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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. The brain-wide modulations of central mGluR5 ligand binding and glutamate levels and profound neuronal activations following systemic glucose administration were further proven by PET, MRS, and intravital two-photon microscopy, respectively, in living rodents. The present findings consistently support the notion that food-associated glucose intake is mechanistically linked to glutamatergic tones in the brain, which are translationally accessible in vivo by bimodal PET and MRS measurements in both clinical and non-clinical settings.

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. The brain-wide modulations of central mGluR5 ligand binding and glutamate levels and profound neuronal activations following systemic glucose administration were further proven by PET, MRS, and intravital two-photon microscopy, respectively, in living rodents. The present findings consistently support the notion that food-associated glucose intake is mechanistically linked to glutamatergic tones in the brain, which are translationally accessible in vivo by bimodal PET and MRS measurements in both clinical and non-clinical settings.

Although striatal dopamine neurotransmission is believed to be functionally linked to the formation of the corticostriatal network, there has been little evidence for this regulatory process in the human brain and its disruptions in neuropsychiatric disorders. Here, we aimed to investigate associations of striatal dopamine transporter (DAT) and D2 receptor availabilities with gray matter (GM) volumes in healthy humans. Positron emission tomography images of D2 receptor (n = 34) and DAT (n = 17) captured with the specific radioligands [11C]raclopride and [18F]FE‐PE2I, respectively, were acquired along with T1‐weighted magnetic resonance imaging data in our previous studies, and were re‐analyzed in this work. We quantified the binding potentials (BP ND) of these radioligands in the limbic, executive, and sensorimotor functional subregions of the striatum. Correlations between the radioligand BP ND and regional GM volume were then examined by voxel‐based morphometry. In line with the functional and anatomical connectivity, [11C]raclopride BP ND in the limbic striatum was positively correlated with volumes of the uncal/parahippocampal gyrus and adjacent temporal areas. Similarly, we found positive correlations between the BP ND of this radioligand in the executive striatum and volumes of the prefrontal cortices and their adjacent areas as well as between the BP ND in the sensorimotor striatum and volumes of the somatosensory and supplementary motor areas. By contrast, no significant correlation was found between [18F]FE‐PE2I BP ND and regional GM volumes. Our results suggest unique structural and functional corticostriatal associations involving D2 receptor in healthy humans, which might be partially independent of the nigrostriatal pathway reflected by striatal DAT., This is the first study to investigate the relationship between regional gray matter volumes and availabilities of both dopamine D2 receptor and transporter in the striatum of healthy adults, by using our previous magnetic resonance imaging and positron emission tomography datasets. We have demonstrated positive correlations between dopamine D2/3 receptor radioligand BP ND in the functional subregions of the striatum and the gray matter (GM) volumes of regions that could be functionally and anatomically connected to each of these striatal subdomains. Meanwhile, no marked correlations were observed between dopamine transporter radioligand BP ND and regional GM volumes.

Although striatal dopamine neurotransmission is believed to be functionally linked to the formation of the corticostriatal network, there has been little evidence for this regulatory process in the human brain and its disruptions in neuropsychiatric disorders. Here, we aimed to investigate associations of striatal dopamine transporter (DAT) and D2 receptor availabilities with gray matter (GM) volumes in healthy humans. Positron emission tomography images of D2 receptor (n = 34) and DAT (n = 17) captured with the specific radioligands [11C]raclopride and [18F]FE-PE2I, respectively, were acquired along with T1-weighted magnetic resonance imaging data in our previous studies, and were re-analyzed in this work. We quantified the binding potentials (BPND) of these radioligands in the limbic, executive, and sensorimotor functional subregions of the striatum. Correlations between the radioligand BPND and regional GM volume were then examined by voxel-based morphometry. In line with the functional and anatomical connectivity, [11C]raclopride BPND in the limbic striatum was positively correlated with volumes of the uncal/parahippocampal gyrus and adjacent temporal areas. Similarly, we found positive correlations between the BPND of this radioligand in the executive striatum and volumes of the prefrontal cortices and their adjacent areas as well as between the BPND in the sensorimotor striatum and volumes of the somatosensory and supplementary motor areas. By contrast, no significant correlation was found between [18F]FE-PE2I BPND and regional GM volumes. Our results suggest unique structural and functional corticostriatal associations involving D2 receptor in healthy humans, which might be partially independent of the nigrostriatal pathway reflected by striatal DAT.

Colony-stimulating factor 1 receptor (CSF1R) is a specific biomarker for microglia. In this study, we developed a novel PET radioligand for CSF1R, 11C-GW2580, and compared it to a reported CSF1R tracer, 11C-CPPC, in mouse models of acute and chronic neuroinflammation and a rhesus monkey. Dynamic 11C-GW2580- and 11C-CPPC-PET images were quantified by reference tissue-based models and standardized uptake value ratio. Both tracers exhibited increased uptake in the lesioned striata of lipopolysaccharide-injected mice and in the forebrains of AppNL-G-F/NL-G-F-knock-in mice, spatially in agreement with an increased 18-kDa translocator protein radioligand retention. Moreover, 11C-GW2580 captured changes in CSF1R availability more sensitively than 11C-CPPC, with a larger dynamic range and a smaller inter-individual variability, in these model animals. PET imaging of CSF1R in a rhesus monkey displayed moderate-to-high tracer retention in the brain at baseline. Homologous blocker (i. e. unlabeled tracer) treatment reduced the uptake of 11C-GW2580 by ∼30% in all examined brain regions except for centrum semi-ovale white matter, but did not affect the retention of 11C-CPPC. In summary, our results demonstrated that 11C-GW2580-PET captured inflammatory microgliosis in the mouse brain with higher sensitivity than a reported radioligand, and displayed saturable binding in the monkey brain, potentially providing an imaging-based quantitative biomarker for reactive microgliosis.

