Anorexia nervosa is associated with higher brain mu-opioid receptor availability.

Anorexia nervosa (AN) is a severe psychiatric disorder, characterized by restricted eating, fear to gain weight, and a distorted body image. Mu-opioid receptor (MOR) functions as a part of complex opioid system and supports both homeostatic and hedonic control of eating behavior. Thirteen patients with AN and thirteen healthy controls (HC) were included in this study.

P2X -receptor binding in new-onset and secondary progressive MS - a [C]SMW139 PET study.

Background: PET imaging of activated microglia has improved our understanding of the pathology behind disability progression in MS, and pro-inflammatory microglia at 'smoldering' lesion rims have been implicated as drivers of disability progression. The P2X R is upregulated in the cellular membranes of activated microglia. A single-tissue dual-input model was applied to quantify P2X R binding in the normal appearing white matter, perilesional areas and thalamus among progressive MS patients, healthy controls and newly diagnosed relapsing MS patients.

Neuroinflammation in Parkinson's disease: A study with [C]PBR28 PET and cerebrospinal fluid markers.

Objective: To investigate neuroinflammation in Parkinson's disease (PD) with [C]PBR28 positron emission tomography (PET) and cerebrospinal fluid (CSF) biomarkers, and the relationship to dopaminergic functioning measured with 6-[F]-fluoro-L-dopa ([F]FDOPA) PET.

Methods: The clinical cohort consisted of 20 subjects with PD and 51 healthy controls (HC). All HC and 15 PD participants underwent [C]PBR28 High Resolution Research Tomograph (HRRT) PET for the quantitative assessment of cerebral binding to the translocator protein (TSPO), a neuroinflammation marker.

Impaired Gait, Postural Instability, and Rigidity in Relation to CB1 Receptor Availability in Parkinson's Disease.

Background: In Parkinson's disease (PD), postural instability and gait disorder (PIGD) symptoms are associated with a worse prognosis for an unknown reason.

Objective: The objective was to explore the relationship between cannabinoid receptor type 1 (CB1R) availability and motor symptoms in PD with [F]FMPEP-d positron emission tomography (PET).

Methods: Fifteen individuals with PD underwent [F]FMPEP-d PET to measure cerebral CB1R availability.

Aberrant type 2 dopamine receptor availability in violent offenders with psychopathy.

Psychopathy is characterized by antisocial behavior, poor behavioral control and lacking empathy, and structural alterations in the corresponding neural circuits. Molecular brain basis of psychopathy remains poorly characterized. Here we studied type 2 dopamine receptor (D2R) and mu-opioid receptor (MOR) availability in convicted violent offenders with high psychopathic traits (n = 11) and healthy matched controls (n = 17) using positron emission tomography (PET).

SGLT2 Inhibitor Dapagliflozin Increases Skeletal Muscle and Brain Fatty Acid Uptake in Individuals With Type 2 Diabetes: A Randomized Double-Blind Placebo-Controlled Positron Emission Tomography Study.

Objective: The aim of this study was to investigate the impact of the sodium-glucose cotransporter 2 (SGLT2) inhibitor dapagliflozin on tissue fatty acid (FA) uptake in the skeletal muscle, brain, small intestine, and subcutaneous and visceral adipose tissue of individuals with type 2 diabetes by using positron emission tomography (PET).

Research Design And Methods: In a 6-week randomized double-blind placebo-controlled trial, 53 patients with type 2 diabetes treated with metformin received either 10 mg dapagliflozin or placebo daily. Tissue FA uptake was quantified at baseline and end of treatment with PET and the long-chain FA analog radiotracer 14(R,S)-[18F]fluoro-6-thia-heptadecanoic acid.

Seasonal variation in D2/3 dopamine receptor availability in the human brain.

Purpose: Brain functional and physiological plasticity is essential to combat dynamic environmental challenges. The rhythmic dopamine signaling pathway, which regulates emotion, reward and learning, shows seasonal patterns with higher capacity of dopamine synthesis and lower number of dopamine transporters during dark seasons. However, seasonal variation of the dopamine receptor signaling remains to be characterized.

