@phdthesis{Schneider2020,
  author    = {Schneider, Felicitas Maria Hannelore},
  title     = {Vergleichende Evaluierung verschiedener Ans{\"a}tze des Memory Enhancement bei neurodegenerativen Prozessen},
  doi       = {10.25972/OPUS-20756},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-207562},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2020},
  abstract  = {Angesichts des dramatischen, weltweiten Anstiegs der Pr{\"a}valenz von Demenzerkrankungen und der aktuellen, unzureichenden Therapieans{\"a}tze ist die Bereitstellung neuer, wirkungsvoller Behandlungsoptionen von gr{\"o}ßter Bedeutung. Technologische, pharmakologische und verhaltensbasierte Verfahren des Memory Enhancement k{\"o}nnten zur L{\"o}sung dieses Problems beitragen: Hierzu z{\"a}hlt die Stammzelltransplantation, die in mehreren Tierstudien zu einer Verbesserung der Ged{\"a}chtnisfunktion f{\"u}hrte. Zudem wird seit L{\"a}ngerem an einer Impfung gegen die Alzheimer-Krankheit mittels β-Amyloid-Antik{\"o}rpern geforscht. Ein weiterer therapeutischer Ansatz f{\"u}r die Alzheimer-Krankheit besteht in der optogenetischen Stimulation spezifischer hippocampaler Engramm-Zellen, durch die bei einem Maus-Modell verloren gegangene Erinnerungen wiederhergestellt werden konnten. Unkonventionelle Pharmazeutika wie Erythropoetin f{\"u}hrten in Tierstudien und bei Patienten mit neuropsychiatrischen Erkrankungen zu einer Verbesserung der kognitiven F{\"a}higkeiten und des Ged{\"a}chtnisses. Eine Modifikation der Ern{\"a}hrung und der Einsatz von Pro- und Pr{\"a}biotika beeinflussen das Ged{\"a}chtnis {\"u}ber eine Manipulation der Darm-Hirn-Achse. Verhaltensbasierte Maßnahmen wie k{\"o}rperliche Aktivit{\"a}t und der Einsatz von Mnemotechniken stellen effektive Ans{\"a}tze des Memory Enhancement dar, welche bereits heute von gesunden Individuen implementiert werden k{\"o}nnen. F{\"u}r die Anwendung von Augmented Reality (AR) konnten kognitionsf{\"o}rdernde Wirkungen beim Lernen neuroanatomischer Themen und dem Zusammenbau von Objekten nachgewiesen werden. Besonders vielversprechend stellt sich die Entwicklung einer Ged{\"a}chtnisprothese dar, durch die vergessene Informationen bei Personen mit stattgehabtem Sch{\"a}del-Hirn-Trauma und apoplektischem Insult reaktiviert werden k{\"o}nnten. Memory Enhancement ist prinzipiell bereits heute bei gesunden und kranken Individuen anwendbar und verspricht wirksame zuk{\"u}nftige Pr{\"a}ventions- und Therapieoptionen. Ein realer Einsatz in der klinischen Praxis ist in naher Zukunft jedoch noch nicht zu erwarten.},
  subject      = {Neurodegeneration},
  language  = {de}
}
@phdthesis{Friedrich2019,
  author    = {Friedrich, Maximilian Uwe},
  title     = {Funktionelle Charakterisierung einer Tripletdeletion in SLC5A4 (SGLT3) als Kandidatengen f{\"u}r das Aufmerksamkeitsdefizit-/ Hyperaktivit{\"a}tssyndrom (ADHS)},
  doi       = {10.25972/OPUS-18479},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-184791},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2019},
  abstract  = {Natrium-Glukose Transporter (SGLT) geh{\"o}ren zur „solute carrier 5" (SLC5) Familie, die sich durch einen sekund{\"a}r aktiven, natriumabh{\"a}ngigen Transport von Zuckern und an-deren Molek{\"u}len nach intrazellul{\"a}r auszeichnen. Die durch das Gen SLC5A4 kodierte Isoform SGLT3 transportiert dagegen keinen Zucker, sondern verh{\"a}lt sich als Glukosesensor, der nach Bindung seiner Liganden eine Membrandepolarisation induziert. In genomweiten Exomsequenzierungsstudien (whole exome sequencing, WES) mehrerer erweiterter Stammb{\"a}ume mit hoher Pr{\"a}valenz des Aufmerksamkeitsdefizit-/Hyperaktivit{\"a}tssyndroms (ADHS) wurde im Vorfeld eine ATG-Tripletdeletion in SLC5A4 identifiziert, die zum Verlust einer Aminos{\"a}ure (ΔM500) in SGLT3 f{\"u}hrt und zumindest partiell mit dem klinischen Ph{\"a}notyp kosegregiert. In der vorliegenden Arbeit wurde die zentralnerv{\"o}se Expression von SGLT3 auf RNA- Ebene mittels Reverse-Transkriptase PCR sowie real-time PCR aus humanen Gesamt-RNAs nachgewiesen. Dabei konnte eine ubiquit{\"a}re Expression im Gehirn mit relativ erh{\"o}hter Expression unter anderem in Striatum und Hypothalamus, deren Dysfunktion in der Pathogenese des ADHS impliziert wurde, gezeigt werden. Da Mutationen in homologen Dom{\"a}nen der eng strukturverwandten Isoformen SGLT1 und SGLT2 sowohl intestinale als auch renale Funktionen schwer beeintr{\"a}chtigen, wurden in dieser Arbeit funktionelle Charakteristika sowohl des wildtypischen als auch der ΔM500 und der benachbarten ΔI501 Deletionsvariante von SGLT3 mittels Zwei-Elektroden Spannungs- und Stromklemme in entsprechend cRNA-injizierten Xenopus laevis