Colony-stimulating factor 1 receptor (CSF1R) is a specific biomarker for microglia. In this study, we developed a novel PET radioligand for CSF1R, C-GW2580, and compared it to a reported CSF1R tracer, C-CPPC, in mouse models of acute and chronic neuroinflammation and a rhesus monkey. Dynamic C-GW2580- and C-CPPC-PET images were quantified by reference tissue-based models and standardized uptake value ratio. Both tracers exhibited increased uptake in the lesioned striata of lipopolysaccharide-injected mice and in the forebrains of -knock-in mice, spatially in agreement with an increased 18-kDa translocator protein radioligand retention. Moreover, C-GW2580 captured changes in CSF1R availability more sensitively than C-CPPC, with a larger dynamic range and a smaller inter-individual variability, in these model animals. PET imaging of CSF1R in a rhesus monkey displayed moderate-to-high tracer retention in the brain at baseline. Homologous blocker (i. e. unlabeled tracer) treatment reduced the uptake of C-GW2580 by ∼30% in all examined brain regions except for centrum semi-ovale white matter, but did not affect the retention of C-CPPC. In summary, our results demonstrated that C-GW2580-PET captured inflammatory microgliosis in the mouse brain with higher sensitivity than a reported radioligand, and displayed saturable binding in the monkey brain, potentially providing an imaging-based quantitative biomarker for reactive microgliosis.

Purpose Phosphodiesterase 7 (PDE7) is an enzyme that selectively hydrolyses cyclic adenosine monophosphate, and its dysfunction is implicated in neuropsychiatric diseases. However, in vivo visualization of PDE7 in human brains has hitherto not been possible. Using the novel PET ligand 11C-MTP38, which we recently developed, we aimed to image and quantify PDE7 in living human brains. Methods Seven healthy males underwent a 90-min PET scan after injection of 11C-MTP38. We performed arterial blood sampling and metabolite analysis of plasma in six subjects to obtain a metabolite-corrected input function. Regional total distribution volumes (VTs) were estimated using compartment models, and Logan plot and Ichise multilinear analysis (MA1). We further quantified the specific radioligand binding using the original multilinear reference tissue model (MRTMO) and standardized uptake value ratio (SUVR) method with the cerebellar cortex as reference. Results PET images with 11C-MTP38 showed relatively high retentions in several brain regions, including in the striatum, globus pallidus, and thalamus, as well as fast washout from the cerebellar cortex, in agreement with the known distribution of PDE7. VT values were robustly estimated by two-tissue compartment model analysis (mean VT = 4.2 for the pallidum), Logan plot, and MA1, all in excellent agreement with each other, suggesting the reversibility of 11C-MTP38 binding. Furthermore, there were good agreements between binding values estimated by indirect method and those estimated by both MRTMO and SUVR, indicating that these methods could be useful for reliable quantification of PDE7. Because MRTMO and SUVR do not require arterial blood sampling, they are the most practical for the clinical use of 11C-MTP38-PET. Conclusion We have provided the first demonstration of PET visualization of PDE7 in human brains. 11C-MTP38 is a promising novel PET ligand for the quantitative investigation of central PDE7.

[11C]K-2, a radiotracer exhibiting high affinity and selectivity for α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (AMPARs), is suitable for the quantification of AMPARs in living human brains and potentially useful in the identification of epileptogenic foci in patients. This study aimed to estimate the radiation doses of [11C]K-2 in various organs and calculate the effective dose after injection of [11C]K-2 in healthy human subjects. Twelve healthy male subjects were registered and divided into two groups (370 or 555 MBq of [11C]K-2), followed by 2 h whole-body scans. We estimated the radiation dose of each organ and then calculated the effective dose for each subject. The highest uptake of [11C]K-2 was observed in the liver, while the brain also showed relatively high uptake. The urinary bladder exhibited the highest radiation dose. The kidneys and liver also showed high radiation doses after [11C]K-2 injections. The effective dose of [11C]K-2 ranged from 5.0 to 5.2 μSv/MBq. Our findings suggest that [11C]K-2 is safe in terms of the radiation dose and adverse effects. The injection of 370–555 MBq (10 to 15 mCi) for PET studies using this radiotracer is applicable in healthy human subjects and enables serial PET scans in a single subject.

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. Twenty MDD and twenty age-matched, healthy controls were examined by PET with a tau radioligand, [11C]PBB3, and an Aβ radioligand, [11C]PiB. Radioligand retentions were quantified as a standardized uptake value ratio (SUVR). We also assessed clinical manifestations of the patients using the 17-item Hamilton Depression Scale, the Geriatric Depression Scale, and psychotic symptoms. Mean cortical [11C]PBB3 SUVRs in MDD patients were significantly higher than those of healthy controls. These values were higher in MDD patients with psychotic symptoms than in those without any. The present findings indicate that tau depositions may underlie MDD, and especially in patients with psychotic symptoms. PET detection of tau accumulations may provide mechanistic insights into neuronal dysfunctions in these cases and could serve as predictions of their clinical consequences.

