford, UK
- Oxford Health NHS Foundation Trust, Oxford, UK
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Emma Butler
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Marwa Hamdan
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Anthony A Grace
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Philip McGuire
- Department of Psychiatry, University of Oxford, Oxford, UK
- Oxford Health NHS Foundation Trust, Oxford, UK
- National Institute for Health Research (NIHR) Oxford Health Biomedical Research Centre (BRC), Oxford, UK
| | - Alice Egerton
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- National Institute of Health Research (NIHR), Maudsley Biomedical Research Centre (BRC), South London and Maudsley NHS Foundation Trust, London, UK
| | - Paolo Fusar-Poli
- Early Psychosis: Interventions & Clinical-detection (EPIC) Lab, Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- Outreach And Support in South London (OASIS) Service, South London and Maudsley NHS Foundation Trust, London, UK
- Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy
- National Institute of Health Research (NIHR), Maudsley Biomedical Research Centre (BRC), South London and Maudsley NHS Foundation Trust, London, UK
| | - Gemma Modinos
- Department of Psychological Medicine, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
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Rincón-Cortés M, Grace AA. Sex-dependent emergence of prepubertal social dysfunction and augmented dopamine activity in a neurodevelopmental rodent model relevant for schizophrenia. Schizophr Res 2023; 262:32-39. [PMID: 37922841 DOI: 10.1016/j.schres.2023.10.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 09/25/2023] [Accepted: 10/28/2023] [Indexed: 11/07/2023]
Abstract
Schizophrenia is a neurodevelopmental psychiatric disorder that often emerges in adolescence, is characterized by social dysfunction, and has an earlier onset in men. These features have been replicated in rats exposed to the mitotoxin methylazoxymethanol acetate (MAM) on gestational day (GD) 17, which as adults exhibit behavioral impairments and dopamine (DA) system changes consistent with a schizophrenia-relevant rodent model. In humans, social withdrawal is a negative symptom that often precedes disease onset and DA system dysfunction and is more pronounced in men. Children and adolescents at high-risk for schizophrenia exhibit social deficits prior to psychotic symptoms (i.e., prodromal phase), which can be used as a predictive marker for future psychopathology. Adult MAM rats also exhibit deficient social interaction, but less is known regarding the emergence of social dysfunction in this model, whether it varies by sex, and whether it is linked to disrupted DA function. To this end, we characterized the ontogeny of social and DA dysfunction in male and female MAM rats during the prepubertal period (postnatal days 33-43) and found sex-specific changes in motivated social behaviors (play, approach) and DA function. Male MAM rats exhibited reduced social approach and increased VTA DA neuron activity compared to saline-treated (SAL) males, whereas female MAM rats exhibited enhanced play behaviors compared to SAL females but no changes in social approach or VTA population activity during this period. These findings demonstrate sex differences in the emergence of social and DA deficits in the MAM model, in which females exhibit delayed emergence.
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Affiliation(s)
- Millie Rincón-Cortés
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA 15260, United States.
| | - Anthony A Grace
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA 15260, United States
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Livingston NR, De Micheli A, McCutcheon R, Butler E, Hamdan M, Grace AA, McGuire P, Egerton A, Fusar-Poli P, Modinos G. Effects of Benzodiazepine Exposure on Real-World Clinical Outcomes in Individuals at Clinical High-Risk for Psychosis. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.08.15.23294108. [PMID: 37645948 PMCID: PMC10462200 DOI: 10.1101/2023.08.15.23294108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Background Animal models indicate GABAergic dysfunction in the development of psychosis, and that benzodiazepine (BDZ) exposure can prevent the emergence of psychosis-relevant phenotypes. However, whether BDZ exposure influences the risk of psychosis in humans is unknown. Methods This observational-cohort study used electronic health record data from 818 individuals at clinical high-risk for psychosis (CHR-P) to investigate whether BDZ exposure (including hypnotics e.g., zopiclone) reduces the risk of developing psychosis and adverse clinical outcomes. Cox proportional-hazards models were employed in both the whole-unmatched sample, and a propensity score matched (PSM) subsample. Results 567 CHR-P individuals were included after data cleaning (105 BDZ-exposed, 462 BDZ-unexposed). 306 (54%) individuals were male, and the mean age was 22.3 years (SD 4.9). The BDZ-exposed and BDZ-unexposed groups differed on several demographic and clinical characteristics, including psychotic symptom severity. In the whole-unmatched sample, BDZ exposure was associated with increased risk of transition to psychosis (HR=1.61; 95%CI:1.03-2.52; P=0.037), psychiatric hospital admission (HR=1.93; 95%CI:1.13-3.29; P=0.017), home visit (HR=1.64; 95%CI:1.18-2.28; P=0.004), and A&E attendance (HR=1.88; 95%CI:1.31-2.72; P<0.001). However, after controlling for confounding-by-indication through PSM, BDZ exposure did not modulate the risk of any outcomes (all P>0.05). In analysis restricted to antipsychotic-naïve individuals, BDZ exposure reduced the risk of transition to psychosis at trend-level (HR=0.59; 95%CI:0.32-1.08; P=0.089). Conclusions BDZ exposure in CHR-P individuals was not associated with a reduction in the risk of psychosis transition or other adverse clinical outcomes. Results in the whole-unmatched sample suggest BDZ prescription may be more likely in CHR-P individuals with higher symptom severity.
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Affiliation(s)
- Nicholas R. Livingston
- Department of Psychological Medicine, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| | - Andrea De Micheli
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
- OASIS Service, South London and Maudsley NHS Foundation Trust, London, UK
| | - Robert McCutcheon
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
- Oxford Health NHS Foundation Trust, Oxford, UK
- Department of Psychiatry, University of Oxford, Oxford, UK
| | - Emma Butler
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| | - Marwa Hamdan
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| | - Anthony A. Grace
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Philip McGuire
- Oxford Health NHS Foundation Trust, Oxford, UK
- Department of Psychiatry, University of Oxford, Oxford, UK
| | - Alice Egerton
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| | - Paolo Fusar-Poli
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
- OASIS Service, South London and Maudsley NHS Foundation Trust, London, UK
- Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy
| | - Gemma Modinos
- Department of Psychological Medicine, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
- MRC Centre for Neurodevelopmental Disorders, King’s College London, London, UK
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Grace AA, Uliana DL. Insights into the Mechanism of Action of Antipsychotic Drugs Derived from Animal Models: Standard of Care versus Novel Targets. Int J Mol Sci 2023; 24:12374. [PMID: 37569748 PMCID: PMC10418544 DOI: 10.3390/ijms241512374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 08/01/2023] [Accepted: 08/01/2023] [Indexed: 08/13/2023] Open
Abstract
Therapeutic intervention for schizophrenia relies on blockade of dopamine D2 receptors in the associative striatum; however, there is little evidence for baseline overdrive of the dopamine system. Instead, the dopamine system is in a hyper-responsive state due to excessive drive by the hippocampus. This causes more dopamine neurons to be in a spontaneously active, hyper-responsive state. Antipsychotic drugs alleviate this by causing depolarization block, or excessive depolarization-induced dopamine neuron inactivation. Indeed, both first- and second-generation antipsychotic drugs cause depolarization block in the ventral tegmentum to relieve positive symptoms, whereas first-generation drugs also cause depolarization in the nigrostriatal dopamine system to lead to extrapyramidal side effects. However, by blocking dopamine receptors, these drugs are activating multiple synapses downstream from the proposed site of pathology: the loss of inhibitory influence over the hippocampus. An overactive hippocampus not only drives the dopamine-dependent positive symptoms, but via its projections to the amygdala and the neocortex can also drive negative and cognitive symptoms, respectively. On this basis, a novel class of drugs that can reverse schizophrenia at the site of pathology, i.e., the hippocampal overdrive, could be effective in alleviating all three classes of symptoms of schizophrenia while also being better tolerated.
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Affiliation(s)
- Anthony A. Grace
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA 15260, USA;
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Sharmin D, Mian MY, Marcotte M, Prevot TD, Sibille E, Witkin JM, Cook JM. Synthesis and Receptor Binding Studies of α5 GABA AR Selective Novel Imidazodiazepines Targeted for Psychiatric and Cognitive Disorders. Molecules 2023; 28:4771. [PMID: 37375326 DOI: 10.3390/molecules28124771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 06/09/2023] [Accepted: 06/12/2023] [Indexed: 06/29/2023] Open
Abstract
GABA mediates inhibitory actions through various GABAA receptor subtypes, including 19 subunits in human GABAAR. Dysregulation of GABAergic neurotransmission is associated with several psychiatric disorders, including depression, anxiety, and schizophrenia. Selective targeting of α2/3 GABAARs can treat mood and anxiety, while α5 GABAA-Rs can treat anxiety, depression, and cognitive performance. GL-II-73 and MP-III-022, α5-positive allosteric modulators have shown promising results in animal models of chronic stress, aging, and cognitive disorders, including MDD, schizophrenia, autism, and Alzheimer's disease. Described in this article is how small changes in the structure of imidazodiazepine substituents can greatly impact the subtype selectivity of benzodiazepine GABAAR. To investigate alternate and potentially more effective therapeutic compounds, modifications were made to the structure of imidazodiazepine 1 to synthesize different amide analogs. The novel ligands were screened at the NIMH PDSP against a panel of 47 receptors, ion channels, including hERG, and transporters to identify on- and off-target interactions. Any ligands with significant inhibition in primary binding were subjected to secondary binding assays to determine their Ki values. The newly synthesized imidazodiazepines were found to have variable affinities for the benzodiazepine site and negligible or no binding to any off-target profile receptors that could cause other physiological problems.
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Affiliation(s)
- Dishary Sharmin
- Department of Chemistry and Biochemistry, Milwaukee Institute of Drug Discovery, University of Wisconsin Milwaukee, Milwaukee, WI 53201, USA
| | - Md Yeunus Mian
- Department of Chemistry and Biochemistry, Milwaukee Institute of Drug Discovery, University of Wisconsin Milwaukee, Milwaukee, WI 53201, USA
| | - Michael Marcotte
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON M5S 2S1, Canada
| | - Thomas D Prevot
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON M5S 2S1, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON M5T 1R8, Canada
| | - Etienne Sibille
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON M5S 2S1, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON M5T 1R8, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON M5T 1R8, Canada
| | - Jeffrey M Witkin
- Department of Chemistry and Biochemistry, Milwaukee Institute of Drug Discovery, University of Wisconsin Milwaukee, Milwaukee, WI 53201, USA
- Laboratory of Antiepileptic Drug Discovery, Ascension, St. Vincent, Indianapolis, IN 46260, USA
| | - James M Cook
- Department of Chemistry and Biochemistry, Milwaukee Institute of Drug Discovery, University of Wisconsin Milwaukee, Milwaukee, WI 53201, USA
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Abstract
PURPOSE OF REVIEW Schizophrenia is a psychiatric disorder that has a significant socioeconomic impact worldwide. Antipsychotic drugs targeting dopamine transmission alleviate psychotic symptoms but with limited efficacy and tolerability. Animal models have long proven useful for drug discovery. The continued need for new treatment highlights the importance of animal models to study schizophrenia. The lack of new therapeutic compounds combined with the shortcomings of clinical design studies potentially decreased the enthusiasm for animal model use. RECENT FINDINGS In the current review, we discuss the central role of animal models for schizophrenia in providing new insights into neurobiological features and therapeutic development. The US National Institute of Mental Health released the Research Domain Criteria to guide preclinical model studies. Here, we point out the advances of this approach and debate its potential limitations when using animal models to study schizophrenia from the drug discovery perspective. SUMMARY Cross-validated animal models for schizophrenia are crucial to comprehend the cause, pathophysiology, and behavioral and biological features of the disease, to advance prevention and treatment, and the need to carefully evaluate and select appropriate paradigms when investigating novel therapeutic targets.
