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In this study, we develop and validate a new Parkinson's disease (PD) mouse model that can be used to better understand how the disease progresses and to test the effects of new, potentially disease-modifying, PD therapies. Our central hypothesis is that mitochondrial dysfunction intercalates with misfolded α-synuclein (α-syn) accumulation in a vicious cycle, leading to the loss of nigral neurons. Our hypothesis builds on the concept that PD involves multiple molecular insults, including mitochondrial dysfunction and aberrant α-syn handling. We predicted that mitochondrial deficits, due to heterozygous loss of Engrailed-1 (En1+/-), combined with bilateral injections of pathogenic α-syn fibrils (PFFs), will act to generate a highly relevant PD model - the En1/SYN model. Here, En1+/- mice received bilateral intrastriatal stereotaxic injections of either PBS or α-syn fibrils and were analyzed using automated behavioral tests and deep learning-assisted histological analysis at 2, 4, and 6 months post-injection. We observed significant and progressive Lewy body-like inclusion pathology in the amygdala, motor cortex, and cingulate cortex, as well as the loss of tyrosine hydroxylase-positive (TH+) cells in the substantia nigra. The En1/SYN model also exhibited significant motor impairments at 6 months post-injection, which were however not exacerbated as we had expected. Still, this model has a comprehensive number of PD-like phenotypes and is therefore superior when compared to the α-syn PFF or En1+/- models alone.
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CONTEXT.: Artificial intelligence is a transforming technology for anatomic pathology. Involvement within the workforce will foster support for algorithm development and implementation. OBJECTIVE.: To develop a supportive ecosystem that enables pathologists with variable expertise in artificial intelligence to create algorithms in a development environment with seamless transition to a production environment. RESULTS.: The development team considered internal development and vended solutions. Because of the extended timeline and resource requirements for internal development, a decision was made to use a vended solution. Vendor proposals were solicited and reviewed by pathologists, IT, and security groups. A vendor was selected and pipelines for development and production were established. Proposals for development were solicited from the pathology department. Eighty-four investigators were selected for the initial cohort, receiving training and access to dedicated subject matter experts. A total of 30 of 31 projects progressed through the model development process of annotating, training, and validation. Based on these projects, 15 abstracts were submitted to national meetings. CONCLUSIONS.: Democratizing artificial intelligence by creating an ecosystem to support pathologists with varying levels of expertise can break down entry barriers, reduce overall cost of algorithm development, improve algorithm quality, and enhance the speed of adoption.
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Symptoms in the urogenital organs are common in multiple system atrophy (MSA), also in the years preceding the MSA diagnosis. It is unknown how MSA is triggered and these observations in prodromal MSA led us to hypothesize that synucleinopathy could be triggered by infection of the genitourinary tract causing É-synuclein (ÉSyn) to aggregate in peripheral nerves innervating these organs. As a first proof that peripheral infections could act as a trigger in MSA, this study focused on lower urinary tract infections (UTIs), given the relevance and high frequency of UTIs in prodromal MSA, although other types of infection might also be important triggers of MSA. We performed an epidemiological nested-case control study in the Danish population showing that UTIs are associated with future diagnosis of MSA several years after infection and that it impacts risk in both men and women. Bacterial infection of the urinary bladder triggers synucleinopathy in mice and we propose a novel role of ÉSyn in the innate immune system response to bacteria. Urinary tract infection with uropathogenic E. coli results in the de novo aggregation of ÉSyn during neutrophil infiltration. During the infection, ÉSyn is released extracellularly from neutrophils as part of their extracellular traps. Injection of MSA aggregates into the urinary bladder leads to motor deficits and propagation of ÉSyn pathology to the central nervous system in mice overexpressing oligodendroglial ÉSyn. Repeated UTIs lead to progressive development of synucleinopathy with oligodendroglial involvement in vivo. Our results link bacterial infections with synucleinopathy and show that a host response to environmental triggers can result in ÉSyn pathology that bears semblance to MSA.