Introduction Isoproterenol is a non-selective β receptor agonist, which is a drug approved for bradycardia and bronchial asthma in many countries. Recently, isoproterenol has been reported to have the potential as a drug for the treatment of Alzheimer's disease by inhibiting the aggregation of tau protein. Isoproterenol is a highly potent drug causing increases in heart rates even when its plasma concentration is very low. Thus, it is critical to know if potentially effective therapeutic levels of isoproterenol can be achieved, maintaining safe plasma levels without any untoward pharmacological effects. The purpose of the study is to investigate the brain pharmacokinetics and biodistribution of 11C-labeled isoproterenol in rodents. Methods We performed positron emission tomography (PET) brain imaging and biodistribution studies of [11C]isoproterenol. 120-min scans with arterial blood sampling were performed in rats. Additionally, plasma and brain homogenates were analyzed with radio-HPLC to characterize its metabolite profiles. As a measure of [11C]isoproterenol brain uptake, total distribution volumes were determined by a pharmacokinetic compartment model. Biodistribution of [11C]isoproterenol was investigated in mice at six-time points from 1-min to 90-min after injection. Results We found a modest brain uptake of [11C]isoproterenol. Its brain pharmacokinetics showed that the concentration of isoproterenol in the brain at equilibrium was about two-fold higher than in the plasma (total distribution volumes 2.0 ± 0.2 cm3/mL). Only unmetabolized isoproterenol was detected in the brain at 30 min after injection, although isoproterenol was rapidly metabolized in plasma. The biodistribution study showed that isoproterenol and its metabolite are excreted mainly via the urinary system. Conclusions, advances in knowledge and implications for patient care In this study, we have shown that rat brain concentrations of isoproterenol are only two-fold of that in plasma at equilibrium. If the brain pharmacokinetics are similar in the human brain, it may be difficult to achieve potentially therapeutic levels of this drug safely in humans. Further studies appear warranted to investigate the brain pharmacokinetics in humans with PET using [11C]isoproterenol.

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. Twenty MDD and twenty age-matched, healthy controls were examined by PET with a tau radioligand, [11C]PBB3, and an Aβ radioligand, [11C]PiB. Radioligand retentions were quantified as a standardized uptake value ratio (SUVR). We also assessed clinical manifestations of the patients using the 17-item Hamilton Depression Scale, the Geriatric Depression Scale, and psychotic symptoms. Mean cortical [11C]PBB3 SUVRs in MDD patients were significantly higher than those of healthy controls. These values were higher in MDD patients with psychotic symptoms than in those without any. The present findings indicate that tau depositions may underlie MDD, and especially in patients with psychotic symptoms. PET detection of tau accumulations may provide mechanistic insights into neuronal dysfunctions in these cases and could serve as predictions of their clinical consequences.

Patients tend to feel stress in association with dental treatment due to uneasiness and fear. We investigated the effects of providing advance notice and stress-coping traits on the physiological stress of patients during dental treatment. Sixty non-dental professionals (male, n = 26; female, n = 34; mean age, 49.9 years) were recruited for this study and informed consent was obtained. Subjects were given simulated dental treatment including three stimuli, air, percussion and running of an air turbine, with or without advance notice of the stimulation during dental treatment. Real-time sympathetic nerve activity (SN) and parasympathetic nerve activity (PN) during the treatment were measured using a biological information monitor. The stress-coping traits of each subject were examined using the Lazarus-Type Stress Coping Inventory (SCI). Correlations between the nerve-activity and scores of eight stress-coping strategies of SCI and the presence/absence of advance notice were analyzed. Age, types of stimuli and order of stimuli significantly affected SN, while age, types of stimuli, and the pattern of stimulation significantly affected PN. The interaction of the stress-coping trait and presence/absence of advance notice significantly affected PN. Providing advance notice may have different effects on physiological stress depending on how the patient copes with stress.

In evaluating the personality attributes and performance of the self, people are inclined to view themselves superior to others, a phenomenon known as superiority illusion (SI). This illusive outlook pervades people’s thoughts, creating hope for the future and promoting mental health. Although a specific cortico-striatal functional connectivity (FC) under dopaminergic modulation was previously shown to be implicated in SI, the underlying whole-brain mechanisms have remained unclarified. Herein, to reveal the neural network subserving individual’s SI, we conducted a data-driven, machine-learning investigation to explore the resting-state FC network across the whole brain. Using the locally-acquired resting-state functional magnetic resonance imaging data (n = 123), we identified a set of 15 FCs most informative in classifying individuals with higher-versus lower-than-average levels of SI in evaluating positive trait words (area under the curve [AUC] = 0.81). Among the 15 FCs, the contribution level to the classification was 11% by the previously-highlighted cortico-striatal FC alone, but 60% by the encompassing cortico-limbico-striatal network cluster. A newly-identified, cortico-thalamic FC and another FC cluster also demonstrated substantial contribution. The classification accuracy was generalized into an independent cohort (n = 36; AUC = 0.73). Importantly, using the same set of 15 FCs, we achieved prediction on an individual’s level of striatal dopamine D2 receptor availability (Pearson correlation, r = 0.46, P = 0.005). This is the first successful identification of the whole-brain neural network that simultaneously predicts the behavioral manifestation and molecular underpinning of an essential psychological process that promotes well-being and mental health.Significance StatementSuperiority illusion (SI) is a basic self-referential framework that pervades people’s thoughts and promotes well-being and mental health. An aberrant form of SI has been reported in psychiatric conditions such as depression. Our hypothesis-free, data-driven investigation revealed the spatially-distributed neural network that for the first time achieved prediction on an individual’s levels of SI and the striatal dopaminergic transmission simultaneously. In principle, this multiple-biological-layer framework can be applicable to any behavioral trait to establish a link with its underlying neural network and neurochemical properties, which could quantitatively present the relation of its aberrant form with the pathophysiology of neuropsychiatric disorders. Future clinical research may aid in deriving a diagnostic biomarker for examining the related behavioral and neurochemical characteristics within individuals.