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Affiliation(s)
- Daniela L Uliana
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Felipe V Gomes
- Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Anthony A Grace
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Pandey A, Kalita KN. Treatment-resistant schizophrenia: How far have we traveled? Front Psychiatry 2022; 13:994425. [PMID: 36111312 PMCID: PMC9468267 DOI: 10.3389/fpsyt.2022.994425] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 08/09/2022] [Indexed: 11/13/2022] Open
Abstract
Treatment-resistant schizophrenia is a lack of adequate response to antipsychotic medications resulting in incomplete functional and social recovery from the illness. Different definitions have been proposed for clinical practice and research work. Antipsychotics that are used in the management of schizophrenia mainly act on multiple dopaminergic pathways which are implicated in the development of symptoms of schizophrenia. Newer antipsychotics also are implicated to affect the serotonergic pathways. Clozapine is the only evidence-based treatment available for the management of treatment-resistant cases. Neurobiologically, there is a considerable overlap between treatment-resistant and treatment-responsive cases. The factors that are implicated in the evolution of treatment resistance are still not conclusive. These make the management of such patients a challenge. However, certain peculiarities of treatment-resistant schizophrenia have been identified which can guide us in the early identification and precise treatment of the treatment-resistant cases.
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Affiliation(s)
- Ambu Pandey
- Department of Psychiatry, Maharshi Devraha Baba Autonomous State Medical College, Deoria, India
| | - Kamal Narayan Kalita
- Department of Psychiatry, Lokpriya Gopinath Bordoloi Regional Institute of Mental Health, Tezpur, India
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Abstract
Despite strong evidence of the neurodevelopmental origins of psychosis, current pharmacological treatment is not usually initiated until after a clinical diagnosis is made, and is focussed on antagonising striatal dopamine receptors. These drugs are only partially effective, have serious side effects, fail to alleviate the negative and cognitive symptoms of the disorder, and are not useful as a preventive treatment. In recent years, attention has turned to upstream brain regions that regulate striatal dopamine function, such as the hippocampus. This review draws together these recent data to discuss why the hippocampus may be especially vulnerable in the pathophysiology of psychosis. First, we describe the neurodevelopmental trajectory of the hippocampus and its susceptibility to dysfunction, exploring this region's proneness to structural and functional imbalances, metabolic pressures, and oxidative stress. We then examine mechanisms of hippocampal dysfunction in psychosis and in individuals at high-risk for psychosis and discuss how and when hippocampal abnormalities may be targeted in these groups. We conclude with future directions for prospective studies to unlock the discovery of novel therapeutic strategies targeting hippocampal circuit imbalances to prevent or delay the onset of psychosis.
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Uliana DL, Zhu X, Gomes FV, Grace AA. Using animal models for the studies of schizophrenia and depression: The value of translational models for treatment and prevention. Front Behav Neurosci 2022; 16:935320. [PMID: 36090659 PMCID: PMC9449416 DOI: 10.3389/fnbeh.2022.935320] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 08/04/2022] [Indexed: 11/29/2022] Open
Abstract
Animal models of psychiatric disorders have been highly effective in advancing the field, identifying circuits related to pathophysiology, and identifying novel therapeutic targets. In this review, we show how animal models, particularly those based on development, have provided essential information regarding circuits involved in disorders, disease progression, and novel targets for intervention and potentially prevention. Nonetheless, in recent years there has been a pushback, largely driven by the US National Institute of Mental Health (NIMH), to shift away from animal models and instead focus on circuits in normal subjects. This has been driven primarily from a lack of discovery of new effective therapeutic targets, and the failure of targets based on preclinical research to show efficacy. We discuss why animal models of complex disorders, when strongly cross-validated by clinical research, are essential to understand disease etiology as well as pathophysiology, and direct new drug discovery. Issues related to shortcomings in clinical trial design that confound translation from animal models as well as the failure to take patient pharmacological history into account are proposed to be a source of the failure of what are likely effective compounds from showing promise in clinical trials.
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Affiliation(s)
- Daniela L. Uliana
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, United States
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA, United States
| | - Xiyu Zhu
- Department of Psychiatry and Behavioral Sciences, University of California, San Francisco, San Francisco, CA, United States
| | - Felipe V. Gomes
- Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Anthony A. Grace
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, United States
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA, United States
- *Correspondence: Anthony A. Grace,
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12
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Wolf DH, Zheng D, Kohler C, Turetsky BI, Ruparel K, Satterthwaite TD, Elliott MA, March ME, Cross AJ, Smith MA, Zukin SR, Gur RC, Gur RE. Effect of mGluR2 positive allosteric modulation on frontostriatal working memory activation in schizophrenia. Mol Psychiatry 2022; 27:1226-1232. [PMID: 34667261 PMCID: PMC9018886 DOI: 10.1038/s41380-021-01320-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 09/09/2021] [Accepted: 09/24/2021] [Indexed: 02/07/2023]
Abstract
Negative symptoms and cognitive deficits contribute strongly to disability in schizophrenia, and are resistant to existing medications. Recent drug development has targeted enhanced NMDA function by increasing mGluR2/3 signaling. However, the clinical utility of such agents remains uncertain, and markers of brain circuit function are critical for clarifying mechanisms and understanding individual differences in efficacy. We conducted a double-blind, placebo-controlled, randomized cross-over (14 day washout) pilot study evaluating adjunctive use of the mGluR2 positive allosteric modulator AZD8529 (80 mg daily for 3 days), in chronic stable patients with schizophrenia (n = 26 analyzed). We focused on 3 T fMRI response in frontostriatal regions during an n-back working memory task, testing the hypothesis that AZD8529 produces fMRI changes that correlate with improvement in negative symptoms and cognition. We found that AZD8529 did not produce significant group-average effects on symptoms or cognitive accuracy. However, AZD8529 did increase n-back fMRI activation in striatum (p < 0.0001) and anterior cingulate/paracingulate (p = 0.002). Greater drug-versus-placebo effects on caudate activation significantly correlated with greater reductions in PANSS negative symptom scores (r = -0.42, p = 0.031), and exploratory correlations suggested broader effects across multiple symptom domains and regions of interest. These findings demonstrate that fMRI responses to mGluR2 positive modulation relate to individual differences in symptom reduction, and could be pursued for future biomarker development. Negative clinical results at the group level should not lead to premature termination of investigation of this mechanism, which may benefit an important subset of individuals with schizophrenia. Imaging biomarkers may reveal therapeutic mechanisms, and help guide treatment toward specific populations.
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Affiliation(s)
- Daniel H. Wolf
- Department of Psychiatry, University of Pennsylvania, Philadelphia PA 19104
| | - David Zheng
- Department of Psychiatry, University of Pennsylvania, Philadelphia PA 19104
| | - Christian Kohler
- Department of Psychiatry, University of Pennsylvania, Philadelphia PA 19104
| | - Bruce I. Turetsky
- Department of Psychiatry, University of Pennsylvania, Philadelphia PA 19104
| | - Kosha Ruparel
- Department of Psychiatry, University of Pennsylvania, Philadelphia PA 19104
| | | | - Mark A. Elliott
- Department of Radiology, University of Pennsylvania, Philadelphia PA 19104
| | - Mary E. March
- Department of Psychiatry, University of Pennsylvania, Philadelphia PA 19104
| | - Alan J. Cross
- AstraZeneca Pharmaceuticals LP, Wilmington DE, 19850.,Present affiliations: Psy Therapeutics, Thornton PA 19373
| | - Mark A. Smith
- AstraZeneca Pharmaceuticals LP, Wilmington DE, 19850.,Vistagen Therapeutics, South San Francisco CA 94080;,Medical College of Georgia, Augusta, GA 30912
| | - Stephen R. Zukin
- AstraZeneca Pharmaceuticals LP, Wilmington DE, 19850.,PRA Health Sciences, Blue Bell PA 19422
| | - Ruben C. Gur
- Department of Psychiatry, University of Pennsylvania, Philadelphia PA 19104.,Department of Radiology, University of Pennsylvania, Philadelphia PA 19104
| | - Raquel E. Gur
- Department of Psychiatry, University of Pennsylvania, Philadelphia PA 19104.,Department of Radiology, University of Pennsylvania, Philadelphia PA 19104
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13
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Weeks JJ, Grace AA, Sved AF. Nicotine Administration Normalizes Behavioral and Neurophysiological Perturbations in the MAM Rodent Model of Schizophrenia. Int J Neuropsychopharmacol 2021; 24:979-987. [PMID: 34622270 PMCID: PMC8653870 DOI: 10.1093/ijnp/pyab064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 09/10/2021] [Accepted: 10/04/2021] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND The present study utilized the methylazoxymethanol (MAM) neurodevelopmental rodent model of schizophrenia (SCZ) to evaluate the hypothesis that individuals with SCZ smoke in an attempt to "self-medicate" their symptoms through nicotine (NIC) intake. METHODS To explore this question, we examined the effects of acute and chronic administration of NIC in 2 established behavioral tests known to be disrupted in the MAM model: prepulse inhibition of startle and novel object recognition. Additionally, we assessed the effects of acute and chronic NIC on 2 indices of the pathophysiology of SCZ modeled by MAM, elevated dopamine neuron population activity in the ventral tegmental area and neuronal activity in the ventral hippocampus, using in vivo electrophysiological recordings. RESULTS Our findings demonstrated that both acute and chronic administration of NIC significantly improved deficits in prepulse inhibition of startle and novel object recognition among MAM rats and normalized elevated ventral tegmental area and ventral hippocampal neuronal activity in these animals. CONCLUSION Together, these findings of NIC-induced improvement of deficits lend support for a "self-medication" hypothesis behind increased cigarette smoking in SCZ and illustrate the potential utility of nicotinic modulation in future pharmacotherapies for certain SCZ symptoms.
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Affiliation(s)
| | - Anthony A Grace
- Center for Neuroscience,Departments of Neuroscience, Psychiatry, and Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Alan F Sved
- Center for Neuroscience,Departments of Neuroscience, Psychiatry, and Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA,Correspondence: Alan F. Sved, PhD, 210 Langley Hall, Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA ()
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14
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Servonnet A, Allain F, Gravel-Chouinard A, Hernandez G, Bourdeau Caporuscio C, Legrix M, Lévesque D, Rompré PP, Samaha AN. Dopaminergic mechanisms underlying the expression of antipsychotic-induced dopamine supersensitivity in rats. Neuropharmacology 2021; 197:108747. [PMID: 34364897 DOI: 10.1016/j.neuropharm.2021.108747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/23/2021] [Accepted: 08/03/2021] [Indexed: 10/20/2022]
Abstract
Antipsychotic treatment can produce a dopamine-supersensitive state, potentiating the response to dopamine receptor stimulation. In both schizophrenia patients and rats, this is linked to tolerance to ongoing antipsychotic treatment. In rodents, dopamine supersensitivity is often confirmed by an exaggerated psychomotor response to d-amphetamine after discontinuation of antipsychotic exposure. Here we examined in rats the dopaminergic mechanisms mediating this enhanced behavioural response, as this could uncover pathophysiological processes underlying the expression of antipsychotic-evoked dopamine supersensitivity. Rats received 0.5 mg/kg/day haloperidol via osmotic minipump for 2 weeks, before treatment was discontinued. After cessation of antipsychotic treatment, rats showed a supersensitive psychomotor response to the D2 agonist quinpirole, but not to the D1 partial agonist SKF38393 or the dopamine reuptake blocker GBR12783. Furthermore, acute D1 receptor blockade (using SCH39166) decreased the exaggerated psychomotor response to d-amphetamine in haloperidol-pretreated rats, whereas acute D2 receptor blockade (using sulpiride) enhanced it. Thus, after discontinuation of antipsychotic treatment, D1- and D2-mediated transmission differentially modulate the expression of a supersensitive response to d-amphetamine. This supersensitive behavioural response was accompanied by enhanced GSK3β activity and suppressed ERK1/2 activity in the nucleus accumbens (but not caudate-putamen), suggesting increased mesolimbic D2 transmission. Finally, after discontinuing haloperidol treatment, neither increasing ventral midbrain dopamine impulse flow nor infusing d-amphetamine into the cerebral ventricles triggered the expression of already established dopamine supersensitivity, suggesting that peripheral effects are required. Thus, while dopamine receptor-mediated signalling regulates the expression of antipsychotic-evoked dopamine supersensitivity, a simple increase in central dopamine neurotransmission is insufficient to trigger this supersensitivity.