Oozyten untersucht. Der hochpotente SGLT3-spezifische Iminozuckeragonist 1-Desoxynojirimycin (DNJ) induzierte an SGLT3-exprimierenden Oozyten in sauren Bedingungen etwa dreifach gr{\"o}ßere Kationeneinstr{\"o}me als D-Glukose, was sowohl im Spannungsklemmen-, und anhand einer entsprechenden Membrandepolarisation im Stromklemmenmodus gezeigt wurde. Die mit der ΔM500 bzw. ΔI501 Variante injizierten Oozyten dagegen zeigten in den maximalen Aktivierungsbedingungen um 92\% bzw. 96\% (p<0,01) reduzierte Kationeneinstr{\"o}me, sodass diese als hochgradig sch{\"a}dliche „Loss of Function" Mutationen in SGLT3 charakterisiert wurden. Dieser Befund wurde mittels bioinformatischer in-silico Effektvorhersage validiert. Um Konsequenzen der Sequenzalteration auf den Membraneinbau der Transporter zu untersuchen, wurden die mit einem gelb fluoreszierenden Farbstoff (YFP) markierten Transporter in Oozytenmembranen mittels Laser-Scanning Mikroskop nachgewiesen und die jeweiligen Mengen der Konstrukte anhand der Fluoreszenzintensit{\"a}ten quantifiziert. Dabei zeigte sich eine um 53\% bzw. 42\% (p<0,01) reduzierte Menge der mutierten Konstrukte ΔM500 bzw. ΔI501 in der Membran, was zus{\"a}tzliche sch{\"a}dliche Effekte der Mutationen auf das sogenannte Membrantargeting der Transporter belegt. Zusammenfassend demonstrieren die Ergebnisse dieser Arbeit, dass die ΔM500 Variante von SGLT3, welcher in ADHS-relevanten Hirnarealen exprimiert wird, dessen sub-stratinduzierte Natriumleitf{\"a}higkeit aufhebt und den Membraneinbau beeintr{\"a}chtigen k{\"o}nnte, was in Wechselwirkung mit anderen genetischen ADHS Risikovarianten das Risiko f{\"u}r ADHS in Mutationstr{\"a}gern beeinflussen kann.},
  subject      = {ADHS},
  language  = {de}
}
@phdthesis{Pennington2018,
  author    = {Pennington, Laura Sophie},
  title     = {The role of Cadherin-13 in serotonergic neurons during different murine developmental stages},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-161331},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2018},
  abstract  = {Abstract Background: Attention-deficit/ hyperactivity disorder (ADHD) ranges among the most common neurodevelopmental disorders worldwide with a prevalence of 3-12\% in childhood and 1-5\% for adults. Over the last decade extensive genetic research has been conducted in order to determine its causative genetic factors. None of the so far identified susceptibility genes, however, could explain the estimated ADHD heritability of 76\%. In this thesis one of the most promising candidates -Cadherin 13 (Cdh13) - was examined in terms of its influence on the central serotonergic (5-HT) system. In addition to that, the Cdh13 protein distribution pattern was analysed over time. Methods: The developing serotonergic system was compared over three embryonic and postnatal stages (E13.5, E17.5 and P7) in different Cdh13 genotypes (WT, HZ and KO) using immunohistochemistry and various double staining protocols. Results: The raphe nuclei of the 5-HT system develop in spite of Cdh13 absence and show a comparable mature constellation. The cells in the KO, however, are slightly more scattered than in the WT. Furthermore the dynamics of their formation is altered, with a transient delay in migration at E13.5. In early developmental stages the total amount of serotonergic cells is reduced in KO and HZ, though their proportional distribution to the raphe nuclei stays constant. Strikingly, at P7 the absolute numbers are comparable again. Concerning the Cdh13 protein, it shows high concentrations on fibres running through hindbrain and midbrain areas at E13.5. This, however, changes over time, and it becomes more evenly spread until P7. Furthermore, its presence in serotonergic cells could be visualised using confocal microscopy. Since the described pattern is only in parts congruent to the localisation of serotonergic neurons, it is most likely that Cdh13 is present in other developing neurotransmitter systems, such as the dopaminergic one, as well. Conclusion: It could be proven that Cdh13 is expressed in serotonergic cells and that its knockout does affect the developing serotonergic system to some degree. Its absence, however, only slightly and transiently affects the measured parameters of serotonergic system development, indicating a possible compensation of CDH13 function by other molecules in the case of Cdh13 deficiency. In addition further indicators could be found for an influence of Cdh13 on outgrowth and path finding of neuronal processes.},
  subject      = {Cadherine},
  language  = {en}
}
@phdthesis{Ziegler2017,
  author    = {Ziegler, Georg Christoph},