In evaluating the personality attributes and performance of the self, people are inclined to view themselves superior to others, a phenomenon known as superiority illusion (SI). This illusive outlook pervades people’s thoughts, creating hope for the future and promoting mental health. Although a specific cortico-striatal functional connectivity (FC) under dopaminergic modulation was previously shown to be implicated in SI, the underlying whole-brain mechanisms have remained unclarified. Herein, to reveal the neural network subserving individual’s SI, we conducted a data-driven, machine-learning investigation to explore the resting-state FC network across the whole brain. Using the locally-acquired resting-state functional magnetic resonance imaging data (n = 123), we identified a set of 15 FCs most informative in classifying individuals with higher-versus lower-than-average levels of SI in evaluating positive trait words (area under the curve [AUC] = 0.81). Among the 15 FCs, the contribution level to the classification was 11% by the previously-highlighted cortico-striatal FC alone, but 60% by the encompassing cortico-limbico-striatal network cluster. A newly-identified, cortico-thalamic FC and another FC cluster also demonstrated substantial contribution. The classification accuracy was generalized into an independent cohort (n = 36; AUC = 0.73). Importantly, using the same set of 15 FCs, we achieved prediction on an individual’s level of striatal dopamine D2 receptor availability (Pearson correlation, r = 0.46, P = 0.005). This is the first successful identification of the whole-brain neural network that simultaneously predicts the behavioral manifestation and molecular underpinning of an essential psychological process that promotes well-being and mental health. Significance Statement Superiority illusion (SI) is a basic self-referential framework that pervades people’s thoughts and promotes well-being and mental health. An aberrant form of SI has been reported in psychiatric conditions such as depression. Our hypothesis-free, data-driven investigation revealed the spatially-distributed neural network that for the first time achieved prediction on an individual’s levels of SI and the striatal dopaminergic transmission simultaneously. In principle, this multiple-biological-layer framework can be applicable to any behavioral trait to establish a link with its underlying neural network and neurochemical properties, which could quantitatively present the relation of its aberrant form with the pathophysiology of neuropsychiatric disorders. Future clinical research may aid in deriving a diagnostic biomarker for examining the related behavioral and neurochemical characteristics within individuals.

BACKGROUND: Contrary to pure cases, the influence of comorbid argyrophilic grain disease (AGD) in progressive supranuclear palsy (PSP) has not been sufficiently evaluated. OBJECTIVES: We compared the clinicoradiological features of 12 patients with PSP with (PSPw/AG) and 8 patients without AGD (PSPw/oAG). METHODS: Medical records and magnetic resonance imaging were checked retrospectively from a single brain bank database. RESULTS: Other than AGD, no differences were observed in any other neurodegenerative pathologies between the 2 groups. Ages at onset and deaths of patients with PSPw/AG were higher than those of patients with PSPw/oAG (77.9 ± 4.9 vs. 68.9 ± 5.9, and 87.0 ± 5.7 vs. 78.1 ± 5.0; P = 0.003 and P = 0.002, respectively). In addition to the later onset of motor symptoms, initial amnestic presentations were limited to 5 patients with PSPw/AG. Both characteristic midbrain atrophy and severe ambient gyrus atrophy were detected exclusively in 8 patients with PSPw/AG. CONCLUSIONS: Initial amnestic presentations and ambient gyrus atrophy may be characteristic of PSPw/AG.

Eleven patients with AD and 6 CN participants were examined using dynamicThe concentration of radioactivity in plasma demonstrated rapid clearance.

The tendency to avoid punishment, called behavioral inhibition system, is an essential aspect of motivational behavior. Behavioral inhibition system is related to negative affect, such as anxiety, depression and pain, but its neural basis has not yet been clarified. To clarify the association between individual variations in behavioral inhibition system and brain 5-HT

Background: Alzheimer’s disease (AD) is conceptualized as a biological continuum encompassing the preclinical (clinically asymptomatic but with evidence of AD pathology) and clinical (symptomatic) phases. Objective: Using 18F-THK5351 as a tracer that binds to both tau and monoamine oxidase B (MAO-B), we investigated the changes in 18F-THK5351 accumulation patterns in AD continuum individuals with positive amyloid PET consisting of cognitively normal individuals (CNp), amnestic mild cognitive impairment (aMCI), and AD and cognitively normal individuals (CNn) with negative amyloid PET. Methods: We studied 69 individuals (32 CNn, 11 CNp, 9 aMCI, and 17 AD) with structural magnetic resonance imaging, 11C-Pittsburgh compound-B (PIB) and 18F-THK5351 PET, and neuropsychological assessment. 18F-THK5351 accumulation was evaluated with visual analysis, voxel-based analysis and combined region of interest (ROI)-based analysis corresponding to Braak neurofibrillary tangle stage. Results: On visual analysis, 18F-THK5351 accumulation was increased with stage progression in the AD continuum. On voxel-based analysis, there was no statistical difference in 18F-THK5351 accumulation between CNp and CNn. However, a slight increase of the bilateral posterior cingulate gyrus in aMCI and definite increase of the bilateral parietal temporal association area and posterior cingulate gyrus/precuneus in AD were detected compared with CNn. On ROI-based analyses, 18F-THK5351 accumulation correlated positively with supratentorial 11C-PIB accumulation and negatively with the hippocampal volume and neuropsychological assessment. Conclusion: The AD continuum showed an increase in 18F-THK5351 with stage progression, suggesting that 18F-THK5351 has the potential to visualize the severity of tau deposition and neurodegeneration in accordance with the AD continuum.

Monoamine oxidase B (MAO-B) is highly abundant in reactive astrocytes and upregulated in neuroinflammatory processes. However, the age-related change of MAO-B in amyloid-negative cognitively unimpaired elderly subjects has not yet been sufficiently evaluated on positron emission tomography (PET).The age-related change ofOn visual inspection, elderly groups showed the spread ofThis study demonstrated age-dependent increase of

Background: Although hippocampal atrophy is a well-known imaging biomarker of Alzheimer’s disease (AD), this finding is not useful to differentiate AD from argyrophilic grain disease (AGD) which is a common AD mimicker presenting with similar amnestic symptoms and medial temporal atrophy. Instead, we propose use of the “sloping shoulders sign”, defined as a distinct configuration of the bilateral hippocampal heads showing lateral and downward slopes on axial magnetic resonance imaging (MRI). Objective: We investigated the diagnostic utility of the “sloping shoulders sign” as a simple radiological discriminator of AD from AGD. Methods: Using axial and coronal three-dimensional MRI, our newly proposed “sloping shoulders sign”, other quantitative indices including the axial hippocampal head angle (AHHA), and well-known medial temporal atrophy (MTA) score were evaluated in pathologically-proven 24 AD and 11 AGD patients. Results: Detection rate of the “sloping shoulders sign” was significantly higher in all AD groups (83%; 20/24) and AD with Braak neurofibrillary tangle V/VI stage subgroup (88%; 15/17) than in AGD patients (18% – 2/11; p

