Large-scale analysis of structural brain asymmetries in schizophrenia via the ENIGMA consortium.

Left-right asymmetry is an important organizing feature of the healthy brain that may be altered in schizophrenia, but most studies have used relatively small samples and heterogeneous approaches, resulting in equivocal findings. We carried out the largest case-control study of structural brain asymmetries in schizophrenia, with MRI data from 5,080 affected individuals and 6,015 controls across 46 datasets, using a single image analysis protocol. Asymmetry indexes were calculated for global and regional cortical thickness, surface area, and subcortical volume measures. Differences of asymmetry were calculated between affected individuals and controls per dataset, and effect sizes were meta-analyzed across datasets. Small average case-control differences were observed for thickness asymmetries of the rostral anterior cingulate and the middle temporal gyrus, both driven by thinner left-hemispheric cortices in schizophrenia. Analyses of these asymmetries with respect to the use of antipsychotic medication and other clinical variables did not show any significant associations. Assessment of age- and sex-specific effects revealed a stronger average leftward asymmetry of pallidum volume between older cases and controls. Case-control differences in a multivariate context were assessed in a subset of the data (N = 2,029), which revealed that 7% of the variance across all structural asymmetries was explained by case-control status. Subtle case-control differences of brain macrostructural asymmetry may reflect differences at the molecular, cytoarchitectonic, or circuit levels that have functional relevance for the disorder. Reduced left middle temporal cortical thickness is consistent with altered left-hemisphere language network organization in schizophrenia.

Subcortical volumetric alterations in four major psychiatric disorders: a mega-analysis study of 5604 subjects and a volumetric data-driven approach for classification.

Differential diagnosis is sometimes difficult in practical psychiatric settings, in terms of using the current diagnostic system based on presenting symptoms and signs. The creation of a novel diagnostic system using objective biomarkers is expected to take place. Neuroimaging studies and others reported that subcortical brain structures are the hubs for various psycho-behavioral functions, while there are so far no neuroimaging data-driven clinical criteria overcoming limitations of the current diagnostic system, which would reflect cognitive/social functioning. Prior to the main analysis, we conducted a large-scale multisite study of subcortical volumetric and lateralization alterations in schizophrenia, bipolar disorder, major depressive disorder, and autism spectrum disorder using T1-weighted images of 5604 subjects (3078 controls and 2526 patients). We demonstrated larger lateral ventricles volume in schizophrenia, bipolar disorder, and major depressive disorder, smaller hippocampus volume in schizophrenia and bipolar disorder, and schizophrenia-specific smaller amygdala, thalamus, and accumbens volumes and larger caudate, putamen, and pallidum volumes. In addition, we observed a leftward alteration of lateralization for pallidum volume specifically in schizophrenia. Moreover, as our main objective, we clustered the 5,604 subjects based on subcortical volumes, and explored whether data-driven clustering results can explain cognitive/social functioning in the subcohorts. We showed a four-biotype classification, namely extremely (Brain Biotype [BB] 1) and moderately smaller limbic regions (BB2), larger basal ganglia (BB3), and normal volumes (BB4), being associated with cognitive/social functioning. Specifically, BB1 and BB2-3 were associated with severe and mild cognitive/social impairment, respectively, while BB4 was characterized by normal cognitive/social functioning. Our results may lead to the future creation of novel biological data-driven psychiatric diagnostic criteria, which may be expected to be useful for prediction or therapeutic selection.

Cerebral cortical structural alteration patterns across four major psychiatric disorders in 5549 individuals.