  title     = {Die SLC2A3-Genduplikation als Kandidatengenvariante der Aufmerksamkeitsdefizit/-Hyperaktivit{\"a}tsst{\"o}rung - molekularbiologische und neurale Korrelate},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-154185},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2017},
  abstract  = {Diese Arbeit widmet sich der Untersuchung einer Kopienzahlvariante (CNV) im Erbgut, die zu einer genomischen Duplikation des SLC2A3-Gens f{\"u}hrt. Die Auswirkungen der SLC2A3- Duplikation wurden im Zellkulturmodell und durch bildgebende Verfahren untersucht. F{\"u}r die SLC2A3-Duplikation konnte eine populationsspezifische Assoziation mit ADHS gezeigt werden (Merker et al. 2017). SLC2A3 kodiert f{\"u}r den neuronalen Glukosetransporter GLUT3, der u.a. Prozesse der Neurotransmitterfreisetzung und Synaptogenese vermittelt und daher wichtig f{\"u}r die Hirnreifung ist. M{\"o}gliche Endpunkte f{\"u}r Endoph{\"a}notypen, die auf einem alterierten Glukosemetabolismus basieren, sind dysfunktionale Hungerregulationsmechanismen ebenso wie eine ver{\"a}nderte neurale Reaktivit{\"a}t gegen{\"u}ber emotionalen Stimuli und Belohnungsreizen. In zwei peripheren Zellmodellen konnte gezeigt werden, dass die SLC2A3-Duplikation Gen-Dosis-abh{\"a}ngig zu einer Steigerung der basalen SLC2A3-mRNA Expression f{\"u}hrt. Ein Expressionsunterschied auf Proteinebene konnte jedoch nicht gefunden werden. Metabolischer Zellstress durch Aushungern der Zellkulturen und eine niedrige Glukosekonzentration im Zellkulturmedium f{\"u}hrten zu einer signifikanten Erh{\"o}hung des schon unter basalen Bedingungen vorhandenen SLC2A3-Expressionsunterschiedes zwischen Duplikations- und Kontrollzelllinien. Dies deutet darauf hin, dass die SLC2A3-Duplikation bei verminderter zellul{\"a}rer Energiezufuhr zu einer {\"U}berkompensation der Glukoseaufnahme f{\"u}hrt. In einer fMRT-Untersuchung wurden erwachsene ADHS-Patienten mit SLC2A3- Duplikation mit ADHS-Patienten und gesunden Kontrollen mit jeweils 2 Genkopien hinsichtlich ereigniskorrelierter neuraler Aktivit{\"a}t als Antwort auf emotionale Stimuli und Essensreize verglichen. Es konnte gezeigt werden, dass die SLC2A3-Duplikation zu einer ver{\"a}nderten Reaktivit{\"a}t gegen{\"u}ber hochkalorischen Essensreizen f{\"u}hrt, was sich in einem durch maschinelles Lernen identifizierten multivariaten neuralen Antwortmuster und einer relativen Untersch{\"a}tzung des Kaloriengehaltes hochkalorischer Nahrung zeigt. Bei der univariaten Gesamthirn-Analyse der Bilddaten wurden keine signifikanten Gruppenunterschiede gefunden, was darauf hinweist, dass unter den gew{\"a}hlten Versuchsbedingungen keine fokal umschriebenen Gruppenunterschiede der Hirnaktivierung bestehen. Diese Arbeit zeigt, dass die SLC2A3-Duplikation zu einer Erh{\"o}hung der SLC2A3- Genexpression mit bisher unbekannten Auswirkungen auf nachgeschaltete Stoffwechselwege und zu einem komplex ver{\"a}nderten neuralen Antwortmuster f{\"u}hrt, das durch einen linearen Zusammenhang nicht zu beschreiben ist. Weitere Untersuchungen auf Zellebene und eine Erweiterung der bildgebenden Verfahren k{\"o}nnten zu einer besseren Einordnung der SLC2A3- Duplikation bez{\"u}glich ihres Anteils an der endoph{\"a}notypischen Varianz der ADHS f{\"u}hren.},
  subject      = {Aufmerksamkeitsdefizit-Syndrom},
  language  = {de}
}
@phdthesis{Nuth2017,
  author    = {Nuth, Linda},
  title     = {Niederfrequente, Tiefe Hirnstimulation bei Parkinson-Patienten mit ON-Freezing. Identifikation von Respondern anhand kinematischer Gangparameter},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-150317},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2017},
  abstract  = {Das ON-Freezing ist ein seltenes, aber generell extrem schwer zu therapierendes Ph{\"a}nomen. Es betrifft Parkinson-Patienten mit und ohne THS. Die derzeitige Literaturlage spiegelt wider, dass es unterschiedliche Strategien gibt, diesem Ph{\"a}nomen zu begegnen. Ein allgemeing{\"u}ltiges Therapiekonzept existiert dabei nicht. F{\"u}r einige Patienten mit STN-THS konnte durch eine Reduktion der Stimulationsfrequenz eine Besserung der Gangst{\"o}rung erzielt werden. Andere profitierten vom Einsatz sogenannter Interleaving-Protokolle mit gleichzeitiger Stimulation der Substantia nigra (Sn). Im Vergleich zu anderen Arbeiten, die keine vorhersagbaren Parameter gefunden oder sich auf Symptome, Auspr{\"a}gung der Subtypen und Erkrankungsdauer oder den Zeitpunkt der Erkrankung konzentriert haben, verfolgten wir die Absicht, die Effekte der LF-Stim des STN auf Parkinson-Patienten mit Gangst{\"o}rung und Freezing-Ph{\"a}nomen zu untersuchen und herauszufinden, ob man Gangparameter identifizieren kann, an Hand derer man das