Positron emission tomography (PET) with [First, the reproducibility of BP estimation using the dual-bolus injection approach was evaluated using PET scans without stimulation in nine healthy volunteers. A 90-min scan was performed with bolus injections of [In the PET scans without stimulation, the dual-bolus injection approach showed a smaller MAD (2%) between BPOur results indicate that the cognitive task-induced changes in dopamine-related systems may be complex and difficult to measure accurately using PET scans. However, the proposed dual-bolus injection approach provided reliable BP estimates with high reproducibility, suggesting that it has the potential to improve the accuracy of PET scans for measuring changes in dopamine concentrations.

Corticobasal degeneration (CBD) is the most common neuropathological substrate for clinically diagnosed corticobasal syndrome (CBS), while identifying CBD pathology in living individuals has been challenging. This study aimed to examine the capability of positron emission tomography (PET) to detect CBD-type tau depositions and neuropathological classification of CBS.Sixteen CBS cases diagnosed by Cambridge's criteria and 12 cognitively healthy controls (HCs) underwent PET scans withSixteen CBS cases consisted of two cases (13%) with amyloid and tau positivities indicative of Alzheimer's disease (AD) pathologies, 11 cases (69%) with amyloid negativity and tau positivity, and three cases (19%) with amyloid and tau negativities. Amyloid(-), tau(+) CBS cases showed increased retentions ofPET-based classification of CBS was in accordance with previous neuropathological reports on the prevalences of AD, non-AD tauopathies, and others in CBS. The current work suggests that

Monoacylglycerol lipase (MAGL) regulates cannabinoid neurotransmission and the pro-inflammatory arachidonic acid pathway by degrading endocannabinoids. MAGL inhibitors may accordingly act as cannabinoid-potentiating and anti-inflammatory agents. Although MAGL dysfunction has been implicated in neuropsychiatric disorders, it has never been visualized in vivo in human brain. The primary objective of the current study was to visualize MAGL in the human brain using the novel PET ligandSeven healthy males underwent 120-min dynamicHere, we provide the first demonstration of in vivo visualization of MAGL in the human brain.

Incident reports are important for improving the quality and safety of medical care. Healthcare workers with less than one year of work experience have been reported to cause the most incidents, and the most common incident is “drug-related”. However, few studies have comprehensively analyzed incidents in dentistry, and the characteristics of dental incidents have not been understood. In this study, to understand the characteristics of dental incidents, we comprehensively analyzed 1291 incident reports submitted to the Tokyo Medical and Dental University Dental Hospital from April 2014 to March 2019. As a result, dental outpatient and dental wards had different types of incidents. In outpatient wards, incidents included many dentistry-specific incidents related to “procedures”. Among them, “poor physical condition of the patient during dental treatment” was the most common incident. In contrast, the most common incident from subjects with less than one year of work experience was “damage to soft tissues around the teeth”. Thus, to improve the quality and safety in dentistry, it is was considered necessary to analyze and understand the characteristics of dentistry-specific incidents and to take appropriate measures and educate dental professionals.

Rationale The tendency to avoid punishment, called behavioral inhibition system, is an essential aspect of motivational behavior. Behavioral inhibition system is related to negative affect, such as anxiety, depression and pain, but its neural basis has not yet been clarified. Objectives To clarify the association between individual variations in behavioral inhibition system and brain 5-HT2A receptor availability and specify which brain networks were involved in healthy male subjects, using [18F]altanserin positron emission tomography and resting-state functional magnetic resonance imaging. Results Behavioral inhibition system score negatively correlated with 5-HT2A receptor availability in anterior cingulate cortex. A statistical model indicated that the behavioral inhibition system score was associated with 5-HT2A receptor availability, which was mediated by the functional connectivity between anterior cingulate cortex and left middle frontal gyrus, both of which involved in the cognitive control of negative information processing. Conclusions Individuals with high behavioral inhibition system displays low 5-HT2A receptor availability in anterior cingulate cortex and this cognitive control network links with prefrontal-cingulate integrity. These findings have implications for underlying the serotonergic basis of physiologies in aversion.

We developed a compact microfluidic measurement system based on a filter-free fluorescence sensor that can selectively identify wavelengths without optical component. Two types of fluorescent beads were successfully identified using this proposed system. The sensor detects the wavelength and intensity of light using a potential peak inside formed by the photogate (PG) voltage. The conventional method detects only electrons moving toward the PG side, but we also focused on electrons moving toward the n-well side of the sensor. Using this current, the wavelength is identified from the ratio of the two currents (I n-well /I PG ). In the past, at least two measurements were required, but with this method, identification can be realized in a single measurement. These results are expected to be applied to the field of cell measurement.

We report the world-first result of visualization of intra-stem ion dynamics of living plants using a novel ion image sensor. A dedicated ion image sensor that can insert to the plant stem was fabricated. The sensor has $128\times 32$ ion-sensitive pixels to capture the ion distribution reflecting the structure of the stem (vascular bundle). Imaging results showed that hydrogen ions moved from the bottom to the top of the stem due to natural transpiration. Ion distribution reflecting the vascular bundle was also clearly visualized and confirmed to correspond with the plant stem cross-sectional structure. This sensor can be used to observe the activity of photosynthesis and possibly maximize production efficiency in agriculture.