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Affiliation(s)
- Alice Servonnet
- Department of Neurosciences, Faculty of Medicine, Université de Montréal, 2900 Edouard-Montpetit boulevard, Montreal, H3T 1J4, Quebec, Canada.
| | - Florence Allain
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, 2900 Edouard-Montpetit boulevard, Montreal, H3T 1J4, Quebec, Canada
| | - Alice Gravel-Chouinard
- Department of Neurosciences, Faculty of Medicine, Université de Montréal, 2900 Edouard-Montpetit boulevard, Montreal, H3T 1J4, Quebec, Canada
| | - Giovanni Hernandez
- Department of Neurosciences, Faculty of Medicine, Université de Montréal, 2900 Edouard-Montpetit boulevard, Montreal, H3T 1J4, Quebec, Canada; Faculty of Pharmacy, Université de Montréal, 2900 Edouard-Montpetit boulevard, Montreal, H3T 1J4, Quebec, Canada
| | - Casey Bourdeau Caporuscio
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, 2900 Edouard-Montpetit boulevard, Montreal, H3T 1J4, Quebec, Canada
| | - Mathilde Legrix
- Department of Neurosciences, Faculty of Medicine, Université de Montréal, 2900 Edouard-Montpetit boulevard, Montreal, H3T 1J4, Quebec, Canada
| | - Daniel Lévesque
- Faculty of Pharmacy, Université de Montréal, 2900 Edouard-Montpetit boulevard, Montreal, H3T 1J4, Quebec, Canada
| | - Pierre-Paul Rompré
- Department of Neurosciences, Faculty of Medicine, Université de Montréal, 2900 Edouard-Montpetit boulevard, Montreal, H3T 1J4, Quebec, Canada
| | - Anne-Noël Samaha
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, 2900 Edouard-Montpetit boulevard, Montreal, H3T 1J4, Quebec, Canada; Groupe de recherche sur le système nerveux central, Faculty of Medicine, Université de Montréal, 2900 Edouard-Montpetit boulevard, Montrea, H3T 1J4, Quebec, Canada.
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15
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Sonnenschein SF, Grace AA. Peripubertal mGluR2/3 Agonist Treatment Prevents Hippocampal Dysfunction and Dopamine System Hyperactivity in Adulthood in MAM Model of Schizophrenia. Schizophr Bull 2021; 47:1806-1814. [PMID: 33928393 PMCID: PMC8530391 DOI: 10.1093/schbul/sbab047] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Pomaglumetad methionil (POM), a group 2 metabotropic glutamate receptor (mGluR2/3) agonist, showed promise as a novel antipsychotic in preclinical research but failed to show efficacy in clinical trials, though it has been suggested that it may be effective in certain patient populations, including early in disease patients. We used the methyazoxymethanol acetate (MAM) rat model of schizophrenia to determine whether POM may prevent the development of dopamine (DA) system dysfunction in a model representative of the hyperdopaminergic state thought to underlie psychosis, compared to control (SAL) rats. MAM and SAL rats were administered either POM (3 mg/kg, i.p.), vehicle (1 ml/kg), or no injection during postnatal day (PD) 31-40. In either late adolescence (PD 47-56) or adulthood (PD 83-96), novel object recognition (NOR) was tested, followed by anesthetized in vivo electrophysiological recordings of VTA DA neuron activity or ventral hippocampal (vHPC) pyramidal neuron activity. MAM rats treated with POM demonstrated increased NOR in adulthood compared to no injection MAM rats, but not compared to vehicle-treated MAM rats. POM-treated MAM rats demonstrated normalized DA neuron population activity and vHPC pyramidal neuron activity compared to vehicle and no injection MAM rats in both late adolescence and adulthood. No significant differences were observed across treatment groups in SAL rats. These results suggest that peripubertal mGluR2/3 agonist administration can prevent the emergence of vHPC pyramidal neuron hyperactivity and increased DA neuron population activity in adult MAM rats.
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Affiliation(s)
- Susan F Sonnenschein
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA,To whom correspondence should be addressed; Department of Psychiatry, University of Pittsburgh, 3501 Forbes Ave. Suite 530, Pittsburgh, PA 15213, US; tel: 989-600-9132, fax: 412-624-9198, e-mail:
| | - Anthony A Grace
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA
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16
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Gomes FV, Grace AA. Beyond Dopamine Receptor Antagonism: New Targets for Schizophrenia Treatment and Prevention. Int J Mol Sci 2021; 22:4467. [PMID: 33922888 PMCID: PMC8123139 DOI: 10.3390/ijms22094467] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/20/2021] [Accepted: 04/22/2021] [Indexed: 02/06/2023] Open
Abstract
Treatment of schizophrenia (SCZ) historically relies on the use of antipsychotic drugs to treat psychosis, with all of the currently available antipsychotics acting through the antagonism of dopamine D2 receptors. Although antipsychotics reduce psychotic symptoms in many patients, they induce numerous undesirable effects and are not effective against negative and cognitive symptoms. These highlight the need to develop new drugs to treat SCZ. An advanced understanding of the circuitry of SCZ has pointed to pathological origins in the excitation/inhibition balance in regions such as the hippocampus, and restoring function in this region, particularly as a means to compensate for parvalbumin (PV) interneuron loss and resultant hippocampal hyperactivity, may be a more efficacious approach to relieve a broad range of SCZ symptoms. Other targets, such as cholinergic receptors and the trace amine-associated receptor 1 (TAAR1), have also shown some promise for the treatment of SCZ. Importantly, assessing efficacy of novel compounds must take into consideration treatment history of the patient, as preclinical studies suggest prior antipsychotic treatment may interfere with the efficacy of these novel agents. However, while novel therapeutic targets may be more effective in treating SCZ, a more effective approach would be to prevent the transition to SCZ in susceptible individuals. A focus on stress, which has been shown to be a predisposing factor in risk for SCZ, is a possible avenue that has shown promise in preclinical studies. Therefore, therapeutic approaches based on our current understanding of the circuitry of SCZ and its etiology are likely to enable development of more effective therapeutic interventions for this complex disorder.
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Affiliation(s)
- Felipe V. Gomes
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto 01000-000, Brazil;
| | - Anthony A. Grace
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA 15260, USA
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17
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Sonnenschein SF, Grace AA. Emerging therapeutic targets for schizophrenia: a framework for novel treatment strategies for psychosis. Expert Opin Ther Targets 2021; 25:15-26. [PMID: 33170748 PMCID: PMC7855878 DOI: 10.1080/14728222.2021.1849144] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 11/05/2020] [Indexed: 01/10/2023]
Abstract
Introduction: Antipsychotic drugs are central to the treatment of schizophrenia, but their limitations necessitate improved treatment strategies. Multiple lines of research have implicated glutamatergic dysfunction in the hippocampus as an early source of pathophysiology in schizophrenia. Novel compounds have been designed to treat glutamatergic dysfunction, but they have produced inconsistent results in clinical trials. Areas covered: This review discusses how the hippocampus is thought to drive psychotic symptoms through its influence on the dopamine system. It offers the reader an evaluation of proposed treatment strategies including direct modulation of GABA or glutamate neurotransmission or reducing the deleterious impact of stress on circuit development. Finally, we offer a perspective on aspects of future research that will advance our knowledge and may create new therapeutic opportunities. PubMed was searched for relevant literature between 2010 and 2020 and related studies. Expert opinion: Targeting aberrant excitatory-inhibitory neurotransmission in the hippocampus and its related circuits has the potential to alleviate symptoms and reduce the risk of transition to psychosis if implemented as an early intervention. Longitudinal multimodal brain imaging combined with mechanistic theories generated from animal models can be used to better understand the progression of hippocampal-dopamine circuit dysfunction and heterogeneity in treatment response.
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Affiliation(s)
| | - Anthony A. Grace
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA, USA
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18
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Servonnet A, Uchida H, Samaha AN. Continuous versus extended antipsychotic dosing in schizophrenia: Less is more. Behav Brain Res 2020; 401:113076. [PMID: 33345826 DOI: 10.1016/j.bbr.2020.113076] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 12/09/2020] [Accepted: 12/11/2020] [Indexed: 11/28/2022]
Abstract
Antipsychotic drugs temper psychotic symptoms by interacting with dopamine D2 receptors to reduce dopamine neurotransmission. Currently, the standard of care involves antipsychotic treatment protocols that achieve steady-state levels of medication. Maintaining patients on continuous treatment is thought to be necessary to keep them stabilised. However, continuous antipsychotic exposure increases the risk of adverse effects over time. These effects include metabolic and cardiovascular disorders, extrapyramidal complications, and dopamine receptor supersensitivity, the latter of which could potentially promote both treatment tolerance and psychosis relapse. In the present review, we describe evidence showing that continuous exposure to antipsychotic drugs can not only worsen long-term outcome, but-past acute phase treatment-it is also unnecessary to effectively manage schizophrenia symptoms. We also describe evidence that regular but extended dosing, allowing predictable periods of lower antipsychotic levels/D2 occupancy, is both safe and effective in patients, and it greatly reduces drug exposure overall. Studies in laboratory animals show that compared to continuous antipsychotic exposure, regular but extended dosing actually has superior antipsychotic-like efficacy, and it also substantially reduces the likelihood of both motor side effects and dopamine receptor supersensitivity. We propose that regular, but extended dosing should be considered in the long-term treatment of people with schizophrenia, because the available evidence suggests it can be just as effective as continuous treatment, while decreasing overall drug exposure and potentially reducing harmful side effects.
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Affiliation(s)
- Alice Servonnet
- Department of Neurosciences, Faculty of Medicine, Université de Montréal, Montreal, Canada
| | - Hiroyuki Uchida
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Anne-Noël Samaha
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montreal, Canada; Groupe de recherche sur le système nerveux central, Faculty of Medicine, Université de Montréal, Montreal, Canada.
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19
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Peris-Yague A, Kiemes A, Cash D, Cotel MC, Singh N, Vernon AC, Modinos G. Region-specific and dose-specific effects of chronic haloperidol exposure on [ 3H]-flumazenil and [ 3H]-Ro15-4513 GABA A receptor binding sites in the rat brain. Eur Neuropsychopharmacol 2020; 41:106-117. [PMID: 33153853 PMCID: PMC7731940 DOI: 10.1016/j.euroneuro.2020.10.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 09/02/2020] [Accepted: 10/16/2020] [Indexed: 11/02/2022]
Abstract
Postmortem studies suggest that schizophrenia is associated with abnormal expression of specific GABAA receptor (GABAAR) α subunits, including α5GABAAR. Positron emission tomography (PET) measures of GABAAR availability in schizophrenia, however, have not revealed consistent alterations in vivo. Animal studies using the GABAAR agonist [3H]-muscimol provide evidence that antipsychotic drugs influence GABAAR availability, in a region-specific manner, suggesting a potential confounding effect of these drugs. No such data, however, are available for more recently developed subunit-selective GABAAR radioligands. To address this, we combined a rat model of clinically relevant antipsychotic drug exposure with quantitative receptor autoradiography. Haloperidol (0.5 and 2 mg/kg/day) or drug vehicle were administered continuously to adult male Sprague-Dawley rats via osmotic mini-pumps for 28 days. Quantitative receptor autoradiography was then performed postmortem using the GABAAR subunit-selective radioligand [3H]-Ro15-4513 and the non-subunit selective radioligand [3H]-flumazenil. Chronic haloperidol exposure increased [3H]-Ro15-4513 binding in the CA1 sub-field of the rat dorsal hippocampus (p<0.01; q<0.01; d=+1.3), which was not dose-dependent. [3H]-flumazenil binding also increased in most rat brain regions (p<0.05; main effect of treatment), irrespective of the haloperidol dose. These data confirm previous findings that chronic haloperidol exposure influences the specific binding of non-subtype selective GABAAR radioligands and is the first to demonstrate a potential effect of haloperidol on the binding of a α1/5GABAAR-selective radioligand. Although caution should be exerted when extrapolating results from animals to patients, our data support a view that exposure to antipsychotics may be a confounding factor in PET studies of GABAAR in the context of schizophrenia.
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Affiliation(s)
- Alba Peris-Yague
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, De Crespigny Park, London SE5 8AF, United Kingdom
| | - Amanda Kiemes
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, De Crespingy Park, London SE5 8AF, United Kingdom
| | - Diana Cash
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, De Crespigny Park, London SE5 8AF, United Kingdom
| | - Marie-Caroline Cotel
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, 5 Cutcombe Road, London SE5 9RT, United Kingdom
| | - Nisha Singh
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, De Crespigny Park, London SE5 8AF, United Kingdom
| | - Anthony C Vernon
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, 5 Cutcombe Road, London SE5 9RT, United Kingdom; MRC Centre for Neurodevelopmental Disorders, King's College London, London, United Kingdom.
| | - Gemma Modinos
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, De Crespigny Park, London SE5 8AF, United Kingdom; Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, De Crespingy Park, London SE5 8AF, United Kingdom; MRC Centre for Neurodevelopmental Disorders, King's College London, London, United Kingdom.
