CDNF and MANF are members of a recently discovered and evolutionarily conserved neurotrophic factor family implicated in supporting the survival and protection of midbrain dopaminergic neurons in the nigrostriatal pathway, which degenerate in Parkinson’s Disease (PD). Increasing evidence demonstrated that MANF overexpression resulted in significant protection and repair of TH+ cells and DA neurons in the substantia nigra (SN). In addition, continuous infusion of CDNF demonstrated greater protection of TH-positive neurons in the SNc and fibers in striatum than GDNF in the 6-OHDA neurotoxin model. Current literature suggests that CDNF and MANF are involved in regulating ER stress and are upregulated in vitro and in vivo during the unfolded protein response (UPR). Thus, this study sought to investigate whether selective knockdown (K/D) of MANF and CDNF causes pathophysiological conditions that lead to the behavioural manifestation of PD in preclinical models. Male Sprague-Dawley rats underwent stereotaxic surgery, whereby 2 μL at 0.5 μL/minute of MANF, CDNF, MANF and CDNF combined, or a scrambled negative control (N=44) of rat lentiviral-mediated shRNA formulations were infused into the SN in reference to bregma: Anterior/Posterior=-5.3 mm, Medial/Lateral=±2.3 mm, Dorsal/Ventral=-7.8 mm. Rats were tested on a battery of behavioural tests for the assessment of PD phenotypes, such as impairments in balance, gait and motor coordination. MANF K/D rats demonstrated PD phenotypes in the rearing duration, beam traversal, rotarod and cylinder test (P <0.05). These results were largely mirrored in the combined MANF and CDNF K/D group, however, CDNF K/D rats failed to demonstrate consistent motor deficits (P >0.05). Additionally, CDNF mRNA expression from the platelets of PD patients revealed no significant differences compared to healthy controls (P >0.05). In conclusion, the etiology of PD remains to be elucidated, and this is the first study to demonstrate that MANF K/D rats recapitulate key motor features of parkinsonism. / Thesis / Master of Science (MSc) / CDNF and MANF are members of a recently discovered and evolutionarily conserved neurotrophic factor family implicated in supporting the survival and protection of midbrain dopaminergic neurons in the nigrostriatal pathway, which degenerate in Parkinson’s Disease (PD). Increasing evidence demonstrated that MANF overexpression resulted in significant protection and repair of DA neurons in the substantia nigra (SN). Current literature suggests that CDNF and MANF are involved in regulating ER stress and are upregulated in cells and in rodents during the unfolded protein response (UPR). Thus, this study sought to investigate whether selective knockdown (K/D) of MANF and CDNF causes the underlying changes in the brain that lead to the behavioural manifestation of PD in preclinical models. 2 μL at 0.5 μL/minute of MANF, CDNF, MANF and CDNF combined, or a scrambled negative control (N=44) of rat lentiviral-mediated shRNA formulations were infused into the SN. Rats were tested on a battery of behavioural tests for the assessment of PD phenotypes, such as impairments in balance, gait and motor coordination. MANF K/D rats demonstrated PD phenotypes in the rearing duration, beam traversal, rotarod and cylinder test (P <0.05). These results were largely mirrored in the combined MANF and CDNF K/D group, however, CDNF K/D rats failed to demonstrate consistent motor deficits (P >0.05). Additionally, CDNF mRNA expression from the platelets of PD patients revealed no significant differences compared to healthy controls (P >0.05). In conclusion, the etiology of PD remains to be elucidated, and this is the first study to demonstrate that MANF K/D rats recapitulate key motor features of parkinsonism.