We developed a $256\times 32$ -pixel needle-type pH image sensor to visualize ion behavior at the cellular level under in vivo conditions. This sensor has a pixel configuration that can be fabricated via a modified CMOS process technology, and it achieved a pixel size of $5.65\times 4.39\ \mu \mathrm{m}^{2}$ . The proposed image sensor is the highest-definition implantable ion image sensor among other conventional image sensors. For in vivo implantation, the sensor's shape was modified to a needle structure of $9.88\times 1.10\ \text{mm}^{2}$ with a thickness of $100\ \mu \mathrm{m}$ . From the measurement results, we verified that the sensor exhibits a high spatiotemporal resolution with a pH sensitivity, pH resolution, and temporal resolution of 56.4 mV/pH, 0.015 pH, and 14.1 fps, respectively. In addition, we detected pH changes in the brain of the experimented mouse during neural hyperexcitation, and successfully reproduced the measured data as 2-D images in real time.

Objective The objectives of the present study were to investigate (1) whether trinary visual interpretation of amyloid positron emission tomography (PET) imaging (negative/equivocal/positive) reflects quantitative amyloid measurements and the time course of 11C-Pittsburgh compound B (PiB) amyloid accumulation, and (2) whether visually equivocal scans represent an early stage of the Alzheimer’s disease (AD) continuum in terms of an intermediate state of quantitative amyloid measurements and the changes in amyloid accumulation over time. Methods From the National Bioscience Database Center Human Database of the Japanese Alzheimer’s Disease Neuroimaging Initiative, we selected 133 individuals for this study including 33 with Alzheimer’s disease dementia (ADD), 52 with late mild cognitive impairment (LMCI), and 48 cognitively normal (CN) subjects who underwent clinical assessment, PiB PET, and structural magnetic resonance imaging (MRI) with 2 or 3-years of follow-up. Sixty-eight of the 133 individuals underwent cerebrospinal fluid amyloid-β1-42 (CSF-Ab42) analysis at baseline. The standard uptake value ratio (SUVR) of PiB PET was calculated with a method using MRI at each visit. The cross-sectional values, longitudinal changes in SUVR, and baseline CSF-Ab42 were compared among groups, which were categorized based on trinary visual reads of amyloid PET (negative/equivocal/positive). Results From the trinary visual interpretation of the PiB PET images, 55 subjects were negative, 8 were equivocal, and 70 were positive. Negative interpretation was most frequent in the CN group (70.8/10.4/18.8%: negative/equivocal/positive), and positive was most frequent in the LMCI group (34.6/1.9/63.5%) and in the ADD group (9.1/6.1/84.8%). The baseline SUVRs were 1.08 ± 0.06 in the negative group, 1.23 ± 0.15 in the equivocal group, and 1.86 ± 0.31 in the positive group (F = 174.9, p 42 level was 463 ± 112 pg/mL in the negative group, 383 ± 125 pg/mL in the equivocal group, and 264 ± 69 pg/mL in the positive group (F = 37, p F = 8.4, p Conclusions Trinary visual interpretation (negative/equivocal/positive) of amyloid PET imaging reflects quantitative amyloid measurements evaluated with PET and the CSF amyloid test as well as the amyloid accumulation over time evaluated with PET over 3 years. Subjects in the early stage of the AD continuum could be identified with an equivocal scan, because they showed intermediate quantitative amyloid PET, CSF measurements, and the amyloid accumulation over time.

Positron emission tomography (PET) scans of imaging receptors require 60–90-min dynamic acquisition for quantitative analysis. Head movement is often observed during scanning, which hampers the reliable estimation of quantitative parameters. This study evaluated image-based motion correction by frame-to-frame realignment for PET studies with [11C]raclopride and [11C]FLB 457 acquired by an Eminence SET-3000GCT/X and investigated the effect of this correction on the quantitative outcomes. First, an optimal method for estimating motion parameters was evaluated by computer simulation. Simulated emission sinograms were reconstructed to the PET images with or without attenuation correction using a µ-map of the transmission scan. Six motion parameters were estimated frame-by-frame by registering each frame of the PET images to several types of reference images and the reliability of registration was compared. Next, in [11C]raclopride and [11C]FLB 457 studies in normal volunteers, six motion parameters for each frame were estimated by the registration method determined from the simulation results. Head movement was corrected by realigning the PET images reconstructed with a motion-included µ-map in which a mismatch between the transmission and emission scans was corrected. After this correction, time-activity curves (TAC) for the striatum or cerebral cortex were obtained and the binding potentials of the receptors (BPND) were estimated using the simplified reference tissue model. In the simulations, the motion parameters could be reliably estimated by registering each frame of the non-attenuation-corrected PET images to their early-phase frame. The motion parameters in the human studies were also obtained using the same method. After correction, a discontinuity of TACs in the striatum and cerebral cortex was remarkably improved and the BPND values in these regions increased. Compared to the motion-corrected PET images reconstructed using the measured µ-map, the images reconstructed using the motion-included µ-map did not result in a remarkable improvement of BPND in the striatum of [11C]raclopride studies, while the BPND in the cerebral cortex changed in some [11C]FLB 457 studies in which large head movement was observed. In PET receptor imaging, head movement during dynamic scans can be corrected by frame-to-frame realignment. This method is easily applicable to clinical studies and provides reliable TACs and BPND.