Ansprechen auf eine LF-Stim vorhersagen kann. Unter der Einschr{\"a}nkung, dass die Zahl der Probanden unserer Studie sehr gering ist, haben wir herausgefunden, dass diejenigen Patienten besser auf eine LF-Stim ansprechen, die unter der Standard-HF-Stim eine signifikant h{\"o}here Ganggeschwindigkeit und eine gr{\"o}ßere Schrittl{\"a}nge aufzeigen und nur ein intermittierendes Freezing haben. Dar{\"u}ber hinaus zeigte sich ein besseres Ansprechen der LF-Stim bei Parkinson-Patienten mit akinetisch-rigidem Parkinson-Ph{\"a}notyp. Unsere Ergebnisse best{\"a}tigen die Annahme, dass sich L-Dopa additiv zur Stimulationstherapie bei manchen Parkinson-Patienten zus{\"a}tzlich positiv auf die motorischen PD-Symptome auswirken kann. In Bezug auf die Verbesserung der Gangparameter zeigte sich in unseren Ergebnissen allerdings, dass L-Dopa eher eine untergeordnete Rolle spielt. Aufgrund der niedrigen Anzahl von Respondern in unserer Studie l{\"a}sst sich daher sicherlich noch keine allgemeing{\"u}ltige Regel ableiten. Es bedarf letztlich weiterer Studien mit gr{\"o}ßeren Untersuchungszahlen, um unsere Thesen zu st{\"u}tzen und abzusichern. In jedem Fall wird aber das ON-Freezing auch weiterhin eine therapeutische Herausforderung bleiben.},
  subject      = {Parkinson},
  language  = {de}
}
@phdthesis{Aboagye2019,
  author    = {Aboagye, Benjamin},
  title     = {Behavioral and physiologic consequences of inducible inactivation of the \(Tryptophan\) \(hydroxylase\) 2 gene in interaction with early-life adversity},
  doi       = {10.25972/OPUS-17358},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173581},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2019},
  abstract  = {Disruptions in brain serotonin (5-hydroxytryptamine, 5-HT) signaling pathways have been associated with etiology and pathogenesis of various neuropsychiatric disorders, but specific neural mechanisms of 5-HT function are yet to be fully elucidated. Tryptophan hydroxylase 2 (TPH2) is the rate-limiting enzyme for brain 5-HT synthesis. Therefore, in this study a tamoxifen (Tam)-inducible cre-mediated conditional gene (Tph2) knockout in adult mouse brain (Tph2icKO) has been established to decipher the specific role of brain 5-HT in the regulation of behavior in adulthood. Immunohistochemistry and high-performance liquid chromatography (HPLC) were used first to test the efficacy of Tam-inducible inactivation of Tph2 and consequential reduction of 5-HT in adult mouse brain. Tam treatment resulted in ≥90\% reduction in the number of 5-HT immuno-reactive cells in the anterior raphe nuclei. HPLC revealed a significant reduction in concentration of 5-HT and its metabolite 5-hydroxyindole acetic acid (5-HIAA) in selected brain regions of Tph2icKO, indicating the effectiveness of the protocol used. Second, standard behavioral tests were used to assess whether reduced brain 5-HT concentrations could alter anxiety-, fear- and depressive-like behavior in mice. No altered anxiety- and depressive-like behaviors were observed in Tph2icKO compared to control mice (Tph2CON) in all indices measured, but Tph2icKO mice exhibited intense and sustained freezing during context-dependent fear memory retrieval. Tph2icKO mice also exhibited locomotor hyperactivity in the aversive environments, such as the open field, and consumed more food and fluid than Tph2CON mice. Lastly, the combined effect of maternal separation (MS) stress and adult brain 5-HT depletion on behavior was assessed in male and female mice. Here, MS stress, 5-HT depletion and their interaction elicited anxiety-like behavior in a sex-dependent manner. MS reduced exploratory behavior in both male and female mice. Reduced 5-HT enhanced anxiety in female, but not in male mice. Furthermore, expression of genes related to the 5-HT system and emotionality (Tph2, Htr1a, Htr2a, Maoa and Avpr1a) was assessed by performing a quantitative real-time PCR. In Tph2icKO mice there was a reduction in expression of Tph2 in the raphe nuclei of both male and female mice. Interaction between MS stress and 5-HT deficiency was detected showing increased Htr2a and Maoa expression in raphe and hippocampus respectively of female mice. In male mice, MS stress and 5-HT depletion interaction effects reduced Avpr1a expression in raphe, while the expression of Htr1a, Htr2a and Maoa was differentially altered by 5-HT depletion and MS in various brain regions.},
  subject      = {Anxiety},
  language  = {en}
}
@phdthesis{Bacmeister2018,
  author    = {Bacmeister, Lucas},
  title     = {Effect of Cadherin-13 inactivation on different GABAergic interneuron populations of the mouse hippocampus},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-172693},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2018},