Aging is associated with cognitive decline in various domains, including memory. The age-related increase in systemic inflammation has been identified as a potential mechanism contributing to these memory impairments. Specifically, elevated inflammation may impair neurotrophic factor production and function, which is important for maintaining brain health. Physical activity has been identified as a potential strategy for preventing or delaying memory decline, given its ability to reduce inflammation and stimulate neurotrophic factor expression. The present study investigated the relationship between cardiorespiratory fitness, a proxy for habitual physical activity, and memory in older adults. Inflammation and neurotrophic factors were examined as potential mechanisms mediating this relationship. Sixty-five community dwelling older adults (Mage = 70.6 ± 4.0) completed the Rockport 1-mile walk test to predict their cardiorespiratory fitness, as well as the Mnemonic Similarity Task to assess memory. Serum samples were collected to examine inflammatory markers, including interleukin-6 (IL-6), interleukin-1beta (IL-1β), tumor necrosis factor-alpha (TNF-α), and C-reactive protein (CRP), as well as neurotrophic factors, including brain derived neurotrophic factor (BDNF) and insulin-like growth factor-1 (IGF-1). No relationship was found between cardiorespiratory fitness and memory (p > .05). However, older adults with greater cardiorespiratory fitness had lower levels of IL-6 (p < .01) and TNF-α (p < .01) and trended towards higher levels of BDNF (p = .078). Furthermore, IL-6 was negatively correlated with IGF-1 (p < .01), suggesting higher inflammation may impair IGF-1 production. Contrary to our hypotheses, sequential mediation analyses revealed no indirect effect of inflammatory markers and neurotrophic factors on the relationship between cardiorespiratory fitness and memory. Our results suggest that cardiorespiratory fitness may promote favourable changes in inflammatory markers and neurotrophic factors, which—given previous literature—could help to support brain health with advancing age. More research is needed to further examine the relationship between cardiorespiratory fitness and memory. / Thesis / Master of Science (MSc)

Als Therapieversuch bei Plexusläsionen wird die Replantation ausgerissener Vorderwurzelfasern durchgeführt. Voraussetzung für die erfolgreiche Regeneration von Motoneuronaxonen sind 1. Überleben einer ausreichenden Anzahl von Motoneuronen 2. erfolgreiche Wiederherstellung der Kontuität ausgerissener Axone mit dem Rückenmark und 3. funktionelle Hochwertigkeit regenerierter Axone. Neurotrophe Faktoren können Überleben und Regenerationsfähigkeit von Motoneuronen fördern. Gegenstand der vorliegenden Arbeit war die Analyse des Einflusses von CNTF und BDNF auf die Regeneration von Motoneuronaxonen nach Ausriss und Replantation im Segment C7 nach einer Überlebenszeit von 3 Wochen bzw. 6 Monaten. Vervollständigt wurden diese Untersuchungen durch detaillierte morphologische Analysen von Spinalganglien, durchtrennter Hinterwurzel und verletztem Hinterhorn. In verschiedenen Gruppen von adulten Kaninchen wurden CNTF, BDNF, oder beide Faktoren auf die ventrolaterale Replantationsstelle appliziert, Kontrollen wurden ohne Faktor belassen (n>5). Die Überlebenszeit der Versuchstiere lag bei 3 Wochen (n=3 Kontrollen) und 6 Monaten (n=27). Aus dem perfundiertem Gewebe wurden Semidünnschnitte durch Vorderwurzel/Spinalganglien und Kryostatserienschnitte durch das Segment C7 angefertigt. DiI-Fluoreszenztracing, Markscheidenfärbung, eine modifizierte Klüver-Barrera-Färbung der Kryostatschnitte sowie eine Touloidinblaufärbung der Semidünnschnitte ermöglichte die morphologische und morphometrische Analyse des Gewebes. Die Anzahl der überlebenden Motoneurone lag nach sechs Monaten bei allen Versuchsgruppen bei etwa 30%. Fluoreszenz-Tracing und Markscheidenfärbungen von Serienschnitten zeigten, dass Axone sowohl über die ursprünglichen ventralen Austrittstellen als auch über die ventrolaterale Replantationsstelle das Rückenmark verließen und im Bereich des Spinalganglions eine kompakte Vorderwurzel bildeten. Ventral austretende Axone zeigten signifikant größere Durchmesser als lateral austretende. Ausmaß und Art der Regeneration waren interindividuell unterschiedlich, die besten