According to the operational diagnostic criteria, psychiatric disorders such as schizophrenia (SZ), bipolar disorder (BD), major depressive disorder (MDD), and autism spectrum disorder (ASD) are classified based on symptoms. While its cluster of symptoms defines each of these psychiatric disorders, there is also an overlap in symptoms between the disorders. We hypothesized that there are also similarities and differences in cortical structural neuroimaging features among these psychiatric disorders. T1-weighted magnetic resonance imaging scans were performed for 5,549 subjects recruited from 14 sites. Effect sizes were determined using a linear regression model within each protocol, and these effect sizes were meta-analyzed. The similarity of the differences in cortical thickness and surface area of each disorder group was calculated using cosine similarity, which was calculated from the effect sizes of each cortical regions. The thinnest cortex was found in SZ, followed by BD and MDD. The cosine similarity values between disorders were 0.943 for SZ and BD, 0.959 for SZ and MDD, and 0.943 for BD and MDD, which indicated that a common pattern of cortical thickness alterations was found among SZ, BD, and MDD. Additionally, a generally smaller cortical surface area was found in SZ and MDD than in BD, and the effect was larger in SZ. The cosine similarity values between disorders were 0.945 for SZ and MDD, 0.867 for SZ and ASD, and 0.811 for MDD and ASD, which indicated a common pattern of cortical surface area alterations among SZ, MDD, and ASD. Patterns of alterations in cortical thickness and surface area were revealed in the four major psychiatric disorders. To our knowledge, this is the first report of a cross-disorder analysis conducted on four major psychiatric disorders. Cross-disorder brain imaging research can help to advance our understanding of the pathogenesis of psychiatric disorders and common symptoms.

The effect of education regarding treatment guidelines for schizophrenia and major depressive disorders on psychiatrists' hypnotic medication prescribing behavior: a multicenter study.

BACKGROUND: To examine whether the "Effectiveness of Guideline for Dissemination and Education in psychiatric treatment (EGIUDE)" project affects the rate of prescriptions of hypnotic medication and the type of hypnotic medications prescribed among psychiatrists, for schizophrenia and major depressive disorder in Japan. METHODS: The EGUIDE project is a nationwide prospective study of evidence-based clinical guidelines for schizophrenia and major depressive disorder in Japan. From 2016 to 2021, clinical and prescribing data from patients discharged from hospitals participating in the EGUIDE project were used to examine hypnotic medication prescriptions The prescribing rate of hypnotics and the prescribing rate of each type of hypnotic (benzodiazepine receptor agonist, nonbenzodiazepine receptor agonist, melatonin receptor agonist, and orexin receptor antagonist) were compared among patients who had been prescribed medication by psychiatrists participating in the EGUIDE project and patients who had been prescribed medication by nonparticipating psychiatrists. Multivariate logistic regression analysis was performed to examine the effect of the EGUIDE project on the prescription of hypnotic medications. RESULTS: A total of 12,161 patients with schizophrenia and 6,167 patients with major depressive disorder were included. Psychiatrists participating in the EGUIDE project significantly reduced the rate of prescribing hypnotic medication and benzodiazepine receptor agonists for both schizophrenia (P < 0.001) and major depressive disorder (P < 0.001) patients. CONCLUSION: This is the first study to investigate the educational effects of guidelines for the treatment of psychiatric disorders on psychiatrists in terms of prescribing hypnotic medications to patients. The EGUIDE project may play an important role in reducing hypnotic medication prescription rates, particularly with respect to benzodiazepine receptor agonists. The results suggest that the EGUIDE project may result in improved therapeutic behavior.

Genetics of autism spectrum disorders and future direction.

Autism spectrum disorders (ASDs) have been increasing in prevalence. ASD is a complex human genetic disorder with high heredity and involves interactions between genes and the environment. A significant inheritance pattern in ASD involves a rare genetic mutation; common copy number variants refer to duplication or deletion of stretches of chromosomal loci or protein-disrupting single-nucleotide variants. Haploinsufficiency is one of the more common single-gene causes of ASD, explaining at least 0.5% of cases. Epigenetic mechanisms, such as DNA methylation, act at an interface of genetic and environmental risk and protective factors. Advances in genome-wide sequencing have broadened the view of the human methylome and have revealed the organization of the human genome into large-scale methylation domains with a footprint over neurologically important genes involved in embryonic development. Psychiatric disorders, including ASD, are expected to be diagnosed based on their genetically regulated pathophysiology and to be linked to their treatment.

