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Therapeutic Potential and Limitation of Serotonin Type 7 Receptor Modulation. Int J Mol Sci 2023; 24:ijms24032070. [PMID: 36768393 PMCID: PMC9916679 DOI: 10.3390/ijms24032070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 01/15/2023] [Accepted: 01/18/2023] [Indexed: 01/21/2023] Open
Abstract
Although a number of mood-stabilising atypical antipsychotics and antidepressants modulate serotonin type 7 receptor (5-HT7), the detailed contributions of 5-HT7 function to clinical efficacy and pathophysiology have not been fully understood. The mood-stabilising antipsychotic agent, lurasidone, and the serotonin partial agonist reuptake inhibitor, vortioxetine, exhibit higher binding affinity to 5-HT7 than other conventional antipsychotics and antidepressants. To date, the initially expected rapid onset of antidepressant effects-in comparison with conventional antidepressants or mood-stabilising antipsychotics-due to 5-HT7 inhibition has not been observed with lurasidone and vortioxetine; however, several clinical studies suggest that 5-HT7 inhibition likely contributes to quality of life of patients with schizophrenia and mood disorders via the improvement of cognition. Furthermore, recent preclinical studies reported that 5-HT7 inhibition might mitigate antipsychotic-induced weight gain and metabolic complication by blocking other monoamine receptors. Further preclinical studies for the development of 5-HT7 modulation against neurodevelopmental disorders and neurodegenerative diseases have been ongoing. To date, various findings from various preclinical studies indicate the possibility that 5-HT7 modifications can provide two independent strategies. The first is that 5-HT7 inhibition ameliorates the dysfunction of inter-neuronal transmission in mature networks. The other is that activation of 5-HT7 can improve transmission dysfunction due to microstructure abnormality in the neurotransmission network-which could be unaffected by conventional therapeutic agents-via modulating intracellular signalling during the neurodevelopmental stage or via loss of neural networks with aging. This review attempts to describe the current and novel clinical applications of 5-HT7 modulation based on preclinical findings.
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Chronic Administrations of Guanfacine on Mesocortical Catecholaminergic and Thalamocortical Glutamatergic Transmissions. Int J Mol Sci 2021; 22:ijms22084122. [PMID: 33923533 PMCID: PMC8073983 DOI: 10.3390/ijms22084122] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/06/2021] [Accepted: 04/14/2021] [Indexed: 01/07/2023] Open
Abstract
It has been established that the selective α2A adrenoceptor agonist guanfacine reduces hyperactivity and improves cognitive impairment in patients with attention-deficit/hyperactivity disorder (ADHD). The major mechanisms of guanfacine are considered to involve the activation of the postsynaptic α2A adrenoceptor of glutamatergic pyramidal neurons in the frontal cortex, but the effects of chronic guanfacine administration on catecholaminergic and glutamatergic transmissions associated with the orbitofrontal cortex (OFC) are yet to be clarified. The actions of guanfacine on catecholaminergic transmission, the effects of acutely local and systemically chronic (for 7 days) administrations of guanfacine on catecholamine release in pathways from the locus coeruleus (LC) to OFC, the ventral tegmental area (VTA) and reticular thalamic-nucleus (RTN), from VTA to OFC, from RTN to the mediodorsal thalamic-nucleus (MDTN), and from MDTN to OFC were determined using multi-probe microdialysis with ultra-high performance liquid chromatography. Additionally, the effects of chronic guanfacine administration on the expression of the α2A adrenoceptor in the plasma membrane fraction of OFC, VTA and LC were examined using a capillary immunoblotting system. The acute local administration of therapeutically relevant concentrations of guanfacine into the LC decreased norepinephrine release in the OFC, VTA and RTN without affecting dopamine release in the OFC. Systemically, chronic administration of therapeutically relevant doses of guanfacine for 14 days increased the basal release of norepinephrine in the OFC, VTA, RTN, and dopamine release in the OFC via the downregulation of the α2A adrenoceptor in the LC, OFC and VTA. Furthermore, systemically, chronic guanfacine administration did not affect intrathalamic GABAergic transmission, but it phasically enhanced thalamocortical glutamatergic transmission. The present study demonstrated the dual actions of guanfacine on catecholaminergic transmission-acute attenuation of noradrenergic transmission and chronic enhancement of noradrenergic transmission and thalamocortical glutamatergic transmission. These dual actions of guanfacine probably contribute to the clinical effects of guanfacine against ADHD.
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Effects of Subchronic Administrations of Vortioxetine, Lurasidone, and Escitalopram on Thalamocortical Glutamatergic Transmission Associated with Serotonin 5-HT7 Receptor. Int J Mol Sci 2021; 22:ijms22031351. [PMID: 33572981 PMCID: PMC7866391 DOI: 10.3390/ijms22031351] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/22/2021] [Accepted: 01/27/2021] [Indexed: 02/06/2023] Open
Abstract
The functional suppression of serotonin (5-HT) type 7 receptor (5-HT7R) is forming a basis for scientific discussion in psychopharmacology due to its rapid-acting antidepressant-like action. A novel mood-stabilizing atypical antipsychotic agent, lurasidone, exhibits a unique receptor-binding profile, including a high affinity for 5-HT7R antagonism. A member of a novel class of antidepressants, vortioxetine, which is a serotonin partial agonist reuptake inhibitor (SPARI), also exhibits a higher affinity for serotonin transporter, serotonin receptors type 1A (5-HT1AR) and type 3 (5-HT3R), and 5-HT7R. However, the effects of chronic administration of lurasidone, vortioxetine, and the selective serotonin reuptake inhibitor (SSRI), escitalopram, on 5-HT7R function remained to be clarified. Thus, to explore the mechanisms underlying the clinical effects of vortioxetine, escitalopram, and lurasidone, the present study determined the effects of these agents on thalamocortical glutamatergic transmission, which contributes to emotional/mood perception, using multiprobe microdialysis and 5-HT7R expression using capillary immunoblotting. Acute local administration of a 5-HT7R agonist and antagonist into the mediodorsal thalamic nucleus (MDTN) enhanced and reduced thalamocortical glutamatergic transmission, induced by N-methyl-D-aspartate (NMDA)/glutamate receptor inhibition in the reticular thalamic nucleus (RTN). Acute local administration of a relevant therapeutic concentration of vortioxetine and lurasidone into the MDTN suppressed the thalamocortical glutamatergic transmission via 5-HT7R inhibition, whereas that of escitalopram activated 5-HT7R. Subchronic administration of effective doses of vortioxetine and lurasidone (for 7 days) reduced the thalamocortical glutamatergic transmission, but escitalopram did not affect it, whereas subchronic administration of these three agents attenuated the stimulatory effects of the 5-HT7R agonist on thalamocortical glutamatergic transmission. Subchronic administration of effective doses of vortioxetine, lurasidone, and escitalopram downregulated the 5-HT7R expression of the plasma membrane in the MDTN; the 5-HT7R downregulation induced by vortioxetine and lurasidone was observed at 3 days, but that induced by escitalopram required a longer duration of 7 days. These results indicate that chronic administration of vortioxetine, escitalopram, and lurasidone generate downregulation of 5-HT7R in the thalamus; however, the direct inhibition of 5-HT7R associated with vortioxetine and lurasidone generates more rapid downregulation than the indirect elevation of the extracellular serotonin level via serotonin transporter inhibition by escitalopram.
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Okubo R, Hasegawa T, Fukuyama K, Shiroyama T, Okada M. Current Limitations and Candidate Potential of 5-HT7 Receptor Antagonism in Psychiatric Pharmacotherapy. Front Psychiatry 2021; 12:623684. [PMID: 33679481 PMCID: PMC7930824 DOI: 10.3389/fpsyt.2021.623684] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 01/29/2021] [Indexed: 12/13/2022] Open
Abstract
Several mood-stabilizing atypical antipsychotics and antidepressants weakly block serotonin (5-HT) receptor type-7 (5-HT7R); however, the contributions of 5-HT7R antagonism to clinical efficacy and pathophysiology are yet to be clarified. A novel mood-stabilizing antipsychotic agent, lurasidone exhibits predominant binding affinity to 5-HT7R when compared with other monoamine receptors. To date, we have failed to discover the superior clinical efficacy of lurasidone on schizophrenia, mood, or anxiety disorders when compared with conventional mood-stabilizing atypical antipsychotics; however, numerous preclinical findings have indicated the possible potential of 5-HT7R antagonism against several neuropsychiatric disorders, as well as the generation of novel therapeutic options that could not be expected with conventional atypical antipsychotics. Traditional experimental techniques, electrophysiology, and microdialysis have demonstrated that the effects of 5-HT receptor type-1A (5-HT1AR) and 5-HT7R on neurotransmission are in contrast, but the effect of 5-HT1AR is more predominant than that of 5-HT7R, resulting in an insufficient understanding of the 5-HT7R function in the field of psychopharmacology. Accumulating knowledge regarding the pharmacodynamic profiles of 5-HT7R suggests that 5-HT7R is one of the key players in the establishment and remodeling of neural development and cytoarchitecture during the early developmental stage to the mature brain, and dysfunction or modulation of 5-HT7R is linked to the pathogenesis/pathophysiology of neuropsychiatric and neurodevelopmental disorders. In this review, to explore candidate novel applications for the treatment of several neuropsychiatric disorders, including mood disorders, schizophrenia, and other cognitive disturbance disorders, we discuss perspectives of psychopharmacology regarding the effects of 5-HT7R antagonism on transmission and intracellular signaling systems, based on preclinical findings.
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Affiliation(s)
- Ruri Okubo
- Division of Neuroscience, Laboratory Department of Neuropsychiatry, Graduate School of Medicine, Mie University, Tsu, Japan
| | - Toshiki Hasegawa
- Division of Neuroscience, Laboratory Department of Neuropsychiatry, Graduate School of Medicine, Mie University, Tsu, Japan
| | - Kouji Fukuyama
- Division of Neuroscience, Laboratory Department of Neuropsychiatry, Graduate School of Medicine, Mie University, Tsu, Japan
| | - Takashi Shiroyama
- Division of Neuroscience, Laboratory Department of Neuropsychiatry, Graduate School of Medicine, Mie University, Tsu, Japan
| | - Motohiro Okada
- Division of Neuroscience, Laboratory Department of Neuropsychiatry, Graduate School of Medicine, Mie University, Tsu, Japan
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Dopamine, Cognitive Impairments and Second-Generation Antipsychotics: From Mechanistic Advances to More Personalized Treatments. Pharmaceuticals (Basel) 2020; 13:ph13110365. [PMID: 33167370 PMCID: PMC7694365 DOI: 10.3390/ph13110365] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 10/31/2020] [Accepted: 11/03/2020] [Indexed: 12/17/2022] Open
Abstract
The pharmacological treatment of cognitive impairments associated with schizophrenia is still a major unmet clinical need. Indeed, treatments with available antipsychotics generate highly variable cognitive responses among patients with schizophrenia. This has led to the general assumption that antipsychotics are ineffective on cognitive impairment, although personalized medicine and drug repurposing approaches might scale down this clinical issue. In this scenario, evidence suggests that cognitive improvement exerted by old and new atypical antipsychotics depends on dopaminergic mechanisms. Moreover, the newer antipsychotics brexpiprazole and cariprazine, which might have superior clinical efficacy on cognitive deficits over older antipsychotics, mainly target dopamine receptors. It is thus reasonable to assume that despite more than 50 years of elusive efforts to develop novel non-dopaminergic antipsychotics, dopamine receptors remain the most attractive and promising pharmacological targets in this field. In the present review, we discuss preclinical and clinical findings showing dopaminergic mechanisms as key players in the cognitive improvement induced by both atypical antipsychotics and potential antipsychotics. We also emphasize the concept that these mechanistic advances, which help to understand the heterogeneity of cognitive responses to antipsychotics, may properly guide treatment decisions and address the unmet medical need for the management of cognitive impairment associated with schizophrenia.
