Publications by authors named "Takayoshi Mamiya"

We held lectures and practices for the regional community residents with the aim of promoting appropriate use of medications. To evaluate the usefulness of our activity, we conducted medicine-related questionnaire surveys (pre- and post-questionnaires) before and after the lectures and practices, and satisfaction with the activity questionnaire surveys (post-questionnaires) after them. We also evaluated the effect of age difference on the results by dividing the participants into elderly (age ≥65) and non-elderly (age <65), before the analysis.

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Novel steroid glycosides, acanthasterosides A1, B1, and B3, have been isolated from the crown-of-thorns starfish Acanthaster planci. Acanthasterosides B1 and B3 having two separated xyloses induced neurite outgrowth as like as nerve growth factor (NGF) in the rat pheochromocytoma cell line PC12, whereas acanthasteroside A1, having one xylose, did not induce neurite outgrowth. The acanthasteroside B3 induced neuritogenesis via the significant activation of p38 mitogen-activated protein kinase after the activation of the small G-protein Cdc42 rather than via Ras-MEK-ERK pathway that is predominantly activated by NGF.

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Clinically, juveniles are more sensitive to stress than adults, and exposure to stress as juveniles prolongs psychiatric symptoms and causes treatment resistance. However, the efficacy of antidepressants for juveniles with psychiatric disorders is unknown. In the present study, we investigated whether the expression or development of impaired social behavior was attenuated by memantine, a non-competitive NMDA receptor antagonist.

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We examined whether galantamine (GAL), a cholinesterase inhibitor and allosteric potentiating ligand for α7 nicotinic acetylcholine receptor (nAChR), had an impact on emotional abnormalities in forebrain-specific cholecystokinin receptor-2 overexpressed transgenic mice. Treatment with GAL (1 mg/kg, s.c.

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Habitual smoking in patients with schizophrenia (SCZ) is considered to improve their own psychoses or to develop a vulnerability to psychological dependence on (-)-nicotine ([-]-NIC) by stimulating nicotinic acetylcholine receptors (nAChRs) in the central nervous system. In the present study, we investigated whether habitual smoking is due to get therapeutic effect or to psychological dependence and which nAChR subunits are associated with them using mice that were repeatedly administered phencyclidine (PCP: 10 mg/kg/day, s.c.

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Stress vulnerability and pathogenic mechanisms in stress-related disorders are strongly associated with the functions of serotonin transporter (SERT). SERT phosphorylation induces a reduction of the serotonin (5-HT, 5-hydroxytryptamine) transport properties, its phosphorylation regulated by protein kinase C (PKC). However, the functional relationship between regulated SERT activity by PKC and stress vulnerability remains unclear.

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Article Synopsis
  • The study investigates the role of nicotinic acetylcholine receptors (nAChRs) in schizophrenia (SCZ) patients' smoking behavior, linking it to changes in gene expression.
  • It finds that levels of the α7 nAChR subunit are decreased in both human cells from SCZ patients and in a mouse model of SCZ, particularly after withdrawal from the drug phencyclidine (PCP).
  • The research suggests that nicotine administration can help alleviate certain symptoms of SCZ by targeting specific nAChRs, indicating that SCZ patients may smoke to self-medicate rather than due to nicotine addiction.
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Selective serotonin reuptake inhibitors are the first-line antidepressants for treating major depressive and post-traumatic stress disorders. These inhibitors directly bind to the serotonin transporter (SERT). Protein kinase C (PKC) is a key regulator of SERT functions as it can attenuate SERT activity through phosphorylation and its subsequent internalization.

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Prenatal nicotine exposure (PNE) causes behavioral abnormalities in offspring, such as an enhancement of impulsivity and decrease in attention at adolescence. Here we examined the effects of galantamine (GAL) on the behavioral and electrophysiological changes induced by PNE in mice. Pregnant C57BL/6J mice were exposed to nicotine (0.

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Background And Purpose: Hispidulin is a flavonoid isolated from Clerodendrum inerme that was found to inhibit intractable motor tics. Previously, we found that hispidulin attenuates hyperlocomotion and the disrupted prepulse inhibition induced by methamphetamine and N-methyl-d-aspartate (NMDA) receptor antagonists, two phenotypes of schizophrenia resembling positive symptoms. Hispidulin can inhibit COMT, a dopamine-metabolizing enzyme in the prefrontal cortex (PFC) that is important for social interaction.

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Meropenem (MEPM) is a broad-spectrum antibiotic prescribed to patients with moderate or severe pneumonia. It is well recognized that appropriate medicine reduces the burden on not only young patients but elderly ones as well. We enrolled 56 patients aged 75 and over who were diagnosed with moderate or severe pneumonia (body temperature: ≧37.

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Background And Purpose: The pathophysiological role of α -subunit-containing GABA receptors, which are mainly expressed in cerebellar granule cells, remains unclear. Recently, we demonstrated that hispidulin, a flavonoid isolated from a local herb that remitted a patient's intractable motor tics, attenuated methamphetamine-induced hyperlocomotion in mice as a positive allosteric modulator (PAM) of cerebellar α GABA receptors. Here, using hispidulin and a selective α GABA receptor PAM, the pyrazoloquinolinone Compound 6, we revealed an unprecedented role of cerebellar α GABA receptors in disrupted prepulse inhibition of the startle response (PPI), which reflects sensorimotor gating deficits manifested in several neuropsychiatric disorders.