Relationships Between Adherence to Guideline Recommendations for Pharmacological Therapy Among Clinicians and Psychotic Symptoms in Patients With Schizophrenia.

BACKGROUND: Clinician adherence to guideline recommendations in the pharmacological therapy of schizophrenia is important for favorable patient outcomes. To evaluate whether prescriptions followed the guidelines for pharmacological therapy of schizophrenia, we recently developed a summary indicator of multiple quality indicators: the individual fitness score (IFS). It is unclear whether adherence to the guidelines is related to patient outcomes. Here, we investigated correlations between the IFS values and psychotic symptoms in patients with schizophrenia. METHODS: We assessed whether patients' current prescriptions adhered to the guideline recommendations using the IFS in 47 patients with treatment-resistant schizophrenia (TRS) and 353 patients with non-TRS (total n = 400), respectively. We investigated correlations between the IFS and total scores and scores on the 5 subscales of the Positive and Negative Syndrome Scale (PANSS). Furthermore, we explored correlations between over 2-year longitudinal changes in IFS values and changes in psychotic symptoms in some patients (n = 77). RESULTS: We found significant negative correlation between the IFS and PANSS total score in all patients with schizophrenia (ß = -0.18, P = 9.80 × 10-5). The IFS was significantly and nominally negatively correlated with the PANSS total score in patients with non-TRS (Spearman's rho = -0.15, P = 4.40 × 10-3) and patients with TRS (rho = -0.37, P = .011), respectively. The IFS was also significantly and nominally negatively correlated with several factors, such as the negative and depressed factors, in patients with non-TRS and patients with TRS, respectively (P < .05). Furthermore, the change in IFS values was marginally negatively correlated with the changes in PANSS total scores and scores on the positive and depressed factors (P < .05). CONCLUSIONS: These findings suggest that efforts to improve clinician adherence to guideline recommendations for pharmacological therapy of schizophrenia, as assessed by the IFS, may lead to better outcomes in patients with schizophrenia.

Combination Psychotropic Use for Schizophrenia With Long-Acting Injectable Antipsychotics and Oral Antipsychotics: A Nationwide Real-World Study in Japan.

BACKGROUND: Although several guidelines recommend monotherapy with antipsychotics for the treatment of schizophrenia, patients who receive long-acting injectable antipsychotics (LAIs) are frequently treated with oral antipsychotics (OAPs). In the present study, we investigated the detailed use of psychotropic medications among patients throughout Japan with schizophrenia who received LAIs or OAPs. METHODS: The present study used data from the project for the Effectiveness of Guidelines for Dissemination and Education in psychiatric treatment from 94 facilities in Japan. The LAI group included patients who received any LAI, and the non-LAI group included patients who took only OAP medications at discharge. The participants of this study were 2518 schizophrenia patients (263 in the LAI group and 2255 in the non-LAI group) who received inpatient treatment and had prescription information at discharge between 2016 and 2020. RESULTS: This study revealed significantly higher rates of polypharmacy antipsychotics, number of antipsychotics, and chlorpromazine equivalents in the LAI group than in the non-LAI group. In contrast, the LAI group showed lower rate of concomitant use of hypnotic and/or antianxiety medication than the non-LAI group. CONCLUSIONS: Presenting these real-world clinical results, we want to encourage clinicians to keep monotherapy in mind for the treatment of schizophrenia, especially by reducing concomitant use of antipsychotics in the LAI group and reducing hypnotic and/or antianxiety medication in the non-LAI group.

Change of prescription for patients with schizophrenia or major depressive disorder during admission: real-world prescribing surveys from the effectiveness of guidelines for dissemination and education psychiatric treatment project.