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. PET data were acquired from 27 subjects in the chronic stage following mild-repetitive or severe TBI and 15 healthy control subjects. Among the TBI patients, 14 were diagnosed as having late-onset symptoms based on the criteria of traumatic encephalopathy syndrome. For quantification of tau burden in TBI brains, we calculated 11C-PBB3 binding capacity (cm3), which is a summed voxel value of binding potentials (BP*ND) multiplied by voxel volume. Main outcomes of the present study were differences in 11C-PBB3 binding capacity between groups, and the association of regional 11C-PBB3 binding capacity with neuropsychiatric symptoms. To confirm 11C-PBB3 binding to tau deposits in TBI brains, we conducted in vitro PBB3 fluorescence and phospho-tau antibody immunofluorescence labelling of brain sections of chronic traumatic encephalopathy obtained from the Brain Bank. Our results showed that patients with TBI had higher 11C-PBB3 binding capacities in the neocortical grey and white matter segments than healthy control subjects. Furthermore, TBI patients with traumatic encephalopathy syndrome showed higher 11C-PBB3 binding capacity in the white matter segment than those without traumatic encephalopathy syndrome, and regional assessments revealed that subgroup difference was also significant in the frontal white matter. 11C-PBB3 binding capacity in the white matter segment correlated with the severity of psychosis. In vitro assays demonstrated PBB3-positive tau inclusions at the depth of neocortical sulci, confirming 11C-PBB3 binding to tau lesions. In conclusion, increased 11C-PBB3 binding capacity is associated with late-onset neuropsychiatric symptoms following TBI, and a close correlation was found between psychosis and 11C-PBB3 binding capacity in the white matter.

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. PET data were acquired from 27 subjects in the chronic stage following mild-repetitive or severe TBI and 15 healthy control subjects. Among the TBI patients, 14 were diagnosed as having late-onset symptoms based on the criteria of traumatic encephalopathy syndrome. For quantification of tau burden in TBI brains, we calculated 11C-PBB3 binding capacity (cm3), which is a summed voxel value of binding potentials (BP* ND) multiplied by voxel volume. Main outcomes of the present study were differences in 11C-PBB3 binding capacity between groups, and the association of regional 11C-PBB3 binding capacity with neuropsychiatric symptoms. To confirm 11C-PBB3 binding to tau deposits in TBI brains, we conducted in vitro PBB3 fluorescence and phospho-tau antibody immunofluorescence labelling of brain sections of chronic traumatic encephalopathy obtained from the Brain Bank. Our results showed that patients with TBI had higher 11C-PBB3 binding capacities in the neocortical grey and white matter segments than healthy control subjects. Furthermore, TBI patients with traumatic encephalopathy syndrome showed higher 11C-PBB3 binding capacity in the white matter segment than those without traumatic encephalopathy syndrome, and regional assessments revealed that subgroup difference was also significant in the frontal white matter. 11C-PBB3 binding capacity in the white matter segment correlated with the severity of psychosis. In vitro assays demonstrated PBB3-positive tau inclusions at the depth of neocortical sulci, confirming 11C-PBB3 binding to tau lesions. In conclusion, increased 11C-PBB3 binding capacity is associated with late-onset neuropsychiatric symptoms following TBI, and a close correlation was found between psychosis and 11C-PBB3 binding capacity in the white matter

(R,S)-Isoproterenol inhibits the formation of toxic granular tau oligomers associated with neuronal loss and development of cognitive disorders, and is an attractive drug candidate for Alzheimer’s disease. To elucidate its behavior in the brain by positron emission tomography, we synthesize (R,S)-[11C]isoproterenol by reductive alkylation of (R,S)-norepinephrine with [2-11C]acetone, which was in turn synthesized in situ under improved conditions afforded a decay-corrected radiochemical yield of 54%. The reductive alkylation using NaBH(OAc)3 as reducing agent in the presence of benzoic acid in DMSO/DMF (60:40 v/v) at 100 °C for 10 min gave (R,S)-[11C]isoproterenol in an 87% radio-high performance liquid chromatography (HPLC) analytical yield. HPLC separation using a strong cation exchange column, followed by pharmaceutical formulation in the presence of d / l -tartaric acid, afforded (R,S)-[11C]isoproterenol with a total radioactivity of 2.0 ± 0.2 GBq, a decay-corrected radiochemical yield of 19 ± 2%, chemical and radiochemical purities of 71% and >99%, respectively, and a molar activity of 100 ± 13 GBq/μmol (n = 3). The overall synthesis time from the end of the bombardment to pharmaceutical formulation was 48 min. A preliminary preclinical PET study in a rat demonstrated the potential of the radioligand for the evaluation of the penetration of (R,S)-isoproterenol in human brain.

Various biosensing platforms for real-time monitoring and mapping of chemical signals in neural networks have been developed based on CMOS process technology. Despite their achievements, however, there remains a demand for an advanced method that can offer detailed insights into cellular functions with higher spatiotemporal resolution. Here, we present a pH image sensor that employs a high-density array of 256 × 256 pixels and readout circuitry designed for fast operation. The sensor's characteristics, such as the pH sensitivity of 55.1 mV/pH and higher frame speed of 1933 fps, are experimentally demonstrated and compared to those of state-of-the-art pH image sensors. Among them, our sensor presents the smallest pitch of 2 μm with a significantly high operation speed. This sensor can successfully detect a pH change, but also transform the measured data to a two-dimensional image series in real time. The practical spatial resolution of images is investigated by an evaluation method that we first propose in this paper. By this method, we confirm that our sensor can discriminate objects distanced over 4 μm apart, which is twice bigger than the pixel pitch. In order to analyze the degraded resolution and image blur, a capacitive coupling effect at an ion-sensitive membrane is suggested as the main factor and demonstrated by simulation.