  abstract  = {Cadherin-13 (CDH13) is an atypical member of the cadherin superfamily, a group of membrane proteins mediating calcium-dependent cellular adhesion. Although CDH13 shows the classical extracellular cadherin structure, the typical transmembrane and cytoplasmic domains are absent. Instead, CDH13 is attached to the cell membrane via a glycosylphosphatidylinositol (GPI) anchor. These findings and many studies from different fields suggest that CDH13 also plays a role as a cellular receptor. Interestingly, many genome-wide association studies (GWAS) have found CDH13 as a risk gene for attention-deficit/hyperactivity disorder (ADHD) and other neurodevelopmental disorders. In previous work from our research group, strong expression of Cdh13 mRNA in interneurons of the hippocampal stratum oriens (SO) was detected. Therefore, double-immunofluorescence studies were used to evaluate the degree of co-expression of CDH13 with seven markers of GABAergic interneuron subtypes. For this purpose, murine brains were double stained against CDH13 and the respective marker and the degree of colocalization in the SO of the hippocampus was assessed. Based on the result of this immunofluorescence study, quantitative differences in interneuron subtypes of the SO between Cdh13 knockout (ko), heterozygote (het) and wildtype (wt) mice were investigated in this dissertation using stereological methods. In addition, genotype- dependent differences in the expression of genes involved in GABAergic and glutamatergic neurotransmission were analyzed by quantitative real-time PCR (qRT-PCR). Primers targeting different GABA receptor subunits, vesicular GABA and glutamate transporter, GABA synthesizing enzymes and their interaction partners were used for this purpose. The results of the stereological quantification of the interneuron subtypes show no significant differences in cell number, cell density or volume of the SO between Cdh13 ko, het and wt mice. On the other hand, qRT-PCR results indicate significant differences in the expression of tropomyosin-related kinase B gene (TrkB), which encodes the receptor of brain-derived neurotrophic factor (BDNF), a regulator of GABAergic neurons. This finding supports a role for CDH13 in the regulation of BDNF signaling in the hippocampus.},
  subject      = {Cadherine},
  language  = {en}
}
@phdthesis{Kiser2019,
  author    = {Kiser, Dominik Pascal},
  title     = {Gene x Environment Interactions in Cdh13-deficient Mice: CDH13 as a Factor for Adaptation to the Environment},
  doi       = {10.25972/OPUS-17959},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-179591},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2019},
  abstract  = {Neurodevelopmental disorders, including attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are disorders of mostly unknown etiopathogenesis, for which both genetic and environmental influences are expected to contribute to the phenotype observed in patients. Changes at all levels of brain function, from network connectivity between brain areas, over neuronal survival, synaptic connectivity and axonal growth, down to molecular changes and epigenetic modifications are suspected to play a key roles in these diseases, resulting in life-long behavioural changes. Genome-wide association as well as copy-number variation studies have linked cadherin-13 (CDH13) as a novel genetic risk factor to neuropsychiatric and neurodevelopmental disorders. CDH13 is highly expressed during embryonic brain development, as well as in the adult brain, where it is present in regions including the hippocampus, striatum and thalamus (among others) and is upregulated in response to chronic stress exposure. It is however unclear how CDH13 interacts with environmentally relevant cues, including stressful triggers, in the formation of long-lasting behavioural and molecular changes. It is currently unknown how the environment influences CDH13 and which long term changes in behaviour and gene expression are caused by their interaction. This work therefore investigates the interaction between CDH13 deficiency and neonatal maternal separation (MS) in mice with the aim to elucidate the function of CDH13 and its role in the response to early-life stress (ELS). For this purpose, mixed litters of wild-type (Cdh13+/+), heterozygous (Cdh13+/-) and homozygous knockout (Cdh13-/-) mice were maternally separated from postnatal day 1 (PN1) to postnatal day 14 (PN14) for 3 hours each day (180MS; PN1-PN14). In a first series of experiments, these mice were subjected to a battery of behavioural tests