Ergebnisse zeigte die Replantation nah am ursprünglichen Austrittsort der Vorderwurzel. Unterschiede zwischen den Gruppen waren nicht deutlich. In Semidünnschnitten durch die regenerierte Vorderwurzel fanden sich nach drei Wochen kaum intakte, myelinisierte Axone, nach sechs Monaten war die Zahl der Axone auf etwa 45% der Zahl der gesunden Seite angestiegen. Regenerierte Axone waren dünn, typische Motoneuronaxone stellten nur einen kleinen Teil der regenerierten Axone. Gruppenunterschiede fanden sich im Axon-Myelinverhältnis, das bei Kontrollen der replantierten Seiten signifikant erniedrigt war. Diese Erniedrigung war noch vorhanden, jedoch nicht mehr signifikant bei Tieren, die mit CNTF- und BDNF-behandelt wurden. Die replantierten Vorderwurzeln der CNTF+BDNF-Gruppe zeigte überwiegend eine signifikant bessere Myelinisierung als die replantierten Kontrollen. An der früheren Hinterwurzeleintrittszone am Rückenmark wurden in Tieren mit geringem Verletzungsausmaß kleine ZNS-Gewebsprotrusionen beobachtet, in denen sich myelinisierte Axone befanden. Diese Axone zeigten eine Wachstumsrichtung in die Peripherie, was auf eine Sprossung der sensorischen Rückenmarksneurone schließen lässt. Innerhalb des Spinalganglions waren Neuron- und Axondichte auf den verletzten Seiten nicht wesentlich verändert. Eine leichte Abnahme des relativen Anteils großer Neurone und Axone wurde in den verletzten Seiten der Kontrollgruppe beobachtet. Für Axone war diese Abnahme statistisch signifikant. Im Gegensatz dazu war dies in Tieren, die mit neurotrophen Faktoren behandelt wurden, nicht zu beobachten. Bei allen Tieren zeigte sich ein beträchtliches Auswachsen von Hinterwurzelaxonen aus dem Spinalganglion. Diese Axone fanden keine spontane Verbindung mit dem proximalen Rest der Wurzel, sondern waren durch Bindegewebe eingehüllt. Bei etwa der Hälfte der Tiere zeigte sich, dass einer Untergruppe dieser Axone in Richtung des Narbengewebes der replantierten Vorderwurzel gewachsen war und über Defekte in der Bindegewebshülle teilweise sogar in die Vorderwurzel einwuchsen. Ein möglicher Einfluss der applizierten neurotrophen Faktoren auf das quantitative Regenerationsergebnis scheint also in diesem Modell gering zu sein. Auf eine qualitative Verbesserung deutet die Normalisierung des Axon-Myelinverhältnisses großer regenerierter Axone bei Kombinationsbehandlung hin. Die im vorliegenden Modell beträchtliche Regenerationskapazität der Hinterwurzel scheint bisher unterschätzt worden zu sein. Das unerwartete Einwachsen von Hinterwurzelaxonen in die Vorderwurzel könnte mit einer funktionellen Beeinträchtigung der regenerierten Vorderwurzel verbunden sein. / Treatment of brachial plexus lesions is attempted by surgical replantation of avulsed nerve roots. Prerequisites for successful regeneration of motoneuron axons are 1. survival of a large number of motoneurons, 2. restoration of connectivity between avulsed nerve roots and spinal cord and 3. high quality of regenerated axons. Regeneration and survival of motoneurons can be supported by neurotrophic factors. In the present study, the influence of CNTF and BDNF on regeneration of motoneurons after C7 ventral root avulsion and replantation after 3 weeks and 6 months was analysed. Additionally, detailed morphological analyses of dorsal root ganglia (DRG), severed dorsal roots and injured dorsal horns were performed. In adult rabbits C7 dorsal roots were severed, ventral roots were avulsed and replanted ventrolaterally. CNTF, BDNF, or both was applied to the replantation site, controls were replanted without application of neurotrophic factors (n>5). After 3 weeks (n= 3 controls) and 6 months (n= 27) after avulsion and replantation semi-thin sections of ventral roots and DRGs as well as cryostat serial sections from C7 spinal cord segment were prepared. DiI-fluorescence tracing, myelin-sheath staining, modified Klüver-Barrera staining of cryostat section and touloidinblue staining of semi-thin sections served for morphological and quantitative analyses. Six months after lesion, a survival of 30% of the C7 motoneurons was found without differences between the experimental groups. Retrograde fluorescent tracing and histological analysis documented that many axons had regrown through the original ventral exit zones or had exited the spinal cord at the lateral