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Atrofia de Múltiples Sistemas , Sinucleinopatías , Infecciones Urinarias , Ratones , Femenino , Animales , Sinucleinopatías/patología , Estudios de Casos y Controles , Escherichia coli , Ratones Transgénicos , alfa-Sinucleína , Atrofia de Múltiples Sistemas/complicaciones , Atrofia de Múltiples Sistemas/patología , Infecciones Urinarias/complicaciones , Inmunidad InnataRESUMEN
There is growing evidence for the key role of microglial functional state in brain pathophysiology. Consequently, there is a need for efficient automated methods to measure the morphological changes distinctive of microglia functional states in research settings. Currently, many commonly used automated methods can be subject to sample representation bias, time consuming imaging, specific hardware requirements and difficulty in maintaining an accurate comparison across research environments. To overcome these issues, we use commercially available deep learning tools Aiforia® Cloud (Aifoira Inc., Cambridge, MA, United States) to quantify microglial morphology and cell counts from histopathological slides of Iba1 stained tissue sections. We provide evidence for the effective application of this method across a range of independently collected datasets in mouse models of viral infection and Parkinson's disease. Additionally, we provide a comprehensive workflow with training details and annotation strategies by feature layer that can be used as a guide to generate new models. In addition, all models described in this work are available within the Aiforia® platform for study-specific adaptation and validation.
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Autophagic dysregulation and lysosomal impairment have been implicated in the pathogenesis of Parkinson's disease, partly due to the identification of mutations in multiple genes involved in these pathways such as GBA, SNCA, ATP13a2 (also known as PARK9), TMEM175 and LRRK2. Mutations resulting in lysosomal dysfunction are proposed to contribute to Parkinson's disease by increasing α-synuclein levels, that in turn may promote aggregation of this protein. Here, we used two different genetic models-one heterozygous for a mutated form of the GBA protein (D409V), and the other heterozygous for an ATP13a2 loss-of-function mutation, to test whether these mutations exacerbate the spread of α-synuclein pathology following injection of α-synuclein preformed fibrils in the olfactory bulb of 12-week-old mice. Contrary to our hypothesis, we found that mice harboring GBA D409V+/- and ATP13a2+/- mutations did not have exacerbated behavioral impairments or histopathology (α-synuclein, LAMP2, and Iba1) when compared to their wildtype littermates. This indicates that in the young mouse brain, neither the GBA D409V mutation or ATP13a2 loss-of-function mutation accelerate the spread of α-synuclein pathology. As a consequence, we postulate that these mutations increase Parkinson's disease risk only by acting in one of the initial, upstream events in the Parkinson's disease pathogenic process. Further, the mutations, and the molecular pathways they impact, appear to play a less important role once the pathogenic process has been triggered and therefore do not specifically influence α-synuclein pathology spread.
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Autofagia/genética , Glucosilceramidasa/genética , Trastornos Parkinsonianos/genética , Agregado de Proteínas , ATPasas de Translocación de Protón/genética , Olfato/genética , alfa-Sinucleína/metabolismo , Animales , Conducta Animal , Heterocigoto , Locomoción , Mutación con Pérdida de Función , Ratones , Mutación , Bulbo Olfatorio , Corteza Olfatoria/patología , Corteza Olfatoria/fisiopatología , Enfermedad de Parkinson/genética , Enfermedad de Parkinson/patología , Enfermedad de Parkinson/fisiopatología , Trastornos Parkinsonianos/patología , Trastornos Parkinsonianos/fisiopatología , Corteza Perirrinal/patología , Corteza Perirrinal/fisiopatología , Síntomas Prodrómicos , Olfato/fisiologíaRESUMEN
Odors are well known to elicit strong emotional and behavioral responses that become strengthened throughout learning, yet the specific cellular systems involved in odor learning and the direct influence of these on behavior are unclear. Here, we investigate the representation of odor-reward associations within two areas recipient of dense olfactory input, the posterior piriform cortex (pPCX) and the olfactory tubercle (OT), using electrophysiological recordings from mice engaged in reward-based learning. Neurons in both regions represent conditioned odors and do so with similar information content, yet the proportion of neurons recruited by conditioned rewarded odors and the magnitudes and durations of their responses are greater in the OT. Using fiber photometry, we find that OT D1-type dopamine-receptor-expressing neurons flexibly represent odors based on reward associations, and using optogenetics, we show that these neurons influence behavioral engagement. These findings contribute to a model whereby OT D1 neurons support odor-guided motivated behaviors.