starting at 8 weeks of age in order to assess motor activity, memory functions as well as measures of anxiety. Subsequently, expression of RNA in various brain regions was measured using quantitativ real-time polymerase chain reaction (qRT-PCR). A second cohort of mice was exposed to the same MS procedure, but was not behaviourally tested, to assess molecular changes in hippocampus using RNA sequencing. Behavioural analysis revealed that MS had an overall anxiolytic-like effect, with mice after MS spending more time in the open arms of the elevated-plus-maze (EPM) and the light compartment in the light-dark box (LDB). As a notable exception, Cdh13-/- mice did not show an increase of time spent in the light compartment after MS compared to Cdh13+/+ and Cdh13+/- MS mice. During the Barnes-maze learning task, mice of most groups showed a similar ability in learning the location of the escape hole, both in terms of primary latency and primary errors. Cdh13-/- control (CTRL) mice however committed more primary errors than Cdh13-/- MS mice. In the contextual fear conditioning (cFC) test, Cdh13-/- mice showed more freezing responses during the extinction recall, indicating a reduced extinction of fear memory. In the step-down test, an impulsivity task, Cdh13-/- mice had a tendency to wait longer before stepping down from the platform, indicative of more hesitant behaviour. In the same animals, qRT-PCR of several brain areas revealed changes in the GABAergic and glutamatergic systems, while also highlighting changes in the gatekeeper enzyme Glykogensynthase-Kinase 3 (Gsk3a), both in relation to Cdh13 deficiency and MS. Results from the RNA sequencing study and subsequent gene-set enrichment analysis revealed changes in adhesion and developmental genes due to Cdh13 deficiency, while also highlighting a strong link between CDH13 and endoplasmatic reticulum function. In addition, some results suggest that MS increased pro-survival pathways, while a gene x environment analysis showed alterations in apoptotic pathways and migration, as well as immune factors and membrane metabolism. An analysis of the overlap between gene and environment, as well as their interaction, highlighted an effect on cell adhesion factors, underscoring their importance for adaptation to the environment. Overall, the stress model resulted in increased stress resilience in Cdh13+/+ and Cdh13+/- mice, a change absent in Cdh13-/- mice, suggesting a role of CDH13 during programming and adaptation to early-life experiences, that can results in long-lasting consequences on brain functions and associated behaviours. These changes were also visible in the RNA sequencing, where key pathways for cell-cell adhesion, neuronal survival and cell-stress adaptation were altered. In conclusion, these findings further highlight the role of CDH13 during brain development, while also shedding light on its function in the adaptation and response during (early life) environmental challenges.},
  subject      = {Cadherine},
  language  = {en}
}
@phdthesis{Post2014,
  author    = {Post, Antonia},
  title     = {Snap25 heterozygous knockout mice as a potential model for attention deficit/hyperactivity disorder (ADHD)},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-122899},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2014},
  abstract  = {SNAP25 (Synaptosomal-Associated Protein of 25 kDa; part of the SNARE complex) is involved in the docking and fusion of synaptic vesicles in presynaptic neurons necessary for the regulation of neurotransmitter release, as well as in axonal growth and synaptic plasticity. In humans, different single nucleotide polymorphisms of SNAP25 have repeatedly been associated with attention deficit/hyperactivity disorder (ADHD). Thus, in this study heterozygous Snap25 knockout mice were investigated as a model of ADHD. Heterozygous (+/-) Snap25 knockout mice as well as their wild-type (+/+) littermates were reared under control conditions or underwent a Maternal Separation (MS) procedure. Starting at the age of 2 months, mice were tested for locomotor activity in a repeated long-term Open Field (OF) task, for attention deficits and impulsive behavior in the 5 Choice Serial Reaction Time Task (5CSRTT), for anxiety-like behavior in the Light-Dark Box (LDB) and for depression-like behavior in the Porsolt Forced Swim Test (FST). The brains of these mice were subsequently tested for the expression of several ADHD related genes in a quantitative Real-Time PCR (qRT-PCR) study. Another group of female mice (+/+; +/-) underwent a one hour OF test after oral administration of 45 mg/kg Methylphenidate (MPH) or placebo. To find an