Background: Schizophrenia is a debilitating and complex mental disorder whose exact etiology remains unknown. There is growing amount of evidence of a relationship between neuroinflammation, as demonstrated by microglial activation, and schizophrenia. Our previous studies have proposed that hyperbilirubinemia plays a role in the pathophysiology of schizophrenia. Furthermore, we suggested the Gunn rat, an animal model of bilirubin encephalopathy, as a possible animal model of schizophrenia. However, the effects of unconjugated bilirubin on microglia, the resident immune cell of the CNS, in Gunn rats have never been investigated. In the present study, we examined how microglial cells respond to bilirubin toxicity in adult Gunn rats. Methods: Using immunohistochemical techniques, we compared the distribution, morphology, and ultrastructural features of microglial cells in Gunn rats with Wistar rats as a normal control. We also determined the ratio of activated and resting microglia and observed microglia-neuron interactions. We characterized the microglial cells in the hippocampal dentate gyrus. Results: We found that microglial cells showed activated morphology in the hilus, subgranular zone, and granular layer of the Gunn rat hippocampal dentate gyrus. There was no significant difference between cell numbers between in Gunn rats and controls. However, there was significant difference in the area of CD11b expression in the hippocampal dentate gyrus. Ultrastructurally, microglial cells often contained rich enlarged rich organelles in the cytoplasm and showed some phagocytic function. Conclusions: We propose that activation of microglia could be an important causal factor of the behavioral abnormalities and neuropathological changes in Gunn rats. These findings may provide basic information for further assessment of the Gunn rat as an animal model of schizophrenia.

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BackgroundAlthough electroconvulsive therapy (ECT) is regarded as one of the efficient treatments for intractable psychiatric disorders, the mechanism of therapeutic action remains unclear. Recently, many studies indicate that ECT affects the immune-related cells, such as microglia, astrocytes, and lymphocytes. Moreover, microglial activation and astrocytic activation have been implicated in the postmortem brains of schizophrenia patients. We previously demonstrated that Gunn rats showed schizophrenia-like behavior and microglial activation in their brains. The present study examined the effects of electroconvulsive shock (ECS), an animal counterpart of ECT, on schizophrenia-like behavior, microgliosis, and astrogliosis in the brain of Gunn rats.MethodsThe rats were divided into four groups, i.e., Wistar sham, Wistar ECS, Gunn sham, and Gunn ECS. ECS groups received ECS once daily for six consecutive days. Subsequently, prepulse inhibition (PPI) test was performed, and immunohistochemistry analysis was carried out to determine the activation degree of microglia and astrocytes in the hippocampus by using anti-CD11b and anti-glial fibrillary acidic protein (GFAP) antibody, respectively.ResultsWe found PPI deficit in Gunn rats compared to Wistar rats, and it was significantly improved by ECS. Immunohistochemistry analysis revealed that immunoreactivity of CD11b and GFAP was significantly increased in Gunn rats compared to Wistar rats. ECS significantly attenuated the immunoreactivity of both CD11b and GFAP in Gunn rats.ConclusionsECS ameliorated schizophrenia-like behavior of Gunn rats and attenuated microgliosis and astrogliosis in the hippocampus of Gunn rats. Accordingly, therapeutic effects of ECT may be exerted, at least in part, by inhibition of glial activation. These results may provide crucial information to elucidate the role of activated glia in the pathogenesis of schizophrenia and to determine whether future therapeutic interventions should attempt to up-regulate or down-regulate glial functions.Electronic supplementary materialThe online version of this article (doi:10.1186/s12974-016-0688-2) contains supplementary material, which is available to authorized users.

This study has contributed significantly in relation to the changing patterns of antidepressant use in all the participating Asian centers in the last 10 years. The findings are important in shaping optimal antidepressant prescription and future policy making.

Introduction: Patterns of clinical use of long-acting injectable (LAI) antipsychotic drugs in many countries, especially in Asia, for treatment of patients diagnosed with chronic psychotic disorders including schizophrenia are not well established. Methods: Within an extensive research consortium, we evaluated prescription rates for first-(FGA) and second-generation antipsychotic (SGA) LAI drugs and their clinical correlates among 3557 subjects diagnosed with schizophrenia across 15 Asian countries and region. Results: Overall, an average of 17.9% (638/3557; range: 0.0%-44.9%) of treated subjects were prescribed LAI antipsychotics. Those given LAI vs orally administered agents were significantly older, had multiple hospitalizations, received multiple antipsychotics more often, at 32.4% higher doses, were more likely to manifest disorganized behavior or aggression, had somewhat superior psychosocial functioning and less negative symptoms, but were more likely to be hospitalized, with higher BMI, and more tremor. Being prescribed an FGA vs SGA LAI agent was associated with male sex, aggression, disorganization, hospitalization, multiple antipsychotics, higher doses, with similar risks of adverse neurological or metabolic effects. Rates of use of LAI antipsychotic drugs to treat patients diagnosed with schizophrenia varied by more than 40-fold among Asian countries and given to an average of 17.9% of treated schizophrenia patients. We identified the differences in the clinical profiles and treatment characteristics of patients who were receiving FGA-LAI and SGA-LAI medications. Discussion: These findings behoove clinicians to be mindful when evaluating patients' need to be on LAI antipsychotics amidst multifaceted considerations, especially downstream adverse events such as metabolic and extrapyramidal side effects.