Publications by authors named "Shuji Iritani"

Article Synopsis
  • - The study investigates the link between rare copy number variations (CNVs) in synaptic genes and bipolar disorder (BD) in a Japanese population, using genome hybridization techniques on nearly 2,000 BD patients and 2,760 controls.
  • - Results indicate a strong association between the RNF216 gene and BD, with significant findings also related to postsynaptic membrane components, suggesting these genetic factors contribute to BD risk.
  • - The findings enhance understanding of BD's genetic underpinnings, highlighting the importance of CNVs in gene regions that may influence the disorder's development.
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  • The study investigates why older patients with schizophrenia might be prone to developing dementia, despite previous findings suggesting their Alzheimer's disease risk is similar to those without schizophrenia.
  • It involved an examination of 32 brains from older schizophrenia patients to analyze dementia-related neuropathologies and compare clinicopathological differences between those with and without dementia.
  • The results revealed two subgroups of dementia in these patients: those with known neurodegenerative diseases and those without identifiable pathology, indicating a need for more thorough research on this issue.
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Human mentality develops with age and is altered in psychiatric disorders, though their underlying mechanism is unknown. In this study, we analyzed nanometer-scale three-dimensional structures of brain tissues of the anterior cingulate cortex from eight schizophrenia and eight control cases. The distribution profiles of neurite curvature of the control cases showed a trend depending on their age, resulting in an age-correlated decrease in the standard deviation of neurite curvature (Pearson's r = -0.

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Article Synopsis
  • The study investigates the differences and similarities in copy number variations (CNVs) related to bipolar disorder (BD), schizophrenia (SCZ), and autism spectrum disorder (ASD) using data from 8708 Japanese individuals.
  • It reveals that BD has a greater burden of smaller exonic deletions, while SCZ and ASD show a prevalence of larger exonic CNVs, with notable differences in the effect sizes and distributions of these CNVs across disorders.
  • Despite these differences, some shared molecular mechanisms, particularly in chromatin biology, were identified, and certain synaptic genes were linked to BD risk, suggesting potential pathways for further research into its causes.
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Objectives: Recent neuroimaging studies have indicated that the mesolimbic pathway, known to work as reward neuronal circuitry, regulates cognitive-behavioral flexibility in prolonged anorexia nervosa (AN). Although AN is associated with the highest mortality rate among psychiatric disorders, there have been few neuropathological studies on this topic. This study aims to identify alterations of the reward circuitry regions, especially in the nucleus accumbens (NAcc), using AN brain tissues.

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Piccolo, a presynaptic cytomatrix protein, plays a role in synaptic vesicle trafficking in the presynaptic active zone. Certain single-nucleotide polymorphisms of the Piccolo-encoding gene are reported to be associated with mental disorders. However, a few studies have evaluated the relationship between Piccolo dysfunction and psychotic symptoms.

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Brain blood vessels constitute a micrometer-scale vascular network responsible for supply of oxygen and nutrition. In this study, we analyzed cerebral tissues of the anterior cingulate cortex and superior temporal gyrus of schizophrenia cases and age/gender-matched controls by using synchrotron radiation microtomography or micro-CT in order to examine the three-dimensional structure of cerebral vessels. Over 1 m of cerebral blood vessels was traced to build Cartesian-coordinate models, which were then used for calculating structural parameters including the diameter and curvature of the vessels.

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Anorexia nervosa (AN) is a serious eating disorder characterized by self-starvation and extreme weight loss. It has the highest mortality rate among all psychiatric disorders. Recent research indicates that malnutrition in AN patients induces various kinds of functional brain damage, but the pathophysiology of AN remains unclear.

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Globular glial tauopathy (GGT) is a recently proposed tauopathy characterized by the globular accumulation of four-repeat (4R) tau in the oligodendroglia (globular oligodendroglial inclusion (GOI)) and astrocytes (globular astrocytic inclusion (GAI)), in addition to deposition in neurons. Although it is proposed that GGT should be classified into three different neuropathological subtypes, previous reports have indicated that subclassification might be difficult in some cases. We report an autopy case of a 79-year-old man with behavioral variant frontotemporal dementia (bvFTD).

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Article Synopsis
  • - The study analyzes brain tissues from the superior temporal gyrus in schizophrenia and control cases, revealing significant differences in neuron structures across different brain areas.
  • - It finds that the structural dissimilarity of neurons varies among individuals, particularly noting that neurite curvature and diameter are inversely related.
  • - Schizophrenia cases exhibit a thinner and more complex neuronal network compared to controls, suggesting a link between neuron structure and the disorder, highlighting the individuality of brain functions.
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  • The study explores the relationship between long-term schizophrenia and dementia symptoms, noting that while schizophrenia patients are at a higher risk for dementia, the prevalence of Alzheimer's appears similar to that of non-afflicted individuals.
  • Researchers conducted a neuropathological assessment on three schizophrenia cases that exhibited cognitive decline after prolonged illness, using various staining techniques to evaluate brain tissues.
  • Results indicated no significant pathological findings in the patients, suggesting that cognitive decline may stem from a combination of preclinical neurodegeneration and inherent vulnerabilities linked to schizophrenia, rather than clear neurodegenerative diseases.
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Article Synopsis
  • * It's noted that while cognitive decline can be an intrinsic symptom of schizophrenia in later life, complications like dementia are not well understood and require further examination.
  • * The findings emphasize the need for awareness that schizophrenic patients can also develop neurodegenerative diseases, indicating a potential dual diagnosis and the necessity for more research on the relationship between schizophrenia and dementia.
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Kraepelin expected that the neuropathological hallmark of schizophrenia would be identified when he proposed the concept of dementia praecox 120 years ago. Although a variety of neuropathological findings have been reported since then, a consensus regarding the pathology of schizophrenia has not been established. The discrepancies have mainly been ascribed to limitations in the disease definition of schizophrenia that accompanies etiological heterogeneity and to the incompleteness of the visualization methodology and technology for biochemical analyses.

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Huntington's disease (HD) is an autosomal-dominant neurodegenerative disorder characterized by the presence of chorea, psychiatric symptoms, and dementia. Although motor symptoms are thought to be correlated with the degeneration of the striatum, there is little information regarding the neuropathological basis of psychiatric symptoms. The ventral part of the striatum is known as the nucleus accumbens (Acb) and is a region of interest as a responsible focus of psychiatric symptoms.

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