BACKGROUND: Polypharmacy of additional psychotropics alongside the main treatment drug (antipsychotics in schizophrenia and antidepressants in major depressive disorder) is common in Japan. Our goal is to align psychotropic prescription in Japan with international standards, while reducing the differences between facilities. To achieve this goal, we aimed to compare prescriptions at the time of hospital admission and discharge. METHODS: Data on prescriptions at admission and discharge from 2016 to 2020 were collected. We divided the patients into four groups: (1) mono_mono group, monotherapy of the main drug at admission and discharge; (2) mono_poly group, monotherapy at admission and polypharmacy at discharge; (3) poly_poly group, polypharmacy at admission and discharge; and (4) poly_mono group, polypharmacy at admission and monotherapy at discharge. We compared the changes in dosage and number of psychotropics among the four groups. RESULTS: For both schizophrenia and major depressive disorder, the patients who received monotherapy with the main drug at admission were likely to receive main drug monotherapy at discharge and vice versa. For schizophrenia, the polypharmacy was prescribed more often in the mono_poly group than that in the mono_mono group. The prescription was not changed at all for more than 10% of the patients. CONCLUSIONS: It is critical to avoid a polypharmacy regimen to ensure that guideline-compliant treatment is provided. We expect higher rates of monotherapy with the main drug after the EGUIDE lectures. TRIAL REGISTRATION: The study protocol was registered in the University Hospital Medical Information Network Registry (UMIN000022645).

Discrimination in the clinical diagnosis between patients with schizophrenia and healthy controls using eye movement and cognitive functions.

AIM: Eye movements and cognitive functions are significantly impaired in patients with schizophrenia. The authors aimed to develop promising clinical diagnostic markers that fit practical digital health applications in psychiatry using eye movement and cognitive function data from 1254 healthy individuals and 336 patients with schizophrenia. METHODS: Multivariate analyses using logistic regression were performed to confirm net performance of eye movements and cognitive functions scored using the Wechsler Adult Intelligence Scale, Third Edition, and Wechsler Memory Scale-Revised. The authors then examined the discrimination performance of pairs containing an eye movement and a cognitive function measure to search the pairs that would be effective in practical application for the discrimination according to the diagnostic criterion between the groups. RESULTS: Multivariate analyses confirmed that eye movements and cognitive functions were effective modalities for discriminating between patients with schizophrenia and healthy controls. The discriminant analyses of the pairs demonstrated that seven eye movement measures and seven scores from cognitive function tests showed high discrimination performance when paired with one measure from the other modality. Moreover, seven pairs of digit-symbol coding or symbol-search and eye movement measures had high and robust discrimination performance. CONCLUSION: Seven pairs of an eye movement and a cognitive function measure were effective, robust, and less time-consuming in assisting with clinical diagnosis by categorizing healthy individuals or patients with schizophrenia. These findings may help develop an objective auxiliary diagnosis method working even on portable devices, which facilitates the consistency of diagnosis, earlier intervention, and shared decision-making.

Effects of electroconvulsive therapy on the use of anxiolytics and sleep medications: a propensity score-matched analysis.

AIM: We investigated the association of electroconvulsive therapy (ECT) with anxiolytic and sleep medication use in patients with major depressive disorder (MDD) and schizophrenia (SZ). METHODS: This nationwide observational study analyzed data from 3483 MDD inpatients and 6663 SZ inpatients. Patients with MDD and SZ were classified into those who underwent ECT during hospitalization and those who did not. A propensity score-matching method was performed to adjust for preadmission characteristics and clinical information, which were expected bias between the two groups. Rates of anxiolytic and sleep medication use at discharge were compared in the matched sample. RESULTS: 500 MDD patients were assigned to both groups. In the matched MDD sample, the rate of anxiolytic and sleep medication use at discharge was significantly lower in the ECT group than in the non-ECT group (64.9% vs. 75.8%, P = 1.7 × 10-4 ). In the ECT group, the rate of anxiolytic and sleep medication use at discharge was significantly lower than that prior to admission (64.9% vs. 73.2%, P = 1.2 × 10-14 ). 390 SZ patients were allocated. In the matched SZ sample, the ECT group was not significantly different from the non-ECT group in the rate of anxiolytics and sleep medications use at discharge (61.3% vs. 68.2%, P = 4.3 × 10-2 ). In the ECT group, the rate of anxiolytics and sleep medications use at discharge was significantly lower than that before admission (61.3% vs. 70.5%, P = 4.4 × 10-4 ), although this was not the primary outcome. CONCLUSION: Reduction of anxiolytic and sleep medication use may be considered positively when ECT is indicated for treatment of MDD.