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Conducta Animal/fisiología , Vías Nerviosas/fisiología , Recompensa , Olfato/fisiología , Animales , Masculino , Ratones Endogámicos C57BL , Neuronas/metabolismo , Tubérculo Olfatorio/fisiología , Corteza Piriforme/fisiología , Receptores de Dopamina D1/metabolismoRESUMEN
Hyposmia is evident in over 90% of Parkinson's disease (PD) patients. A characteristic of PD is intraneuronal deposits composed in part of α-synuclein fibrils. Based on the analysis of post-mortem PD patients, Braak and colleagues suggested that early in the disease α-synuclein pathology is present in the dorsal motor nucleus of the vagus, as well as the olfactory bulb and anterior olfactory nucleus, and then later affects other interconnected brain regions. Here, we bilaterally injected α-synuclein preformed fibrils into the olfactory bulbs of wild type male and female mice. Six months after injection, the anterior olfactory nucleus and piriform cortex displayed a high α-synuclein pathology load. We evaluated olfactory perceptual function by monitoring odor-evoked sniffing behavior in a plethysmograph at one-, three- and six-months after injection. No overt impairments in the ability to engage in sniffing were evident in any group, suggesting preservation of the ability to coordinate respiration. At all-time points, females injected with fibrils exhibited reduced odor detection sensitivity, which was observed with the semi-automated plethysmography apparatus, but not a buried pellet test. In future studies, this sensitive methodology for assessing olfactory detection deficits could be used to define how α-synuclein pathology affects other aspects of olfactory perception and to clarify the neuropathological underpinnings of these deficits.
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Conducta Animal , Odorantes , Bulbo Olfatorio/fisiopatología , Enfermedad de Parkinson/fisiopatología , Animales , Modelos Animales de Enfermedad , Femenino , Masculino , Ratones Endogámicos C57BL , Pletismografía , RespiraciónRESUMEN
The ventral striatum is a collection of brain structures, including the nucleus accumbens, ventral pallidum and the olfactory tubercle (OT). While much attention has been devoted to the nucleus accumbens, a comprehensive understanding of the ventral striatum and its contributions to neurological diseases requires an appreciation for the complex neurochemical makeup of the ventral striatum's other components. This review summarizes the rich neurochemical composition of the OT, including the neurotransmitters, neuromodulators and hormones present. We also address the receptors and transporters involved in each system as well as their putative functional roles. Finally, we end with briefly reviewing select literature regarding neurochemical changes in the OT in the context of neurological disorders, specifically neurodegenerative disorders. By overviewing the vast literature on the neurochemical composition of the OT, this review will serve to aid future research into the neurobiology of the ventral striatum.
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Tubérculo Olfatorio , Animales , Humanos , Estriado VentralRESUMEN
This study tested the hypotheses that maternal and paternal effects differentially influence expression of their offspring's adult behavior and underlying neural mechanisms. We predicted that maternal influences would be greater than paternal influences on male offspring. We tested these hypotheses by cross-breeding two phenotypically-, behaviorally- and neuroanatomically-distinct populations of prairie voles (Microtus ochrogaster) from Illinois, which are highly prosocial, and Kansas, which are significantly less prosocial. Females from each population were crossed with males from the other population. F1 crosses were tested as adults to determine the effect of parentage on the expression of prosocial behavior and aggression, using a same-sex dyadic encounter and a heterosexual partner preference test, and for the expression of oxytocin (OT) and arginine vasopressin (AVP) in the paraventricular nucleus of the hypothalamus (PVN). As predicted, all significant differences in males, behavioral, OT and AVP immunoreactivity, were associated exclusively with maternal influences. There was a significant effect of treatment in the OT immunoreactivity of females. The effect of treatment in females' OT was associated with an interaction of population and sex, while same-sex social interactions differences were associated with population. Finally, in females, paternity influenced heterosexual bonds, with females with Illinois sires forming a partner preference. The results indicate that maternal influences dominate in male offspring, suggesting a parent-of-origin effect, while paternal effects are limited to selected prosocial behavioral expression in daughters.