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Candidate Strategies for Development of a Rapid-Acting Antidepressant Class That Does Not Result in Neuropsychiatric Adverse Effects: Prevention of Ketamine-Induced Neuropsychiatric Adverse Reactions. Int J Mol Sci 2020; 21:ijms21217951. [PMID: 33114753 PMCID: PMC7662754 DOI: 10.3390/ijms21217951] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 10/19/2020] [Accepted: 10/23/2020] [Indexed: 02/08/2023] Open
Abstract
Non-competitive N-methyl-D-aspartate/glutamate receptor (NMDAR) antagonism has been considered to play important roles in the pathophysiology of schizophrenia. In spite of severe neuropsychiatric adverse effects, esketamine (racemic enantiomer of ketamine) has been approved for the treatment of conventional monoaminergic antidepressant-resistant depression. Furthermore, ketamine improves anhedonia, suicidal ideation and bipolar depression, for which conventional monoaminergic antidepressants are not fully effective. Therefore, ketamine has been accepted, with rigorous restrictions, in psychiatry as a new class of antidepressant. Notably, the dosage of ketamine for antidepressive action is comparable to the dose that can generate schizophrenia-like psychotic symptoms. Furthermore, the psychotropic effects of ketamine precede the antidepressant effects. The maintenance of the antidepressive efficacy of ketamine often requires repeated administration; however, repeated ketamine intake leads to abuse and is consistently associated with long-lasting memory-associated deficits. According to the dissociative anaesthetic feature of ketamine, it exerts broad acute influences on cognition/perception. To evaluate the therapeutic validation of ketamine across clinical contexts, including its advantages and disadvantages, psychiatry should systematically assess the safety and efficacy of either short- and long-term ketamine treatments, in terms of both acute and chronic outcomes. Here, we describe the clinical evidence of NMDAR antagonists, and then the temporal mechanisms of schizophrenia-like and antidepressant-like effects of the NMDAR antagonist, ketamine. The underlying pharmacological rodent studies will also be discussed.
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Okada M, Fukuyama K, Shiroyama T, Murata M. A Working Hypothesis Regarding Identical Pathomechanisms between Clinical Efficacy and Adverse Reaction of Clozapine via the Activation of Connexin43. Int J Mol Sci 2020; 21:ijms21197019. [PMID: 32987640 PMCID: PMC7583770 DOI: 10.3390/ijms21197019] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 09/04/2020] [Accepted: 09/22/2020] [Indexed: 12/11/2022] Open
Abstract
Clozapine (CLZ) is an approved antipsychotic agent for the medication of treatment-resistant schizophrenia but is also well known as one of the most toxic antipsychotics. Recently, the World Health Organization’s (WHO) global database (VigiBase) reported the relative lethality of severe adverse reactions of CLZ. Agranulocytosis is the most famous adverse CLZ reaction but is of lesser lethality compared with the other adverse drug reactions of CLZ. Unexpectedly, VigiBase indicated that the prevalence and relative lethality of pneumonia, cardiotoxicity, and seizures associated with CLZ were more serious than that of agranulocytosis. Therefore, haematological monitoring in CLZ patients monitoring system provided success in the prevention of lethal adverse events from CLZ-induced agranulocytosis. Hereafter, psychiatrists must amend the CLZ patients monitoring system to protect patients with treatment-resistant schizophrenia from severe adverse CLZ reactions, such as pneumonia, cardiotoxicity, and seizures, according to the clinical evidence and pathophysiology. In this review, we discuss the mechanisms of clinical efficacy and the adverse reactions of CLZ based on the accumulating pharmacodynamic findings of CLZ, including tripartite synaptic transmission, and we propose suggestions for amending the monitoring and medication of adverse CLZ reactions associated with pneumonia, cardiotoxicity, and seizures.
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Affiliation(s)
- Motohiro Okada
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, Tsu 514-8507, Japan; (K.F.); (T.S.)
- Correspondence: ; Tel.: +81-59-231-5018
| | - Kouji Fukuyama
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, Tsu 514-8507, Japan; (K.F.); (T.S.)
| | - Takashi Shiroyama
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, Tsu 514-8507, Japan; (K.F.); (T.S.)
| | - Masahiko Murata
- National Hospital Organization Sakakibara Hospital, 777 Sakakibara, Tsu, Mie 514-1292, Japan;
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Okada M, Fukuyama K. Interaction between Mesocortical and Mesothalamic Catecholaminergic Transmissions Associated with NMDA Receptor in the Locus Coeruleus. Biomolecules 2020; 10:biom10070990. [PMID: 32630356 PMCID: PMC7407123 DOI: 10.3390/biom10070990] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/24/2020] [Accepted: 06/30/2020] [Indexed: 12/13/2022] Open
Abstract
Noncompetitive N-methyl-D-aspartate/glutamate receptor (NMDAR) antagonists contribute to the pathophysiology of schizophrenia and mood disorders but improve monoaminergic antidepressant-resistant mood disorder and suicidal ideation. The mechanisms of the double-edged sword clinical action of NMDAR antagonists remained to be clarified. The present study determined the interaction between the NMDAR antagonist (MK801), α1 adrenoceptor antagonist (prazosin), and α2A adrenoceptor agonist (guanfacine) on mesocortical and mesothalamic catecholaminergic transmission, and thalamocortical glutamatergic transmission using multiprobe microdialysis. The inhibition of NMDAR in the locus coeruleus (LC) by local MK801 administration enhanced both the mesocortical noradrenergic and catecholaminergic coreleasing (norepinephrine and dopamine) transmissions. The mesothalamic noradrenergic transmission was also enhanced by local MK801 administration in the LC. These mesocortical and mesothalamic transmissions were activated by intra-LC disinhibition of transmission of γ-aminobutyric acid (GABA) via NMDAR inhibition. Contrastingly, activated mesothalamic noradrenergic transmission by MK801 enhanced intrathalamic GABAergic inhibition via the α1 adrenoceptor, resulting in the suppression of thalamocortical glutamatergic transmission. The thalamocortical glutamatergic terminal stimulated the presynaptically mesocortical catecholaminergic coreleasing terminal in the superficial cortical layers, but did not have contact with the mesocortical selective noradrenergic terminal (which projected terminals to deeper cortical layers). Furthermore, the α2A adrenoceptor suppressed the mesocortical and mesothalamic noradrenergic transmissions somatodendritically in the LC and presynaptically/somatodendritically in the reticular thalamic nucleus (RTN). These discrepancies between the noradrenergic and catecholaminergic transmissions in the mesocortical and mesothalamic pathways probably constitute the double-edged sword clinical action of noncompetitive NMDAR antagonists.
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Vortioxetine Subchronically Activates Serotonergic Transmission via Desensitization of Serotonin 5-HT 1A Receptor with 5-HT 3 Receptor Inhibition in Rats. Int J Mol Sci 2019; 20:ijms20246235. [PMID: 31835640 PMCID: PMC6940928 DOI: 10.3390/ijms20246235] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 12/09/2019] [Accepted: 12/09/2019] [Indexed: 01/07/2023] Open
Abstract
Vortioxetine is a novel, multimodal antidepressant with unique targets, including the inhibition of the serotonin transporter (SET), of serotonin 5-HT3 (5-HT3R), and of 5-HT7 (5-HT7R) receptors and partial agonism to serotonin 5-HT1A (5-HT1AR) receptors in humans. Vortioxetine has a lower affinity to 5-HT1AR and 5-HT7R in rats compared with humans, but several behavior studies have demonstrated its powerful antidepressant-like actions. In spite of these efforts, detailed effects of the subchronic administration of vortioxetine on serotonergic transmission remain to be clarified. This study examined the mechanisms underlying the clinical effects of vortioxetine by measuring the releases of 5-HT and GABA in the medial prefrontal cortex (mPFC) of freely moving rats compared with the selective SET inhibitor, escitalopram. Inhibition of 5-HT3R in the mPFC enhanced regional 5-HT release via GABAergic disinhibition. Activation of somatodendritic 5-HT1AR in the dorsal raphe nucleus (DRN) and presynaptic 5-HT1AR in the mPFC inhibited 5-HT release in the mPFC. Escitalopram subchronically activated mesocortical serotonergic transmission via desensitization of 5-HT1AR in the mPFC and DRN and of 5-HT3R in the mPFC; however, vortioxetine also subchronically activated mesocortical serotonergic transmission via desensitization of 5-HT1AR in the mPFC and DRN but not of 5-HT3R in the mPFC. These demonstrations, the desensitization of 5-HT1AR with the inhibition of 5-HT3R (without 5-HT3R desensitization), at least partially, contribute to the multimodal antidepressant action of vortioxetine in rats.
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Okada M, Fukuyama K, Nakano T, Ueda Y. Pharmacological Discrimination of Effects of MK801 on Thalamocortical, Mesothalamic, and Mesocortical Transmissions. Biomolecules 2019; 9:biom9110746. [PMID: 31752219 PMCID: PMC6920874 DOI: 10.3390/biom9110746] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Revised: 11/14/2019] [Accepted: 11/16/2019] [Indexed: 01/07/2023] Open
Abstract
N-methyl-d-aspartate/glutamate receptor (NMDAR) is one of the major voltage-sensitive ligand-gated cation channel. Several noncompetitive NMDAR antagonists contribute to pathophysiology of schizophrenia and mood disorders; however, the effects of inhibition of NMDAR on several transmitter system have not been well clarified. Thus, this study determined the selective NMDAR antagonist, MK801 (dizocilpine), on thalamocortical, mesothalamic, and mesocortical transmissions associated with l-glutamate, GABA, serotonin, norepinephrine, and dopamine using multiprobe microdialysis. Perfusion with MK801 into the medial prefrontal cortex (mPFC) increased and decreased respective regional releases of monoamine and GABA without affecting l-glutamate. The mPFC MK801-induced monoamine release is generated by the regional GABAergic disinhibition. Perfusion with MK801 into the reticular thalamic nucleus (RTN) decreased GABA release in the mediodorsal thalamic nucleus (MDTN) but increased releases of l-glutamate and catecholamine without affecting serotonin in the mPFC. The RTN MK801-induced l-glutamate release in the mPFC was generated by GABAergic disinhibition in the MDTN, but RTN MK801-induced catecholamine release in the mPFC was generated by activation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate/glutamate receptor (AMPAR) which received l-glutamate release from thalamocortical glutamatergic terminals in the mPFC. Perfusion with MK801 into the dorsal raphe nucleus (DRN) decreased GABA release in the DRN but selectively increased serotonin release in the MDTN and mPFC. These DRN MK801-induced serotonin releases in the both mPFC and MDTN were also generated by GABAergic disinhibition in the DRN. These results indicate that the GABAergic disinhibition induced by NMDAR inhibition plays important roles in the MK801-induced releases of l-glutamate and monoamine in thalamic nuclei and cortex.