Effect of education regarding treatment guidelines for schizophrenia and depression on the treatment behavior of psychiatrists: A multicenter study.

AIM: This study aims to examine the real-world effectiveness of education regarding clinical guidelines for psychiatric disorders using 'the Effectiveness of guidelines for dissemination and education in psychiatric treatment (EGUIDE)' project. METHODS: The EGUIDE project is a nationwide prospective implementation study of two clinical practice guidelines, i.e., the Guideline for Pharmacological Therapy of Schizophrenia and the Treatment Guidelines for Major Depressive Disorders, in Japan. Between 2016 and 2019, 782 psychiatrists belonging to 176 hospitals with psychiatric wards participated in the project and attended lectures on clinical practice guidelines. The proportions of guideline-recommended treatments in 7405 patients with schizophrenia and 3794 patients with major depressive disorder at participating hospitals were compared between patients under the care of psychiatrists participating in the project and those not participating in the project. Clinical and prescribing data on the patients discharged from April to September each year from participating hospitals of the project were also analyzed. RESULTS: The proportions of three quality indicators (antipsychotic monotherapy regardless of whether other psychotropics medication, antipsychotic monotherapy without other psychotropics and no prescription of anxiolytics or hypnotics) for schizophrenia were higher among participating psychiatrists than among nonparticipating psychiatrists. As similar results were obtained in major depressive disorder, the effectiveness of the project for the dissemination of guideline-recommended treatment has been replicated. CONCLUSION: This strategy of providing education regarding the clinical guidelines for psychiatric disorders was effective in improving the treatment-related behavior of psychiatrists. The use of this education-based strategy might contribute to resolving the mental health treatment gap.

Neuroimaging studies within Cognitive Genetics Collaborative Research Organization aiming to replicate and extend works of ENIGMA.

Reproducibility is one of the most important issues for generalizing the results of clinical research; however, low reproducibility in neuroimaging studies is well known. To overcome this problem, the Enhancing Neuroimaging Genetics through Meta-Analysis (ENIGMA) consortium, an international neuroimaging consortium, established standard protocols for imaging analysis and employs either meta- and mega-analyses of psychiatric disorders with large sample sizes. The Cognitive Genetics Collaborative Research Organization (COCORO) in Japan promotes neurobiological studies in psychiatry and has successfully replicated and extended works of ENIGMA especially for neuroimaging studies. For example, (a) the ENIGMA consortium showed subcortical regional volume alterations in patients with schizophrenia (n = 2,028) compared to controls (n = 2,540) across 15 cohorts using meta-analysis. COCORO replicated the volumetric changes in patients with schizophrenia (n = 884) compared to controls (n = 1,680) using the ENIGMA imaging analysis protocol and mega-analysis. Furthermore, a schizophrenia-specific leftward asymmetry for the pallidum volume was demonstrated; and (b) the ENIGMA consortium identified white matter microstructural alterations in patients with schizophrenia (n = 1,963) compared to controls (n = 2,359) across 29 cohorts. Using the ENIGMA protocol, a study from COCORO showed similar results in patients with schizophrenia (n = 696) compared to controls (n = 1,506) from 12 sites using mega-analysis. Moreover, the COCORO study found that schizophrenia, bipolar disorder (n = 211) and autism spectrum disorder (n = 126), but not major depressive disorder (n = 398), share similar white matter microstructural alterations, compared to controls. Further replication and harmonization of the ENIGMA consortium and COCORO will contribute to the generalization of their research findings.