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Arginina Vasopresina/metabolismo , Herencia Materna/fisiología , Oxitocina/metabolismo , Núcleo Hipotalámico Paraventricular/metabolismo , Herencia Paterna/fisiología , Conducta Social , Análisis de Varianza , Animales , Arvicolinae , Femenino , Masculino , Apareamiento , Caracteres SexualesRESUMEN
OBJECTIVE: In this study, empathy is quantified using a novel social test. Empathy and prosocial behavior are linked to the expression of oxytocin in humans and rodent models. Specifically, prosocial behavior in prairie voles (Microtus ochrogaster) has been linked to the expression of oxytocin in the paraventricular nucleus of the hypothalamus. The animal's behavior was considered empathic if it spends significantly more time attempting to remove a loos fitting restraint (tether) from the stimulus animal than time in contact with a, simultaneously presented, non-social object similar to the tether. The behavioral data was cross-referenced with the number of neurons expressing oxytocin and arginine vasopressin, as well as the density of dopaminergic neurons (identified by the expression of tyrosine hydroxylase), in the paraventricular nucleus of the hypothalamus. These proteins influence empathic behavior in humans, non-human primates, rats, mice, and prairie voles. RESULTS: The consistency between neuroanatomical mechanisms linked to empathy, and the durations of time spent engaging in empathic contact, support the prediction that the empathic contact in this test is a distinct prosocial behavior, lacking prior behavioral training or the naturally occurring ethological relevance of other prosocial behaviors, and is a measure of empathy.
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Arginina Vasopresina/genética , Arvicolinae/psicología , Conducta Animal/fisiología , Conducta Cooperativa , Empatía/fisiología , Oxitocina/genética , Animales , Arginina Vasopresina/metabolismo , Arvicolinae/fisiología , Neuronas Dopaminérgicas/citología , Neuronas Dopaminérgicas/metabolismo , Femenino , Expresión Génica , Humanos , Hipotálamo/citología , Hipotálamo/metabolismo , Masculino , Modelos Animales , Oxitocina/metabolismo , Núcleo Hipotalámico Paraventricular/citología , Núcleo Hipotalámico Paraventricular/metabolismo , Tirosina 3-Monooxigenasa/genética , Tirosina 3-Monooxigenasa/metabolismoRESUMEN
This study tested the hypothesis that site-specific estrogen receptor alpha (ERα) expression is a critical factor in the expression of male prosocial behavior and aggression. Previous studies have shown that in the socially monogamous prairie vole (Microtus ochrogaster) low levels of ERα expression, in the medial amygdala (MeA), play an essential role in the expression of high levels of male prosocial behavior and that increasing ERα expression reduced male prosocial behavior. We used an shRNA adeno-associated viral vector to knock down/inhibit ERα in the MeA of the polygynous male meadow vole (M. pennsylvanicus), which displays significantly higher levels of ERα in the MeA than its monogamous relative. Control males were transfected with a luciferase expressing AAV vector. After treatment males participated in three social behavior tests, a same-sex dyadic encounter, an opposite-sex social preference test and an alloparental test. We predicted that decreasing MeA ERα would increase male meadow vole's prosocial behavior and reduce aggression. The results generally supported the hypothesis. Specifically, MeA knockdown males displayed lower levels of defensive aggression during dyadic encounters and increased levels of overall side-x-side physical contact with females during the social preference test, eliminating the partner preference observed in controls. There was no effect on pup interactions, with both treatments expressing low levels of alloparental behavior. Behaviors affected were similar to those in male prairie voles with increased ERα in the BST rather than the MeA, suggesting that relative changes of expression within these nuclei may play a critical role in regulating prosocial behavior.