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Blonanserin suppresses impulsive action in rats. J Pharmacol Sci 2019; 141:127-130. [PMID: 31690490 DOI: 10.1016/j.jphs.2019.09.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 08/12/2019] [Accepted: 09/11/2019] [Indexed: 12/12/2022] Open
Abstract
High impulsivity will increase the risk of criminal behavior, drug abuse, and suicide. We chose two drugs by following a strategy recently we proposed for identifying potential anti-impulsivity drugs, and examined the effects on impulsive action in rats by using a 3-choice serial reaction time task. We showed that the administration of blonanserin, an atypical antipsychotic, reduced impulsive actions in a U-shaped manner. 1-(2-Pyriidinyl)-piperazine, an active metabolite of buspirone or tandospirone, also slightly reduced impulsive actions, though it impaired motor functions. These results affirm the validity of our strategy, but require its refinement for developing anti-impulsivity drugs.
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Okada M, Fukuyama K, Okubo R, Shiroyama T, Ueda Y. Lurasidone Sub-Chronically Activates Serotonergic Transmission via Desensitization of 5-HT1A and 5-HT7 Receptors in Dorsal Raphe Nucleus. Pharmaceuticals (Basel) 2019; 12:ph12040149. [PMID: 31590422 PMCID: PMC6958501 DOI: 10.3390/ph12040149] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Revised: 09/20/2019] [Accepted: 10/04/2019] [Indexed: 02/06/2023] Open
Abstract
Lurasidone is an atypical mood-stabilizing antipsychotic agent with unique receptor-binding profile, including 5-HT7 receptor (5-HT7R) antagonism. Effects of 5-HT7R antagonism on transmitter systems of schizophrenia and mood disorders, however, have not been well clarified. Thus, this study examined the mechanisms underlying the clinical effects of lurasidone by measuring mesocortical serotonergic transmission. Following systemic and local administrations of lurasidone, MK801 and 5-HT receptor modulators, we determined releases of 5-HT in dorsal raphe nucleus (DRN), mediodorsal thalamic nucleus (MDTN) and medial prefrontal cortex (mPFC) and γ-aminobutyric acid (GABA) in DRN using multiprobe microdialysis with ultra-high-performance liquid chromatography (UHPLC). Serotonergic and GABAergic neurons in the DRN are predominantly regulated by inhibitory 5-HT1A receptor (5-HT1AR) and excitatory 5-HT7R, respectively. Lurasidone acutely generates GABAergic disinhibition by 5-HT7R antagonism, but concomitant its 5-HT1AR agonism prevents serotonergic hyperactivation induced by 5-HT7R inhibition. During treatments with 5-HT1AR antagonist in DRN, lurasidone dose-dependently increased 5-HT release in the DRN, MDTN and mPFC. Contrary, lurasidone chronically enhanced serotonergic transmission and GABAergic disinhibition in the DRN by desensitizing both 5-HT1AR and 5-HT7R. These effects of lurasidone acutely prevented MK801-evoked 5-HT release by GABAergic disinhibition via N-methyl-D-aspartate (NMDA)/glutamate receptor (NMDA-R)-mediated inhibition of 5-HT1AR function, but enhanced MK801-induced 5-HT release by desensitizing 5-HT1AR and 5-HT7R. These results indicate that acutely lurasidone fails to affect 5-HT release, but chronically enhances serotonergic transmission by desensitizing both 5-HT1AR and 5-HT7R. These unique properties of lurasidone ameliorate the dysfunctions of NMDA-R and augment antidepressive effects.
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Affiliation(s)
- Motohiro Okada
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, Tsu 514-8507, Japan.
| | - Kouji Fukuyama
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, Tsu 514-8507, Japan.
| | - Ruri Okubo
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, Tsu 514-8507, Japan.
| | - Takashi Shiroyama
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, Tsu 514-8507, Japan.
| | - Yuto Ueda
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, Tsu 514-8507, Japan.
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Okada M, Fukuyama K, Ueda Y. Lurasidone inhibits NMDA receptor antagonist-induced functional abnormality of thalamocortical glutamatergic transmission via 5-HT 7 receptor blockade. Br J Pharmacol 2019; 176:4002-4018. [PMID: 31347694 PMCID: PMC6811777 DOI: 10.1111/bph.14804] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 05/22/2019] [Accepted: 07/09/2019] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND AND PURPOSE Lurasidone is an atypical mood-stabilizing antipsychotic with a unique receptor-binding profile, including 5-HT7 receptor antagonism; however, the detailed effects of 5-HT7 receptor antagonism on various transmitter systems relevant to schizophrenia, particularly the thalamo-insular glutamatergic system and the underlying mechanisms, are yet to be clarified. EXPERIMENTAL APPROACH We examined the mechanisms underlying the clinical effects of lurasidone by measuring the release of l-glutamate, GABA, dopamine, and noradrenaline in the reticular thalamic nucleus (RTN), mediodorsal thalamic nucleus (MDTN) and insula of freely moving rats in response to systemic injection or local infusion of lurasidone or MK-801 using multiprobe microdialysis with ultra-HPLC. KEY RESULTS Systemic MK-801 (0.5 mg·kg-1 ) administration increased insular release of l-glutamate, dopamine, and noradrenaline but decreased GABA release. Systemic lurasidone (1 mg·kg-1 ) administration also increased insular release of l-glutamate, dopamine, and noradrenaline but without affecting GABA. Local lurasidone administration into the insula (3 μM) did not affect MK-801-induced insular release of l-glutamate or catecholamine, whereas local lurasidone administration into the MDTN (1 μM) inhibited MK-801-induced insular release of l-glutamate and catecholamine, similar to the 5-HT7 receptor antagonist SB269970. CONCLUSIONS AND IMPLICATIONS The present results indicate that MK-801-induced insular l-glutamate release is generated by activation of thalamo-insular glutamatergic transmission via MDTN GABAergic disinhibition resulting from NMDA receptor inhibition in the MDTN and RTN. Lurasidone inhibited this MK-801-evoked insular l-glutamate release through inhibition of excitatory 5-HT7 receptor in the MDTN. These effects on thalamo-insular glutamatergic transmission may contribute to the antipsychotic and mood-stabilizing actions of lurasidone.
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Affiliation(s)
- Motohiro Okada
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of MedicineMie UniversityTsuJapan
| | - Kouji Fukuyama
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of MedicineMie UniversityTsuJapan
| | - Yuto Ueda
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of MedicineMie UniversityTsuJapan
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Fukuyama K, Kato R, Murata M, Shiroyama T, Okada M. Clozapine Normalizes a Glutamatergic Transmission Abnormality Induced by an Impaired NMDA Receptor in the Thalamocortical Pathway via the Activation of a Group III Metabotropic Glutamate Receptor. Biomolecules 2019; 9:biom9060234. [PMID: 31213006 PMCID: PMC6628267 DOI: 10.3390/biom9060234] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Revised: 06/12/2019] [Accepted: 06/12/2019] [Indexed: 12/14/2022] Open
Abstract
Pharmacological mechanisms of gold-standard antipsychotics against treatment-refractory schizophrenia, such as clozapine (CLZ), remain unclear. We aimed to explore the mechanisms of CLZ by investigating the effects of MK801 and CLZ on tripartite synaptic transmission in the thalamocortical glutamatergic pathway using multi-probe microdialysis and primary cultured astrocytes. l-glutamate release in the medial prefrontal cortex (mPFC) was unaffected by local MK801 administration into mPFC but was enhanced in the mediodorsal thalamic nucleus (MDTN) and reticular thalamic nucleus (RTN) via GABAergic disinhibition in the RTN–MDTN pathway. The local administration of therapeutically relevant concentrations of CLZ into mPFC and MDTN increased and did not affect mPFC l-glutamate release. The local administration of the therapeutically relevant concentration of CLZ into mPFC reduced MK801-induced mPFC l-glutamate release via presynaptic group III metabotropic glutamate receptor (III-mGluR) activation. However, toxic concentrations of CLZ activated l-glutamate release associated with hemichannels. This study demonstrated that RTN is a candidate generator region in which impaired N-methyl-d-aspartate (NMDA)/glutamate receptors likely produce thalamocortical hyperglutamatergic transmission. Additionally, we identified several mechanisms of CLZ relating to its superiority in treatment-resistant schizophrenia and its severe adverse effects: (1) the prevention of thalamocortical hyperglutamatergic transmission via activation of mPFC presynaptic III-mGluR and (2) activation of astroglial l-glutamate release associated with hemichannels. These actions may contribute to the unique clinical profile of CLZ.
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Affiliation(s)
- Kouji Fukuyama
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, Tsu 514-8507, Japan.
| | - Ryo Kato
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, Tsu 514-8507, Japan.
| | - Masahiko Murata
- National Hospital Organization Sakakibara Hospital, 777 Sakakibara, Tsu, Mie 514-1292, Japan.
| | - Takashi Shiroyama
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, Tsu 514-8507, Japan.
| | - Motohiro Okada
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, Tsu 514-8507, Japan.
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Takeuchi S, Hida H, Uchida M, Naruse R, Yoshimi A, Kitagaki S, Ozaki N, Noda Y. Blonanserin ameliorates social deficit through dopamine-D 3 receptor antagonism in mice administered phencyclidine as an animal model of schizophrenia. Neurochem Int 2019; 128:127-134. [PMID: 30998952 DOI: 10.1016/j.neuint.2019.04.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 04/02/2019] [Accepted: 04/15/2019] [Indexed: 01/02/2023]
Abstract
Blonanserin differs from other antipsychotic drugs, such as risperidone and olanzapine, and exhibits a higher affinity for dopamine-D2/3 receptors than for serotonin 5-HT2A receptors. We investigated the involvement of dopamine-D3 receptors in the effect of blonanserin on the social deficit observed in an animal model of schizophrenia and sought to elucidate the molecular mechanism underlying its action. Mice received phencyclidine (PCP: 10 mg/kg/day, s.c.), a non-competitive N-methyl-d-aspartate (NMDA) receptor antagonist, once a day for 14 consecutive days. We then evaluated the sociability, using a social interaction test, and the expression of GluN1 subunit, an essential subunit of the NMDA receptors, in these mice. Blonanserin significantly ameliorated the PCP-induced social deficit, whereas olanzapine and haloperidol did not. This effect of blonanserin was antagonized by 7-OH-DPAT, a dopamine-D3 receptor agonist, and SCH23390, a dopamine-D1 receptor antagonist. However, the ameliorating effect of blonanserin was not inhibited by DOI, a serotonin 5-HT2A receptor agonist. The PCP-induced social deficit was also ameliorated by U99194, a dopamine-D3 receptor antagonist and SKF38393, a dopamine-D1 receptor agonist, being effects antagonized by 7-OH-DPAT or SCH23390. Blonanserin significantly inhibited the decrease in the phosphorylation levels of GluN1 at Ser897 by protein kinase A (PKA) in the prefrontal cortex (PFC) in PCPadministered mice. These results suggest that activation of NMDA receptors due to Ser897-phosphorylation of GluN1 subunit, which is a step linked to dopamine-D1 receptor-PKA signaling through dopamine-D3 receptor antagonism in the PFC, is required for the ameliorating effect of blonanserin on the PCP-induced social deficit. These findings also provide in vivo evidence that blonanserin antagonism of the dopamine-D3 receptors may be useful as a novel treatment strategy and that the dopamine-D3 receptors can be a novel therapeutic target molecule for the social deficit observed in schizophrenia.