Clozapine Treatment Is Associated With Higher Prescription Rate of Antipsychotic Monotherapy and Lower Prescription Rate of Other Concomitant Psychotropics: A Real-World Nationwide Study.

BACKGROUND: Although clozapine is effective for treatment-resistant schizophrenia (TRS), the rate of clozapine prescription is still low. Whereas antipsychotic monotherapy is recommended in clinical practice guidelines, the rate of antipsychotic polypharmacy is still high. There is little evidence on whether a clozapine prescription influences changes in the rate of monotherapy and polypharmacy, including antipsychotics and other psychotropics. We therefore hypothesized that the rate of antipsychotic monotherapy in patients with TRS who were prescribed clozapine would be higher than that in patients with schizophrenia who were not prescribed clozapine. METHODS: We assessed 8306 patients with schizophrenia nationwide from 178 institutions in Japan from 2016 to 2019. We analyzed the psychotropic prescription data at discharge in patients diagnosed with TRS and with no description of TRS (ND-TRS) based on the diagnosis listed in the discharge summary. RESULTS: The rate of antipsychotic monotherapy in the TRS with clozapine group (91.3%) was significantly higher than that in the TRS without clozapine group (45.9%; P < 2.0 × 10-16) and the ND-TRS without clozapine group (54.7%; P < 2.0 × 10-16). The rate of antipsychotic monotherapy without any other concomitant psychotropics in the TRS with clozapine group (26.5%) was significantly higher than that in the TRS without clozapine group (12.6%; P = 1.1 × 10-6) and the ND-TRS without clozapine group (17.0%; P = 5.9 × 10-6). CONCLUSIONS: Clozapine prescription could be associated with a high rate of antipsychotic monotherapy. Patients will benefit from the correct diagnosis of TRS and thus from proper clozapine prescription.

Trends in big data analyses by multicenter collaborative translational research in psychiatry.

The underlying pathologies of psychiatric disorders, which cause substantial personal and social losses, remain unknown, and their elucidation is an urgent issue. To clarify the core pathological mechanisms underlying psychiatric disorders, in addition to laboratory-based research that incorporates the latest findings, it is necessary to conduct large-sample-size research and verify reproducibility. For this purpose, it is critical to conduct multicenter collaborative research across various fields, such as psychiatry, neuroscience, molecular biology, genomics, neuroimaging, cognitive science, neurophysiology, psychology, and pharmacology. Moreover, collaborative research plays an important role in the development of young researchers. In this respect, the Enhancing Neuroimaging Genetics through Meta-Analysis (ENIGMA) consortium and Cognitive Genetics Collaborative Research Organization (COCORO) have played important roles. In this review, we first overview the importance of multicenter collaborative research and our target psychiatric disorders. Then, we introduce research findings on the pathophysiology of psychiatric disorders from neurocognitive, neurophysiological, neuroimaging, genetic, and basic neuroscience perspectives, focusing mainly on the findings obtained by COCORO. It is our hope that multicenter collaborative research will contribute to the elucidation of the pathological basis of psychiatric disorders.

The characteristics of discharge prescriptions including pro re nata psychotropic medications for patients with schizophrenia and major depressive disorder from the survey of the "Effectiveness of guidelines for dissemination and education in psychiatric treatment (EGUIDE)" project.