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20
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Borsoi M, Nunes LED, Barbosa AR, Lima MS, Medeiros I, Pranke MA, Antonio CB, Rates SMK, Neves GA. Intermittent repeated stress but not ketamine changes mice response to antidepressants. Neurosci Lett 2020; 741:135452. [PMID: 33166638 DOI: 10.1016/j.neulet.2020.135452] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 10/08/2020] [Accepted: 10/12/2020] [Indexed: 12/19/2022]
Abstract
Discovery of the rapid antidepressant effect of ketamine has been considered one of the most important advances in major depressive disorder treatment. Several studies report a significant benefit to patients that lasts up to 19 days after treatment. However, concerns arise from the long-term use of ketamine, thus a safe and effective strategy for maintaining its antidepressant effect is still necessary. To this end, our work assessed the effects of imipramine and fluoxetine after repeated ketamine treatment in male mice. Ketamine (30 mg/kg/day for 14 days) induced an anti-immobility effect in the forced swimming (FS) paradigm, detected 1 and 3 days after treatment. Seven days after the last ketamine injection, mice received imipramine (20 mg/kg) or fluoxetine (30 mg/kg). Imipramine and fluoxetine did not change mice's immobility time, regardless of the pre-treatment (saline or ketamine). Since both drugs' anti-immobility effect was demonstrated in the classical FS test, we can assume that repeated exposure to intermittent stress inhibited the antidepressant drugs' anti-immobility effects. Moreover, pre-exposure to ketamine did not counteract stress-induced changes in mice response to antidepressants. Since exposure to forced swim and i.p. injections are stressful to rodents, each stressor's contribution to the blunted response to antidepressants was investigated. Our data demonstrated that both stressors (FS and i.p. injections) influenced the reported effect. In summary, our results showed that exposure to intermittent repeated stress inhibited the anti-immobility effect of imipramine and fluoxetine in mice and corroborated findings demonstrating that exposure to stress can blunt patients' response to antidepressants.
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Affiliation(s)
- Milene Borsoi
- Laboratory of Experimental Psychopharmacology, School of Pharmacy, Federal University of Rio Grande do Sul, Av. Ipiranga 2752, sala 503-B, Porto Alegre, RS, CEP 90610-000, Brazil
| | - Luis Eduardo D Nunes
- Laboratory of Molecular Pharmacology, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Av. Carlos Chagas Filho, 373, bloco J, sala J1-029, Rio de Janeiro, RJ, CEP 21941-902, Brazil
| | - Amanda R Barbosa
- Laboratory of Molecular Pharmacology, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Av. Carlos Chagas Filho, 373, bloco J, sala J1-029, Rio de Janeiro, RJ, CEP 21941-902, Brazil
| | - Mariana S Lima
- Laboratory of Molecular Pharmacology, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Av. Carlos Chagas Filho, 373, bloco J, sala J1-029, Rio de Janeiro, RJ, CEP 21941-902, Brazil
| | - Isabelle Medeiros
- Laboratory of Molecular Pharmacology, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Av. Carlos Chagas Filho, 373, bloco J, sala J1-029, Rio de Janeiro, RJ, CEP 21941-902, Brazil
| | - Mariana A Pranke
- Laboratory of Experimental Psychopharmacology, School of Pharmacy, Federal University of Rio Grande do Sul, Av. Ipiranga 2752, sala 503-B, Porto Alegre, RS, CEP 90610-000, Brazil
| | - Camila B Antonio
- Laboratory of Experimental Psychopharmacology, School of Pharmacy, Federal University of Rio Grande do Sul, Av. Ipiranga 2752, sala 503-B, Porto Alegre, RS, CEP 90610-000, Brazil
| | - Stela M K Rates
- Laboratory of Experimental Psychopharmacology, School of Pharmacy, Federal University of Rio Grande do Sul, Av. Ipiranga 2752, sala 503-B, Porto Alegre, RS, CEP 90610-000, Brazil
| | - Gilda A Neves
- Laboratory of Experimental Psychopharmacology, School of Pharmacy, Federal University of Rio Grande do Sul, Av. Ipiranga 2752, sala 503-B, Porto Alegre, RS, CEP 90610-000, Brazil; Laboratory of Molecular Pharmacology, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Av. Carlos Chagas Filho, 373, bloco J, sala J1-029, Rio de Janeiro, RJ, CEP 21941-902, Brazil.
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The mGluR2/3 agonist pomaglumetad methionil normalizes aberrant dopamine neuron activity via action in the ventral hippocampus. Neuropsychopharmacology 2020; 45:2106-2113. [PMID: 32663839 PMCID: PMC7547679 DOI: 10.1038/s41386-020-0764-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 05/27/2020] [Accepted: 07/08/2020] [Indexed: 11/09/2022]
Abstract
The group 2 metabotropic glutamate receptor (mGluR2/3) agonist, pomaglumetad methionil (POM), showed promise as a novel antipsychotic in preclinical research but failed to show efficacy in clinical trials, though it has been suggested that it may be effective in certain patient populations. Although previous studies have shown that mGluR2/3 agonists have no effect on dopamine (DA) in wild type rats, we used the methylzoxymethanol acetate (MAM) model to determine whether POM may indirectly normalize DA neuron activity in a model representative of the hyperdopaminergic state thought to underlie psychosis, compared to SAL rats, using in vivo, anesthetized, electrophysiological recordings. POM dose-dependently reduced the number of spontaneously active DA neurons in the VTA of MAM rats to control levels without affecting DA firing in SAL rats, which persisted following 14d repeated treatment with POM. In female MAM rats, POM significantly reduced DA neuron population activity only during proestrous and estrous stages. MAM rats also demonstrated dose-dependent improvement in novel object recognition following acute POM, which was not observed in SAL rats. Similar to the MAM rats, DA neuron population activity was increased in a hippocampal-dependent manner following acute restraint stress. Administration of POM prior to 2 h restraint stress prevented the restraint-induced increase in DA neuron population activity, and this effect was blocked by pretreatment with an mGluR2/3 antagonist. Thus, the ability of POM to reduce the hyperdopaminergic activity in both MAM rats and in wild type rats following restraint stress suggests that it can indirectly regulate DA neuron activity, which may underlie its potential therapeutic effects.
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Egerton A, Grace AA, Stone J, Bossong MG, Sand M, McGuire P. Glutamate in schizophrenia: Neurodevelopmental perspectives and drug development. Schizophr Res 2020; 223:59-70. [PMID: 33071070 DOI: 10.1016/j.schres.2020.09.013] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 08/12/2020] [Accepted: 09/20/2020] [Indexed: 12/14/2022]
Abstract
Research into the neurobiological processes that may lead to the onset of schizophrenia places growing emphasis on the glutamatergic system and brain development. Preclinical studies have shown that neurodevelopmental, genetic, and environmental factors contribute to glutamatergic dysfunction and schizophrenia-related phenotypes. Clinical research has suggested that altered brain glutamate levels may be present before the onset of psychosis and relate to outcome in those at clinical high risk. After psychosis onset, glutamate dysfunction may also relate to the degree of antipsychotic response and clinical outcome. These findings support ongoing efforts to develop pharmacological interventions that target the glutamate system and could suggest that glutamatergic compounds may be more effective in specific patient subgroups or illness stages. In this review, we consider the updated glutamate hypothesis of schizophrenia, from a neurodevelopmental perspective, by reviewing recent preclinical and clinical evidence, and discuss the potential implications for novel therapeutics.
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Affiliation(s)
- Alice Egerton
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.
| | - Anthony A Grace
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA, USA
| | - James Stone
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Matthijs G Bossong
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Michael Sand
- Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, CT, USA
| | - Philip McGuire
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
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Merritt K, Catalan A, Cowley S, Demjaha A, Taylor M, McGuire P, Cooper R, Morrison P. Glyceryl trinitrate in first-episode psychosis unmedicated with antipsychotics: A randomised controlled pilot study. J Psychopharmacol 2020; 34:839-847. [PMID: 32436761 PMCID: PMC7376621 DOI: 10.1177/0269881120922967] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND There is a pressing need for new classes of treatment for psychosis. A key therapeutic target for novel compounds is the NMDA receptor, which may be modulated by nitric oxide donors such as sodium nitroprusside (SNP). Recent studies of SNP in patients with psychosis have mixed results, and the drug has to be administered intravenously. Glyceryl trinitrate (GTN) is a well-established cardiovascular medicine that is also a nitric oxide donor, and can be given orally. AIMS We explored the safety and potential effects of GTN in unmedicated patients with a first episode of psychosis. METHODS This was a single-centre, randomised, double-blind, placebo-controlled trial from December 2016 to April 2019 (ClinicalTrials.gov identifier: NCT02906553). Patients received 3 × sprays of GTN or placebo for three consecutive days, and were re-assessed on Days 1, 2, 3 and 7. The primary outcome was cognition (Jumping to Conclusions task), secondary outcomes were symptoms (Positive and Negative Syndrome Scale (PANSS)), verbal memory (Hopkins Verbal Learning task), and mood (Bond-Lader Visual Analogue Scales). RESULTS Nineteen patients were randomised, and 13 participants were included in the analyses. Compared with placebo, GTN was well tolerated, but was not associated with significant effects on cognition, symptoms, or mood. Bayesian statistics indicate that our results were 2× more likely under the null hypothesis than the alternative hypothesis, providing anecdotal evidence that GTN does not improve psychotic symptoms. CONCLUSIONS We found no indication of an effect of GTN on symptoms of psychosis or cognition.
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Affiliation(s)
- Kate Merritt
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, London, UK,Division of Psychiatry, University College London, London, UK,Kate Merritt, Department of Psychosis Studies, Institute of Psychiatry, Psychology &
Neuroscience, 16 De Crespigny Park, London, SE5 8AF, UK.
| | - Ana Catalan
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, London, UK,Osakidetza Basque Health Service, Department Psychiatry, Basurto University Hospital, Bilbao, Spain,Department of Neuroscience, University of the Basque Country, Leioa, Spain
| | - Samuel Cowley
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, London, UK
| | - Arsime Demjaha
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, London, UK
| | - Matthew Taylor
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, London, UK,University Department of Psychiatry, Warneford Hospital, Oxford, UK
| | - Philip McGuire
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, London, UK
| | - Ruth Cooper
- Newham Centre for Mental Health, Unit for Social and Community Psychiatry, Queen Mary University of London, UK,East London NHS Foundation Trust, Newham Centre for Mental Health, London, UK
| | - Paul Morrison
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, London, UK
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24
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Phosphodiesterase 10A Inhibitor Monotherapy Is Not an Effective Treatment of Acute Schizophrenia. J Clin Psychopharmacol 2020; 39:575-582. [PMID: 31688451 DOI: 10.1097/jcp.0000000000001128] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Current treatments for psychotic symptoms associated with schizophrenia often provide inadequate efficacy with unacceptable adverse effects. Improved therapeutics have long been a goal of research. Preclinical testing suggests that phosphodiesterase 10A (PDE10A) inhibitors may provide a novel approach to treating psychosis associated with schizophrenia. METHODS The efficacy and safety of a highly selective PDE10A inhibitor, PF-02545920, was evaluated in a phase 2 multicenter, randomized, double-blind, placebo-controlled, parallel-group study. Eligible patients (18-65 years) with an acute exacerbation of schizophrenia were randomized 2:2:1:2 to PF-02545920 (5 or 15 mg every 12 hours [Q12H] titrated), risperidone (3 mg Q12H), or placebo for 28 days (n = 74:74:37:74). The primary objectives were to evaluate the efficacy of PF-02545920 using the Positive and Negative Syndrome Scale (PANNS) and safety/tolerability. RESULTS At day 28, PF-02545920 (either dose) was not significantly different from placebo for mean change from baseline in the PANNS total score (primary end point) or most other end points. Pharmacokinetics exposures seemed adequate for binding/inhibiting PDE10A enzyme. Risperidone was statistically different from placebo for the PANNS total score, demonstrating study sensitivity. Incidence rates for adverse events were similar among the groups. Both doses of PF-02545920 were generally well tolerated. Dystonia occurred in 1, 6, 0, and 3 patients in the PF-02545920 5 mg Q12H, PF-02545920 15 mg Q12H, risperidone, and placebo groups, respectively. CONCLUSIONS Neither dose of PF-02545920 was superior to placebo for the primary and most secondary end points. This indicates that PDE10A inhibition does not produce an antipsychotic effect in patients with acute exacerbation of schizophrenia.