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Affiliation(s)
- Saori Takeuchi
- Division of Clinical Sciences and Neuropsychopharmacology, Faculty of Pharmacy, Meijo University, Nagoya, 468-8503, Japan
| | - Hirotake Hida
- Division of Clinical Sciences and Neuropsychopharmacology, Faculty of Pharmacy, Meijo University, Nagoya, 468-8503, Japan
| | - Mizuki Uchida
- Division of Clinical Sciences and Neuropsychopharmacology, Graduate School of Pharmacy, Meijo University, Nagoya, 468-8503, Japan
| | - Ryo Naruse
- Division of Clinical Sciences and Neuropsychopharmacology, Faculty of Pharmacy, Meijo University, Nagoya, 468-8503, Japan
| | - Akira Yoshimi
- Division of Clinical Sciences and Neuropsychopharmacology, Faculty of Pharmacy, Meijo University, Nagoya, 468-8503, Japan
| | - Shinji Kitagaki
- Department of Medical Chemistry, Graduate School of Pharmacy, Meijo University, Nagoya, 468-8503, Japan
| | - Norio Ozaki
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, 466-8560, Japan
| | - Yukihiro Noda
- Division of Clinical Sciences and Neuropsychopharmacology, Faculty of Pharmacy, Meijo University, Nagoya, 468-8503, Japan; Division of Clinical Sciences and Neuropsychopharmacology, Graduate School of Pharmacy, Meijo University, Nagoya, 468-8503, Japan; Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, 466-8560, Japan.
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Okada M, Fukuyama K, Kawano Y, Shiroyama T, Ueda Y. Memantine protects thalamocortical hyper-glutamatergic transmission induced by NMDA receptor antagonism via activation of system xc<sup/>. Pharmacol Res Perspect 2019; 7:e00457. [PMID: 30631447 PMCID: PMC6323135 DOI: 10.1002/prp2.457] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 12/14/2018] [Indexed: 12/26/2022] Open
Abstract
Deficiencies in N-methyl-d-aspartate (NMDA)/glutamate receptor (NMDAR) signaling have been considered central to the cognitive impairments of schizophrenia; however, an NMDAR antagonist memantine (MEM) improves cognitive impairments of Alzheimer's disease and schizophrenia. These mechanisms of paradoxical clinical effects of NMDAR antagonists remain unclear. To explore the mechanisms by which MK801 and MEM affect thalamocortical transmission, we determined interactions between local administrations of MK801, MEM, system xc- (Sxc), and metabotropic glutamate receptors (mGluRs) on extracellular glutamate and GABA levels in the mediodorsal thalamic nucleus (MDTN) and medial prefrontal cortex (mPFC) using dual-probe microdialysis with ultra-high-pressure liquid chromatography. Effects of MK801 and MEM on Sxc activity were also determined using primary cultured astrocytes. Sxc activity was enhanced by MEM, but was unaffected by MK801. MK801 enhanced thalamocortical glutamatergic transmission by GABAergic disinhibition in the MDTN. In the MDTN and the mPFC, MEM weakly increased glutamate release by activating Sxc, whereas MEM inhibited thalamocortical glutamatergic transmission. Paradoxical effects of MEM were induced following secondary activation of inhibitory II-mGluR and III-mGluR by exporting glutamate from astroglial Sxc. The present results suggest that the effects of therapeutically relevant concentrations of MEM on thalamocortical glutamatergic transmission are predominantly caused by activation of Sxc rather than inhibition of NMDAR. These demonstrations suggest that the combination between reduced NMDAR and activated Sxc contribute to the neuroprotective effects of MEM. Furthermore, activation of Sxc may compensate for the cognitive impairments that are induced by hyperactivation of thalamocortical glutamatergic transmission following activation of Sxc/II-mGluR in the MDTN and Sxc/II-mGluR/III-mGluR in the mPFC.
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Affiliation(s)
- Motohiro Okada
- Department of NeuropsychiatryDivision of NeuroscienceGraduate School of MedicineMie UniversityTsuMieJapan
| | - Kouji Fukuyama
- Department of NeuropsychiatryDivision of NeuroscienceGraduate School of MedicineMie UniversityTsuMieJapan
| | - Yasuhiro Kawano
- Department of NeuropsychiatryDivision of NeuroscienceGraduate School of MedicineMie UniversityTsuMieJapan
| | - Takashi Shiroyama
- Department of NeuropsychiatryDivision of NeuroscienceGraduate School of MedicineMie UniversityTsuMieJapan
| | - Yuto Ueda
- Department of NeuropsychiatryDivision of NeuroscienceGraduate School of MedicineMie UniversityTsuMieJapan
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Okada M, Fukuyama K, Kawano Y, Shiroyama T, Suzuki D, Ueda Y. Effects of acute and sub-chronic administrations of guanfacine on catecholaminergic transmissions in the orbitofrontal cortex. Neuropharmacology 2019; 156:107547. [PMID: 30802458 DOI: 10.1016/j.neuropharm.2019.02.029] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 02/15/2019] [Accepted: 02/21/2019] [Indexed: 12/20/2022]
Abstract
The selective α2A adrenoceptor agonist guanfacine reduces hyperactivity and improves cognitive impairment in patients with attention-deficit/hyperactivity disorder (ADHD). The major mechanisms of guanfacine have been considered to involve activation of postsynaptic α2A adrenoceptor in frontal pyramidal neurons. However, the effects of chronic guanfacine administration on catecholaminergic transmissions associated with the orbitofrontal cortex (OFC) remain unclear. To explore the mechanisms of action of guanfacine on catecholaminergic transmission, the effects of its acute local or sub-chronic systemic administration on catecholamine release within pathways from locus coeruleus (LC) to OFC and reticular thalamic nucleus (RTN), from RTN to mediodorsal thalamic nucleus (MDTN), and from MDTN to OFC were determined using multi-probe microdialysis with ultra-high performance liquid chromatography. Acute OFC local administration of guanfacine did not affect catecholamine release in OFC. Acute LC local and sub-chronic systemic administrations of guanfacine reduced norepinephrine release in LC, OFC and RTN, and also reduced GABA release in MDTN, whereas AMPA-induced (perfusion with AMPA into NDTN) releases of l-glutamate, norepinephrine and dopamine in OFC were enhanced by sub-chronic systemic guanfacine administration. This study identified that catecholaminergic transmission is composed of three pathways: direct noradrenergic and co-releasing catecholaminergic LC-OFC pathways and intermediate LC-OFC (LC-RTN-MDTN-OFC) pathway. We demonstrated the dual actions of guanfacine on catecholaminergic transmission: attenuation of direct noradrenergic LC-OFC transmission at the resting stage and enhancement of direct co-releasing catecholaminergic LC-OFC transmission via GABAergic disinhibition in the intermediate LC-OFC pathway. These dual actions of guanfacine probably contribute to clinical actions of guanfacine against ADHD and its comorbid symptoms. This article is part of the Special Issue entitled 'Current status of the neurobiology of aggression and impulsivity'.
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Affiliation(s)
- Motohiro Okada
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan.
| | - Kouji Fukuyama
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan
| | - Yasuhiro Kawano
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan
| | - Takashi Shiroyama
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan
| | - Dai Suzuki
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan
| | - Yuto Ueda
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan
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Huang M, Kwon S, Rajagopal L, He W, Meltzer HY. 5-HT 1A parital agonism and 5-HT 7 antagonism restore episodic memory in subchronic phencyclidine-treated mice: role of brain glutamate, dopamine, acetylcholine and GABA. Psychopharmacology (Berl) 2018; 235:2795-2808. [PMID: 30066135 DOI: 10.1007/s00213-018-4972-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 07/11/2018] [Indexed: 12/12/2022]
Abstract
RATIONALE The effect of atypical antipsychotic drugs (AAPDs), e.g., lurasidone, to improve cognitive impairment associated with schizophrenia (CIAS), has been suggested to be due, in part, to enhancing release of dopamine (DA), acetylcholine (ACh), and glutamate (Glu) in cortex and hippocampus. RESULTS The present study found acute lurasidone reversed the cognitive deficit in novel object recognition (NOR) in subchronic (sc) phencyclidine (PCP)-treated mice, an animal model for CIAS. This effect of lurasidone was blocked by pretreatment with the 5-HT1AR antagonist, WAY-100635, or the 5-HT7R agonist, AS 19. Lurasidone significantly increased medial prefrontal cortex (mPFC) ACh, DA, and Glu efflux, all of which were blocked by WAY-100635, with similar effects in the dorsal striatum (dSTR), except for the absence of an effect on Glu increase. AS 19 inhibited Glu, but not DA efflux, in the dSTR. The selective 5-HT7R antagonist, SB-26970, increased mPFC DA, 5-HT, Glu, and, importantly, also GABA efflux and striatal DA, NE, 5-HT, and Glu efflux, indicating tonic inhibition of the release of these neurotransmitters by 5-HT7R stimulation. These results provide new evidence that GABA release in the mPFC is tonically inhibited by 5-HT7R stimulation and suggest that a selective 5-HT7R antagonist might be clinically useful to enhance cortical GABAergic release. All SB-269970 effects were blocked by AS 19 or WAY-100635, suggesting 5-HT1AR agonism is necessary for the release of these neurotransmitters by SB-269970. Lurasidone increased ACh, DA, and NE but not Glu efflux in mPFC and dSTR DA and Glu efflux in 5-HT7 KO mice. CONCLUSION We conclude that lurasidone-induced Glu efflux in mPFC requires 5-HT7R antagonism while its effects on cortical ACh and DA efflux are mainly due to 5-HT1AR stimulation.
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Affiliation(s)
- Mei Huang
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, 303 E. Chicago Ave., Ward Building 7-014, Chicago, IL, 60611, USA
| | - Sunoh Kwon
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, 303 E. Chicago Ave., Ward Building 7-014, Chicago, IL, 60611, USA.,K-herb Research Center, Korea Institute of Oriental Medicine, Daejeon, 34054, Republic of Korea
| | - Lakshmi Rajagopal
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, 303 E. Chicago Ave., Ward Building 7-014, Chicago, IL, 60611, USA
| | - Wenqi He
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, 303 E. Chicago Ave., Ward Building 7-014, Chicago, IL, 60611, USA
| | - Herbert Y Meltzer
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, 303 E. Chicago Ave., Ward Building 7-014, Chicago, IL, 60611, USA.
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van den Brink WJ, Palic S, Köhler I, de Lange ECM. Access to the CNS: Biomarker Strategies for Dopaminergic Treatments. Pharm Res 2018; 35:64. [PMID: 29450650 PMCID: PMC5814527 DOI: 10.1007/s11095-017-2333-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 12/18/2017] [Indexed: 12/26/2022]
Abstract
Despite substantial research carried out over the last decades, it remains difficult to understand the wide range of pharmacological effects of dopaminergic agents. The dopaminergic system is involved in several neurological disorders, such as Parkinson's disease and schizophrenia. This complex system features multiple pathways implicated in emotion and cognition, psychomotor functions and endocrine control through activation of G protein-coupled dopamine receptors. This review focuses on the system-wide effects of dopaminergic agents on the multiple biochemical and endocrine pathways, in particular the biomarkers (i.e., indicators of a pharmacological process) that reflect these effects. Dopaminergic treatments developed over the last decades were found to be associated with numerous biochemical pathways in the brain, including the norepinephrine and the kynurenine pathway. Additionally, they have shown to affect peripheral systems, for example the hypothalamus-pituitary-adrenal (HPA) axis. Dopaminergic agents thus have a complex and broad pharmacological profile, rendering drug development challenging. Considering the complex system-wide pharmacological profile of dopaminergic agents, this review underlines the needs for systems pharmacology studies that include: i) proteomics and metabolomics analysis; ii) longitudinal data evaluation and mathematical modeling; iii) pharmacokinetics-based interpretation of drug effects; iv) simultaneous biomarker evaluation in the brain, the cerebrospinal fluid (CSF) and plasma; and v) specific attention to condition-dependent (e.g., disease) pharmacology. Such approach is considered essential to increase our understanding of central nervous system (CNS) drug effects and substantially improve CNS drug development.
