Diverse tau pathologies in late-life mood disorders revealed by PET and autopsy assays.

Introduction: Late-life mood disorders (LLMDs) may represent prodromal manifestations of neurodegenerative dementia; however, the neuropathological basis of LLMDs, including depression and bipolar disorder, remains unclear. We aimed to investigate the involvement of Alzheimer's disease (AD) and non-AD tau pathologies in LLMD participants.

Methods: Fifty-two LLMD participants and 47 age- and sex-matched healthy controls (HCs) underwent tau and amyloid beta (Aβ) positron emission tomography (PET) imaging using F-florzolotau and C-Pittsburgh compound B.

Diffusion Tensor Image Analysis Along the Perivascular Space in Former Professional Athletes with Repetitive Mild Traumatic Brain Injury History.

Rationale And Objectives: The long-term changes in the glymphatic system of former professional athletes exposed to repetitive mild traumatic brain injuries remain poorly understood. This study aimed to use diffusion tensor image analysis along the perivascular space (DTI-ALPS) to evaluate the glymphatic system activity and correlate the ALPS index with neuropsychiatric symptoms in former professional athletes.

Materials And Methods: 30 former professional athletes and 24 age- and sex-matched controls underwent DTI with 3 T magnetic resonance imaging, and neuropsychiatric tests were performed in the athlete group.

-Linked Parkinson Syndrome in Female Heterozygotes Is Associated With PET-Detectable Tau Pathology.

Background And Objectives: A previous postmortem study of men with Christianson syndrome, a disorder caused by loss-of-function mutations in the gene , reported a mechanistic link between pathologic tau accumulation and progressive symptoms such as cerebellar atrophy and cognitive decline. This study aimed to characterize the relationships between neuropathologic manifestations and tau accumulation in heterozygous women with mutation.

Methods: We conducted a multimodal neuroimaging and plasma biomarker study on 3 middle-aged heterozygous women with mutations (proband 1: mid-50s; proband 2: early 50s; proband 3: mid-40s) presenting with progressive extrapyramidal symptoms.

Alterations of striatal phosphodiesterase 10 A and their association with recurrence rate in bipolar I disorder.

Phosphodiesterase 10 A (PDE10A), a pivotal element of the second messenger signaling downstream of the dopamine receptor stimulation, is conceived to be crucially involved in the mood instability of bipolar I disorder (BD-I) as a primary causal factor or in response to dysregulated dopaminergic tone. We aimed to determine whether striatal PDE10A availability is altered in patients with BD-I and assessed its relationship with the clinical characteristics of BD-I. This case-control study used positron emission tomography (PET) with 2-(2-(3-(4-(2-[F]fluoroethoxy)phenyl)-7-methyl-4-oxo-3,4-dihydroquinazolin-2-yl)ethyl)-4-isopropoxyisoindoline-1,3-dione ([F]MNI-659), a radioligand that binds to PDE10A, to examine the alterations of the striatal PDE10A availability in the living brains of individuals with BD-I and their association with the clinical characteristics of BD-I.

Optimisation of pharmacotherapy in psychiatry through therapeutic drug monitoring, molecular brain imaging and pharmacogenetic tests: Focus on antipsychotics.

Background: For psychotic disorders (i.e. schizophrenia), pharmacotherapy plays a key role in controlling acute and long-term symptoms.

Performance of plasma Aβ42/40, measured using a fully automated immunoassay, across a broad patient population in identifying amyloid status.

Background: Plasma biomarkers have emerged as promising screening tools for Alzheimer's disease (AD) because of their potential to detect amyloid β (Aβ) accumulation in the brain. One such candidate is the plasma Aβ42/40 ratio (Aβ42/40). Unlike previous research that used traditional immunoassay, recent studies that measured plasma Aβ42/40 using fully automated platforms reported promising results.

Astrogliosis marker 11C-SL25.1188 PET in traumatic brain injury with persistent symptoms.

Traumatic brain injury (TBI) is common but little is known why up to a third of patients have persisting symptoms. Astrogliosis, a pathophysiological response to brain injury, may be a potential therapeutic target, but demonstration of astrogliosis in the brain of humans with TBI and persistent symptoms is lacking. Astroglial marker monoamine oxidase B (MAO-B) total distribution volume (11C-SL25.

Association of protein distribution and gene expression revealed by positron emission tomography and postmortem gene expression in the dopaminergic system of the human brain.

Purpose: The topological distribution of dopamine-related proteins is determined by gene transcription and subsequent regulations. Recent research strategies integrating positron emission tomography with a transcriptome atlas have opened new opportunities to understand the influence of regulation after transcription on protein distribution. Previous studies have reported that messenger (m)-RNA expression levels spatially correlate with the density maps of serotonin receptors but not with those of transporters.

Serotonergic Neurotransmission in Limbic Regions May Reflect Therapeutic Response of Depressive Patients: A PET Study With 11C-WAY-100635 and 18F-MPPF.

Background: Central serotonin (5-hydroxytryptamine [5-HT]) neurotransmission has been implicated in the etiology of depression. Most antidepressants ameliorate depressive symptoms by increasing 5-HT at synaptic clefts, but their effect on 5-HT receptors has yet to be clarified. 11C-WAY-100635 and 18F-MPPF are positron emission tomography (PET) radioligands for 5-HT1A receptors.

