Publications by authors named "Anna Stoll"

Article Synopsis
  • The text discusses the importance of annotating multiple brain regions in mouse models for neuroscience research and highlights the limitations of manual annotation by trained pathologists, which slows down the overall process.
  • It introduces AnNoBrainer, an open-source software tool that uses deep learning and other advanced techniques to automate brain region annotation on pathology slides, aiming to improve efficiency.
  • AnNoBrainer has shown to be accurate and reproducible, cutting annotation time by about 50%, and meets expert standards, thereby facilitating faster image analysis in neuroscience labs.
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Mutations in the gene, which encodes the abundant brain G-protein G , result in neurologic disorders characterized by developmental delay, epilepsy, and movement abnormalities. There are over 50 mutant alleles associated with disorders; the R209H mutation results in dystonia, choreoathetosis, and developmental delay without seizures. Mice heterozygous for the human mutant allele ( ) exhibit hyperactivity in open field tests but no seizures.

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Background: Parkinson's disease (PD) is a neurodegenerative disorder that is characterized by the presence of proteinaceous alpha-synuclein (α-syn) inclusions (Lewy bodies), markers of neuroinflammation and the progressive loss of nigrostriatal dopamine (DA) neurons. These pathological features can be recapitulated in vivo using the α-syn preformed fibril (PFF) model of synucleinopathy. We have previously determined that microglia proximal to PFF-induced nigral α-syn inclusions increase in soma size, upregulate major-histocompatibility complex-II (MHC-II) expression, and increase expression of a suite of inflammation-associated transcripts.

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Parkinson's disease (PD) is characterized by the accumulation of misfolded alpha-synuclein (α-syn) protein, forming intraneuronal Lewy body (LB) inclusions. The α-syn preformed fibril (PFF) model of PD recapitulates α-syn aggregation, progressive nigrostriatal degeneration and motor dysfunction; however, little is known about the time course of PFF-induced alterations in basal and evoked dopamine (DA). In vivo microdialysis is well suited for identifying small changes in neurotransmitter levels over extended periods.

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Parkinson's disease (PD) pathology is characterized by alpha-synuclein (α-syn) aggregates, degeneration of dopamine neurons in the substantia nigra pars compacta (SNpc), and neuroinflammation. The presence of reactive glia correlates with deposition of pathological α-syn in early-stage PD. Thus, understanding the neuroinflammatory response of microglia and astrocytes to synucleinopathy may identify therapeutic targets.

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Article Synopsis
  • - Understanding the early phases of synucleinopathy, particularly before neurodegeneration occurs, is crucial for developing therapies and studying disease progression, as shown in a rat model that mimics Parkinson's disease pathology.
  • - In the study, researchers utilized laser capture microdissection and RNA sequencing to identify transcriptional changes in the substantia nigra, revealing that immune response-related transcripts increase while neurotransmission and dopamine pathway-related transcripts decrease during early synucleinopathy.
  • - Verification of 29 specific transcripts associated with neurotransmission and dopamine pathways was conducted and findings indicated that decreases in transcripts like Syt1 and Slc6a3 were present in neurons with pSyn inclusions, shedding light on the molecular mechanisms that may drive
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Article Synopsis
  • Parkinson's disease (PD) is rapidly increasing globally, especially in industrialized regions, indicating potential environmental influences, specifically from pollutants like dieldrin, a pesticide.
  • Research on mice reveals that exposure to dieldrin during development makes them more vulnerable to neuron damage and motor function deficits when exposed to α-synuclein, a protein linked to PD.
  • The study shows that while dieldrin exposure increases dopamine release in certain brain areas affected by α-synuclein, it doesn't change VMAT2 activity, suggesting that early exposure to dieldrin may heighten the brain's response to neurodegeneration without obvious signs of damage.
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Article Synopsis
  • Parkinson's disease (PD) involves neurodegeneration marked by alpha-synuclein accumulation and neuroinflammation, which can be studied in a rat model using preformed fibrils (PFF).
  • The study aimed to assess if depleting microglia with a CSF1R inhibitor (Pexidartinib) influences alpha-synuclein aggregation or neuron degeneration in this model.
  • Results showed that microglial depletion did not reduce alpha-synuclein accumulation or neuron loss, and unexpectedly led to an increase in the size of the remaining microglia.
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Neuroinflammation has become a well-accepted pathologic hallmark of Parkinson's disease (PD). However, it remains unclear whether inflammation, triggered by α-syn aggregation and/or degeneration, contributes to the progression of the disease. Studies examining neuroinflammation in PD are unable to distinguish between Lewy body-associated inflammation and degeneration-associated inflammation, as both pathologies are present simultaneously.

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β2-adrenoreceptor (β2AR) agonists have been associated with a decreased risk of developing Parkinson's disease (PD) and are hypothesized to decrease expression of both alpha-synuclein mRNA (Snca) and protein (α-syn). Effects of β2AR agonist clenbuterol on the levels of Snca mRNA and α-syn protein were evaluated in vivo (rats and mice) and in rat primary cortical neurons by two independent laboratories. A modest decrease in Snca mRNA in the substantia nigra was observed after a single acute dose of clenbuterol in rats, however, this decrease was not maintained after multiple doses.