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25
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Antipsychotic-evoked dopamine supersensitivity. Neuropharmacology 2020; 163:107630. [DOI: 10.1016/j.neuropharm.2019.05.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 04/29/2019] [Accepted: 05/07/2019] [Indexed: 12/15/2022]
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26
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Koszła O, Targowska-Duda KM, Kędzierska E, Kaczor AA. In Vitro and In Vivo Models for the Investigation of Potential Drugs Against Schizophrenia. Biomolecules 2020; 10:biom10010160. [PMID: 31963851 PMCID: PMC7022578 DOI: 10.3390/biom10010160] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 01/12/2020] [Accepted: 01/13/2020] [Indexed: 02/06/2023] Open
Abstract
Schizophrenia (SZ) is a complex psychiatric disorder characterized by positive, negative, and cognitive symptoms, and is not satisfactorily treated by current antipsychotics. Progress in understanding the basic pathomechanism of the disease has been hampered by the lack of appropriate models. In order to develop modern drugs against SZ, efficient methods to study them in in vitro and in vivo models of this disease are required. In this review a short presentation of current hypotheses and concepts of SZ is followed by a description of current progress in the field of SZ experimental models. A critical discussion of advantages and limitations of in vitro models and pharmacological, genetic, and neurodevelopmental in vivo models for positive, negative, and cognitive symptoms of the disease is provided. In particular, this review concerns the important issue of how cellular and animal systems can help to meet the challenges of modeling the disease, which fully manifests only in humans, as experimental studies of SZ in humans are limited. Next, it is emphasized that novel clinical candidates should be evaluated in animal models for treatment-resistant SZ. In conclusion, the plurality of available in vitro and in vivo models is a consequence of the complex nature of SZ, and there are extensive possibilities for their integration. Future development of more efficient antipsychotics reflecting the pleiotropy of symptoms in SZ requires the incorporation of various models into one uniting model of the multifactorial disorder and use of this model for the evaluation of new drugs.
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Affiliation(s)
- Oliwia Koszła
- Department of Synthesis and Chemical Technology of Pharmaceutical Substances, Faculty of Pharmacy, Medical University of Lublin, 4A Chodźki St., PL-20093 Lublin, Poland;
| | - Katarzyna M. Targowska-Duda
- Department of Biopharmacy, Faculty of Pharmacy, Medical University of Lublin, 4A Chodźki St., PL-20093 Lublin, Poland
| | - Ewa Kędzierska
- Department of Pharmacology and Pharmacodynamics, Faculty of Pharmacy, Medical University of Lublin, 4A Chodźki St., PL-20093 Lublin, Poland;
| | - Agnieszka A. Kaczor
- Department of Synthesis and Chemical Technology of Pharmaceutical Substances, Faculty of Pharmacy, Medical University of Lublin, 4A Chodźki St., PL-20093 Lublin, Poland;
- School of Pharmacy, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
- Correspondence:
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27
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Potkin SG, Kane JM, Correll CU, Lindenmayer JP, Agid O, Marder SR, Olfson M, Howes OD. The neurobiology of treatment-resistant schizophrenia: paths to antipsychotic resistance and a roadmap for future research. NPJ SCHIZOPHRENIA 2020; 6:1. [PMID: 31911624 PMCID: PMC6946650 DOI: 10.1038/s41537-019-0090-z] [Citation(s) in RCA: 167] [Impact Index Per Article: 41.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 10/31/2019] [Indexed: 01/13/2023]
Abstract
Treatment-resistant schizophrenia (TRS), the persistence of positive symptoms despite ≥2 trials of adequate dose and duration of antipsychotic medication with documented adherence, is a serious clinical problem with heterogeneous presentations. TRS can vary in its onset (at the first episode of psychosis or upon relapse), in its severity, and in the response to subsequent therapeutic interventions (i.e., clozapine, electroconvulsive therapy). The heterogeneity of TRS indicates that the underlying neurobiology of TRS may differ not only from treatment-responsive schizophrenia but also among patients with TRS. Several hypotheses have been proposed for the neurobiological mechanisms underlying TRS, including dopamine supersensitivity, hyperdopaminergic and normodopaminergic subtypes, glutamate dysregulation, inflammation and oxidative stress, and serotonin dysregulation. Research supporting these hypotheses is limited in part by variations in the criteria used to define TRS, as well as by the biological and clinical heterogeneity of TRS. Clinical trial designs for new treatments should be informed by this heterogeneity, and further clinical research is needed to more clearly understand the underlying neurobiology of TRS and to optimize treatment for patients with TRS.
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Affiliation(s)
| | - John M Kane
- Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Department of Psychiatry and Molecular Medicine, Hempstead, NY, USA
- The Zucker Hillside Hospital, Glen Oaks, NY, USA
- The Feinstein Institute for Medical Research, Psychiatric Neuroscience Center of Excellence, Manhasset, NY, USA
| | - Christoph U Correll
- Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Department of Psychiatry and Molecular Medicine, Hempstead, NY, USA
- The Zucker Hillside Hospital, Glen Oaks, NY, USA
- The Feinstein Institute for Medical Research, Psychiatric Neuroscience Center of Excellence, Manhasset, NY, USA
- Charité Universitätsmedizin, Department of Child and Adolescent Psychiatry, Berlin, Germany
| | | | - Ofer Agid
- Centre for Addiction and Mental Health, Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Stephen R Marder
- The Semel Institute for Neuroscience at UCLA, Los Angeles, CA, USA
- The VA Desert Pacific Mental Illness Research, Education, and Clinical Center, Los Angeles, CA, USA
| | - Mark Olfson
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY, USA
| | - Oliver D Howes
- King's College, London, UK.
- MRC London Institute of Medical Sciences, Imperial College, London, UK.
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28
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O’Donnell P, Rosen L, Alexander R, Murthy V, Davies CH, Ratti E. Strategies to Address Challenges in Neuroscience Drug Discovery and Development. Int J Neuropsychopharmacol 2019; 22:445-448. [PMID: 31139821 PMCID: PMC6600465 DOI: 10.1093/ijnp/pyz027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 05/06/2019] [Accepted: 05/27/2019] [Indexed: 01/17/2023] Open
Abstract
The paucity of novel drugs for neuropsychiatric indications contrasts with the remarkable recent advances in neuroscience research. We have identified 5 challenges the field needs to address and recommend potential solutions. First, we need to drive discovery efforts based on human data. Second, we need to think more carefully about animal models, embracing them as tools to test pathophysiological alterations. Third, we need to develop strategies to select more homogenous groups of patients in our clinical trials. Fourth, we need to develop and validate translational biomarkers, which can be used for pharmacodynamic assessments as well as for patient selection. Fifth, we need to adopt more reliable and objective measures to capture clinical efficacy. The tools that will allow these solutions to be implemented may already be in place but not routinely adopted or are still being developed. Overall, a change in mindset to adopt science- and data-driven paths is needed.
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Affiliation(s)
- Patricio O’Donnell
- Takeda Pharmaceuticals, Cambridge, Massachusetts,Correspondence: Patricio O’Donnell, MD, PhD, Takeda Pharmaceuticals, 350 Massachusetts Ave., Cambridge, MA 02139 ()
| | - Laura Rosen
- Takeda Pharmaceuticals, Cambridge, Massachusetts
| | | | | | - Ceri H Davies
- Takeda Pharmaceuticals Company Limited, Fujisawa, Kanagawa, Japan
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29
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Insights on current and novel antipsychotic mechanisms from the MAM model of schizophrenia. Neuropharmacology 2019; 163:107632. [PMID: 31077730 DOI: 10.1016/j.neuropharm.2019.05.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 04/25/2019] [Accepted: 05/07/2019] [Indexed: 12/18/2022]
Abstract
Current antipsychotic drugs (APDs) act on D2 receptors, and preclinical studies demonstrate that repeated D2 antagonist administration downregulates spontaneously active DA neurons by producing overexcitation-induced inactivation of firing (depolarization block). Animal models of schizophrenia based on the gestational MAM administration produces offspring with adult phenotypes consistent with schizophrenia, including ventral hippocampal hyperactivity and a DA neuron overactivity. The MAM model reveals that APDs act differently in a hyperdopamineregic system compared to a normal one, including rapid onset of depolarization block in response to acute D2 antagonist administration and downregulation of DA neuron population activity following acute and repeated D2 partial agonist administration, none of which are observed in normal rats. Novel target compounds have been developed based on the theory that glutamatergic dysfunction is central to schizophrenia pathology. Despite showing promise in preclinical research, none of the novel drugs succeeded in clinical trials. However, preclinical research is generally performed in normal, drug-naïve rats, whereas models with disease-relevant pathology and prior APD exposure may improve the predictive validity of preclinical research. Indeed, in MAM rats, chronic D2 antagonist treatment leads to persistent DA supersensitivity that interferes with the response to drugs that target upstream pathology. Moreover, MAM rats revealed that the peri-pubertal period is a stress-sensitive window that can be targeted to prevent the development of MAM pathology in adulthood. Neurodevelopmental models, such as the MAM model, can thus be used to test potential pharmacotherapies that may be able to treat schizophrenia in early stages of the disease. This article is part of the issue entitled 'Special Issue on Antipsychotics'.
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30
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Sonnenschein SF, Gill KM, Grace AA. State-dependent effects of the D 2 partial agonist aripiprazole on dopamine neuron activity in the MAM neurodevelopmental model of schizophrenia. Neuropsychopharmacology 2019; 44:572-580. [PMID: 30267014 PMCID: PMC6333840 DOI: 10.1038/s41386-018-0219-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 08/31/2018] [Accepted: 09/09/2018] [Indexed: 01/21/2023]
Abstract
Aripiprazole is an antipsychotic drug characterized by partial agonist activity at D2 receptors to normalize both hyperdopaminergic and hypodopaminergic states. Traditional D2 antagonist antipsychotic drugs have been shown previously to reduce dopamine neuron activity through action on D2 autoreceptors to produce an overexcitation-induced cessation of cell firing, referred to as depolarization block. It is unclear whether aripiprazole reduces dopamine neuron activity via inhibition or, as seen following D2 antagonist administration, depolarization block. The impact of acute and repeated aripiprazole treatment was examined in the methylazoxymethanol acetate (MAM) rodent model to observe its effects on a hyperdopaminergic system, compared to normal rats. We found that administration of aripiprazole acutely or after 1 or 7 days of withdrawal from 21-day repeated treatment led to a decrease in the number of spontaneously active dopamine neurons in MAM rats but not in controls. This reduction was not reversed by apomorphine (100-200 µg/kg i.p. or 20 µg/kg i.v.) administration, suggesting that it was not due to depolarization block. In contrast, 1 h after induction of depolarization block of dopamine neurons by acute haloperidol treatment (0.6 mg/kg i.p.), aripiprazole (1 mg/kg, i.p.) reversed the depolarization block state. Therefore, aripiprazole rapidly reduced the hyperdopaminergic activity selectively in MAM rats. The reduction is unlikely due to depolarization block and persists following 7-day withdrawal from repeated treatment. Aripiprazole also removes haloperidol-induced depolarization block in MAM rats, which may underlie the acute psychotic state often observed with switching to this treatment.