replantation site. However, many laterally exiting axons had not grown out directly from the ventral horn through the lateral white matter but had elongated vertically before leaving the spinal cord. The mean axonal diameter was significantly higher in regenerated axons that had exited through the original ventral exit zones in comparison with axons which had grown out laterally. Application of BDNF and/or CNTF did not show any effects on the pathways of regeneration into the replanted root. Three weeks after ventral root avulsion and replantation the number of axons was rare. After six months, the number of myelinated axons increased to 45% compared to unlesioned sides. Regenerated axons were mainly of small caliber with few axons showing typical properties of motoneuron axons. In controls myelination was significantly reduced compared to the unlesioned sides. This was not observed after CNTF, BDNF and CNTF+BDNF treatment. In CNTF+BDNF treated animals myelination was significantly increased compared to replanted controls in the majority of cases. At the dorsal root entry zone, small myelinated axons extended into central tissue protrusions, in cases with well-preserved morphology. This suggested sprouting of spinal neuron processes into the central dorsal root remnant. In lesioned DRGs, the density of neurons and myelinated axons was not significantly altered, but a slight decrease in the relative frequency of large neurons and an increase of small myelinated axons was noted (significant for axons). Unexpectedly, differences in the degree of these changes were found between control and neurotrophic factor-treated animals. Central axons of DRG neurons formed dorsal root stumps of considerable length which were attached to fibrous tissue surrounding the replanted ventral root. In cases where gaps were apparent in dorsal root sheaths, a subgroup of dorsal root axons entered this fibrous tissue. Continuity of sensory axons with the spinal cord was never observed. Some axons coursed ventrally in the direction of the spinal nerve. In summary, the number of surviving motoneurons and regenerating axons appeared not to be influenced by a single- dose application of neurotrophic factors in this model. However, improvement of myelination indicated that the quality of regeneration can be increased especially by CNTF+BDNF- treatment. Moreover, the considerable capacity of dorsal root regeneration we observed in this study has possibly been underestimated previously. The unexpected ingrowth of dorsal root axons into the regenerated ventral roots could be harmful for ventral root regeneration.

Ependymin (EPN) is a neurotrophic factor (NTF) that functions in goldfish long-term memory formation and optic nerve elongation (Shashoua, 1976; Shashoua, 1977; Shashoua, 1985). Goldfish EPN, or CMX-8933 (a short goldfish EPN mimetic studied by our lab), surprisingly have several demonstrated effects on mammalian cells, including neuroregenerative effects in a rat stroke model (Shashoua et al, 2003), and the activation of therapeutic superoxide dismutase (SOD) (Parikh, 2003) and transcription factor AP-1 (Adams et al, 2003) in mouse neuroblastoma cells or rat primary cortical neuronal cultures. Among its various functions, AP-1 can function as a master switch in long-term memory consolidation (Sanyal et al, 2002), so it may be a key event in EPN's mechanism of action. AP-1 activation is also a characteristic associated with other full-sized neurotrophic factors, including nerve growth factor and brain-derived nerve growth factor. This thesis was divided into three parts. The purpose of part I was to determine whether our previously observed upregulation of SOD by CMX-8933 is dependent upon (or merely concurrent with) AP-1 activation. Four independent SOD immunoblot experiments demonstrated that pre-treatment of rat primary cortical cultures with trifluoromethyl pyrimidine carboxylate (TFPC), a specific inhibitor of AP-1, significantly (p = 0.0004) decreased cellular levels of SOD by 67% at its IC50 concentration of 1 ìM, and completely inhibited the upregulation at 10 and 100 ìM concentrations. Thus, the CMX-8933-induced upregulation of SOD appears to depend (directly or indirectly) on AP-1 activation. Part II of this thesis included the use of bioinformatics to re-verify exciting recent observations