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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

[pt] CONDICIONAMENTO AO MEDO ESPECÍFICO NAS LINHAGENS DOS CARIOCAS DE ALTO (CAC) E BAIXO CONGELAMENTO (CBC) / [en] SPECIFIC FEAR CONDITIONING IN CARIOCA HIGH-AND LOW-CONDITIONED FREEZING RATS

CAROLINA MACEDO DE SOUZA 14 May 2020 (has links)
[pt] Os distúrbios de ansiedade compreendem uma ampla gama de condições psiquiátricas, incluindo transtorno de ansiedade generalizada (TAG) e fobia específica. Nas últimas décadas, o uso de modelos animais de ansiedade ofereceu importantes insights sobre a interação dessas psicopatologias. Aqui nós investigamos se os ratos Cariocas de alto e baixo congelamento (CAC e CBC, respectivamente), um modelo animal de TAG, mostram fenótipos comportamentais de alto e baixo congelamento similar no condicionamento de medo ao som. Ratos adultos das linhagens CAC (n igual 16), CBC (n igual 16) e ratos Wistar normais (controle, CTL) foram testados em um paradigma de condicionamento clássico de medo ao som durante 3 dias. Respostas de congelamento foram medidas e usadas como evidência de condicionamento de medo. No geral, os ratos CAC e CBC, bem como os animais CTL, apresentaram um condicionamento de medo ao estímulo condicionado auditivo. No entanto, os animais CBC também mostraram uma rápida extinção ao estímulo condicionado auditivo. Discutimos esses resultados de acordo com dados comportamentais e neuronais observados em linhagens de roedores de alta e baixa ansiedade. / [en] Anxiety disorders comprise a broad range of psychiatric conditions, including general anxiety (GAD) and specific phobias. For the last decades the use of animal models of anxiety has offered important insights into the understanding of the association between these psychopathologies. Here we investigate whether Carioca high and low conditioned freezing rats (CHF and CLF, respectively), a GAD animal model of anxiety, show similar high and low freezing behavioral phenotypes for cued auditory fear conditioning. Adult CHF (n equal 16), CLF (n equal 16) and normal age-matched Wistar rats (control, CTL) were tested in a classical auditory cued fear conditioning paradigm over 3 days. Freezing responses were measured and used as evidence of fear conditioning. Overall, both CHF and CLF rats as well as CTL animals displayed fear conditioning to the auditory CS. However, CLF animals showed a rapid extinction to the auditory conditioned stimulus compared to CHF and CTL rats. We discuss these findings in the context of the behavioural and neuronal differences observed in rodent lines of high and low anxiety traits.
212

The Relationship Between Gut Microbiota and Metabolites in the Expression of Generalized Anxiety Disorder

Thrasher, Devinne January 2020 (has links)
Anxiety disorders are the most prevalent psychiatric conditions within primary care, affecting up to 29% of people across their lifetime. Generalized Anxiety disorder (GAD) is frequently comorbid with Major Depressive Disorder (MDD), resulting in greater functional impairment. Gut microbiota have been shown to modulate brain chemistry and function, possibly also playing a role in the genesis of anxiety. Bacteria are also able to produce, or interact with the host metabolism of neuroactive substances, including classical neurotransmitters and trace amines, like octopamine, which although found in trace concentrations in the mammalian brain, can affect CNS function. Specifically, trace amines can affect catecholamine release, reuptake and biosynthesis, and modulate dopamine and serotonin metabolism. We investigated whether microbiota from patients with GAD with no signs of immune activation can alter behaviour in gnotobiotic mice and whether this is accompanied by changes in metabolites within the gastrointestinal tract. Germ-free NIH Swiss mice (n=35) were colonized with microbiota from either a GAD patient (n=18) with severe anxiety, comorbid depression, and low serum and fecal octopamine, or an age and sex-matched healthy control (HC) (n=17). Three weeks post- colonization, mouse behaviour was assessed by standard psychometric tests. Emotionality z-scores were calculated to provide a robust integrated behavioural assessment. Microbiota profiles were assessed by 16S rRNA based Illumina, fecal β-defensin-3 level was measured by ELISA. After sacrifice, mouse brain BDNF and GDNF expression was assessed by immunofluorescence, and gene expression in the hippocampus, amygdala, and olfactory bulbs was assessed by Nanostring. Stool and cecum metabolites were measured in all colonized mice by multisegment injection-capillary electrophoresis-mass spectrometry (MSI-CE-MS). There were no differences in fecal β-defensin levels between mice colonized with GAD microbiota as compared to mice colonized with HC microbiota. However, GAD mice exhibited greater anxiety and depressive-like behavior compared to HC mice in the digging and tail suspensions tests. Behavioural z-scoring across all six standard psychometric tests showed a significant increase in group emotionality score means of GAD-colonized mice compared to HC-colonized mice. Mice colonized with microbiota from a GAD patient had distinct bacterial profiles from mice colonized with HC microbiota. Compared to HC mice, GAD mice had lower levels of dopamine, octopamine and acetylcholine in cecum contents. Furthermore, GAD mice had higher expression of BDNF in the amygdala, lower expression of BDNF in the hippocampus, and lower expression of GDNF in the midbrain. GAD mice also had lower expression of CCR2 in the hippocampus, higher Cnlp/CAMP in the amygdala and olfactory bulb, and higher Nfkb1 in the olfactory bulb compared to HC mice. Our results suggest that microbiota from a selected patient with GAD has the ability to induce anxiety and depressive-like behavior, by mechanisms independent of immune system, likely by altered production of biogenic amines and neurotransmitters. / Thesis / Master of Science (MSc)
213

Die Bedeutung peripartaler mütterlicher Angst- und depressiver Störungen für die frühkindliche Entwicklung: Ergebnisse einer prospektiv-longitudinalen Studie

Sommer, Maria, Knappe, Susanne, Garthus-Niegel, Susan, Weidner, Kerstin, Martini, Julia 05 April 2024 (has links)
Theoretischer Hintergrund: Aktuelle Studien zeigen spezifische Zusammenhänge von peripartalen psychischen Störungen und kindlichen Entwicklungsauffälligkeiten. Fragestellung: Haben Kinder von Müttern mit einer peripartalen Angst- oder depressiven Störung ein erhöhtes Risiko für (visuo–)‌motorische, sprachliche und kognitive Entwicklungsauffälligkeiten? Methode: In der prospektiven MARI-Studie (N = 306) wurden peripartale psychische Störungen mit dem CIDI-V in jedem Schwangerschaftstrimester sowie 2, 4 und 16 Monate nach der Geburt erhoben. Die kindliche Entwicklung wurde mit dem Neuropsychologischen Entwicklungs-Screening im Alter von 4 (N = 263) und 16 Monaten (N = 241) erfasst. Ergebnisse: Maternale depressive Störungen vor der Schwangerschaft waren negativ mit der visuellen Entwicklung (4 Monate; OR = 3.3) und der Haltungs- und Bewegungssteuerung (16 Monate; OR = 4.4) des Kindes assoziiert. Diskussion: Entwicklungsauffälligkeiten könnten u. a. durch ein verändertes Interaktionsverhalten (z. B. weniger Blickkontakt/Ermutigung) betroffener Mütter begründet sein. / Theoretical background: Anxiety and depressive disorders are among the most prevalent perinatal disorders, and specific associations with child development have to be distinguished to derive early targeted interventions. Objective: Are children of mothers with peripartum anxiety or depressive disorder at increased risk for (visuo–)‌motor, language, and cognitive developmental abnormalities? Method: In this prospective-longitudinal MARI study, N = 306 women were examined three time during pregnancy and at 2, 4, and 16 months after delivery using the Composite International Diagnostic Interview for Women (CIDI-V) to assess their anxiety and depressive disorders. Child development was assessed at 4 (N = 263) and 16 months postpartum (N = 241) using a standardized development test (Neuropsychologisches Entwicklungs-Screening, NES). Results: Maternal depressive disorders prior to pregnancy were associated with infant visual development at 4 months (OR = 3.3) and motor development at 16 months (OR = 4.4) postpartum. The results remained stable after adjustment for preterm delivery and perceived maternal social support. Discussion and conclusion: Developmental adversities in infants of mothers with prior depressive disorders might be explained by altered mother-child interaction (e. g., less eye contact, less engagement). Early identification of expectant mothers with a history of depressive disorders is crucial for early targeted intervention. Further studies are needed to examine the mechanisms of transmission to derive innovative approaches for prevention.
214

Analysis of genetic variation in microrna-mediated regulation and the susceptibility to anxiety disorders

Muiños Gimeno, Margarita 18 December 2009 (has links)
We have investigated genetic variation in microRNA-mediated regulation as a susceptibility factor for anxiety disorders following two different approaches. We first studied two isoforms of the candidate gene NTRK3 by re-sequencing its different 3'UTRs in patients with Panic (PD) and Obsessive Compulsive disorders (OCD) as well as controls. Two rare variants that altered microRNA-mediated regulation were identified in PD. Conversely, association of a common SNP with OCD hoarding subtype was found. Moreover, we have also studied a possible involvement of microRNAs in anxiety disorders. Consequently, we have analysed the genomic organisation and genetic variation of miRNA-containing regions to construct a panel of SNPs for association analysis. Case-control studies revealed several associations. However, it is worth remarking the associations of miR-22 and miR-488 with PD; two microRNAs for which functional assays and transcriptome analysis after microRNA overexpression showed significant repression of a subset of genes involved in physiological pathways linked to PD development. / Hem investigat la variació genètica a la regulació mediada per microRNAs com a factors de susceptibilitat pels trastorns d'ansietat seguint dues aproximacions diferents. Primer vam estudiar dues isoformes del gen candidat NTRK3 mitjançant la reseqüenciació dels seus diferents 3'UTRs a pacients de pànic (TP), a pacients amb trastorn obsessiu compulsiu (TOC) i a controls. Dues variants rares que alteren la regulació mediada per microRNAs foren identificades per TP. D'altra banda, es trobà associació d'un SNP comú amb el subtipus acumulador de TOC. A més, també hem estudiat la possible implicació dels microRNAs als trastorns d'ansietat. Conseqüentment, hem analitzat l'organització genòmica i la variació genètica a regions que contenen microRNAs per construir un panell d'SNPs per fer anàlisis d'associació. Els estudis cas-control van revelar algunes associacions. Tanmateix, val la pena destacar les associacions del miR-22 i el miR-488 amb TP; dos microRNAs pels quals assajos funcionals i anàlisis de transcriptoma després de la seva sobreexpressió han mostrat una repressió significativa d'un grup de gens implicats en vies fisiològiques lligades al desenvolupament del TP.

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