NMDA Receptor Hypofunction Leads to Generalized and Persistent Aberrant γ Oscillations Independent of Hyperlocomotion and the State of Consciousness

International audienceNMDAr antagonists acutely produces, in the rodent CNS, generalized aberrant gamma oscillations, which are not dependent on hyperlocomotion-related brain state or conscious sensorimotor processing. These findings suggest that NMDAr hypofunction-related generalized gamma hypersynchronies represent an aberrant diffuse network noise, a potential electrophysiological correlate of a psychotic-like state. Such generalized noise might cause dysfunction of brain operations, including the impairments in cognition and sensorimotor integration seen in schizophrenia

Genetic association between G protein-coupled receptor kinase 6/β-arrestin 2 and dopamine supersensitivity psychosis in schizophrenia

Yasunori Oda,1 Nobuhisa Kanahara,2 Hiroshi Kimura,1 Hiroyuki Watanabe,2 Kenji Hashimoto,3 Masaomi Iyo1 1Department of Psychiatry, Chiba University Graduate School of Medicine, Chiba, Japan; 2Division of Medical Treatment and Rehabilitation, 3Division of Clinical Neuroscience, Chiba University Center for Forensic Mental Health, Chiba, Japan Background/aim: Dopamine supersensitivity psychosis (DSP), clinically characterized by unstable and severe psychosis or tardive dyskinesia and often categorized as treatment-resistant schizophrenia, is promoted by long-term antipsychotic treatment. An upregulation of the dopamine D2 receptor caused by antipsychotic(s) is involved in the development of DSP. The present study explored the potential roles of G protein-coupled receptor kinase 6 (GRK6) and β-arrestin 2 (ARRB2) that are involved in the trafficking of DRD2 in patients with DSP. Methods: We conducted a genetic association study of GRK6/ARRB2 between the patients with DSP episodes [DSP(+) group: N=108] and the patients without DSP(-) episodes [DSP(-) group: N=169] from the total group of patients (N=333). Based on the patients’ treatment history, a DSP episode was defined as withdrawal psychosis, developed tolerance to antipsychotic effect, and tardive dyskinesia (the remaining 56 patients were excluded due to insufficient information). Results: The results revealed that none of the allelic or genotyping distributions of five single nucleotide polymorphisms (SNPs) of GRK6 and three SNPs of ARRB2 showed any significant difference between the DSP(+) and DSP(-) groups. Conclusion: The results suggest that the SNP analyses of these two molecules fail to classify patients into the potential clinical subtype of DSP(+) or DSP(-) group. However, since GRK6 and ARRB2 are surely involved in dopamine D2 receptor metabolism, further studies based on prospective observations of the onset of DSP under specific antipsychotic treatments are needed. Keywords: antipsychotic, dopamine D2 receptor, tardive dyskinesia, treatment-resistan

CO2 laser with silent discharge excitation

Translated from Japanese (Mitsubishi Denki Giho 1982 v. 56(5) p. 18-22)SIGLEAvailable from British Library Document Supply Centre- DSC:9312.57(WI-Trans--769)T / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Supplementary Material for: Antipsychotic-Induced Dopamine Supersensitivity Psychosis: Pharmacology, Criteria, and Therapy

<p>The first-line treatment for psychotic disorders remains antipsychotic drugs with receptor antagonist properties at D₂-like dopamine receptors. However, long-term administration of antipsychotics can upregulate D₂ receptors and produce receptor supersensitivity manifested by behavioral supersensitivity to dopamine stimulation in animals, and movement disorders and supersensitivity psychosis (SP) in patients. Antipsychotic-induced SP was first described as the emergence of psychotic symptoms with tardive dyskinesia (TD) and a fall in prolactin levels following drug discontinuation. In the era of first-generation antipsychotics, 4 clinical features characterized drug-induced SP: rapid relapse after drug discontinuation/dose reduction/switch of antipsychotics, tolerance to previously observed therapeutic effects, co-occurring TD, and psychotic exacerbation by life stressors. We review 3 recent studies on the prevalence rates of SP, and the link to treatment resistance and psychotic relapse in the era of second-generation antipsychotics (risperidone, paliperidone, perospirone, and long-acting injectable risperidone, olanzapine, quetiapine, and aripiprazole). These studies show that the prevalence rates of SP remain high in schizophrenia (30%) and higher (70%) in treatment-resistant schizophrenia. We then present neurobehavioral findings on antipsychotic-induced supersensitivity to dopamine from animal studies. Next, we propose criteria for SP, which describe psychotic symptoms and co-occurring movement disorders more precisely. Detection of mild/borderline drug-induced movement disorders permits early recognition of overblockade of D₂ receptors, responsible for SP and TD. Finally, we describe 3 antipsychotic withdrawal syndromes, similar to those seen with other CNS drugs, and we propose approaches to treat, potentially prevent, or temporarily manage SP.</p