that EPN-like proteins exist in mammals, termed mammalian-ependymin-related proteins or MERPs (Apostolopoulos et al, 2001). If our analyses were convincing, human EPN mimetics would then be designed and tested for AP-1 activation. Computer alignments and hydropathy plots performed with EPN amino acid sequences deduced from gene entries in GenBank verified the existence of mammalian homologs containing highly conserved domains with fish EPN's, suggesting the possibilities of similar protein conformation and function. Two human EPN mimetics were designed, hEPN-1 (8 aa long, corresponding to the same region as CMX-8933) and hEPN-2 (14 aa long, containing CMX-8933 and 6 upstream aa). Several mimetic doses were tested on mouse Neuro-2a cultures for nuclear translocation of c-Jun and c-Fos proteins (comprising the AP-1 particle upregulated by fish CMX-8933). Seven independent c-Jun immunoblot experiments, and five c-Fos experiments, demonstrated a strong (as high as 25-fold) dose-dependent increase in the nuclear titers of the AP-1 proteins. Both peptides had statistically equivalent effects. Thus, human EPN appears to exist, and two mimetics derived from its sequence appear to be biologically active against mouse neuroblastoma cells. Since hEPN-1 and -2 have only a few residues in common with CMX-8933, we hypothesize that the mimetic shape rather than sequence may be important for biological activity. In part III of this thesis, the biological effects of hEPN-1 and hEPN-2 on mouse Neuro-2a cells were studied further using RT-PCR to analyze potential increases in specific mRNAs. mRNAs related to growth, energy production, and protein translation were tested since previous data in our lab (Kaska, 2003) indicated mRNAs for translational elongation factor-2 (EF-2), and ribosomal proteins L19 and S12 were upregulated in rat primary cortical cultures by fish mimetic CMX-8933 (Kaska, 2003). Treatment of Neuro-2a cells with 1.0 ìg/ml hEPN-1 (the highest dose tested for the AP-1 translocation experiments) for 24 hrs appeared to increase (N = 1) mRNAs for ATP Synthase-C, ribosomal protein L19, and translational EF-2, relative to the levels of housekeeper polyubiquitin. Thus hEPN-1 may be involved in processes related to growth. Altogether, the data from this thesis extends our knowledge of fish EPN mimetic CMX-8933 (showing that its induction of SOD requires AP-1), demonstrates that human EPN may exist (bioinformatics), shows that two human EPN mimetics are biologically active (induce AP-1 translocation), and shows that one mimetic hEPN-1 may activate several mRNAs related to growth in mouse Neuro-2a cells.

This study analyzed sex differences in methylphenidate (MPH) sensitization and corresponding changes in glial cell-derived neurotrophic factor (GDNF) and brain-derived neurotprhic factor protein (BDNF) in adolescent male and female rats. After habituation to a locomotor arena, animals were sensitized to MPH (5mg/kg) or saline from postnatal day (P) 33–49, tested every second day. On P50, one group of animals were injected with saline and behavior assessed for conditioned hyperactivity. Brain tissue was harvested on P51 and analyzed for GDNF protein. A second group of animals was also sensitized to MPH from P33 to 49, and expression of behavioral sensitization was analyzed on a challenge given at P60, and BDNF protein analyzed at P61. Females demonstrated more robust sensitization to MPH than males, but only females given MPH during sensitization demonstrated conditioned hyperactivity. Interestingly, MPH resulted in a significant increase in striatal and accumbal GDNF with no sex differences revealed. Results of the challenge revealed that females sensitized and challenged with MPH demonstrated increased activity compared to all other groups. Regarding BDNF, only males given MPH demonstrated an increase in dorsal striatum, whereas MPH increased accumbal BDNF with no sex differences revealed. A hierarchical regression analysis revealed that behavioral sensitization and the conditioned hyperactivity test were reliable predictors of striatal and accumbal GDNF, whereas sensitization and activity on the challenge were reliable predictors of accumbal BDNF, but had no relationship to striatal BDNF. These data have implications for the role of MPH in addiction and dopamine system plasticity.