optimized dosage for this MPH challenge, a pilot study was performed. Wild-type C57BL/6 mice were tested in a long-term OF with several dosages of MPH both intraperitoneally (i.p.) and orally. The brains of these animals were afterwards investigated for neurotransmitter concentrations. In this pilot study the dosages of MPH that were similarly behaviorally effective without causing symptoms of overdosing were 7.5-15 mg/kg intraperitoneally and 30-60 mg/kg orally. However, even though it was possible to find intraperitoneal and oral doses that correlate behaviorally, the neurochemistry was mostly different. In the study on Snap25-deficient mice, unstressed controls showed a hyperactive phenotype in the second of two long-term OF sessions (60 min) spaced three weeks apart. Considering all groups, there was a significant interaction of stress and genotype in the second session, with animals subjected to MS being overall hyperactive with no genotype differences. In the training phase of the 5CSRTT only effects of stress were found, with MS animals finding and consuming fewer rewards. In the single test trial, several genotype effects became apparent, with tendencies for the number of correct nose pokes and the number of rewards eaten, and a significant effect for the number of rewards eaten directly after the correct response. In all of these variables +/- mice performed worse than their wild-type littermates. In the LDB +/- mice entered the lit compartment of the arena earlier than the controls, thus showing attenuated anxiety-like behavior. Regarding depressive-like behavior in the FST, male +/- mice spent significantly less time struggling than male +/+ mice. In the gene expression study, +/- mice had lower expression levels of Maoa and Comt, and higher expression levels of Nos1 than wild-types. Finally, the locomotor activity response to MPH was exaggerated in +/- mice as compared to controls. Heterozygous Snap25 knockout mice show some of the behavioral characteristics of ADHD, as for example a mild hyperactivity in a familiar environment, difficulties in the correct execution of a given task and even some behavior that can be interpreted as delay aversion. Additionally, expression levels of three ADHD related genes were changed in these animals. Although the exaggerated locomotor activity response to MPH is not to be expected of an ADHD model, the difference in the response between +/+ and +/- mice nonetheless implicates a potential dysfunction of the brain dopaminergic system.},
  subject      = {Aufmerksamkeitsdefizit-Syndrom},
  language  = {en}
}
@phdthesis{Schraut2015,
  author    = {Schraut, Karla-Gerlinde},
  title     = {Epigenetic programming by prenatal stress in female serotonin transporter deficient mice},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-120270},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2015},
  abstract  = {Early life stress, including exposure to prenatal stress (PS), has been shown to affect the developing brain and induce severe effects on emotional health in later life, concomitant with an increased risk for psychopathology. However, some individuals are more vulnerable to early-life stress, while others adapt successfully, i.e. they are resilient and do not succumb to adversity. The molecular substrates promoting resilience in some individuals and vulnerability in other individuals are as yet poorly investigated. A polymorphism in the serotonin transporter gene (5­HTT/SLC6A4) has been suggested to play a modulatory role in mediating the effects of early-life adversity on psychopathology, thereby rendering carriers of the lower-expressing short (s)-allele more vulnerable to developmental adversity, while long (l)-allele carriers are relatively resilient. The molecular mechanisms underlying this gene x environment interaction (GxE) are not well understood, however, epigenetic mechanisms such as DNA methylation and histone modifications have been discussed to contribute as they are at the interface of environment and the genome. Moreover, developmental epigenetic programming has also been postulated to underlie differential vulnerability/resilience independent of genetic variation. The present work comprises two projects investigating the effects of prenatal maternal restraint stress in 5-HTT deficient mice. In the first study, we examined to which extent previously observed changes in behavior and hippocampal gene expression of female 5-Htt+/- prenatally stressed (PS) offspring were associated with changes in DNA methylation patterns. Additionally, we investigated the expression of genes involved in myelination in hippocampus and amygdala of those animals using RT-qPCR. The genome-wide hippocampal DNA methylation screening was performed using methylated-DNA immunoprecipitation (MeDIP) on Affymetrix GeneChip® Mouse Promoter 1.0R arrays. In order to correlate individual gene-specific DNA methylation, mRNA expression and behavior, we used hippocampal DNA from the same mice as assessed before. 