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Affiliation(s)
- Susan F. Sonnenschein
- 0000 0004 1936 9000grid.21925.3dDepartments of Neuroscience, Psychiatry and Psychology, Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260 USA
| | - Kathryn M. Gill
- 0000 0004 1936 9000grid.21925.3dDepartments of Neuroscience, Psychiatry and Psychology, Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260 USA
| | - Anthony A. Grace
- 0000 0004 1936 9000grid.21925.3dDepartments of Neuroscience, Psychiatry and Psychology, Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260 USA
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Grace AA, Gomes FV. The Circuitry of Dopamine System Regulation and its Disruption in Schizophrenia: Insights Into Treatment and Prevention. Schizophr Bull 2019; 45:148-157. [PMID: 29385549 PMCID: PMC6293217 DOI: 10.1093/schbul/sbx199] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Despite evidence for a role of the dopamine system in the pathophysiology of schizophrenia, there has not been substantial evidence that this disorder originates from a pathological change within the dopamine system itself. Current data from human imaging studies and preclinical investigations instead point to a disruption in afferent regulation of the dopamine system, with a focus on the hippocampus. We found that the hippocampus in the methylazoxymethanol acetate (MAM) rodent developmental disruption model of schizophrenia is hyperactive and dysrhythmic, possibly due to loss of parvalbumin interneurons, leading to a hyperresponsive dopamine system. Whereas current therapeutic approaches target dopamine receptor blockade, treatment at the site of pathology may be a more effective therapeutic avenue. This model also provided insights into potential means for prevention of schizophrenia. Specifically, given that stress is a risk factor in schizophrenia, and that stress can damage hippocampal parvalbumin interneurons, we tested whether alleviating stress early in life can effectively circumvent transition to schizophrenia-like states. Administering diazepam prepubertally at an antianxiety dose in MAM rats was effective at preventing the emergence of the hyperdopaminergic state in the adult. Moreover, multiple stressors applied to normal rats at the same time point resulted in pathology similar to the MAM rat. These data suggest that a genetic predisposition leading to stress hyper-responsivity, or exposure to substantial stressors, could be a primary factor leading to the emergence of schizophrenia later in life, and furthermore treating stress at a critical period may be effective in circumventing this transition.
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Affiliation(s)
- Anthony A Grace
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA,To whom correspondence should be addressed; Departments of Neuroscience, Psychiatry and Psychology, A210 Langley Hall, University of Pittsburgh, Pittsburgh, PA 15260, US; tel: 412-624-4609, fax: 412-624-9198, e-mail:
| | - Felipe V Gomes
- Departments of Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA
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Amato D, Kruyer A, Samaha AN, Heinz A. Hypofunctional Dopamine Uptake and Antipsychotic Treatment-Resistant Schizophrenia. Front Psychiatry 2019; 10:314. [PMID: 31214054 PMCID: PMC6557273 DOI: 10.3389/fpsyt.2019.00314] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 04/23/2019] [Indexed: 01/07/2023] Open
Abstract
Antipsychotic treatment resistance in schizophrenia remains a major issue in psychiatry. Nearly 30% of patients with schizophrenia do not respond to antipsychotic treatment, yet the underlying neurobiological causes are unknown. All effective antipsychotic medications are thought to achieve their efficacy by targeting the dopaminergic system. Here we review early literature describing the fundamental mechanisms of antipsychotic drug efficacy, highlighting mechanistic concepts that have persisted over time. We then reconsider the original framework for understanding antipsychotic efficacy in light of recent advances in our scientific understanding of the dopaminergic effects of antipsychotics. Based on these new insights, we describe a role for the dopamine transporter in the genesis of both antipsychotic therapeutic response and primary resistance. We believe that this discussion will help delineate the dopaminergic nature of antipsychotic treatment-resistant schizophrenia.
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Affiliation(s)
- Davide Amato
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | - Anna Kruyer
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | - Anne-Noël Samaha
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Andreas Heinz
- Department of Psychiatry, Charité University Medicine Berlin, Campus Charité Mitte, Berlin, Germany
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Wang Z, Yu Z, Pan Z, Zhao K, Zhao Q, Zhou D, Shen HW, Wu X. Impaired Binocular Depth Perception in First-Episode Drug-Naive Patients With Schizophrenia. Front Psychol 2018; 9:850. [PMID: 29904365 PMCID: PMC5990910 DOI: 10.3389/fpsyg.2018.00850] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 05/11/2018] [Indexed: 11/13/2022] Open
Abstract
Binocular depth perception (BDP) is one of the most demanding visual function that involves both dorsal and ventral visual information streams. Substantial research has been conducted on the disruption of BDP in patients with schizophrenia. However, research on first-episode and drug-naive patients with schizophrenia (FEDN) is limited. To assess the BDP of schizophrenia patients while controlling for the effects of antipsychotics and the duration of illness. We investigated BDP in patients with schizophrenia via the Titmus Stereopsis Test in this study, by matching the patients into three groups: FEDN (n = 17), long duration of illness and medicine treatment (LDMT) (n = 31) and the healthy control group (n = 40). Results showed that both the FEDN (mean = 1.71, 95% confidence interval [CI]: [1.57, 1.84]) and LDMT (1.73, 95% CI: [1.66, 1.81]) patients displayed a significant decline (p = 0.01, Cohen's d = 0.67, p = 0.001, Cohen's d = 0.92, respectively) in depth perception compared to the healthy control (1.55, 95% CI: [1.48, 1.61]) group. Additionally, there were no significant differences (p = 0.68, Cohen's d = 0.11) between the FEDN and LDMT groups, and no correlation (Pearson r = -0.16, p = 0.38, R2 = 0.03) was observed between the duration of illness and impaired BDP in the LDMT group. The proportion of individuals with stereopsis detection in either FEDN (12/17) or LDMT (26/31) groups under stereo threshold 63 arc seconds (″), were significantly lower (Pearson χ2 = 6.29, p = 0.043, φc = 0.27) compared to the healthy control group (38/40). Significant difference in stereopsis detection also occurred at 50″ (Pearson χ2 = 12.31, p = 0.001, φc = 0.37), 40″ (Pearson χ2 = 12.38, p = 0.002, φc = 0.38), 32″ (Pearson χ2 = 6.69, p = 0.035, φc = 0.28), 25″ (Pearson χ2 = 14.82, p = 0.001, φc = 0.41) and 20″ (Pearson χ2 = 6.73, p = 0.034, φc = 0.28) between the three groups. These findings showed a moderately strong association between schizophrenia and defective stereopsis.
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Affiliation(s)
| | - Zhipeng Yu
- School of Medicine, Ningbo University, Ningbo, China
| | - Zhichao Pan
- School of Medicine, Ningbo University, Ningbo, China
| | - Keyu Zhao
- School of Medicine, Ningbo University, Ningbo, China
| | - Qiqi Zhao
- School of Medicine, Ningbo University, Ningbo, China
| | | | - Hao-Wei Shen
- School of Medicine, Ningbo University, Ningbo, China
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Gill KM, Miller SA, Grace AA. Impaired contextual fear-conditioning in MAM rodent model of schizophrenia. Schizophr Res 2018; 195:343-352. [PMID: 28927551 PMCID: PMC5854517 DOI: 10.1016/j.schres.2017.08.064] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 08/31/2017] [Accepted: 08/31/2017] [Indexed: 12/19/2022]
Abstract
The methylazoxymethanol acetate (MAM) rodent neurodevelopmental model of schizophrenia exhibits aberrant dopamine system activation attributed to hippocampal dysfunction. Context discrimination is a component of numerous behavioral and cognitive functions and relies on intact hippocampal processing. The present study explored context processing behaviors, along with dopamine system activation, during fear learning in the MAM model. Male offspring of dams treated with MAM (20mg/kg, i.p.) or saline on gestational day 17 were used for electrophysiological and behavioral experiments. Animals were tested on the immediate shock fear conditioning paradigm, with either different pre-conditioning contexts or varying amounts of context pre-exposure (0-10 sessions). Amphetamine-induced locomotor activity and dopamine neural activity was measured 1-week after fear conditioning. Saline, but not MAM animals, demonstrated enhanced fear responses following a single context pre-exposure in the conditioning context. One week following fear learning, saline rats with 2 or 7min of context pre-exposure prior to fear conditioning also demonstrated enhanced amphetamine-induced locomotor response relative to MAM animals. Dopamine neuron recordings showed fear learning-induced reductions in spontaneous dopamine neural activity in MAM rats that was further reduced by amphetamine. Apomorphine administration confirmed that reductions in dopamine neuron activity in MAM animals resulted from over excitation, or depolarization block. These data show a behavioral insensitivity to contextual stimuli in MAM rats that coincide with a less dynamic dopamine response after fear learning.
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Affiliation(s)
- Kathryn M Gill
- University of Pittsburgh, Pittsburgh, PA 15260, Departments of Neuroscience, Psychiatry and Psychology, USA.
| | - Sarah A Miller
- University of Pittsburgh, Pittsburgh, PA 15260, Departments of Neuroscience, Psychiatry and Psychology, USA
| | - Anthony A Grace
- University of Pittsburgh, Pittsburgh, PA 15260, Departments of Neuroscience, Psychiatry and Psychology, USA
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Li G, Stephen MR, Kodali R, Zahn NM, Poe MM, Tiruveedhula VVNPB, Huber AT, Schussman MK, Qualmann K, Panhans CM, Raddatz NJ, Baker DA, Prevot TD, Banasr M, Sibille E, Arnold LA, Cook JM. Synthesis of chiral GABA A receptor subtype selective ligands as potential agents to treat schizophrenia as well as depression. ARKIVOC 2018; 2018:158-182. [PMID: 32774192 PMCID: PMC7413308 DOI: 10.24820/ark.5550190.p010.460] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
A series of novel imidazobenzodiazepine analogs of the lead chiral ligand SH-053-2'F-S-CH3 (2), an α2/α3/α5 (Bz)GABA (A)ergic receptor subtype selective ligand, which reversed PCP-induced prepulse inhibition (PPI) of acoustic startle, were synthesized. These chiral (S)-CH3 ligands are targeted for the treatment of schizophrenia and depression. These new ligands were designed by modifying the liable ester functionality in 2 to improve the metabolic stability, cytotoxicity, and activity as compared to 2. Based on the data to date, the most promising ligands are the N-cyclopropyl amide GL-I-55 (8c) and the methyl bioisostere GL-I-65 (9a). The in vitro metabolic stability, cytotoxicity and in vivo locomotor effects are described in this report. Based on these results, 8c and 9a are the most promising for further in vivo pharmacology.
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Affiliation(s)
- Guanguan Li
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
| | - Michael R Stephen
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
| | - Revathi Kodali
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
| | - Nicolas M Zahn
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
| | - Michael M Poe
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
| | - V V N Phani Babu Tiruveedhula
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
| | - Alec T Huber
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
| | - Melissa K Schussman
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
| | - Krista Qualmann
- Department of Biomedical Science, Marquette University, Milwaukee, Wisconsin 53233, United States
| | - Cristina M Panhans
- Department of Biomedical Science, Marquette University, Milwaukee, Wisconsin 53233, United States
| | - Nicholas J Raddatz
- Department of Biomedical Science, Marquette University, Milwaukee, Wisconsin 53233, United States
| | - David A Baker
- Department of Biomedical Science, Marquette University, Milwaukee, Wisconsin 53233, United States
| | - Thomas D Prevot
- Campbell Family Mental Health Research Institute of CAMH, Toronto, Canada
| | - Mounira Banasr
- Campbell Family Mental Health Research Institute of CAMH, Toronto, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Canada
- Department of Psychiatry, University of Toronto, Toronto, Canada
| | - Etienne Sibille
- Campbell Family Mental Health Research Institute of CAMH, Toronto, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Canada
- Department of Psychiatry, University of Toronto, Toronto, Canada
| | - Leggy A Arnold
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
| | - James M Cook
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
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Huang J, Zhao D, Liu Z, Liu F. Repurposing psychiatric drugs as anti-cancer agents. Cancer Lett 2018; 419:257-265. [PMID: 29414306 DOI: 10.1016/j.canlet.2018.01.058] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 01/17/2018] [Accepted: 01/19/2018] [Indexed: 01/11/2023]
Abstract
Cancer is a major public health problem and one of the leading contributors to the global disease burden. The high cost of development of new drugs and the increasingly severe burden of cancer globally have led to increased interest in the search and development of novel, affordable anti-neoplastic medications. Antipsychotic drugs have a long history of clinical use and tolerable safety; they have been used as good targets for drug repurposing. Being used for various psychiatric diseases for decades, antipsychotic drugs are now reported to have potent anti-cancer properties against a wide variety of malignancies in addition to their antipsychotic effects. In this review, an overview of repurposing various psychiatric drugs for cancer treatment is presented, and the putative mechanisms for the anti-neoplastic actions of these antipsychotic drugs are reviewed.