published_or_final_version / abstract / Zoology / Doctoral / Doctor of Philosophy

Master of Science / Department of Biochemistry / Gerald Reeck / Aphids mount a remarkable salivary secretion to overcome plant host defenses. Our group has previously reported a gene unique to aphids enriched in the salivary glands of the pea aphid A. pisum, C002, which is required for successful feeding on its host plant Vicia fava. Here I present an analysis of genetic variation within the available EST data for C002 in pea aphids. From 596 total ESTs, 332 are full-length, and segregate into 8 validated haplotypes based on the criteria I set in place to access the quality of EST data. Additionally, Armet, is a putative multi-functional gene implicated as a neurotrophic factor during development, and as a part of the unfolded protein response during stress. I employ RNA interference in the model organism T. castaneum to determine the effect of transcript knockdown during development from early in-star larval stages, through pupation, and its effect on adult emergence. I report that knockdown of Armet transcript significantly hinders the ability for beetles to emerge from the pupae.

HINTERGRUND: Der brain-derived neurotrophic factor (BDNF) reguliert die synaptische Plastizität und spielt somit eine wichtige Rolle in der Gedächtnisbildung und -erhaltung. Deswegen gibt es eingehende Untersuchungen dieses neurotrophischen Faktors in Bezug auf Demenzerkrankungen, vor allem der Alzheimer Demenz. In dieser Studie wurde nach einem Zusammenhang zwischen BDNF Blutplasmawerten und der Alzheimer Demenz in einer longitudinalen Kohortenstudie, der Vienna-Transdanube-Aging(VITA)-Studie gesucht. METHODEN: Die VITA-Studie ist eine kommunale Kohortenstudie aller 75jährigen Einwohner einer geographischen Region Wiens. Es wurden die BDNF Plasmawerte der Basisuntersuchung und der ersten Folgeuntersuchung 30 Monate später als mögliche Biomarker für die Alzheimer Demenz untersucht. Assoziationen zwischen BDNF Plasmawerten und anderen epidemiologischen Eckdaten wurden ebenfalls analysiert. ERGEBNISSE: Wir konnten keine Assoziation zwischen BDNF Plasmawerten und der Entwicklung oder einer bereits bestehenden Alzheimer Demenz finden. Geschlecht, Body-Maß-Index und Depression stellten sich als Komorbiditäts-Faktoren von Demenz-erkrankungen dar. SCHLUSSFOLGERUNG: BDNF Plasmawerte sind diesen Ergebnissen nach kein so viel versprechender molekularer Marker für Alzheimer Demenz wie erhofft. BDNF wird jedoch weiterhin in vielen interessanten Studienprotokollen untersucht, da es sowohl im Blutserum als auch im Hirngewebe nachgewiesen werden kann und somit viele diagnostische und therapeutische Ansätze inspiriert. / BACKGROUND: Brain-derived neurotrophic factor (BDNF) regulates the plasticity of synapses and plays an important role in developing and sustaining memory. Therefore it is intensely researched with regard to dementia, especially Alzheimer’s disease. In this study, we searched for a relationship between BDNF plasma levels and Alzheimer’s disease in a longitudinal cohort, the Vienna-Transdanube-Aging (VITA)-study. METHODS: The VITA is a prospective community-based cohort study of all 75 years old inhabitants of a geographical region of Vienna. We have investigated the BDNF plasma levels of the baseline and the first follow-up 30 months later as a possible biomarker for Alzheimer’s disease. Associations between BDNF plasma levels and other epidemiologic data were also analyzed. RESULTS: We found no association between BDNF plasma levels and the development or existence of Alzheimer’s disease. Gender, body-mass-index and depression were shown to be co-morbid to dementia. CONCLUSION: According to these results, BDNF plasma levels are not as promising as a molecular marker for Alzheimer’s disease as hoped for. BDNF, though, is still subject to many interesting study protocols, as it can be detected also in blood serum and brain tissue and therefore invites many diagnostic and therapeutic scenarios.