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Amígdala del Cerebelo/metabolismo , Conducta Animal/fisiología , Receptor alfa de Estrógeno/metabolismo , Conducta Social , Animales , Arvicolinae , Receptor alfa de Estrógeno/antagonistas & inhibidores , Receptor alfa de Estrógeno/genética , Técnicas de Silenciamiento del Gen , Masculino , Conducta Paterna/fisiologíaRESUMEN
Animals choose between sensory stimuli, a highly complex behavior which includes detection, discrimination, preference, and memory processes. Rodents are reported to display robust preferences for some odors, for instance, in the context of choosing among possible mates or food items. In contrast to the apparent robustness of responses toward these and other "ethologically relevant" odors, little is known about the robustness of behaviors toward odors which have no overt role in the rodent ecological niche, so-called "nonethologically relevant" odors. We developed an apparatus for monitoring the nose-poking behavior of mice and used this apparatus to explore the prevalence and stability of choices among different odors both across mice, and within mice over successive days. Mice were tested with a panel of either ethologically relevant or nonethologically relevant odors in an olfactory multiple-choice test. Significant preferences to nonethologically relevant odors were observed across the population of mice, with longer investigation durations to some odors more than to others. However, we found substantial inter-mouse variability in these responses, and that responses to these odors even varied within mice across days of testing. Tests with ethologically relevant odors revealed that responses toward these odors were also variable across mice, but within individual mice, responses were somewhat stable. This work establishes an olfactory multiple-choice test for monitoring odor investigation, choice, and preference behaviors and the application of this apparatus to assess across- and within-mouse odor-preference choice stability. These results highlight that odor preferences, as assayed by measuring choice behaviors, are variable. (PsycINFO Database Record
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Conducta Animal , Conducta de Elección , Percepción Olfatoria , Animales , Escala de Evaluación de la Conducta , Individualidad , Masculino , Ratones Endogámicos C57BL , Actividad Motora , Nariz , Odorantes , Olfato , Factores de TiempoRESUMEN
BACKGROUND: A traditional lecture-based pedagogy conveys information and content while lacking sufficient development of critical thinking skills and problem solving. A puzzle-based pedagogy creates a broader contextual framework, and fosters critical thinking as well as logical reasoning skills that can then be used to improve a student's performance on content specific assessments. This paper describes a pedagogical comparison of traditional lecture-based teaching and puzzle-based teaching in a Human Anatomy and Physiology II Lab. METHODS: Using a single subject/cross-over design half of the students from seven sections of the course were taught using one type of pedagogy for the first half of the semester, and then taught with a different pedagogy for the second half of the semester. The other half of the students were taught the same material but with the order of the pedagogies reversed. Students' performance on quizzes and exams specific to the course, and in-class assignments specific to this study were assessed for: learning outcomes (the ability to form the correct conclusion or recall specific information), and authentic academic performance as described by (Am J Educ 104:280-312, 1996). RESULTS: Our findings suggest a significant improvement in students' performance on standard course specific assessments using a puzzle-based pedagogy versus a traditional lecture-based teaching style. Quiz and test scores for students improved by 2.1 and 0.4% respectively in the puzzle-based pedagogy, versus the traditional lecture-based teaching. Additionally, the assessments of authentic academic performance may only effectively measure a broader conceptual understanding in a limited set of contexts, and not in the context of a Human Anatomy and Physiology II Lab. CONCLUSION: In conclusion, a puzzle-based pedagogy, when compared to traditional lecture-based teaching, can effectively enhance the performance of students on standard course specific assessments, even when the assessments only test a limited conceptual understanding of the material.
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Anatomía/educación , Escolaridad , Fisiología/educación , Enseñanza , Educación de Pregrado en Medicina/métodos , Evaluación Educacional , Humanos , Enseñanza/métodosRESUMEN
Impacts on brain and behavior have been reported in laboratory rodents after developmental exposure to bisphenol A (BPA), raising concerns about possible human effects. Epidemiological data suggest links between prenatal BPA exposure and altered affective behaviors in children, but potential mechanisms are unclear. Disruption of mesolimbic oxytocin (OT)/vasopressin (AVP) pathways have been proposed, but supporting evidence is minimal. To address these data gaps, we employed a novel animal model for neuroendocrine toxicology: the prairie vole (Microtus ochrogaster), which are more prosocial than lab rats or mice. Male and female prairie vole pups were orally exposed to 5-µg/kg body weight (bw)/d, 50-µg/kg bw/d, or 50-mg/kg bw/d BPA or vehicle over postnatal days 8-14. Subjects were tested as juveniles in open field and novel social tests and for partner preference as adults. Brains were then collected and assessed for immunoreactive (ir) tyrosine hydroxylase (TH) (a dopamine marker) neurons in the principal bed nucleus of the stria terminalis (pBNST) and TH-ir, OT-ir, and AVP-ir neurons in the paraventricular nucleus of the hypothalamus (PVN). Female open field activity indicated hyperactivity at the lowest dose and anxiety at the highest dose. Effects on social interactions were also observed, and partner preference formation was mildly inhibited at all dose levels. BPA masculinized principal bed nucleus of the stria terminalis TH-ir neuron numbers in females. Additionally, 50-mg/kg bw BPA-exposed females had more AVP-ir neurons in the anterior PVN and fewer OT-ir neurons in the posterior PVN. At the 2 lowest doses, BPA eliminated sex differences in PVN TH-ir neuron numbers and reversed this sex difference at the highest dose. Minimal behavioral effects were observed in BPA-exposed males. These data support the hypothesis that BPA alters affective behaviors, potentially via disruption of OT/AVP pathways.