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Affiliation(s)
- Willem Johan van den Brink
- Division of Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The Netherlands
| | - Semra Palic
- Division of Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The Netherlands
| | - Isabelle Köhler
- Division of Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The Netherlands
| | - Elizabeth Cunera Maria de Lange
- Division of Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The Netherlands.
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Limaye RP, Patil AN. Blonanserin - A Novel Antianxiety and Antidepressant Drug? An Experimental Study. J Clin Diagn Res 2016; 10:FC17-FC21. [PMID: 27790460 PMCID: PMC5071960 DOI: 10.7860/jcdr/2016/19347.8530] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Accepted: 06/15/2016] [Indexed: 12/28/2022]
Abstract
INTRODUCTION Many psychiatric disorders show signs and symptoms of anxiety and depression. A drug with both, effects and lesser adverse effects is always desired. Blonanserin is a novel drug with postulated effect on anxiety and depression. AIM The study was aimed to evaluate the effect of Blonanserin on anxiety and depression in animal models. MATERIALS AND METHODS By using elevated plus maze test and forced swimming test, the antianxiety and antidepressant effects were evaluated. Animal ethics protocols were followed strictly. Total 50 rats (10 rats per group) were used for each test. As a control drug diazepam and imipramine were used in elevated plus maze and forced swimming test respectively. Blonanserin was tested for 3 doses 0.075, 0.2 and 0.8mg. These doses were selected from previous references as well as by extrapolating human doses. RESULTS This study showed an antianxiety effect of Blonanserin comparable to diazepam, which was statistically significant. Optimal effect was observed with 0.075mg, followed by 0.2 and 0.8mg. It also showed an antidepressant effect which was statistically significant. Optimal effect was observed at 0.2mg dose. CONCLUSION The results showed that at a dose range of 0.075 and 0.2mg Blonanserin has potential to exert an adjuvant antianxiety and antidepressant activity in animal models. In order to extrapolate this in patient, longer clinical studies with comparable doses should be planned. The present study underlines potential of Blonanserin as a novel drug for such studies.
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Affiliation(s)
- Ramchandra Prabhakar Limaye
- Professor, Department of Pharmacology, Bharati Vidyapeeth Deemed University Medical College and Hospital, Sangli, Maharashtra, India
| | - Aditi Nitin Patil
- Assistant Professor, Department of Pharmacology, Bharati Vidyapeeth Deemed University Medical College and Hospital, Sangli, Maharashtra, India
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Huang M, Kwon S, Oyamada Y, Rajagopal L, Miyauchi M, Meltzer HY. Dopamine D3 receptor antagonism contributes to blonanserin-induced cortical dopamine and acetylcholine efflux and cognitive improvement. Pharmacol Biochem Behav 2015; 138:49-57. [DOI: 10.1016/j.pbb.2015.09.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 09/09/2015] [Accepted: 09/11/2015] [Indexed: 12/01/2022]
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Baba S, Enomoto T, Horisawa T, Hashimoto T, Ono M. Blonanserin extensively occupies rat dopamine D3 receptors at antipsychotic dose range. J Pharmacol Sci 2015; 127:326-31. [PMID: 25837930 DOI: 10.1016/j.jphs.2015.01.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Revised: 01/04/2015] [Accepted: 01/22/2015] [Indexed: 12/14/2022] Open
Abstract
Antagonism of the dopamine D3 receptor has been hypothesized to be beneficial for schizophrenia cognitive deficits, negative symptoms and extrapyramidal symptoms. However, recent animal and human studies have shown that most antipsychotics do not occupy D3 receptors in vivo, despite their considerable binding affinity for this receptor in vitro. In the present study, we investigated the D3 receptor binding of blonanserin, a dopamine D2/D3 and serotonin 5-HT2A receptors antagonist, in vitro and in vivo. Blonanserin showed the most potent binding affinity for human D3 receptors among the tested atypical antipsychotics (risperidone, olanzapine and aripiprazole). Our GTPγS-binding assay demonstrated that blonanserin acts as a potent full antagonist for human D3 receptors. All test-drugs exhibited antipsychotic-like efficacy in methamphetamine-induced hyperactivity in rats. Treatment with blonanserin at its effective dose blocked the binding of [(3)H]-(+)-PHNO, a D2/D3 receptor radiotracer, both in the D2 receptor-rich region (striatum) and the D3 receptor-rich region (cerebellum lobes 9 and 10). On the other hand, the occupancies of other test-drugs for D3 receptors were relatively low. In conclusion, we have shown that blonanserin, but not other tested antipsychotics, extensively occupies D3 receptors in vivo in rats.
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Affiliation(s)
- Satoko Baba
- Drug Research Division, Sumitomo Dainippon Pharma Co., Ltd., 33-94 Enoki-cho, Suita, Osaka 564-0053, Japan
| | - Takeshi Enomoto
- Drug Research Division, Sumitomo Dainippon Pharma Co., Ltd., 33-94 Enoki-cho, Suita, Osaka 564-0053, Japan.
| | - Tomoko Horisawa
- Drug Research Division, Sumitomo Dainippon Pharma Co., Ltd., 33-94 Enoki-cho, Suita, Osaka 564-0053, Japan
| | - Takashi Hashimoto
- Drug Research Division, Sumitomo Dainippon Pharma Co., Ltd., 33-94 Enoki-cho, Suita, Osaka 564-0053, Japan
| | - Michiko Ono
- Drug Research Division, Sumitomo Dainippon Pharma Co., Ltd., 33-94 Enoki-cho, Suita, Osaka 564-0053, Japan
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Serotonin in antipsychotic drugs action. Behav Brain Res 2015; 277:125-35. [DOI: 10.1016/j.bbr.2014.07.025] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 07/17/2014] [Accepted: 07/18/2014] [Indexed: 12/13/2022]
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Ninomiya Y, Miyamoto S, Tenjin T, Ogino S, Miyake N, Kaneda Y, Sumiyoshi T, Yamaguchi N. Long-term efficacy and safety of blonanserin in patients with first-episode schizophrenia: a 1-year open-label trial. Psychiatry Clin Neurosci 2014; 68:841-849. [PMID: 24835911 DOI: 10.1111/pcn.12202] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Revised: 04/19/2014] [Accepted: 05/11/2014] [Indexed: 11/30/2022]
Abstract
AIMS The purpose of this study was to evaluate the long-term effectiveness and safety of blonanserin, a second-generation antipsychotic drug developed in Japan, in patients with first-episode schizophrenia. METHODS Twenty-three antipsychotic-naïve patients with first-episode schizophrenia were treated within an open-label, 1-year, prospective trial of blonanserin (2-24 mg/day). Clinical evaluations were conducted at baseline and 2, 6, and 12 months after the start of treatment. The main outcome measures were changes in subjective well-being and subjective quality of life, as assessed by the Subjective Well-being under Neuroleptic treatment scale Short form-Japanese version and the Schizophrenia Quality of Life Scale-Japanese version, respectively. Secondary outcome measures included the Positive and Negative Syndrome Scale, the Brief Assessment of Cognition in Schizophrenia-Japanese version, laboratory tests, bodyweight, and extrapyramidal symptoms. RESULTS Fourteen patients (60.9%) remained on the study at 1 year. In the intention-to-treat analysis, significant improvements were observed in several subscales on the Subjective Well-being under Neuroleptic treatment scale Short form-Japanese version, the Schizophrenia Quality of Life Scale-Japanese version, and the Brief Assessment of Cognition in Schizophrenia-Japanese version, and in all factor scores on the Positive and Negative Syndrome Scale. Improvement in depressive symptoms with blonanserin treatment was positively correlated with improvements in subjective well-being and subjective quality of life, as well as verbal memory. No significant changes were noted for any safety measure during the 1-year study period. CONCLUSIONS Blonanserin was well tolerated and effective for the treatment of first-episode schizophrenia in terms of subjective wellness, cognition, and a wide range of pathological symptoms. Further large-scale studies are warranted to confirm our findings.
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Affiliation(s)
- Yuriko Ninomiya
- Department of Neuropsychiatry, St. Marianna University School of Medicine, Kanagawa, Japan
| | - Seiya Miyamoto
- Department of Neuropsychiatry, St. Marianna University School of Medicine, Kanagawa, Japan
| | - Tomomi Tenjin
- Department of Neuropsychiatry, St. Marianna University School of Medicine, Kanagawa, Japan
| | - Shin Ogino
- Department of Neuropsychiatry, St. Marianna University School of Medicine, Kanagawa, Japan
| | - Nobumi Miyake
- Department of Neuropsychiatry, St. Marianna University School of Medicine, Kanagawa, Japan
| | | | | | - Noboru Yamaguchi
- Department of Neuropsychiatry, St. Marianna University School of Medicine, Kanagawa, Japan
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Antipsychotic treatment modulates glutamate transport and NMDA receptor expression. Eur Arch Psychiatry Clin Neurosci 2014; 264 Suppl 1:S67-82. [PMID: 25214389 DOI: 10.1007/s00406-014-0534-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 09/02/2014] [Indexed: 12/21/2022]
Abstract
Schizophrenia patients often suffer from treatment-resistant cognitive and negative symptoms, both of which are influenced by glutamate neurotransmission. Innovative therapeutic strategies such as agonists at metabotropic glutamate receptors or glycin reuptake inhibitors try to modulate the brain's glutamate network. Interactions of amino acids with monoamines have been described on several levels, and first- and second-generation antipsychotic agents (FGAs, SGAs) are known to exert modulatory effects on the glutamatergic system. This review summarizes the current knowledge on effects of FGAs and SGAs on glutamate transport and receptor expression derived from pharmacological studies. Such studies serve as a control for molecular findings in schizophrenia brain tissue and are clinically relevant. Moreover, they may validate animal models for psychosis, foster basic research on antipsychotic substances and finally lead to a better understanding of how monoaminergic and amino acid neurotransmissions are intertwined. In the light of these results, important differences dependent on antipsychotic substances, dosage and duration of treatment became obvious. While some post-mortem findings might be confounded with multifold drug effects, others are unlikely to be influenced by antipsychotic treatment and could represent important markers of schizophrenia pathophysiology. In similarity to the convergence of toxic and psychotomimetic effects of dopaminergic, serotonergic and anti-glutamatergic substances, the therapeutic mechanisms of SGAs might merge on a yet to be defined molecular level. In particular, serotonergic effects of SGAs, such as an agonism at 5HT1A receptors, represent important targets for further clinical research.