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Affiliation(s)
- Jing Huang
- Department of Neurosurgery, Xiangya Hospital, Central South University (CSU), Changsha, China; Department of Psychiatry, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China; Mental Health Institute of the Second Xiangya Hospital, Central South University, Chinese National Clinical Research Center for Mental Disorders (Xiangya), Changsha, Hunan, 410011, China; Chinese National Technology Institute on Mental Disorders, Hunan Key Laboratory of Psychiatry and Mental Health, Changsha, Hunan, 410011, China
| | - Danwei Zhao
- Xiangya Medical School, Central South University, Changsha, Hunan, China
| | - Zhixiong Liu
- Department of Neurosurgery, Xiangya Hospital, Central South University (CSU), Changsha, China
| | - Fangkun Liu
- Department of Neurosurgery, Xiangya Hospital, Central South University (CSU), Changsha, China.
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Kesby JP, Eyles DW, McGrath JJ, Scott JG. Dopamine, psychosis and schizophrenia: the widening gap between basic and clinical neuroscience. Transl Psychiatry 2018; 8:30. [PMID: 29382821 PMCID: PMC5802623 DOI: 10.1038/s41398-017-0071-9] [Citation(s) in RCA: 196] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 10/10/2017] [Accepted: 10/26/2017] [Indexed: 12/18/2022] Open
Abstract
The stagnation in drug development for schizophrenia highlights the need for better translation between basic and clinical research. Understanding the neurobiology of schizophrenia presents substantial challenges but a key feature continues to be the involvement of subcortical dopaminergic dysfunction in those with psychotic symptoms. Our contemporary knowledge regarding dopamine dysfunction has clarified where and when dopaminergic alterations may present in schizophrenia. For example, clinical studies have shown patients with schizophrenia show increased presynaptic dopamine function in the associative striatum, rather than the limbic striatum as previously presumed. Furthermore, subjects deemed at high risk of developing schizophrenia show similar presynaptic dopamine abnormalities in the associative striatum. Thus, our view of subcortical dopamine function in schizophrenia continues to evolve as we accommodate this newly acquired information. However, basic research in animal models has been slow to incorporate these clinical findings. For example, psychostimulant-induced locomotion, the commonly utilised phenotype for positive symptoms in rodents, is heavily associated with dopaminergic activation in the limbic striatum. This anatomical misalignment has brought into question how we assess positive symptoms in animal models and represents an opportunity for improved translation between basic and clinical research. The current review focuses on the role of subcortical dopamine dysfunction in psychosis and schizophrenia. We present and discuss alternative phenotypes that may provide a more translational approach to assess the neurobiology of positive symptoms in schizophrenia. Incorporation of recent clinical findings is essential if we are to develop meaningful translational animal models.
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Affiliation(s)
- JP Kesby
- 0000 0000 9320 7537grid.1003.2Queensland Brain Institute, The University of Queensland, St. Lucia, QLD Australia ,0000 0000 9320 7537grid.1003.2Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Herston, QLD Australia
| | - DW Eyles
- 0000 0000 9320 7537grid.1003.2Queensland Brain Institute, The University of Queensland, St. Lucia, QLD Australia ,0000 0004 0606 3563grid.417162.7Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Wacol, QLD Australia
| | - JJ McGrath
- 0000 0000 9320 7537grid.1003.2Queensland Brain Institute, The University of Queensland, St. Lucia, QLD Australia ,0000 0004 0606 3563grid.417162.7Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Wacol, QLD Australia ,0000 0001 1956 2722grid.7048.bNational Centre for Register-based Research, Aarhus University, Aarhus C, Denmark
| | - JG Scott
- 0000 0000 9320 7537grid.1003.2Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Herston, QLD Australia ,0000 0004 0606 3563grid.417162.7Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Wacol, QLD Australia ,0000 0001 0688 4634grid.416100.2Metro North Mental Health, Royal Brisbane and Women’s Hospital, Herston, QLD Australia
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Servonnet A, Minogianis EA, Bouchard C, Bédard AM, Lévesque D, Rompré PP, Samaha AN. Neurotensin in the nucleus accumbens reverses dopamine supersensitivity evoked by antipsychotic treatment. Neuropharmacology 2017; 123:10-21. [DOI: 10.1016/j.neuropharm.2017.05.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 05/09/2017] [Accepted: 05/13/2017] [Indexed: 12/20/2022]
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Nakata Y, Kanahara N, Kimura H, Watanabe H, Iyo M. Efficacy of clozapine on dopamine supersensitivity psychosis in schizophrenia. Int Clin Psychopharmacol 2017; 32:169-173. [PMID: 28067751 DOI: 10.1097/yic.0000000000000160] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Although the effectiveness of clozapine (CLZ) for patients with treatment-resistant schizophrenia (TRS) has been well established, its active mechanism has not been completely clarified. Several clinical studies showed that neuroleptic-induced dopamine supersensitivity psychosis (DSP) could be involved in the etiology of TRS. We preliminarily explored the possible beneficial effect of CLZ for dopamine supersensitivity schizophrenia. The present study is a case series. We followed 15 patients with DSP for about 2.5 years from the introduction of CLZ and compared the prevalence of episodes (particularly, rebound psychosis, tolerance to antipsychotic effects, or tardive dyskinesia) between the period before and during CLZ treatment. Our observation over 2.5 years following the introduction of CLZ showed that 13 of the 15 DSP patients presented no further DSP episodes. One patient showed continued tardive dyskinesia, which had already existed in the preperiod, and the other patient presented with rebound psychosis that appeared immediately after discontinuation of CLZ. The results of the present study indicated that DSP in schizophrenic patients treated with general antipsychotics disappeared over the subsequent 2.5 years under CLZ treatment, suggesting that the agent ameliorates the dopamine supersensitivity state induced by previous antipsychotic treatment.
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Affiliation(s)
- Yusuke Nakata
- aDepartment of Psychiatry, Graduate School of Medicine bDivision of Medical Treatment and Rehabilitation, Center for Forensic Mental Health, Chiba University, Chiba, Japan cClinic for Psychiatry and Psychotherapy, Ludwig Maximilians University of Munich, Munich, Germany
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40
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Abstract
Learning and memory are dependent on interactive excitatory and inhibitory mechanisms. In this review, we discuss a mechanism called disinhibition, which is the release of an inhibitory constraint that effectively results in an increased activity in the target neurons (for example, principal or projection neurons). We focus on discussing the role of disinhibition in learning and memory at a basic level and in disease models with cognitive deficits and highlight a strategy to reverse cognitive deficits caused by excess inhibition, through disinhibition of α5-containing GABA
A receptors mediating tonic inhibition in the hippocampus, based on subtype-selective negative allosteric modulators as a novel class of drugs.
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Affiliation(s)
- Hanns Möhler
- Institute of Pharmacology, University of Zurich, Zurich, Switzerland; Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology Zurich, Zurich, Switzerland
| | - Uwe Rudolph
- Laboratory of Genetic Neuropharmacology, McLean Hospital, Belmont, MA, USA; Department of Psychiatry, Harvard Medical School, Boston, MA, USA
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41
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Grace AA. Dopamine System Dysregulation and the Pathophysiology of Schizophrenia: Insights From the Methylazoxymethanol Acetate Model. Biol Psychiatry 2017; 81:5-8. [PMID: 26705848 PMCID: PMC4870144 DOI: 10.1016/j.biopsych.2015.11.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 11/04/2015] [Indexed: 12/26/2022]
Affiliation(s)
- Anthony A. Grace
- Department of Neuroscience, A210 Langley Hall, University of Pittsburgh, Pittsburgh, PA 15260, USA, Tel: +1 412 624 4609, FAX: +1 412 624 9198,
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42
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Geerts H, Spiros A, Roberts P. Phosphodiesterase 10 inhibitors in clinical development for CNS disorders. Expert Rev Neurother 2016; 17:553-560. [DOI: 10.1080/14737175.2017.1268531] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Hugo Geerts
- In Silico Biosciences Perelman School of Medicine, University of Pennsylvania, Berwyn, PA, USA
| | - Athan Spiros
- In Silico Biosciences Perelman School of Medicine, University of Pennsylvania, Berwyn, PA, USA
| | - Patrick Roberts
- In Silico Biosciences Perelman School of Medicine, University of Pennsylvania, Berwyn, PA, USA
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43
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Bortz D, Upton B, Mikkelsen J, Bruno J. Positive allosteric modulators of the α7 nicotinic acetylcholine receptor potentiate glutamate release in the prefrontal cortex of freely-moving rats. Neuropharmacology 2016; 111:78-91. [DOI: 10.1016/j.neuropharm.2016.08.033] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 08/20/2016] [Accepted: 08/24/2016] [Indexed: 12/23/2022]
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de Bartolomeis A, Marmo F, Buonaguro EF, Latte G, Tomasetti C, Iasevoli F. Switching antipsychotics: Imaging the differential effect on the topography of postsynaptic density transcripts in antipsychotic-naïve vs. antipsychotic-exposed rats. Prog Neuropsychopharmacol Biol Psychiatry 2016; 70:24-38. [PMID: 27177972 DOI: 10.1016/j.pnpbp.2016.04.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 04/17/2016] [Accepted: 04/27/2016] [Indexed: 10/24/2022]
Abstract
The postsynaptic density (PSD) has been regarded as a functional switchboard at the crossroads of a dopamine-glutamate interaction, and it is putatively involved in the pathophysiology of psychosis. Indeed, it has been demonstrated that antipsychotics may modulate several PSD transcripts, such as PSD-95, Shank, and Homer. Despite switching antipsychotics is a frequent strategy to counteract lack of efficacy and/or side effect onset in clinical practice, no information is available on the effects of sequential treatments with different antipsychotics on PSD molecules. The aim of this study was to evaluate whether a previous exposure to a typical antipsychotic and a switch to an atypical one may affect the expression of PSD transcripts, in order to evaluate potential neurobiological correlates of this common clinical practice, with specific regards to putative synaptic plasticity processes. We treated male Sprague-Dawley rats intraperitoneally for 15days with haloperidol or vehicle, then from the sixteenth day we switched the animals to amisulpride or continued to treat them with vehicle or haloperidol for 15 additional days. In this way we got six first treatment/second treatment groups: vehicle/vehicle, vehicle/haloperidol, vehicle/amisulpride, haloperidol/vehicle, haloperidol/haloperidol, haloperidol/amisulpride. In this paradigm, we evaluated the expression of brain transcripts belonging to relevant and interacting PSD proteins, both of the Immediate-Early Gene (Homer1a, Arc) and the constitutive classes (Homer1b/c and PSD-95). The major finding was the differential effect of amisulpride on gene transcripts when administered in naïve vs. antipsychotic-pretreated rats, with modifications of the ratio between Homer1a/Homer1b transcripts and differential effects in cortex and striatum. These results suggest that the neurobiological effects on PSD transcripts of amisulpride, and possibly of other antipsychotics, may be greatly affected by prior antipsychotic treatments and may impact significantly on the switching procedure.