Glutamatergic Neurometabolite Levels in Bipolar Disorder: A Systematic Review and Meta-analysis of Proton Magnetic Resonance Spectroscopy Studies.

Background: The glutamatergic system is thought to play an important role in the pathophysiology of bipolar disorder (BD). While there has been an increase in proton magnetic resonance spectroscopy studies examining this neurotransmission system, the results are inconsistent. Possible reasons for the inconsistency, including clinical features such as mood state and childhood versus adulthood age, were not addressed in previous meta-analyses.

Findings of F-PI-2620 tau PET imaging in patients with Alzheimer's disease and healthy controls in relation to the plasma P-tau181 levels in a Japanese sample.

Background: Alzheimer's disease (AD) is the most common cause of dementia worldwide. In AD, abnormal tau accumulates within neurons of the brain, facilitated by extracellular β-amyloid deposition, leading to neurodegeneration, and eventually, cognitive impairment. As this process is thought to be irreversible, early identification of abnormal tau in the brain is crucial for the development of new therapeutic interventions.

Publication Rate in English of Abstracts Presented at the Annual Meeting of the Japanese Society of Psychiatry and Neurology.

Background: Relatively low publication rates of abstracts presented at scientific meetings (i.e., 37.

Glutamatergic and GABAergic metabolite levels in schizophrenia-spectrum disorders: a meta-analysis of H-magnetic resonance spectroscopy studies.

Background: The glutamate (Glu) and gamma aminobutyric acid (GABA) hypotheses of schizophrenia were proposed in the 1980s. However, current findings on those metabolite levels in schizophrenia have been inconsistent, and the relationship between their abnormalities and the pathophysiology of schizophrenia remains unclear. To summarize the nature of the alterations of glutamatergic and GABAergic systems in schizophrenia, we conducted meta-analyses of proton magnetic resonance spectroscopy (H-MRS) studies examining these metabolite levels.

Dynamic alterations in the central glutamatergic status following food and glucose intake: multimodal assessments in humans and animal models.

Fluctuations of neuronal activities in the brain may underlie relatively slow components of neurofunctional alterations, which can be modulated by food intake and related systemic metabolic statuses. Glutamatergic neurotransmission plays a major role in the regulation of excitatory tones in the central nervous system, although just how dietary elements contribute to the tuning of this system remains elusive. Here, we provide the first demonstration by bimodal positron emission tomography (PET) and magnetic resonance spectroscopy (MRS) that metabotropic glutamate receptor subtype 5 (mGluR5) ligand binding and glutamate levels in human brains are dynamically altered in a manner dependent on food intake and consequent changes in plasma glucose levels.

Treatment effects on neurometabolite levels in schizophrenia: A meta-analysis dataset of proton magnetic resonance spectroscopy.

This article describes a dataset for a meta-analysis that aimed to investigate the effects of treatment on the neurometabolite status in patients with schizophrenia (DOI of original article: https://doi.org/10.1016/j.

Excess tau PET ligand retention in elderly patients with major depressive disorder.

Depression is one of the common psychiatric disorders in old age. Major depressive disorder (MDD) has been identified as a risk factor or prodrome for neurodegenerative dementias, suggesting neuropathological overlaps and a continuum between MDD and neurodegenerative disorders. In this study, we examined tau and amyloid-β (Aβ) accumulations in the brains of MDD and healthy controls using positron emission tomography (PET) to explore pathological substrates of this illness.

Treatment effects on neurometabolite levels in schizophrenia: A systematic review and meta-analysis of proton magnetic resonance spectroscopy studies.

Background: Although there is growing evidence of alterations in the neurometabolite status associated with the pathophysiology of schizophrenia, how treatments influence these metabolite levels in patients with schizophrenia remains poorly studied.

Methods: We conducted a literature search using Embase, Medline, and PsycINFO to identify proton magnetic resonance spectroscopy studies that compared neurometabolite levels before and after treatment in patients with schizophrenia. Six neurometabolites (glutamate, glutamine, glutamate + glutamine, gamma-aminobutyric acid, N-acetylaspartate, myo-inositol) and six regions of interest (frontal cortex, temporal cortex, parieto-occipital cortex, thalamus, basal ganglia, hippocampus) were investigated.

Primary functional brain connections associated with melancholic major depressive disorder and modulation by antidepressants.

The limited efficacy of available antidepressant therapies may be due to how they affect the underlying brain network. The purpose of this study was to develop a melancholic MDD biomarker to identify critically important functional connections (FCs), and explore their association to treatments. Resting state fMRI data of 130 individuals (65 melancholic major depressive disorder (MDD) patients, 65 healthy controls) were included to build a melancholic MDD classifier, and 10 FCs were selected by our sparse machine learning algorithm.

PET-detectable tau pathology correlates with long-term neuropsychiatric outcomes in patients with traumatic brain injury.

Tau deposits is a core feature of neurodegenerative disorder following traumatic brain injury (TBI). Despite ample evidence from post-mortem studies demonstrating exposure to both mild-repetitive and severe TBIs are linked to tau depositions, associations of topology of tau lesions with late-onset psychiatric symptoms due to TBI have not been explored. To address this issue, we assessed tau deposits in long-term survivors of TBI by PET with 11C-PBB3, and evaluated those associations with late-life neuropsychiatric outcomes.