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Huang M, Panos JJ, Kwon S, Oyamada Y, Rajagopal L, Meltzer HY. Comparative effect of lurasidone and blonanserin on cortical glutamate, dopamine, and acetylcholine efflux: role of relative serotonin (5-HT)2A
and DA D2
antagonism and 5-HT1A
partial agonism. J Neurochem 2013; 128:938-49. [DOI: 10.1111/jnc.12512] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 10/22/2013] [Accepted: 10/23/2013] [Indexed: 01/09/2023]
Affiliation(s)
- Mei Huang
- Department of Psychiatry and Behavioral Sciences; Northwestern Feinberg School of Medicine; Chicago Illinois USA
| | - John J. Panos
- Department of Psychiatry and Behavioral Sciences; Northwestern Feinberg School of Medicine; Chicago Illinois USA
| | - Sunoh Kwon
- Department of Psychiatry and Behavioral Sciences; Northwestern Feinberg School of Medicine; Chicago Illinois USA
| | - Yoshihiro Oyamada
- Department of Psychiatry and Behavioral Sciences; Northwestern Feinberg School of Medicine; Chicago Illinois USA
- Dainippon Sumitomo Pharma Co. Ltd.; Osaka Japan
| | - Lakshmi Rajagopal
- Department of Psychiatry and Behavioral Sciences; Northwestern Feinberg School of Medicine; Chicago Illinois USA
| | - Herbert Y. Meltzer
- Department of Psychiatry and Behavioral Sciences; Northwestern Feinberg School of Medicine; Chicago Illinois USA
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27
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Fukuyama K, Tanahashi S, Hamaguchi T, Nakagawa M, Shiroyama T, Motomura E, Okada M. Differential mechanisms underlie the regulation of serotonergic transmission in the dorsal and median raphe nuclei by mirtazapine: a dual probe microdialysis study. Psychopharmacology (Berl) 2013; 229:617-26. [PMID: 23657423 DOI: 10.1007/s00213-013-3122-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Accepted: 04/15/2013] [Indexed: 01/05/2023]
Abstract
RATIONALE Blockade of α2 adrenoceptors and histamine H1 receptors plays important roles in the antidepressant and hypnotic effects of mirtazapine. OBJECTIVES However, it remains unclear how mirtazapine's actions at these receptors interact to affect serotonergic transmission in the dorsal (DRN) and median (MRN) raphe nuclei. METHOD Using dual-probe microdialysis, we determined the roles of α2 and H1 receptors in the effects of mirtazapine on serotonergic transmission in the DRN and MRN and their respective projection regions, the frontal (FC) and entorhinal (EC) cortices. RESULTS Mirtazapine (<30 μM) failed to alter extracellular serotonin levels when perfused alone into the raphe nuclei, but when co-perfused with a 5-HT1A receptor antagonist, mirtazapine increased serotonin levels in the DRN, MRN, FC, and EC. Serotonin levels in the DRN and FC were decreased by blockade and increased by activation of H1 receptors in the DRN. Serotonin levels in the MRN and EC were not affected by H1 agonists/antagonists perfused in the MRN. The increase in serotonin levels in the DRN and FC induced by DRN H1 receptor activation was attenuated by co-perfusion with mirtazapine. Furthermore, the increase in serotonin levels (DRN/FC) induced by DRN α2 adrenoceptor blockade was attenuated by concurrent DRN H1 blockade, whereas the increase in serotonin levels (MRN/EC) induced by MRN α2 adrenoceptor inhibition was unaffected by concurrent MRN H1 receptor blockade. CONCLUSION These results suggest that enhanced serotonergic transmission resulting from α2 adrenoceptor blockade is offset by subsequent activation of 5-HT1A receptors and, in the DRN but not MRN, H1 receptor inhibition. These pharmacological actions of mirtazapine may explain its antidepressant and hypnotic actions.
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MESH Headings
- Adrenergic alpha-2 Receptor Antagonists/administration & dosage
- Adrenergic alpha-2 Receptor Antagonists/pharmacology
- Animals
- Dose-Response Relationship, Drug
- Entorhinal Cortex/drug effects
- Entorhinal Cortex/metabolism
- Frontal Lobe/drug effects
- Frontal Lobe/metabolism
- Histamine Agonists/pharmacology
- Histamine H1 Antagonists/administration & dosage
- Histamine H1 Antagonists/pharmacology
- Male
- Mianserin/administration & dosage
- Mianserin/analogs & derivatives
- Mianserin/pharmacology
- Microdialysis
- Mirtazapine
- Raphe Nuclei/drug effects
- Raphe Nuclei/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptor, Serotonin, 5-HT1A/drug effects
- Receptor, Serotonin, 5-HT1A/metabolism
- Receptors, Adrenergic, alpha-2/drug effects
- Receptors, Adrenergic, alpha-2/metabolism
- Serotonin/metabolism
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Affiliation(s)
- Kouji Fukuyama
- Department of Neuropsychiatry, Division of Neuroscience, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan
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Gregory KJ, Herman EJ, Ramsey AJ, Hammond AS, Byun NE, Stauffer SR, Manka JT, Jadhav S, Bridges TM, Weaver CD, Niswender CM, Steckler T, Drinkenburg WH, Ahnaou A, Lavreysen H, Macdonald GJ, Bartolomé JM, Mackie C, Hrupka BJ, Caron MG, Daigle TL, Lindsley CW, Conn PJ, Jones CK. N-aryl piperazine metabotropic glutamate receptor 5 positive allosteric modulators possess efficacy in preclinical models of NMDA hypofunction and cognitive enhancement. J Pharmacol Exp Ther 2013; 347:438-57. [PMID: 23965381 DOI: 10.1124/jpet.113.206623] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Impaired transmission through glutamatergic circuits has been postulated to play a role in the underlying pathophysiology of schizophrenia. Furthermore, inhibition of the N-methyl-d-aspartate (NMDA) subtype of ionotropic glutamate receptors (NMDAR) induces a syndrome that recapitulates many of the symptoms observed in patients with schizophrenia. Selective activation of metabotropic glutamate receptor subtype 5 (mGlu5) may provide a novel therapeutic approach for treatment of symptoms associated with schizophrenia through facilitation of transmission through central glutamatergic circuits. Here, we describe the characterization of two novel N-aryl piperazine mGlu5 positive allosteric modulators (PAMs): 2-(4-(2-(benzyloxy)acetyl)piperazin-1-yl)benzonitrile (VU0364289) and 1-(4-(2,4-difluorophenyl)piperazin-1-yl)-2-((4-fluorobenzyl)oxy)ethanone (DPFE). VU0364289 and DPFE induced robust leftward shifts in the glutamate concentration-response curves for Ca(2+) mobilization and extracellular signal-regulated kinases 1 and 2 phosphorylation. Both PAMs displayed micromolar affinity for the common mGlu5 allosteric binding site and high selectivity for mGlu5. VU0364289 and DPFE possessed suitable pharmacokinetic properties for dosing in vivo and produced robust dose-related effects in reversing amphetamine-induced hyperlocomotion, a preclinical model predictive of antipsychotic-like activity. In addition, DPFE enhanced acquisition of contextual fear conditioning in rats and reversed behavioral deficits in a mouse model of NMDAR hypofunction. In contrast, DPFE had no effect on reversing apomorphine-induced disruptions of prepulse inhibition of the acoustic startle reflex. These mGlu5 PAMs also increased monoamine levels in the prefrontal cortex, enhanced performance in a hippocampal-mediated memory task, and elicited changes in electroencephalogram dynamics commensurate with procognitive effects. Collectively, these data support and extend the role for the development of novel mGlu5 PAMs for the treatment of psychosis and cognitive deficits observed in individuals with schizophrenia.
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Affiliation(s)
- K J Gregory
- Department of Pharmacology and Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee (K.J.G., E.J.H., A.S.H., N.E.B., S.R.S., J.T.M., S.J., T.M.B., C.D.W., C.M.N., C.W.L., P.J.C., C.K.J.); Drug Discovery Biology, MIPS, Monash University, Parkville, Victoria, Australia (K.J.G.); Department of Pharmacology and Toxicology, University of Toronto, Ontario, Canada (A.J.R.); Institute of Imaging and Science, Vanderbilt University (N.E.B.); Janssen Research & Development, Beerse, Belgium (T.S., W.H.D., A.A., H.L., G.J.M., C.M., B.J.H.); Janssen Research & Development, Toledo, Spain (J.M.B.); Department of Cell Biology, Duke University, Durham, North Carolina (M.G.C., T.L.D.); Department of Chemistry, Vanderbilt University Medical Center, Nashville, Tennessee (C.W.L.); and U.S. Department of Veterans Affairs, Nashville, Tennessee (C.K.J.)
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Yamamura S, Hoshikawa M, Dai K, Saito H, Suzuki N, Niwa O, Okada M. ONO-2506 inhibits spike-wave discharges in a genetic animal model without affecting traditional convulsive tests via gliotransmission regulation. Br J Pharmacol 2013; 168:1088-100. [PMID: 22882023 DOI: 10.1111/j.1476-5381.2012.02132.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Revised: 07/18/2012] [Accepted: 07/23/2012] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND AND PURPOSE Anticonvulsants have been developed according to the traditional neurotransmission imbalance hypothesis. However, the anticonvulsive pharmacotherapy currently available remains unsatisfactory. To develop new antiepileptic drugs with novel antiepileptic mechanisms, we have tested the antiepileptic actions of ONO-2506, a glial modulating agent, and its effects on tripartite synaptic transmission. EXPERIMENTAL APPROACH Dose-dependent effects of ONO-2506 on maximal-electroshock seizure (MES), pentylenetetrazol-induced seizure (PTZ) and epileptic discharge were determined in a genetic model of absence epilepsy in mice (Cacna1a(tm2Nobs/tm2Nobs) strain). Antiepileptic mechanisms of ONO-2506 were analysed by examining the interaction between ONO-2506 and transmission-modulating toxins (tetanus toxin, fluorocitrate, tetrodotoxin) on release of l-glutamate, d-serine, GABA and kynurenic acid in the medial-prefrontal cortex (mPFC) of freely moving rats using microdialysis and primary cultured rat astrocytes. KEY RESULTS ONO-2506 inhibited spontaneous epileptic discharges in Cacna1a(tm2Nobs/tm2Nobs) mice without affecting MES or PTZ. Given systemically, ONO-2506 increased basal release of GABA and kynurenic acid in the mPFC through activation of both neuronal and glial exocytosis, but inhibited depolarization-induced releases of all transmitters. ONO-2506 increased basal glial release of kynurenic acid without affecting those of l-glutamate, d-serine or GABA. However, ONO-2506 inhibited AMPA-induced releases of l-glutamate, d-serine, GABA and kynurenic acid. CONCLUSIONS AND IMPLICATIONS ONO-2506 did not affect traditional convulsive tests but markedly inhibited epileptic phenomena in the genetic epilepsy mouse model. ONO-2506 enhanced release of inhibitory neuro- and gliotransmitters during the resting stage and inhibited tripartite transmission during the hyperactive stage. The results suggest that ONO-2506 is a novel potential glial-targeting antiepileptic drug. LINKED ARTICLE This article is commented on by Onat, pp. 1086-1087 of this issue. To view this commentary visit http://dx.doi.org/10.1111/bph.12050.
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Affiliation(s)
- Satoshi Yamamura
- Department of Psychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, Tsu, Japan
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30
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Kuramashi A, Abe H, Koganemaru G, Matsuo H, Ikeda T, Ebihara K, Funahashi H, Takeda R, Nishimori T, Ishida Y. Effect of blonanserin on methamphetamine-induced disruption of latent inhibition and c-Fos expression in rats. Neurosci Lett 2013; 549:97-102. [DOI: 10.1016/j.neulet.2013.06.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 06/03/2013] [Accepted: 06/13/2013] [Indexed: 11/17/2022]
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Peselmann N, Schmitt A, Gebicke-Haerter PJ, Zink M. Aripiprazole differentially regulates the expression of Gad67 and γ-aminobutyric acid transporters in rat brain. Eur Arch Psychiatry Clin Neurosci 2013; 263:285-97. [PMID: 22968646 DOI: 10.1007/s00406-012-0367-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 08/29/2012] [Indexed: 12/13/2022]
Abstract
The molecular etiology of schizophrenia comprises abnormal neurotransmission of the amino acid GABA (γ-aminobutyric acid). Neuropathological studies convincingly revealed reduced expression of glutamic acid decarboxylase (Gad67) in GABAergic interneurons. Several antipsychotics influence the expression of GABAergic genes, but aripiprazole (APZ), a partial dopaminergic and serotonergic receptor agonist, has not been involved into these studies so far. We treated Sprague-Dawley rats for 4 weeks or 4 months with APZ suspended in drinking water and doses of 10 and 40 mg per kg body weight. Gene expression of Gad67, the vesicular GABA transporter Slc32a1 (solute carrier family, Vgat), the transmembrane transporters Slc6a1 (Gat1) and Slc6a11 (Gat3) was assessed by semiquantitative radioactive in situ hybridization. APZ treatment resulted in time- and dose-dependent effects with qualitative differences between brain regions. In the 10-mg group, Slc6a1 was strongly induced after 4 weeks in the hippocampus, amygdala, and cerebral cortex, followed by an induction of Gad67 in the same regions after 4 months, while frontocortical regions as well as basal ganglia showed dose-dependent reductions of Gad67 expression after 4 months. In several frontocortical and subcortical regions, we observed a decrease of Slc32a1 and an increase of Slc6a11 expression. In conclusion, APZ modulates gene expression of GABAergic marker genes involved into pathogenetic theories of schizophrenia. APZ only partially mirrors the effects of other antipsychotics with some important differences regarding brain regions. The findings might be explained by regulatory connections between serotonergic, GABAergic, and dopaminergic neurotransmission and should be validated in behavioral animal models of psychotic disorders.