Milnacipran treatment and potential biomarkers in depressed patients following an initial SSRI treatment failure: a prospective, open-label, 24-week study

Tasuku Hashimoto,1,2 Daiji Sakurai,1 Yasunori Oda,1 Tadashi Hasegawa,3 Nobuhisa Kanahara,4 Tsuyoshi Sasaki,3 Hideki Komatsu,3,5 Junpei Takahashi,1,5 Takahiro Oiwa,6 Yoshimoto Sekine,4,5 Hiroyuki Watanabe,1 Masaomi Iyo1,3 1Department of Psychiatry, Chiba University Graduate School of Medicine, 2Sodegaura Satsukidai Hospital, 3Department of Psychiatry, Chiba University Hospital, 4Division of Medical Treatment and Rehabilitation, Centre for Forensic Mental Health, Chiba University, 5Choshi Kokoro Clinic, 6Mobara Shinkeika Hospital, Chiba, Japan Background: We assessed the effect of switching patients with major depressive disorder to milnacipran following an initial selective serotonin reuptake inhibitor treatment failure, and explored potential biomarkers in their blood.Methods: We conducted a prospective, open-label, 24-week trial. Depression was assessed with the 17-item Hamilton Depression Rating Scale. Patients showing a &ge;50% reduction in Hamilton Depression Rating Scale scores from baseline to final visit were considered responders. Regarding adverse effects (AEs), moderate-to-severe AEs were specifically identified as effects that required any medical treatment or that induced treatment withdrawals. We also measured blood levels of various molecules including inflammatory cytokines.Results: Of the 30 participants who enrolled, 17 completed this study. The responder rate was 30% (n=10). Baseline serum levels of interleukin-6 (Z=-2.155; P=0.031) and interleukin-8 (Z=-2.616; P=0.009) were significantly higher when moderate-to-severe AEs were present (n=13 patients with moderate-to-severe AEs). Serum levels of macrophage inflammatory protein-1&beta; showed a significant continuous decrease from the baseline level (Friedman&rsquo;s test: &chi;2=23.9, df=4, P&lt;0.001) only in non-responders.Conclusion: These results demonstrate that serum levels of interleukin-6, interleukin-8, and macrophage inflammatory protein-1&beta; as potential blood biomarkers could be utilized to identify the responsiveness of patients to serotonin and norepinephrine reuptake inhibitor like milnacipran, or to identify those patients who may experience AEs strong enough to warrant discontinuation of treatment. Keywords: major depressive disorder, milnacipran, biomarkers, adverse effects, cytokine

Production and measurement of the MQXA series of LHC low- beta insertion quadrupoles

The inner triplet quadrupole magnets (MQXA) for the LHC low-beta insertion have been developed. The quadrupoles provide a field gradient of 215 T/m at 1.9 K in a coil aperture of 70 mm diameter and with an effective magnetic length of 6.37 m. The series of 20 magnets have been produced in industry, and full testing has been done at KEK. We present an overview of the production and the results from mechanical and magnetic measurements

Fabrication and mechanical behavior of a prototype for the LHC low-β\beta quadrupole magnets

Superconducting low-beta quadrupole magnets for the LHC insertion regions are being developed at KEK as part of the collaboration between CERN and KEK. Magnet production technology developed at KEK has been transferred to a manufacturer of production magnets. In order to verify the production technology, fabrication jigs, tools, and procedures, the first full-scale prototype, MQXA-P1, was fabricated. Mechanical characteristics of MQXA-P1 were measured during the magnet assembly process, and it satisfied specifications needed for the production magnets. The validity of the magnet design and fabrication method was confirmed. (14 refs)