BACKGROUND: Several guidelines recommend monotherapy in pharmacotherapy for schizophrenia and major depressive disorder. The content of regular prescriptions has been reported in several studies, but not enough research has been conducted on the content of pharmacotherapy, including pro re nata (PRN) medications. The purpose of this study was to evaluate the content of pharmacotherapy, including PRN medications, and to clarify the relationship with regular prescriptions. METHODS: We used data from the "Effectiveness of Guidelines for Dissemination And Education in psychiatric treatment" (EGUIDE) project to investigate the presence or absence of PRN psychotropic medications at discharge for each drug category. We compared the PRN psychotropic prescription ratio at discharge by diagnosis for each drug category. The antipsychotic monotherapy ratio and no prescription ratio of other psychotropics for schizophrenia at discharge and the antidepressant monotherapy ratio and no prescription ratio of other psychotropics for major depressive disorder at discharge were calculated for each regular prescription, including PRN psychotropic medications, as quality indicators (QIs). Spearman's rank correlation test was performed for QI values of regular prescriptions and the QI ratio between regular prescriptions and prescriptions including PRN medications for each diagnosis. RESULTS: The PRN psychotropic prescription ratio at discharge was 28.7% for schizophrenia and 30.4% for major depressive disorder, with no significant differences by diagnosis. The prescription ratios of PRN antipsychotic medications and PRN antiparkinsonian medications were significantly higher for schizophrenia. The prescription ratios of PRN anxiolytic and hypnotic and PRN antidepressant medications were significantly higher for patients with major depressive disorder. For both schizophrenia and major depressive disorder, the QI was lower for discharge prescriptions, including PRN medications, than for regular prescriptions. QI values for regular prescriptions and the QI ratio were positively correlated. CONCLUSIONS: Considering PRN psychotropic medications, the monotherapy ratio and no prescription ratio of other psychotropics at discharge decreased in pharmacotherapy for schizophrenia and major depressive disorder. A higher ratio of monotherapy and no prescription of other psychotropics on regular prescriptions may result in less concomitant use of PRN psychotropic medications. Further studies are needed to optimize PRN psychotropic prescriptions.

Macaque monkeys show reversed ocular following responses to two-frame-motion stimulus presented with inter-stimulus intervals.

When two-frame apparent motion stimuli are presented with an appropriate inter-stimulus interval (ISI), motion is perceived in the direction opposite to the actual image shift. Herein, we measured a simple eye movement, ocular following responses (OFRs), in macaque monkeys to examine the ISI reversal effect on oculomotor. Two-frame movies with an ISI induced reversed OFRs. Without ISI, the OFRs to the two-frame movie were induced in the direction of the stimulus shift. However, with ISIs ≥10 ms, OFRs in the direction opposite to the phase shift were observed. This directional reversal persisted for ISIs up to 160 ms; for longer ISIs virtually no ocular response was observed. Furthermore, longer exposure to the initial image (Motion onset delay: MOD) reduced OFRs. We show that these dependences on ISIs/MODs can be explained by the motion energy model. Furthermore, we examined the dependence on ISI reversal using various spatial frequencies. To account for our findings, the optimal frequency of the temporal filters of the energy model must decrease between 0.5 and 1 cycles/°, suggesting that there are at least two channels with different temporal characteristics. These results are consistent with those from humans, suggesting that the temporal filters embedded in human and macaque visual systems are similar. Thus, the macaque monkey is a good animal model for the early visual processing of humans to understand the neural substrates underlying the visual motion detectors that elicit OFRs.

Evidence for Altered Phosphoinositide Signaling-Associated Molecules in the Postmortem Prefrontal Cortex of Patients with Schizophrenia.