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Affiliation(s)
- Nina Peselmann
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, J5, 68159 Mannheim, Germany
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32
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Fliegel S, Brand I, Spanagel R, Noori HR. Ethanol-induced alterations of amino acids measured by in vivo microdialysis in rats: a meta-analysis. In Silico Pharmacol 2013; 1:7. [PMID: 25505652 PMCID: PMC4230485 DOI: 10.1186/2193-9616-1-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Accepted: 05/07/2013] [Indexed: 12/14/2022] Open
Abstract
PURPOSE In recent years in vivo microdialysis has become an important method in research studies investigating the alterations of neurotransmitters in the extracellular fluid of the brain. Based on the major involvement of glutamate and γ-aminobutyric acid (GABA) in mediating a variety of alcohol effects in the mammalian brain, numerous microdialysis studies have focused on the dynamical behavior of these systems in response to alcohol. METHODS Here we performed multiple meta-analyses on published datasets from the rat brain: (i) we studied basal extracellular concentrations of glutamate and GABA in brain regions that belong to a neurocircuitry involved in neuropsychiatric diseases, especially in alcoholism (Noori et al., Addict Biol 17:827-864, 2012); (ii) we examined the effect of acute ethanol administration on glutamate and GABA levels within this network and (iii) we studied alcohol withdrawal-induced alterations in glutamate and GABA levels within this neurocircuitry. RESULTS For extraction of basal concentrations of these neurotransmitters, datasets of 6932 rats were analyzed and the absolute basal glutamate and GABA levels were estimated for 18 different brain sites. In response to different doses of acute ethanol administration, datasets of 529 rats were analyzed and a non-linear dose response (glutamate and GABA release) relationship was observed in several brain sites. Specifically, glutamate in the nucleus accumbens shows a decreasing logarithmic dose response curve. Finally, regression analysis of 11 published reports employing brain microdialysis experiments in 104 alcohol-dependent rats reveals very consistent augmented extracellular glutamate and GABA levels in various brain sites that correlate with the intensity of the withdrawal response were identified. CONCLUSIONS In summary, our results provide standardized basal values for future experimental and in silico studies on neurotransmitter release in the rat brain and may be helpful to understand the effect of ethanol on neurotransmitter release. Furthermore, this study illustrates the benefit of meta-analyses using the generalization of a wide range of preclinical data.
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Affiliation(s)
- Sarah Fliegel
- Institute of Psychopharmacology, Central Institute of Mental Health, Faculty of Medicine Mannheim, University of Heidelberg, J5, 68159 Mannheim, Germany
| | - Ines Brand
- Institute of Psychopharmacology, Central Institute of Mental Health, Faculty of Medicine Mannheim, University of Heidelberg, J5, 68159 Mannheim, Germany
| | - Rainer Spanagel
- Institute of Psychopharmacology, Central Institute of Mental Health, Faculty of Medicine Mannheim, University of Heidelberg, J5, 68159 Mannheim, Germany
| | - Hamid R Noori
- Institute of Psychopharmacology, Central Institute of Mental Health, Faculty of Medicine Mannheim, University of Heidelberg, J5, 68159 Mannheim, Germany
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Schirmbeck F, Rausch F, Englisch S, Eifler S, Esslinger C, Meyer-Lindenberg A, Zink M. Differential effects of antipsychotic agents on obsessive-compulsive symptoms in schizophrenia: a longitudinal study. J Psychopharmacol 2013; 27:349-57. [PMID: 23095245 DOI: 10.1177/0269881112463470] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Indirect evidence supports the assumption that antiserotonergic second-generation antipsychotics (SGA) induce and aggravate obsessive-compulsive symptoms (OCS) in schizophrenia. However, multimodal studies assessing the long-term interaction of pharmacotherapy and psychopathology are missing. Over 12 months, we followed-up 75 schizophrenia patients who were classified into two groups according to antipsychotic treatment: clozapine or olanzapine (group I) versus aripiprazole or amisulpride (group II). We applied the Yale Brown Obsessive Compulsive Scale (YBOCS) and investigated between-group changes over time as the primary endpoint. Group I showed markedly higher YBOCS scores at both time points. Repeated measure analyses of variance (ANOVAs) revealed significant interaction effects of group and time (per protocol sample (PP): p=0.006). This was due to persistently high OCS severity within group I, and decreasing YBOCS scores within group II. OCS severity correlated significantly with the negative and general psychopathology subscales of the Positive and Negative Syndrome Scale (PANSS), as well as with depressive symptoms. The progressive differences in OCS severity between our groups support the assumption of differential pharmacodynamic effects on comorbid OCS in schizophrenia. Further studies should address the pathogenetic mechanism, define patients at risk and facilitate early detection as well as therapeutic interventions.
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Affiliation(s)
- Frederike Schirmbeck
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany.
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Horiguchi M, Meltzer HY. Blonanserin reverses the phencyclidine (PCP)-induced impairment in novel object recognition (NOR) in rats: role of indirect 5-HT(1A) partial agonism. Behav Brain Res 2013; 247:158-64. [PMID: 23538066 DOI: 10.1016/j.bbr.2013.03.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 03/11/2013] [Accepted: 03/16/2013] [Indexed: 10/27/2022]
Abstract
Blonanserin is an atypical antipsychotic drug (APD) which, compared to other atypical APDs, is a relatively selective serotonin (5-HT)2A and dopamine D2 antagonist. Comparing blonanserin with more broadly acting atypical APDs could be useful to test the contributions of actions at other monoamine receptors, e.g. 5-HT1A receptors, to the reversal of PCP-induced novel object recognition (NOR) deficit. In this study, we tested the effect of blonanserin alone, and in combination with 5-HT1A agents, on NOR deficit induced by subchronic treatment with the N-methyl-D-aspartate (NMDA) receptor antagonist, phencyclidine (PCP; 2 mg/kg), b.i.d., for 7 days. Blonanserin, 1mg/kg, but not 0.3mg/kg, improved the PCP-induced NOR deficit. However, at 1mg/kg, object exploration was diminished. Co-administration of sub-effective doses of blonanserin (0.3 mg/kg) and the 5-HT1A partial agonist, tandospirone (0.2 mg/kg), significantly reversed the NOR deficit without diminishing activity during the acquisition or retention periods. The combination of WAY100635 (0.6 mg/kg), a 5-HT1A antagonist, and blonanserin (1 mg/kg), also diminished object exploration which prevented assessment of the effect of this combination on NOR. WAY100635 (0.6 mg/kg) blocked the ameliorating effect of risperidone (0.1 mg/kg), another atypical APD with low affinity for 5-HT1A receptors, but did not impair exploration. These results suggest that blonansein and risperidone, atypical APDs which lack a direct action on 5-HT1A receptors require 5-HT1A receptor stimulation to reverse the subchronic PCP-induced NOR deficit and provide a support for clinical trial of blonanserin in combination with tandospirone to ameliorate cognitive impairment in schizophrenia and to have fewer side effects.
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Affiliation(s)
- M Horiguchi
- Division of Psychiatry and Behavioural Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
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Tenjin T, Miyamoto S, Ninomiya Y, Kitajima R, Ogino S, Miyake N, Yamaguchi N. Profile of blonanserin for the treatment of schizophrenia. Neuropsychiatr Dis Treat 2013; 9:587-94. [PMID: 23766647 PMCID: PMC3677929 DOI: 10.2147/ndt.s34433] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Blonanserin was developed as an antipsychotic drug in Japan and approved for the treatment of schizophrenia. It belongs to a series of 4-phenyl-2-(1-piperazinyl)pyridines and acts as an antagonist at dopamine D2, D3, and serotonin 5-HT2A receptors. Blonanserin has low affinity for 5-HT2C, adrenergic α1, histamine H1, and muscarinic M1 receptors, but displays relatively high affinity for 5-HT6 receptors. In several short-term double-blind clinical trials, blonanserin had equal efficacy as haloperidol and risperidone for positive symptoms in patients with chronic schizophrenia and was also superior to haloperidol for improving negative symptoms. Blonanserin is generally well tolerated and has a low propensity to cause metabolic side effects and prolactin elevation. We recently reported that blonanserin can improve some types of cognitive function associated with prefrontal cortical function in patients with first-episode and chronic schizophrenia. Taken together, these results suggest that blonanserin may be a promising candidate for a first-line antipsychotic for acute and maintenance therapy for schizophrenia. Further comparative studies are warranted to clarify the benefit/risk profile of blonanserin and its role in the treatment of schizophrenia.
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Affiliation(s)
- Tomomi Tenjin
- Department of Neuropsychiatry, St Marianna University School of Medicine, Kawasaki, Kanagawa, Japan
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Tanahashi S, Yamamura S, Nakagawa M, Motomura E, Okada M. Clozapine, but not haloperidol, enhances glial D-serine and L-glutamate release in rat frontal cortex and primary cultured astrocytes. Br J Pharmacol 2012; 165:1543-55. [PMID: 21880034 DOI: 10.1111/j.1476-5381.2011.01638.x] [Citation(s) in RCA: 113] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND AND PURPOSE Deficient transmission at the glutamate NMDA receptor is considered a key component of the pathophysiology of schizophrenia. However, the effects of antipsychotic drugs on the release of the endogenous NMDA receptor partial agonist, D-serine, remain to be clarified. EXPERIMENTAL APPROACH We determined the interaction between antipsychotic drugs (clozapine and haloperidol) and transmission-modulating toxins (tetanus toxin, fluorocitrate, tetrodotoxin) on the release of L-glutamate and D-serine in the medial prefrontal cortex (mPFC) of freely moving rats, using microdialysis, and primary cultures of astrocytes using extreme high-pressure liquid chromatography. KEY RESULTS Release of L-glutamate and D-serine in the mPFC and in cultured astrocytes was inhibited by tetanus toxin (a synaptobrevin inhibitor) and fluorocitrate (a glial toxin), whereas tetrodotoxin (a voltage-sensitive Na(+) blocker) inhibited depolarization-induced L-glutamate release in the mPFC without affecting that of D-serine. Clozapine (1 and 5 mg·kg(-1)), but not haloperidol (0.5 and 1 mg·kg(-1)), dose-dependently increased L-glutamate and D-serine release from both astrocytes and mPFC. Clozapine-induced release of L-glutamate and D-serine was also reduced by tetanus toxin and fluorocitrate. Tetrodotoxin reduced clozapine-induced mPFC L-glutamate release but not that of D-serine. Clozapine-induced L-glutamate release preceded clozapine-induced D-serine release. MK-801 (a NMDA receptor antagonist) inhibited the delayed clozapine-induced L-glutamate release without affecting that of D-serine. CONCLUSIONS AND IMPLICATIONS Clozapine predominantly activated glial exocytosis of D-serine, and this clozapine-induced D-serine release subsequently enhances neuronal L-glutamate release via NMDA receptor activation. The enhanced D-serine associated glial transmission seems a novel mechanism of action of clozapine but not haloperidol.