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Background: Positron emission tomography (PET) imaging in early Parkinson's disease (PD) subjects reveals that increased dopamine (DA) turnover and reduced dopamine transporter (DAT) density precede decreases in DA synthesis and storage. The rat α-synuclein preformed fibril (α-syn PFF) model provides a platform to investigate DA dynamics during multiple stages of α-syn inclusion-triggered nigrostriatal degeneration.

Objectives: We investigated multiple aspects of in vivo dopaminergic deficits longitudinally and similarities to human PD using translational PET imaging readouts.

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Cytochrome P450s (CYPs) are an essential family of enzymes in the human body. They play a crucial role in metabolism, especially in human steroid biosynthesis. Reactions catalyzed by these enzymes are highly stereo- and regio-specific.

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Preclinical studies show a link between subthalamic nucleus (STN) deep brain stimulation (DBS) and neuroprotection of nigrostriatal dopamine (DA) neurons, potentially through brain-derived neurotrophic factor (BDNF) signaling. However, the question of whether DBS of the STN can be disease-modifying in Parkinson's disease (PD) remains unanswered. In particular, the impact of STN DBS on α-synuclein (α-syn) aggregation, inclusion-associated neuroinflammation, and BDNF levels has yet to be examined in the context of synucleinopathy.

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Anabolic androgenic steroids (AAS) are prohibited as doping substances in sports by the World Anti-Doping Agency. Concentrations and concentration ratios of endogenous AAS (steroid profile markers) in urine samples collected from athletes are used to detect their administration. Certain (non-prohibited) drugs have been shown to influence the steroid profile and thereby sophisticate anti-doping analysis.

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Anabolic androgenic steroids (AAS) are prohibited as performance-enhancing drugs in sports. Among them, testosterone and its precursors are often referred to as "pseudoendogenous" AAS, that is, endogenous steroids that are prohibited when administered exogenously. To detect their misuse, among other methods, the World Anti-Doping Agency-accredited laboratories monitor the steroid profile (concentrations and concentration ratios of endogenous steroids, precursors and metabolites) in urine samples collected from athletes in and out of competition.

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Cytochrome P450 enzymes (CYPs) are capable of catalyzing regio- and stereo-specific oxy functionalization reactions, which otherwise are major challenges in organic chemistry. In order to make the best possible use of these biocatalysts it is imperative to understand their specificities. Human CYP21A2 (steroid 21-hydroxylase) acts on the side-chain attached to C-17 in ring D of a steroid substrate, but the configuration of ring A also plays a prominent role in substrate cognition.

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Article Synopsis
  • Animal models that mimic the features of Parkinson's disease, such as α-synuclein accumulation and neurodegeneration in the nigrostriatal system, are essential for research in the field.
  • Researchers optimized the preformed fibril (PFF) synucleinopathy model in rodents by varying the amounts of α-syn PFFs injected to enhance α-syn accumulation and neurodegeneration.
  • Results showed that increased doses of α-syn PFFs led to greater inclusion formation and loss of dopamine neurons, alongside observable motor deficits, providing a reliable model for studying disease mechanisms and potential therapies.
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Article Synopsis
  • Mitochondrial impairment and abnormal calcium levels are linked to Parkinson's disease, leading to reduced ATP and increased calpain activation, which affects the integrity of Parkin, a protein involved in maintaining cellular health.
  • Experiments with mitochondrial inhibitors (such as oligomycin) showed that they cause calpain to cleave Parkin into smaller fragments, while other agents induced different types of cleavage that suggest involvement in apoptosis.
  • Pre-treatment with certain inhibitors can stabilize Parkin and reduce its cleavage, highlighting the potential connection between Parkin phosphorylation and its cleavage due to mitochondrial dysfunction and calcium imbalance, which may play a role in the progression of Parkinson's disease.
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Animal models have significantly advanced our understanding of Parkinson's disease (PD). Alpha-synuclein (α-syn) has taken center stage due to its genetic connection to familial PD and localization to Lewy bodies, one pathological hallmark of PD. Animal models developed on the premise of elevated alpha-synuclein via germline manipulation or viral vector-mediated overexpression are used to investigate PD pathophysiology and vet novel therapeutics.

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Anabolic androgenic steroids (AAS) are misused very frequently in sport competitions as performance enhancing agents. One of the doping compounds that has been detected with increased frequency in the last few years is dehydrochloromethyltestosterone (DHCMT, 4-chloro-17β-hydroxy-17α-methylandrosta-1,4-dien-3-one; brand name Oral Turinabol). The long-term DHCMT metabolite 20βOH-NorDHCMT (4-chloro-17β-hydroxymethyl-17α-methyl-18-norandrosta-1,4,13-trien-3-one) was reported earlier to be detectable in urine samples for more than 22 days after DHCMT administration; however, purified reference material was not available so far.

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Fowlpox (FP)-vectored avian influenza (FP-AI) vaccines are used in 1-day-old chickens, but they have also recently been shown to be immunogenic in ducks. The objectives of this work were 1) to evaluate safety and to compare the immunogenicity in ducks of three poxvirus vectors (fowlpox, canarypox, and vaccinia) expressing the same hemagglutinin gene from an H5N1 isolate, 2) to study the effect of the dose of the FP-AI and the presence of an adjuvant in 1-day-old Pekin ducks on antibody response after a boost with inactivated vaccine given 3 wk later, and 3) to confirm the immunogenicity of such a heterologous prime-boost vaccination scheme in 1-day-old Muscovy ducks. Immunogenicity induced by the three poxvirus vectors was comparable, and the FP vector was selected for the other studies.

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