Phosphoinositides (PIs) play important roles in the structure and function of the brain. Associations between PIs and the pathophysiology of schizophrenia have been studied. However, the significance of the PI metabolic pathway in the pathology of schizophrenia is unknown. We examined the expression of PI signaling-associated proteins in the postmortem brain of schizophrenia patients. Protein expression levels of phosphatidylinositol 4-phosphate 5-kinase type-1 gamma (PIP5K1C), phosphatidylinositol 4-kinase alpha (PIK4CA, also known as PIK4A), phosphatase and tensin homolog deleted from chromosome 10 (PTEN), protein kinase B (Akt), and glycogen synthase kinase 3ß (GSK3ß) were measured using enzyme-linked immunosorbent assays and multiplex fluorescent bead-based immunoassays of the prefrontal cortex (PFC) of postmortem samples from 23 schizophrenia patients and 47 normal controls. We also examined the association between PIK4CA expression and its genetic variants in the same brain samples. PIK4CA expression was lower, whereas Akt expression was higher, in the PFC of schizophrenia patients than in that of controls; PIP5K1C, PTEN, and GSK3ß expression was not different. No single-nucleotide polymorphism significantly affected protein expression. We identified molecules involved in the pathology of schizophrenia via this lipid metabolic pathway. These results suggest that PIK4CA is involved in the mechanism underlying the pathogenesis of schizophrenia and is a potential novel therapeutic target.

Does Treatment Response With Antidementia Drugs After 6 Months in Alzheimer's Disease Predict Long-term Treatment Outcome?

BACKGROUND: Alzheimer's disease (AD) is a chronic, progressive disorder that causes declines in cognitive and physical functions. This condition places severe burdens on families and caregivers. Delaying progressive declines in cognitive function and reducing their burden are thus important. Relationships between early treatment response and subsequent outcomes of schizophrenia and major depressive disorder have been reported. We thus aimed to investigate the relationships between treatment response to antidementia drugs in AD after 6 months (M) and subsequent outcomes. METHODS: Eligible individuals comprised 194 patients diagnosed with presumed AD. Of these, 110 patients who received antidementia drugs for the first time and were assessed using the Mini-Mental State Examination (MMSE) at 6 M, 12 M, and 24 M were categorized as responders (n = 84) or nonresponders (n = 26). Responders were defined as showing a change in MMSE after 6 M the same as or lower than that in the natural course according to previously reported data. RESULTS: No significant differences in baseline characteristics (age, sex, education, or comorbidities) were seen between groups. Mean MMSE score at baseline was significantly lower in responders (18.0) than in nonresponders (20.7; P = 0.008). Mean change from baseline MMSE was significantly smaller in responders than in nonresponders at both 12 M (-0.46 vs -2.5; P = 0.04) and 24 M (-0.78 vs -4.4; P = 0.001). CONCLUSIONS: Treatment response with antidementia drugs after 6 M predicted better outcomes at 12 M and 24 M. Treatment response should be assessed every 6 M, and treatment should be reconsidered accordingly.

Minimal amount of tissue-based pH measurement to improve quality control in neuropsychiatric post-mortem brain studies.

AIM: Tissue pH and RNA integrity are crucial quality-control indicators of human post-mortem brain tissues in the identification of the pathogeneses of neuropsychiatric disorders, but pH has not been measured as often due to limitations in the amount of tissue available. This study was designed to develop and validate a protocol for tissue pH evaluation using a minimal amount of human post-mortem tissues. METHODS: A procedure that included a proper ratio of brain tissue weight to water for homogenization and the duration of homogenization was designed based on preliminary experiments using mouse brain tissues. The minimal (10 mg) and typical (100 mg) amounts of post-mortem brain tissue from 52 subjects were homogenized in 5 volumes (50 µL/10 mg tissue) and 10 volumes (1000 µL/100 mg tissue) of nuclease-free water and subjected to pH measurements using an InLab Ultra micro pH electrode. RESULTS: The pH values based on the new protocol using a minimal amount of tissue significantly correlated with measurements of the standard protocol (r2 = 0.86). The correlation coefficients of the pH values between gray and white matter of the same brain region, and the values between different brain regions were 0.73 and 0.54, respectively. CONCLUSION: The proposed protocol used one-tenth of the tissue amount of current standard protocol and enabled us to evaluate the exact quality of post-mortem brain tissue subjected to subsequent analyses. The application of this protocol may improve the detection of biological phenomena of interest in post-mortem brain studies by diminishing confounding factors.