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Affiliation(s)
- Shunske Tanahashi
- Department of Psychiatry, Division of Neuroscience, Graduate School of Medicine, Brain Science and Animal Model Research Center, Mie University, 2-174 Edobashi, Tsu, Mie, Japan
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Peng M, Liu J, Lu D, Yang YJ. Development and validation of a stability-indicating gas chromatographic method for quality control of residual solvents in blonanserin: a novel atypical antipsychotic agent. J Chromatogr Sci 2012; 50:727-32. [PMID: 22595261 DOI: 10.1093/chromsci/bms069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Blonanserin is a novel atypical antipsychotic agent for the treatment of schizophrenia. Ethyl alcohol, isopropyl alcohol and toluene are utilized in the synthesis route of this bulk drug. A new validated gas chromatographic (GC) method for the simultaneous determination of residual solvents in blonanserin is described in this paper. Blonanserin was dissolved in N, N-dimethylformamide to make a sample solution that was directly injected into a DB-624 column. A postrun oven temperature at 240°C for approximately 2 h after the analysis cycle was performed to wash out blonanserin residue in the GC column. Quantitation was performed by external standard analyses and the validation was carried out according to International Conference on Harmonization validation guidelines Q2A and Q2B. The method was shown to be specific (no interference in the blank solution), linear (correlation coefficients ≥0.99998, n = 10), accurate (average recoveries between 94.1 and 101.7%), precise (intra-day and inter-day precision ≤2.6%), sensitive (limit of detection ≤0.2 ng, and limit of quantitation ≤0.7 ng), robust (small variations of carrier gas flow, initial oven temperature, temperature ramping rate, injector and detector temperatures did not significantly affect the system suitability test parameters and peak areas) and stable (reference standard and sample solutions were stable over 48 h). This extensively validated method is ready to be used for the quality control of blonanserin.
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Affiliation(s)
- Ming Peng
- Department of Chemistry, Shanghai Institute for Food and Drug Control, 201203 Shanghai, China.
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Prefrontal dopamine release and sensory-specific satiety altered in rats with neonatal ventral hippocampal lesions. Behav Brain Res 2012; 231:97-104. [DOI: 10.1016/j.bbr.2012.02.041] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Revised: 02/23/2012] [Accepted: 02/26/2012] [Indexed: 11/15/2022]
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Suzuki H, Gen K. The relationship between the plasma concentration of blonanserin, and its plasma anti-serotonin 5-HT(2A) activity/anti-dopamine D₂ activity ratio and drug-induced extrapyramidal symptoms. Psychiatry Clin Neurosci 2012; 66:146-52. [PMID: 22353327 DOI: 10.1111/j.1440-1819.2011.02311.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS Blonanserin is a second-generation antipsychotic that was developed in Japan. We investigated the relationships between plasma concentration, the plasma anti-5-HT(2A) activity/anti-D₂ activity (S/D) ratio and extrapyramidal symptoms (EPS) in blonanserin dosing. METHODS The subjects were 29 outpatients with schizophrenia. We assessed EPS using the Drug-Induced Extrapyramidal Symptoms Scale (DIEPSS). The plasma concentrations were measured by high performance liquid chromatography, and the plasma anti-D₂ and anti-5-HT(2A) activities were measured by [³H]-spiperone and [³H]-ketanserin radioreceptor assays. RESULTS The results revealed that there were significant correlations between both the plasma concentration and the DIEPSS total score (P<0.05). A negative correlative tendency was found between the S/D ratio and the DIEPSS total score. Furthermore, the plasma concentrations were divided into a low plasma concentration group and a high plasma concentration group, and the S/D ratios were divided into a low S/D ratio group and a high S/D ratio group. We then compared each group based on the DIEPSS total scores. The score in the high plasma concentration-low S/D ratio group was significantly higher than in the high plasma concentration-high S/D ratio, low plasma concentration-high S/D ratio and low plasma concentration-low S/D ratio groups (P<0.05 for all). CONCLUSIONS These findings indicate that the incidence of EPS during treatment with blonanserin is mainly determined by plasma concentration, but the incidence of EPS may be inhibited when anti-5HT(2A) activity is predominant over anti-D₂ activity.
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Affiliation(s)
- Hidenobu Suzuki
- Department of Psychiatry, Tanzawa Hospital, Hadano Department of Psychiatry, Seimo Hospital, Gunma, Japan.
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Tanahashi S, Ueda Y, Nakajima A, Yamamura S, Nagase H, Okada M. Novel δ1-receptor agonist KNT-127 increases the release of dopamine and L-glutamate in the striatum, nucleus accumbens and median pre-frontal cortex. Neuropharmacology 2012; 62:2057-67. [PMID: 22266218 DOI: 10.1016/j.neuropharm.2012.01.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Revised: 01/02/2012] [Accepted: 01/09/2012] [Indexed: 11/29/2022]
Abstract
The effects of systemic δ1-agonist on neurotransmission remains obscure, since no selective δ1-agonist exists that can penetrate the blood-brain barrier. Recently, we succeeded in synthesizing a putative δ1-receptor agonist, KNT-127, which has been demonstrated the effectiveness of systemic administration against anxiety and depressive-like behavior. To clarify the functional selectivity of KNT-127 and neurotransmission regulating system of δ1-receptor, the present study investigated the interaction between KNT-127 and δ-receptor antagonists on the release of dopamine, L-glutamate and GABA in nucleus accumbens (NAc), striatum and median pre-frontal cortex (mPFC) using multi-probe microdialysis. Intraperitoneal administration of KNT-127 increased the release of dopamine and L-glutamate in three regions, but decreased and increased GABA releases in respective NAc and mPFC without affecting that in striatum. The effects of KNT-127 in the three regions were abrogated by δ1-antagonist but not by δ2-antagonist. MK801 inhibited KNT-127-induced dopamine release in striatum and NAc, but enhanced that in mPFC, inhibited KNT-127-induced mPFC GABA release without affecting KNT-127-induced GABA reduction in NAc. Muscimol enhanced KNT-127-induced dopamine release in mPFC. Sulpiride inhibited KNT-127-induced reduction of GABA release in NAc. The results indicated that KNT-127 is a selective δ1-agonist, and suggested that δ1-receptor directly activates the release of dopamine and L-glutamate in the striatum, NAc and mPFC, but not that of GABA in the three regions. δ1-receptor indirectly inhibited GABA release in NAc via activated dopaminergic transmission, while δ1-receptor indirectly enhanced GABA release in mPFC via activated glutamatergic transmission.
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Affiliation(s)
- Shunsuke Tanahashi
- Department of Psychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, 2-174 Edobashi, Tsu, Mie 514-8507, Japan
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Tenjin T, Miyamoto S, Miyake N, Ogino S, Kitajima R, Ojima K, Arai J, Teramoto H, Tsukahara S, Ito Y, Tadokoro M, Anai K, Funamoto Y, Kaneda Y, Sumiyoshi T, Yamaguchi N. Effect of blonanserin on cognitive function in antipsychotic-naïve first-episode schizophrenia. Hum Psychopharmacol 2012; 27:90-100. [PMID: 22278973 DOI: 10.1002/hup.1276] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVE The purpose of this study was to evaluate the effects of blonanserin, a novel antipsychotic, on cognitive function in first-episode schizophrenia. METHODS Twenty-four antipsychotic-naïve patients with first-episode schizophrenia participated in the study. Blonanserin was given in an open-label design for 8 weeks. The Brief Assessment of Cognition in Schizophrenia-Japanese language version (BACS-J) was administered as the primary outcome measure at baseline and 8 weeks. Clinical evaluation included the Positive and Negative Syndrome Scale (PANSS), the Schizophrenia Quality of Life Scale-Japanese language version (SQLS-J), and the Clinical Global Impression-Severity of Illness Scale (CGI-S). To exclude the possibility of retest effects on the BACS-J, 10 age-matched patients with chronic schizophrenia treated with blonanserin were tested at baseline and after an 8-week interval. RESULTS Twenty first-episode patients completed the study. Repeated measures analysis of covariance revealed a significant group-by-time interaction effect on the letter fluency task due to better performance in the first-episode group, but not in the control group. Main effect of time or group-by-time interaction effect on the Tower of London task was not significant; however, the first-episode group, but not the control group, showed substantial improvement with a moderate effect size. All items on the PANSS, SQLS-J, and CGI-S significantly improved after 8 weeks of treatment. CONCLUSIONS These results suggest that blonanserin improves some types of cognitive function associated with prefrontal cortical function.
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Affiliation(s)
- Tomomi Tenjin
- Department of Neuropsychiatry, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan.
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Tanahashi S, Yamamura S, Nakagawa M, Motomura E, Okada M. Dopamine D2 and serotonin 5-HT1A receptors mediate the actions of aripiprazole in mesocortical and mesoaccumbens transmission. Neuropharmacology 2011; 62:765-74. [PMID: 21925189 DOI: 10.1016/j.neuropharm.2011.08.031] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Revised: 07/29/2011] [Accepted: 08/22/2011] [Indexed: 12/01/2022]
Abstract
The antipsychotic agent aripiprazole acts as a partial agonist of dopamine D2 and serotonin 5-HT1A receptors. However, the detailed actions of aripiprazole in mesolimbic and mesocortical transmission remain to be clarified. To address this, we examined the effects of systemic and local administrations of aripiprazole on extracellular levels of dopamine and GABA in medial prefrontal cortex (mPFC), nucleus accumbens (NAc), and anterior (aVTA) and posterior (pVTA) ventral tegmental areas. Intraperitoneal injection of aripiprazole (0.5mg/kg) increased dopamine release in mPFC without affecting those in aVTA, pVTA, or NAc, whereas 10mg/kg decreased the release in all four regions. Local sulpiride administration in aVTA increased concentration-dependently dopamine release in both aVTA and NAc without affecting that in mPFC, whereas local aripiprazole administration in aVTA concentration-dependently decreased dopamine release in aVTA and mPFC without affecting that in NAc. Blockade of 5-HT1A receptor in aVTA produced aripiprazole-induced dopamine release in aVTA and prevented the aripiprazole-induced reduction of dopamine release in mPFC. Local administration of aripiprazole in mPFC increased dopamine and decreased GABA releases, whereas local administration of sulpiride had no effect on dopamine or GABA. In mPFC, blockade of 5-HT1A receptor prevented the aripiprazole-induced dopamine elevation and GABA reduction; however, under the activation of GABA(A) receptor, local perfusion with aripiprazole in mPFC decreased GABA release without affecting dopamine release. The results suggested that the combination of 5-HT1A and D2 partial agonistic actions of aripiprazole against mesocortical and mesoaccumbens transmission, explains, at least in part, the atypical antipsychotic properties of aripiprazole. This article is part of a Special Issue entitled 'Post-Traumatic Stress Disorder'.
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Affiliation(s)
- Shunsuke Tanahashi
- Department of Psychiatry, Graduate School of Medicine, Mie University Brain Science and Animal Model Center (BSAM), Mie University, 2-174 Edobashi, Tsu, Mie 514-8507, Japan
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