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We previously identified a novel molecule, SHATI/NAT8L, as having an inhibitory effect on methamphetamine dependence. We generated Shati/Nat8l knockout (KO) mice and found that they showed neurochemical changes and behavioral abnormalities related to attention deficit/hyperactivity disorder (AD/HD). In this study, we assessed validities of the Shati/Nat8l KO mice as a new animal model for AD/HD through a behavioral pharmacology approach.

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3,4-Methylenedioxymethamphetamine (MDMA) is known to induce dependence and psychosis in humans. Brain-derived neurotrophic factor (BDNF) is involved in the synaptic plasticity and neurotrophy in midbrain dopaminergic neurons. This study aimed to investigate the role of BDNF in MDMA-induced dependence and psychosis.

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Increased risk of attention-deficit/hyperactivity disorder (AD/HD) is partly associated with the early developmental exposure to nicotine in tobacco smoke. Emerging reports link tobacco smoke exposure or prenatal nicotine exposure (PNE) with AD/HD-like behaviors in rodent models. We have previously reported that PNE induces cognitive behavioral deficits in offspring and decreases the contents of dopamine (DA) and its turnover in the prefrontal cortex (PFC) of offspring It is well known that the dysfunction of DAergic system in the brain is one of the core factors in the pathophysiology of AD/HD.

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Histone deacetylase 6 (Hdac6), a multifunctional cytoplasmic deacetylase, is abundant in brain. We previously demonstrated that global Hdac6 depletion causes aberrant emotional behaviors in mice. Identification of affected brain systems and its molecular basis will lead to new insights into relations between protein acetylation events and psychiatric disorders.

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Depression is known to occur frequently in chronic hepatitis C viral (HCV) patients receiving interferon (IFN)-α therapy. In this study, we investigated whether indoleamine 2,3-dioxygenase1 (IDO1)-mediated tryptophan (TRP) metabolism plays a critical role in depression occurring as a side effect of IFN-α therapy. Increases in serum kynurenine (KYN) and 3-hydroxykynurenine (3-HK) concentrations and in the ratios of KYN/TRP and 3-HK/kynurenic acid (KA) were much larger in depressive HCV patients than in non-depressed patients following therapy.

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Rationale: We previously reported that prenatal treatment with phencyclidine (PCP) induces glutamatergic dysfunction in the prefrontal cortex (PFC), leading to schizophrenia-like behavioral deficits in adult mice. However, little is known about the prenatal effect of PCP treatment on other types of neurons.

Objectives: We focused on γ-aminobutyric acid (GABA)-ergic interneurons and evaluated the effect of prenatal PCP exposure on the neurodevelopment of GABAergic interneurons in the PFC.

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We previously identified a novel molecule "SHATI/NAT8L" that exerts an inhibitory effect on methamphetamine (METH)-induced behavioral deficits. Recently, it has been reported that SHATI might function as an aspartate N-acetyltransferase, which synthesizes N-acetylaspartate (NAA) in vitro. However, whether SHATI actually synthesizes NAA in vivo in the brain is still unclear.

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Cigarette smoking during pregnancy is associated with various disabilities in the offspring such as attention deficit/hyperactivity disorder, learning disabilities, and persistent anxiety. We have reported that nicotine exposure in female mice during pregnancy, in particular from embryonic day 14 (E14) to postnatal day 0 (P0), induces long-lasting behavioral deficits in offspring. However, the mechanism by which prenatal nicotine exposure (PNE) affects neurodevelopment, resulting in behavioral deficits, has remained unclear.

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Background: The dysbindin-1 gene (DTNBP1: dystrobrevin binding protein 1) is a promising schizophrenia susceptibility gene, known to localize almost exclusively to neurons in the brain, and participates in the regulation of neurotransmitter release, membrane-surface receptor expression, and synaptic plasticity. Sandy mice, with spontaneous Dtnbp1 deletion, display behavioral abnormalities relevant to symptoms of schizophrenia. However, it remains unknown if dysbindin-1 gain-of-function is beneficial or detrimental.

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In this study we investigated whether κ-opioid receptor stimulation by dynorphin A (1-13), a potent fragment of endogenous peptide, attenuated repeated stress-induced behavioral impairments in mice. In order to reduce the motivation to escape, mice were preexposed to inescapable electric footshock (day 0), and then dynorphin A (1-13) was administered to mice prior to the stress from the next day for 4 d (days 1-4). Dynorphin A (1-13) (1500 pmol/5 µL intracerebroventricular (i.

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Accumulating evidence suggests that dysregulation of histone modification is involved in the pathogenesis and/or pathophysiology of psychiatric disorders. However, the abnormalities in histone modification in the animal model of schizophrenia and the efficacy of antipsychotics for such abnormalities remain unclear. Here, we investigated the involvement of histone modification in phencyclidine-induced behavioral abnormalities and the effects of antipsychotics on these abnormalities.

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In a previous report, we identified a novel molecule, SHATI/NAT8L, having an inhibitory effect on methamphetamine (METH)-induced hyperlocomotion, sensitization, and conditioned place preference (CPP). SHATI/NAT8L attenuates the METH-induced increase in dopamine overflow in the nucleus accumbens (NAc) by promoting plasmalemmal and vesicular dopamine uptake. However, the biological functions of the protein remain unclear.

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We previously identified a new molecule, "SHATI/NAT8L," which has an inhibitory effect on methamphetamine (METH)-induced hyperlocomotion, sensitization, and conditioned place preference. Nevertheless, the extent of SHATI localization and its functions are only partially understood. In this study, we used the FLAG-tag method to investigate SHATI localization.

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