Alterations in type 2 dopamine receptors across neuropsychiatric conditions: A large-scale PET cohort.

Purpose: Aberrant dopaminergic function is linked with motor, psychotic, and affective symptoms, but studies have typically compared a single patient group with healthy controls.

Methods: Here, we investigated the variation in striatal (caudate nucleus, nucleus accumbens, and putamen) and thalamic type 2 dopamine receptor (DR) availability using [C]raclopride positron emission tomography (PET) data from a large sample of 437 humans including healthy controls, and subjects with Parkinson's disease (PD), antipsychotic-naïve schizophrenia, severe violent behavior, pathological gambling, depression, and overweight. We analyzed regional group differences in DR availability.

Midlife insulin resistance, APOE genotype, and change in late-life brain beta-amyloid accumulation - A 5-year follow-up [C]PIB-PET study.

We studied if midlife insulin resistance (IR) and APOE genotype would predict brain beta-amyloid (Aβ) accumulation and Aβ change in late-life in 5-year follow-up [C]PIB-PET study. 43 dementia-free participants were scanned twice with [C]PIB-PET in their late-life (mean age at follow-up 75.4 years).

Quantitative Perfusion Imaging with Total-Body PET.

Recently, PET systems with a long axial field of view have become the current state of the art. Total-body PET scanners enable unique possibilities for scientific research and clinical diagnostics, but this new technology also raises numerous challenges. A key advantage of total-body imaging is that having all the organs in the field of view allows studying biologic interaction of all organs simultaneously.

Insulin-stimulated brain glucose uptake correlates with brain metabolites in severe obesity: A combined neuroimaging study.

The human brain undergoes metabolic adaptations in obesity, but the underlying mechanisms have remained largely unknown. We compared concentrations of often reported brain metabolites measured with magnetic resonance spectroscopy (H-MRS, 3 T MRI) in the occipital lobe in subjects with obesity and lean controls under different metabolic conditions (fasting, insulin clamp, following weight loss). Brain glucose uptake (BGU) quantified with F-fluorodeoxyglucose positron emission tomography (F-FDG-PET)) was also performed in a subset of subjects during clamp.

Adenosine A receptor availability in cerebral gray and white matter of patients with Parkinson's disease.

Objective: Atrophic changes in cerebral gray matter of patients with PD have been reported extensively. There is evidence suggesting an association between cortical gyrification changes and white matter abnormalities. Adenosine A receptors have been shown to be upregulated in cerebral white matter and on reactive astrocytes in preclinical models of neurodegenerative diseases.

Insulin resistance and body mass index are associated with TSPO PET in cognitively unimpaired elderly.

Metabolic risk factors are associated with peripheral low-grade inflammation and an increased risk for dementia. We evaluated if metabolic risk factors i.e.

APOE ε4 gene dose effect on imaging and blood biomarkers of neuroinflammation and beta-amyloid in cognitively unimpaired elderly.

Background: Neuroinflammation, characterized by increased reactivity of microglia and astrocytes in the brain, is known to be present at various stages of the Alzheimer's disease (AD) continuum. However, its presence and relationship with amyloid pathology in cognitively normal at-risk individuals is less clear. Here, we used positron emission tomography (PET) and blood biomarker measurements to examine differences in neuroinflammation and beta-amyloid (Aβ) and their association in cognitively unimpaired homozygotes, heterozygotes, or non-carriers of the APOE ε4 allele, the strongest genetic risk for sporadic AD.

Adenosine A receptor availability in patients with early- and moderate-stage Parkinson's disease.

Introduction: Adenosine 2A (A) receptors co-localize with dopamine Dreceptors in striatopallidal medium spiny neurons of the indirect pathway. A receptor activation in the striatum or pallidum decreases Dsignaling. In contrast, A receptor antagonism may help potentiate it.

Cannabinoid Receptor Type 1 in Parkinson's Disease: A Positron Emission Tomography Study with [ F]FMPEP-d.

