Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Psychiatry and Clinical Neurosciences  

Aims: Schizophrenia (SZ) is associated with abnormalities in both spontaneous and task-evoked neural oscillations, and growing evidence shows that shift patterns of oscillatory activity between resting and task states are also disturbed. However, no study has simultaneously examined the frequency- and state-specific characteristics of oscillatory deficits in SZ. Using an auditory steady-state response (ASSR) paradigm, we aimed to examine the differential sensitivity of oscillatory measures to SZ and to assess rest–task shifts across multiple frequency bands. Methods: We recorded resting-state activity and 40 Hz ASSR of 66 neurotypical controls (NC) and 68 SZ patients using electroencephalography (EEG). 40 Hz stimulus-evoked activity was measured using evoked power, phase-locking factor (PLF), and phase-locking angle, whereas multi-frequency (4–100 Hz) spontaneous activity during ASSR and resting states was assessed using induced and resting power. The state-dependent shifts in spontaneous activity between the resting and ASSR states were evaluated over a broad frequency range. Results: Both induced and resting power in the low-frequency range (4–10 Hz) were elevated over widespread regions in SZ patients relative to NC. Gamma-band (39–100 Hz) induced power then demonstrated excellent ability to discriminate between SZ and NC. In addition, SZ patients showed a reduced rest–task shift in the theta-beta band (5–23 Hz) spontaneous power, most pronounced in the alpha-band (8–13 Hz). Conclusion: The present study confirmed the utility of gamma-band induced power during ASSR stimulation for differentiating SZ patients from NC. Importantly, our results also highlight the pathophysiological significance of the reduced rest–task shift pattern of spontaneous activity mainly in the alpha-band in SZ patients.

DOI： 10.1111/pcn.13880

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Asian Journal of Psychiatry  

DOI： 10.1016/j.ajp.2026.104890

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Molecular Psychiatry  

Background: The 40-Hz auditory steady-state response (ASSR) is a potential biomarker for schizophrenia (SZ), bipolar disorder (BD), and autism spectrum disorder (ASD). However, the specific differences in ASSR across these disorders remain unclear. Moreover, the neurophysiological characteristics of the stimulation frequency in ASSR have not been fully elucidated. Hence, we conducted meta-analyses to comprehensively analyze 20-Hz, 40-Hz, and 80-Hz ASSR in individuals with SZ, BD, and ASD. Methods: We included the studies published until January 2025, identified through a literature search in PubMed and the reference lists of relevant studies. We analyzed 52 studies, including 2116 patients with SZ, 271 individuals at clinical high-risk for psychosis (CHR-P), 110 first-degree relatives of patients with SZ (FDR-SZ), 294 patients with BD, 117 patients with ASD, and 2758 healthy controls (HC). Results: The analyses indicated pronounced reductions in power and inter-trial phase coherence (ITPC) of 40-Hz ASSR in SZ, BD, and power reduction in ASD compared with HC. In addition, reduced power and ITPC were also observed in 40-Hz ASSR in FDR-SZ but not in CHR-P. Power reductions in 80-Hz ASSR were noted in individuals with SZ, while ITPC of 20-Hz ASSR was reduced in the SZ group but not in the BD group. Conclusions: These findings indicate that 40-Hz ASSR serves as a potential biomarker for psychotic disorders, whereas deficits at 20 Hz and 80 Hz may be specific to schizophrenia, reflecting distinct neural dysfunctions across diagnostic categories. Further studies are warranted to confirm these results.

DOI： 10.1038/s41380-026-03452-3

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Seizure  

DOI： 10.1016/j.seizure.2025.09.007

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Frontiers in Neural Circuits  

An accurate diagnostic method using biological indicators is critically needed for bipolar disorder (BD) and major depressive disorder (MDD). The excitatory glutamate α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) is a crucial regulator of synaptic function, and its dysregulation may play a central role in the pathophysiology of psychiatric disorders. Our recently developed positron emission tomography (PET) tracer, [¹¹C]K-2, enables the quantitative visualization of AMPAR distribution and is considered useful for characterizing synaptic phenotypes in patients with psychiatric disorders. This study aimed to develop a machine learning-based method to differentiate bipolar disorder from major depressive disorder using AMPAR density. Sixteen patients with BD and 27 patients with MDD, all in depressive episodes, underwent PET scans with [¹¹C]K-2 and structural magnetic resonance imaging. AMPAR density was estimated using the standardized uptake value ratio from 30 to 50 min after tracer injection, normalized to whole brain radioactivity. A partial least squares model was trained to predict diagnoses based on AMPAR density, and its performance was evaluated using a leave-one-pair-out cross-validation. Significant differences in AMPAR density were observed in the parietal lobe, cerebellum, and frontal lobe, notably the dorsolateral prefrontal cortex between patients with BD and patients with MDD during a depressive episode. The model achieved an area under the curve of 0.80, sensitivity of 75.0%, and specificity of 77.8%. These findings suggest that AMPAR density measured with [¹¹C]K-2 can effectively distinguish BD from MDD and may aid diagnosis, especially in patients with ambiguous symptoms or incomplete clinical presentation.

DOI： 10.3389/fncir.2025.1624179

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Language：Japanese  

Language：Japanese  

Language：Japanese  

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Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)   Publisher：九州精神神経学会  

Authorship：Lead author   Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：日本生物学的精神医学会  

統合失調症をはじめとした精神疾患では病態解明や介入手段の確立をめざして,各領域でさまざまなアプローチが試みられてきた。神経生理学研究においても数多くの指標に着目した報告があるが,なかでも神経振動は特に有望なバイオマーカーの候補と目されている。神経振動は脳内における興奮性と抑制性の伝達物質のバランスを基盤として,脳内情報伝達を担うリズミカルな皮質電気活動であり,統合失調症においても聴覚定常反応課題をはじめとして一貫性のある異常所見が得られている。また,ベースラインの自発振動と課題刺激で賦活された振動との間で十分な切り替えがなされないことも,計算論的神経科学の観点から説明が可能な統合失調症の特徴として指摘されている。神経振動は基礎と臨床を繋ぐトランスレーショナル・リサーチを可能にするだけでなく,今後は大規模データ解析によってもますます発展が見込まれている。(著者抄録)