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Affiliation(s)
- Andrea de Bartolomeis
- Laboratory of Molecular and Translational Psychiatry, Department of Neuroscience, School of Medicine, University "Federico II", Naples, Italy.
| | - Federica Marmo
- Laboratory of Molecular and Translational Psychiatry, Department of Neuroscience, School of Medicine, University "Federico II", Naples, Italy
| | - Elisabetta F Buonaguro
- Laboratory of Molecular and Translational Psychiatry, Department of Neuroscience, School of Medicine, University "Federico II", Naples, Italy
| | - Gianmarco Latte
- Laboratory of Molecular and Translational Psychiatry, Department of Neuroscience, School of Medicine, University "Federico II", Naples, Italy
| | - Carmine Tomasetti
- Laboratory of Molecular and Translational Psychiatry, Department of Neuroscience, School of Medicine, University "Federico II", Naples, Italy
| | - Felice Iasevoli
- Laboratory of Molecular and Translational Psychiatry, Department of Neuroscience, School of Medicine, University "Federico II", Naples, Italy
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45
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Zimmerman EC, Grace AA. The Nucleus Reuniens of the Midline Thalamus Gates Prefrontal-Hippocampal Modulation of Ventral Tegmental Area Dopamine Neuron Activity. J Neurosci 2016; 36:8977-84. [PMID: 27559178 PMCID: PMC4995308 DOI: 10.1523/jneurosci.1402-16.2016] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 07/01/2016] [Accepted: 07/06/2016] [Indexed: 01/27/2023] Open
Abstract
UNLABELLED The circuitry mediating top-down control of dopamine (DA) neurons in the ventral tegmental area (VTA) is exceedingly complex. Characterizing these networks will be critical to our understanding of fundamental behaviors, such as motivation and reward processing, as well as several disease states. Previous work suggests that the medial prefrontal cortex (mPFC) exerts a profound influence on VTA DA neuron firing. Recently, our group reported that inhibition of the infralimbic subdivision of the medial prefrontal cortex (ilPFC) increases the proportion of VTA DA neurons that are spontaneously active (i.e., "population activity") and that this effect depends on activity in the ventral subiculum of the hippocampus (vSub). However, there is no direct projection from the mPFC to the vSub. Anatomical evidence suggests that communication between the two structures is mediated by the nucleus reuniens of the midline thalamus (RE). Here, we used in vivo electrophysiological and behavioral approaches in rats to explore the role of the RE in the circuitry governing VTA DA neuron firing. We show that pharmacological stimulation of the RE enhances VTA DA neuron population activity and amphetamine-induced hyperlocomotion, a behavioral indicator of an over-responsive DA system. Furthermore, the effect of RE stimulation on population activity is prevented if vSub is also inhibited. Finally, pharmacological inhibition of ilPFC enhances VTA DA neuron population activity, but this effect does not occur if RE is also inhibited. These findings suggest that disruption of ilPFC-RE-vSub communication could lead to a dysregulated, hyperdopaminergic state, and may play a role in psychiatric disorders. SIGNIFICANCE STATEMENT Dopamine (DA) neurons in the ventral tegmental area (VTA) are involved in a variety of fundamental brain functions. To understand the neurobiological basis for these functions it is essential to identify regions controlling DA neuron activity. The medial prefrontal cortex (mPFC) is emerging as a key regulator of DA neuron activity, but the circuitry by which it exerts its influence remains poorly described. Here, we show that the nucleus reuniens of the midline thalamus gates mPFC control of VTA DA neuron firing by the hippocampus. These data identify a unique role for this corticothalamic-hippocampal circuit, and suggest that dysfunction in these regions likely influences the pathophysiology of psychiatric disorders.
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Affiliation(s)
- Eric C Zimmerman
- Departments of Neuroscience, Psychiatry, and Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Anthony A Grace
- Departments of Neuroscience, Psychiatry, and Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
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Li M. Antipsychotic-induced sensitization and tolerance: Behavioral characteristics, developmental impacts, and neurobiological mechanisms. J Psychopharmacol 2016; 30:749-70. [PMID: 27371498 PMCID: PMC4944179 DOI: 10.1177/0269881116654697] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Antipsychotic sensitization and tolerance refer to the increased and decreased drug effects due to past drug use, respectively. Both effects reflect the long-term impacts of antipsychotic treatment on the brain and result from the brain's adaptive response to the foreign property of the drug. In this review, clinical evidence of the behavioral aspect of antipsychotic sensitization and tolerance is selectively reviewed, followed by an overview of preclinical literature that examines these behavioral characteristics and the related pharmacological and nonpharmacological factors. Next, recent work on the developmental impacts of adolescent antipsychotic sensitization and tolerance is presented and recent research that delineates the neurobiological mechanisms of antipsychotic sensitization and tolerance is summarized. A theoretical framework based on "drug learning and memory" principles is proposed to account for the phenomena of antipsychotic sensitization and tolerance. It is maintained that antipsychotic sensitization and tolerance follow basic principles of learning or acquisition ("induction") and memory ("expression"). The induction and expression of both effects reflect the consequences of associative and nonassociative processing and are strongly influenced by various pharmacological, environmental, and behavioral factors. Drug-induced neuroplasticity, such as functional changes of striatal dopamine D2 and prefrontal serotonin (5-HT)2A receptors and their mediated signaling pathways, in principle, is responsible for antipsychotic sensitization and tolerance. Understanding the behavioral characteristics and neurobiological underpinnings of antipsychotic sensitization and tolerance has greatly enhanced our understanding of mechanisms of antipsychotic action, and may have important implications for future drug discovery and clinical practice.
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Affiliation(s)
- Ming Li
- Department of Psychology, University of Nebraska-Lincoln, Lincoln, NE, USA
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47
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Goetghebeur PJ, Swartz JE. True alignment of preclinical and clinical research to enhance success in CNS drug development: a review of the current evidence. J Psychopharmacol 2016; 30:586-94. [PMID: 27147593 DOI: 10.1177/0269881116645269] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Central nervous system pharmacological research and development has reached a critical turning point. Patients suffering from disorders afflicting the central nervous system are numerous and command significant attention from the pharmaceutical industry. However, given the numerous failures of promising drugs, many companies are no longer investing in or, indeed, are divesting from this therapeutic area. Central nervous system drug development must change in order to develop effective therapies to treat these patients. Preclinical research is a cornerstone of drug development; however, it is frequently criticised for its lack of predictive validity. Animal models and assays can be shown to be more predictive than reported and, on many occasions, the lack of thorough preclinical testing is potentially to blame for some of the clinical failures. Important factors such as translational aspects, nature of animal models, variances in acute versus chronic dosing, development of add-on therapies and understanding of the full dose-response relationship are too often neglected. Reducing the attrition rate in central nervous system drug development could be achieved by addressing these important questions before novel compounds enter the clinical phase. This review illustrates the relevance of employing these criteria to translational central nervous system research, better to ensure success in developing new drugs in this therapeutic area.
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Affiliation(s)
| | - Jina E Swartz
- CNS Therapeutic Area Unit, Takeda Development Centre Europe Ltd, London, UK
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48
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Litman RE, Smith MA, Doherty JJ, Cross A, Raines S, Gertsik L, Zukin SR. AZD8529, a positive allosteric modulator at the mGluR2 receptor, does not improve symptoms in schizophrenia: A proof of principle study. Schizophr Res 2016; 172:152-7. [PMID: 26922656 DOI: 10.1016/j.schres.2016.02.001] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 01/27/2016] [Accepted: 02/01/2016] [Indexed: 10/22/2022]
Abstract
INTRODUCTION Activation of metabotropic glutamate (mGluR2/3) receptors has been proposed as an alternative mechanism to dopaminergic-based antipsychotics to correct glutamatergic deficits hypothesized to underlie schizophrenia symptoms. This study investigates the efficacy and safety of AZD8529, a selective positive allosteric modulator (PAM) at the mGlu2 receptor, in symptomatic patients with schizophrenia. METHODS Patients were randomized to receive AZD8529 40 mg, risperidone 4 mg, or placebo as monotherapy. Treatment lasted for 28 days, and clinical efficacy was assessed using Positive and Negative Syndrome Scale (PANSS) and Clinical Global Impression (CGI) scores. RESULTS There were no significant differences between patients treated with AZD8529 versus placebo in change from baseline to endpoint in PANSS total, negative and positive symptom subscale, or CGI-S scores. In contrast, risperidone demonstrated significant efficacy relative to placebo. CONCLUSION These results do not support a role for the mGluR-2 PAM AZD8529 as an antipsychotic and indicate that positive modulation of mGluR type 2 receptors alone is not sufficient for antipsychotic effects in acutely ill schizophrenia patients.
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Affiliation(s)
- Robert E Litman
- CBH Health, LLC, 9210 Corporate Blvd., Suite 110, Rockville, MD, United States; Georgetown University, 3700 O St. NW, Washington, DC 20057, United States
| | - Mark A Smith
- AstraZeneca Pharmaceuticals, 1800 Concord Pike, Wilmington, DE 19542, United States; Teva Pharmaceuticals, 41 Moores Rd., Frazer, PA 19355, United States
| | - James J Doherty
- AstraZeneca Pharmaceuticals, 1800 Concord Pike, Wilmington, DE 19542, United States; Sage Therapeutics, 215 First St., Cambridge, MA 02142, United States
| | - Alan Cross
- AstraZeneca Pharmaceuticals, 1800 Concord Pike, Wilmington, DE 19542, United States
| | - Shane Raines
- AstraZeneca Pharmaceuticals, 1800 Concord Pike, Wilmington, DE 19542, United States; 2b Analytics, LLC, 128 Westminster Dr., Wallingford, PA 19086, United States
| | - Lev Gertsik
- California Clinical Trials Medical Group, 1560 East Chevy Chase Dr., Suite 140, Glendale, CA 91206, United States
| | - Stephen R Zukin
- AstraZeneca Pharmaceuticals, 1800 Concord Pike, Wilmington, DE 19542, United States; Forest Research Institute, Jersey City, NJ, United States; Haborside Financial Center, Plaza V, Jersey City, NJ 07311, United States
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Grayson B, Barnes SA, Markou A, Piercy C, Podda G, Neill JC. Postnatal Phencyclidine (PCP) as a Neurodevelopmental Animal Model of Schizophrenia Pathophysiology and Symptomatology: A Review. Curr Top Behav Neurosci 2016; 29:403-428. [PMID: 26510740 DOI: 10.1007/7854_2015_403] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Cognitive dysfunction and negative symptoms of schizophrenia remain an unmet clinical need. Therefore, it is essential that new treatments and approaches are developed to recover the cognitive and social impairments that are seen in patients with schizophrenia. These may only be discovered through the use of carefully validated, aetiologically relevant and translational animal models. With recent renewed interest in the neurodevelopmental hypothesis of schizophrenia, postnatal administration of N-methyl-D-aspartate receptor (NMDAR) antagonists such as phencyclidine (PCP) has been proposed as a model that can mimic aspects of schizophrenia pathophysiology. The purpose of the current review is to examine the validity of this model and compare it with the adult subchronic PCP model. We review the ability of postnatal PCP administration to produce behaviours (specifically cognitive deficits) and neuropathology of relevance to schizophrenia and their subsequent reversal by pharmacological treatments. We review studies investigating effects of postnatal PCP on cognitive domains in schizophrenia in rats. Morris water maze and delayed spontaneous alternation tasks have been used for working memory, attentional set-shifting for executive function, social novelty discrimination for selective attention and prepulse inhibition of acoustic startle for sensorimotor gating. In addition, we review studies on locomotor activity and neuropathology. We also include two studies using dual hit models incorporating postnatal PCP and two studies on social behaviour deficits following postnatal PCP. Overall, the evidence we provide supports the use of postnatal PCP to model cognitive and neuropathological disturbances of relevance to schizophrenia. To date, there is a lack of evidence to support a significant advantage of postnatal PCP over the adult subchronic PCP model and full advantage has not been taken of its neurodevelopmental component. When thoroughly characterised, it is likely that it will provide a useful neurodevelopmental model to complement other models such as maternal immune activation, particularly when combined with other manipulations to produce dual or triple hit models. However, the developmental trajectory of behavioural and neuropathological changes induced by postnatal PCP and their relevance to schizophrenia must be carefully mapped out. Overall, we support further development of dual (or triple) hit models incorporating genetic, neurodevelopmental and appropriate environmental elements in the search for more aetiologically valid animal models of schizophrenia and neurodevelopmental disorders (NDDs).
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Affiliation(s)
- B Grayson
- Manchester Pharmacy School, University of Manchester, Oxford Road, Manchester, M13 9PT, UK.
| | - S A Barnes
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive, La Jolla, San Diego, CA, 92093-0603, USA
| | - A Markou
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive, La Jolla, San Diego, CA, 92093-0603, USA
| | - C Piercy
- Manchester Pharmacy School, University of Manchester, Oxford Road, Manchester, M13 9PT, UK
| | - G Podda
- Manchester Pharmacy School, University of Manchester, Oxford Road, Manchester, M13 9PT, UK
| | - J C Neill
- Manchester Pharmacy School, University of Manchester, Oxford Road, Manchester, M13 9PT, UK
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50
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El Hage C, Bédard AM, Samaha AN. Antipsychotic treatment leading to dopamine supersensitivity persistently alters nucleus accumbens function. Neuropharmacology 2015; 99:715-25. [DOI: 10.1016/j.neuropharm.2015.03.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2014] [Revised: 03/13/2015] [Accepted: 03/14/2015] [Indexed: 10/23/2022]
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