Background: The endocannabinoid system is a widespread neuromodulatory system affecting several biological functions and processes. High densities of type 1 cannabinoid (CB1) receptors and endocannabinoids are found in basal ganglia, which makes them an interesting target group for drug development in basal ganglia disorders such as Parkinson's disease (PD).

Objective: The aim of this study was to investigate CB1 receptors in PD with [ F]FMPEP-d positron emission tomography (PET) and the effect of dopaminergic medication on the [ F]FMPEP-d binding.

ASIC-E4: Interplay of Beta-Amyloid, Synaptic Density and Neuroinflammation in Cognitively Normal Volunteers With Three Levels of Genetic Risk for Late-Onset Alzheimer's Disease - Study Protocol and Baseline Characteristics.

Background: Detailed characterization of early pathophysiological changes in preclinical Alzheimer's disease (AD) is necessary to enable development of correctly targeted and timed disease-modifying treatments. ASIC-E4 study ("Beta-Amyloid, Synaptic loss, Inflammation and Cognition in healthy ε4 carriers") combines state-of-the-art neuroimaging and fluid-based biomarker measurements to study the early interplay of three key pathological features of AD, i.e.

Phenotyping of multiple sclerosis lesions according to innate immune cell activation using 18 kDa translocator protein-PET.

Chronic active lesions are promotors of neurodegeneration and disease progression in multiple sclerosis. They harbour a dense rim of activated innate immune cells at the lesion edge, which promotes lesion growth and thereby induces damage. Conventional MRI is of limited help in identifying the chronic active lesions, so alternative imaging modalities are needed.

Effect of dopaminergic medication on adenosine 2A receptor availability in patients with Parkinson's disease.

Objective: To assess the necessity of withdrawing dopaminergic medication in Parkinson's disease (PD) patients for accurate estimation of adenosine 2A receptor (AR) availability using [C]TMSX PET imaging. This was accomplished by studying the short-term effect of the cessation of dopaminergic medication on AR availability in non-dyskinetic patients with PD treated with dopaminergic medication.

Methods: Eight PD patients (age 67.

Association of Early β-Amyloid Accumulation and Neuroinflammation Measured With [C]PBR28 in Elderly Individuals Without Dementia.

Objective: To examine whether early β-amyloid (Aβ) accumulation and metabolic risk factors are associated with neuroinflammation in elderly individuals without dementia.

Methods: We examined 54 volunteers (mean age 70.0 years, 56% women, 51% ɛ4 carriers) with the translocator protein (TSPO) tracer [C]PBR28 to assess neuroinflammation and with [C] Pittsburgh compound B (PiB) to assess cerebral Aβ accumulation.

High serum neurofilament associates with diffuse white matter damage in MS.

Objective: To evaluate to which extent serum neurofilament light chain (NfL) increase is related to diffusion tensor imaging-MRI measurable diffuse normal-appearing white matter (NAWM) damage in MS.

Methods: Seventy-nine patients with MS and 10 healthy controls underwent MRI including diffusion tensor sequences and serum NfL determination by single molecule array (Simoa). Fractional anisotropy and mean, axial, and radial diffusivities were calculated within the whole and segmented (frontal, parietal, temporal, occipital, cingulate, and deep) NAWM.

Brain TSPO-PET predicts later disease progression independent of relapses in multiple sclerosis.

Overactivation of microglia is associated with most neurodegenerative diseases. In this study we examined whether PET-measurable innate immune cell activation predicts multiple sclerosis disease progression. Activation of microglia/macrophages was measured using the 18-kDa translocator protein (TSPO)-binding radioligand 11C-PK11195 and PET imaging in 69 patients with multiple sclerosis and 18 age- and sex-matched healthy controls.

Association of neuroinflammation with episodic memory: a [C]PBR28 PET study in cognitively discordant twin pairs.

Alzheimer's disease is associated with chronic response of innate immune system, referred as neuroinflammation. PET radioligands binding to the 18 kDa translocator protein are potential biomarkers of neuroinflammation. Translocator protein PET studies in mild cognitive impairment and Alzheimer's disease have indicated controversial results, possibly reflecting interindividual variation and heterogeneity of study populations.