5-Htt genotype, PS and their interaction differentially affected the DNA methylation signature of numerous genes, a part of which were also differentially expressed. More specifically, we identified a differentially methylated region in the Myelin basic protein (Mbp) gene, which was associated with Mbp expression in a 5-Htt-, PS- and 5-Htt x PS-dependent manner. Subsequent fine-mapping linked the methylation status of two specific CpG sites in this region to Mbp expression and anxiety-related behavior. We furthermore found that not only the expression of Mbp but of large gene set associated with myelination was affected by a 5-Htt x PS interaction in a brain-region specific manner. In conclusion, hippocampal DNA methylation patterns and expression profiles of female PS 5-Htt+/- mice suggest that distinct molecular mechanisms, some of which are associated with changes in gene promoter methylation, and processes associated with myelination contribute to the behavioral effects of the 5-Htt genotype, PS exposure, and their interaction. In the second study, we aimed at investing the molecular substrates underlying resilience to PS. For this purpose, we exposed 5-Htt+/+ dams to the same restraint stress paradigm and investigated the effects of PS on depression- and anxiety-like behavior and corticosterone (CORT) secretion at baseline and after acute restraint stress in female 5-Htt+/+ and 5-Htt+/- offspring. We found that PS affected the offspring's social behavior in a negative manner. When specifically examining those PS animals, we grouped the PS offspring of each genotype into a social, resilient and an unsocial, vulnerable group. While anxiety-like behavior in the EPM was reduced in unsocial, but not social, PS 5-Htt+/+ animals when compared to controls, this pattern could not be found in animals of the other genotype, indicating that social anxiety and state anxiety in the EPM were independent of each other. We then assessed genome-wide hippocampal gene expression profiles using mRNA sequencing in order to identify pathways and gene ontology (GO) terms enriched due to 5-Htt genotype (G), PS exposure (E) and their interaction (GxE) as well as enriched in social, but not unsocial, PS offspring, and vice versa. Numerous genes were affected by 5-Htt genotype, PS and most of all a GxE-interaction. Enrichment analysis using enrichr identified that the genotype affected mitochondrial respiration, while GxE-interaction-affected processes associated primarily with myelination and chromatin remodeling. We furthermore found that 5-Htt+/- mice showed profound expression changes of numerous genes in a genomic region located 10 mio kb upstream of the 5 Htt locus on the same chromosome. When looking at social vs. unsocial mice, we found that a much higher number of genes was regulated in 5 Htt+/- animals than in 5-Htt+/+ animals, reflecting the impact of GxE-interaction. Double the number of genes was regulated in social PS vs. control mice when compared to unsocial PS vs. control in both genotypes, suggesting that the successful adaption to PS might have required more active processes from the social group than the reaction to PS from the unsocial group. This notion is supported by the up-regulation of mitochondrial respiration in social, but not in unsocial, PS 5-Htt+/- mice when compared to controls, as those animals might have been able to raise energy resources the unsocial group was not. Next to this, processes associated with myelination seemed to be down-regulated in social 5-Htt+/- mice, but not in unsocial animals, when compared to controls. Taken together, PS exposure affected sociability and anxiety-like behavior dependent on the 5-Htt genotype in female offspring. Processes associated with myelination and epigenetic mechanisms involved in chromatin remodeling seemed be affected in a GxE-dependent manner in the hippocampus of these offspring. Our transcriptome data furthermore suggest that mitochondrial respiration and, with this, energy metabolism might be altered in 5-Htt+/- offspring when compared to 5-Htt+/+ offspring. Moreover, myelination and mitochondrial respiration might contribute to resilience towards PS exposure in 5-Htt+/- offspring, possibly by affecting brain connectivity and energy capabilities.},
  subject      = {Stress},
  language  = {en}
}