Background [11 C]pyridinyl-butadienyl-benzothiazole 3 is a PET imaging agent designed for capturing pathological tau aggregates in diverse neurodegenerative disorders, and would be of clinical utility for neuropathological investigations of PSP. Objectives To explore the usefulness of [11 C]pyridinyl-butadienyl-benzothiazole 3/PET in assessing characteristic distributions of tau pathologies and their association with clinical symptoms in the brains of living PSP patients. Methods We assessed 13 PSP patients and 13 age-matched healthy control subjects. Individuals negative for amyloid β PET with [11 C]Pittsburgh compound B underwent clinical scoring, MR scans, and [11 C]pyridinyl-butadienyl-benzothiazole 3/PET. Results There were significant differences in binding potential for [11 C]pyridinyl-butadienyl-benzothiazole 3 between PSP patients and healthy control subjects (P = 0.02). PSP patients exhibited greater radioligand retention than healthy control subjects in multiple brain regions, including frontoparietal white matter, parietal gray matter, globus pallidus, STN, red nucleus, and cerebellar dentate nucleus. [11 C]pyridinyl-butadienyl-benzothiazole 3 deposition in frontoparietal white matter, but not gray matter, was correlated with general severity of parkinsonian and PSP symptoms, whereas both gray matter and white matter [11 C]pyridinyl-butadienyl-benzothiazole 3 accumulations in the frontoparietal cortices were associated with nonverbal cognitive impairments. Autoradiographic and fluorescence labeling with pyridinyl-butadienyl-benzothiazole 3 was observed in gray matter and white matter of PSP motor cortex tissues. Conclusions Our findings support the in vivo detectability of tau fibrils characteristic of PSP by [11 C]pyridinyl-butadienyl-benzothiazole 3/PET, and imply distinct and synergistic contributions of gray matter and white matte tau pathologies to clinical symptoms. [11 C]pyridinyl-butadienyl-benzothiazole 3/PET potentially provides a neuroimaging-based index for the evolution of PSP tau pathologies promoting the deterioration of motor and cognitive functions. © 2019 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Background/purpose: Hypertension is a risk factor for stroke and heart disease. Psycho-social reasons are thought to influence blood pressure fluctuation in the dental clinic, but no previous studies have investigated these relationships. In this study, we analyzed a correlation between patients’ blood pressure values and their backgrounds. Materials and methods: We measured blood pressure in 4990 outpatients at our hospital. After determining the age groups in which blood pressure deviated from national averages, patients were classified into the Hypertension group and Normal group. Differences between these groups with regard to the prevalence of systemic disease, dental history and reasons for dental consultation were analyzed. Results: Average systolic blood pressure of males in their 20's, 30's, 40's and females in their 20's, 30's, 40's, 50's was significantly higher than national averages. In these age groups, disease prevalence was significantly higher in the Hypertension group than in the Normal group. Furthermore, the Hypertension group expressed psycho-social reasons for dental consultation more frequently than the Normal group. Conclusion: Relatively younger patients tended to show higher systolic blood pressure. It was suggested that psycho-social backgrounds as well as medical causes influenced the blood pressure increase. Keywords: Hypertension, Biopsychosocial model, First visit medical interview

ObjectiveTo characterize the distribution of tau pathology in patients with amyotrophic lateral sclerosis/parkinsonism dementia complex on the Kii Peninsula (Kii ALS/PDC) by tau PET using [11C]PBB3 as ligand.MethodsThis is a cross-sectional study of 5 patients with ALS/PDC and one asymptomatic participant with a dense family history of ALS/PDC from the Kii Peninsula who took part in this study. All were men, and their age was 76 ± 8 (mean ± SD) years. Thirteen healthy men (69 ± 6 years) participated as healthy controls (HCs). Dynamic PET scans were performed following injection of [11C]PBB3, and parametric PET images were generated by voxel-by-voxel calculation of binding potential (BP*ND) using a multilinear reference tissue model. [11C] Pittsburgh compound B (PiB) PET, MRI, and cognitive tests were also performed.ResultsA voxel-based comparison of [11C]PBB3 BP*ND illustrated PET-detectable tau deposition in the cerebral cortex and white matter, and pontine basis including the corticospinal tract in Kii ALS/PDC patients compared with HCs (uncorrected p < 0.05). Group-wise volume of interest analysis of [11C]PBB3 BP*ND images showed increased BP*ND in the hippocampus and in frontal and parietal white matters of Kii ALS/PDC patients relative to HCs (p < 0.05, Holm-Sidak multiple comparisons test). BP*ND in frontal, temporal, and parietal gray matters correlated with Mini-Mental State Examination scores in Kii ALS/PDC patients (p < 0.05). All Kii ALS/PDC patients were negative for [11C]PiB (β-amyloid) except one with marginal positivity.Conclusion[11C]PBB3 PET visualized the characteristic topography of tau pathology in Kii ALS/PDC, corresponding to clinical phenotypes of this disease.

Histamine HTo measure the histamine HAdministration of enerisant hydrochloride decreased the radioligand binding in a dose-dependent manner. The estimated receptor occupancy values at 2 h varied as a function of its dose or plasma concentration. The time course of the occupancy showed persistently high levels ( 85%) in the two subjects with higher doses (25 and 12.5 mg). The occupancy was also initially high at 2 h and 6 h with the lower dose of 5 mg, but it decreased to 69.7% at 26 h.The target engagement of enerisant was demonstrated in the brains of living human subjects. The occupancy of histamine HThis study was retrospectively registered with ClinicalTrials.gov (NCT04631276) on November 17, 2020.

[11C]K-2, a radiotracer exhibiting high affinity and selectivity for α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (AMPARs), is suitable for the quantification of AMPARs in living human brains and potentially useful in the identification of epileptogenic foci in patients. This study aimed to estimate the radiation doses of [11C]K-2 in various organs and calculate the effective dose after injection of [11C]K-2 in healthy human subjects. Twelve healthy male subjects were registered and divided into two groups (370 or 555 MBq of [11C]K-2), followed by 2 h whole-body scans. We estimated the radiation dose of each organ and then calculated the effective dose for each subject. The highest uptake of [11C]K-2 was observed in the liver, while the brain also showed relatively high uptake. The urinary bladder exhibited the highest radiation dose. The kidneys and liver also showed high radiation doses after [11C]K-2 injections. The effective dose of [11C]K-2 ranged from 5.0 to 5.2 μSv/MBq. Our findings suggest that [11C]K-2 is safe in terms of the radiation dose and adverse effects. The injection of 370–555 MBq (10 to 15 mCi) for PET studies using this radiotracer is applicable in healthy human subjects and enables serial PET scans in a single subject.