Thesis advisor: Barbara E. Wolfe / Background: Anorexia nervosa (AN) is a serious mental illness with physical and emotional consequences. Currently, there are limited effective treatments available to address this devastating condition. One possible biomarker implicated in this condition is brain derived neurotrophic factor (BDNF), a member of the neuron growth family. Pre-clinical studies indicate administration of BDNF is associated with decreased food intake and weight loss. Serum BDNF levels also have been shown to be reduced in AN compared to healthy controls (HC). In studies of selective serotonin reuptake inhibitors (SSRI's), blood levels of BDNF have been shown to increase following SSRI administration. This study sought to examine the possible relationship between peripheral BDNF levels and influence of an SSRI, and augmentation with 5-hydroxytryptophan (5-HTP) in persons with AN and HC's. Methods: This study examined previously collected samples from an investigation assessing the influence of SSRI administration and augmentation with 5-HTP on serotonin function in AN. The original study utilized a randomized double-blind placebo-controlled design. AN (n=16) and HC (n=49) subjects were randomized to 1 of 3 treatment conditions (fluoxetine, fluoxetine plus 5-HTP, and placebo) for 7 days of drug administration. Blood samples were collected following an overnight fast and stored at -70°C prior to batch analysis (ELISA). Results: Plasma BDNF levels in AN subjects (59.7 (SD 43.3) pg/ml) were not significantly (p=0.24) different from HC's (76.2 (SD 49.0) pg/ml). There were no significant differences between SSRI, SSRI plus 5-HTP, and placebo treatment groups within or between AN and HC groups. Conclusions: Although BDNF levels in AN subjects were lower than HC, the difference was not statistically significant. After 7 days of SSRI, SSRI plus 5-HTP, or placebo, there were no differences in BDNF levels between or within groups. The possibility exists that 7 days is not long enough to see an expressed effect of SSRI's on BDNF. Future studies would benefit from longer duration of SSRI's, assessing potential covariates (e.g. BMI, depression), and a larger sample. / Thesis (PhD) — Boston College, 2013. / Submitted to: Boston College. Connell School of Nursing. / Discipline: Nursing.

Olfactory Granule cells (GCs) are a population of inhibitory interneurons responsible for maintaining normal olfactory bulb (OB) function and circuitry. Through dendrodendritic synapses with the OBs projection neurons, the GCs regulate information sent to the olfactory cortices. Throughout adulthood, GCs continue to integrate into the OB and contribute to olfactory circuitry. However, only ~50% will integrate and survive longterm. Factors aiding in the survival and morphological development of these neurons are still being explored. The neurotrophin brain-derived neurotrophic factor (BDNF) aids in the survival and dendritic spine maturation/maintenance in several populations of CNS neurons. Investigators show that increasing BDNF in the adult-rodent SVZ stimulates proliferation and increases numbers of new OB GCs. However, attempts to replicate these experiments failed to find that BDNF affects proliferation or survival of adult-born granule cells (abGCs). BDNFs regulation of dendritic spines in the CNS is well characterized. In the OB, absence of BDNF’s receptor on abGCs hinders normal spine development and demonstrates a role for BDNF /TrkB signaling in abGCs development. In this study, we use transgenic mice over-expressing endogenous BDNF in the OB (TgBDNF) to determine how sustained increased in BDNF affect the morphology of olfactory GCs and the survival and development of abGCs. Using protein assays, we discovered that TgBDNF mice have higher BDNF protein levels in their OB. We employed a Golgi-cox staining technique to show that increased BDNF expression leads to an increase in dendritic spines, mainly the mature, headed-type spine on OB GCs. With cell birth-dating using 5-bromo-2’- deoxyuridine (BrdU), immunofluorescent cell markers, TUNEL staining and confocal microscopy, we demonstrate that over-expression of BDNF in the OB does not increase survival of abGCs or reduce cell death in the GC population. Using virally labeled abGCs, we concluded that abGCs in TgBDNF mice had similar integration patterns compared to wild-type (WT) mice, but maintained increases in apical headed-type spine density from 12 to 60 days PI. The evidence combined demonstrates that although increased BDNF does not promote cell survival, BDNF modifies GC morphology and abGC development through its regulation of dendritic spine development, maturation and maintenance in vivo. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection