Brain-derived neurotrophic factor (BDNF), a neurotrophin involved in the regulation of food intake and body weight, has been implicated in the development and maintenance of Anorexia nervosa (AN). The majority of previous studies reported lower BDNF levels in acutely underweight AN patients (acAN) and increasing levels after weight rehabilitation. Here, we investigated serum BDNF concentrations in the largest known AN sample to date, both before and after weight restoration therapy. Serum BDNF was measured in 259 female volunteers: 77 in-patient acAN participants of the restrictive type (47 reassessed after short-term weight rehabilitation), 62 individuals long-term recovered from AN, and 120 healthy controls. We validated our findings in a post-hoc mega-analysis in which we reanalyzed combined data from the current sample and those from our previous study on BDNF in AN (combined sample: 389 participants). All analyses carefully accounted for known determinants of BDNF (age, sex, storage time of blood samples). We further assessed relationships with relevant clinical variables (body-mass-index, physical activity, symptoms). Contrary to our hypotheses, we found zero significant differences in either cross-sectional or longitudinal comparisons and no significant relationships with clinical variables. Together, our study suggests that BDNF may not be a reliable state- or trait-marker in AN after all.

No description available.

Obesity is associated with deficits in cognitive function, particularly within the domain of executive function (EF). EF refers to higher order cognitive processes that regulate our ability to sustain attention, inhibit subconscious tendencies, remember and manipulate information for immediate use, and remain cognitively flexible. Deficits in EF in overweight and obese individuals may impact the success of weight loss and maintenance efforts. Therefore, understanding the biological links between obesity and EF, as well as the ability to reverse EF deficits with weight loss, is imperative. The first study aimed to determine the effect of weight loss in overweight and obese, middle-aged and older adults on serum brain-derived neurotrophic fact (BDNF), S100 calcium binding protein B (S100B), and glial fibrillary acidic protein (GFAP). Serum samples (n=21; 50-75 years, BMI 25-40 kg/m2) were pooled from two prior weight loss studies. Fasting blood measurements were taken before and after 8- or 12-weeks of hypocaloric diet-induced weight loss (1200 or 1500 kcal/d). Body Mass Index (BMI), body weight, waist circumference, and percent body fat (All p<0.001) decreased with weight loss. Serum BDNF (p=0.871), S100B (p=0.898), and GFAP (p=0.506) did not change following weight loss. The second study aimed to determine the correlation between the magnitude of change in serum BDNF, S100B, and GFAP and the magnitude of improvement in EF performance on three computer-based tests. Participants (n=8; 50-75 years, BMI 25-40 kg/m2) completed 4-weeks of hypocaloric diet-induced weight loss (1200 or 1500 kcal/d), followed by 4-weeks of weight maintenance (hypocaloric diet + steps/d goal). Fasting blood and EF measurements were completed at baseline, and weeks 4 and 8. BMI (p=0.001), body weight (p=0.001), waist circumference (p=0.002), and percent body fat (p=0.001) decreased from baseline to week 8. Serum BDNF (p=0.359), S100B (p=0.277), and GFAP (p=0.585) did not change following weight loss. Go/No-Go (GNG) errors of commission (p=0.009) and AX-Continuous Performance Test (AX-CPT) correct response time (p=0.041) decreased following the weight loss. The change in serum GFAP was inversely correlated with GNG errors of omission (r=-0.716, p=0.046) and AX-CPT correct hits (r=-0.737, p=0.037), and positively correlated with AX-CPT correct response time (r=0.859, p=0.006). In conclusion, although weight loss does not influence serum BDNF, S100B, or GFAP levels, it may have a positive effect on inhibitory control in overweight and obese, middle-aged and older adults. Further research is needed to understand the relationship between serum BDNF, S100B, and GFAP and executive function. / Master of Science / Obesity is associated with lower brain function, particularly in executive function (EF). EF refers to advanced thought processes that help to maintain focus, practice self-control, solve problems, and easily switch between tasks. Lower EF in individuals with overweight and obesity may impact the success of weight loss and maintenance efforts. Because of this, understanding body processes that may link obesity and lower EF, as well as the ability to improve EF with weight loss, is very important. The first study aimed to determine the effect of weight loss on blood proteins responsible for brain health: brain-derived neurotrophic fact (BDNF), S100 calcium binding protein B (S100B), and glial fibrillary acidic protein (GFAP). Twenty-one blood samples from overweight and obese, middle-aged and older adults were combined from two completed weight loss studies. In these studies, blood was measured before and after 8- or 12-weeks of a weight loss (low calorie diet;1200 or 1500 Calories per day). Body Mass Index (BMI), body weight, waist circumference, and percent body fat all decreased with weight loss; however, levels of BDNF, S100B, and GFAP in the blood did not change. The second study aimed to determine the relationship between blood BDNF, S100B, and GFAP and performance on three computer-based tests of EF before and after weight loss. Eight overweight and obese, middle-aged and older adults completed 4-weeks of weight loss (low-calorie diet; 1200 or 1500 Calories per day), followed by 4-weeks of weight maintenance. BMI, body weight, waist circumference, and percent body fat all decreased following the weight loss and maintenance intervention (week 8). Blood BDNF, S100B, and GFAP levels did not change, but performance on two EF measures improved: participants made less errors of commission (doing something when not supposed to) and had faster reaction time following the intervention, indicating better self-control. Additionally, greater increases in GFAP were associated with less errors of omission (not doing something when supposed to), fewer correct responses, and slower reaction time. In conclusion, although weight loss did not affect blood BDNF, S100B, or GFAP levels, it may improve self-control in overweight and obese, middle-aged and older adults. Further research is needed to understand the relationship between weight loss, blood proteins of brain health, and EF.

Einleitung: Bei der Dystonie handelt es sich um eine Erkrankung des zentralen Nervensystems. Sie ist charakterisiert durch ungewollte, dauerhafte oder wiederkehrende Muskelkontraktionen, die zu abnormalen Bewegungsabläufen und Haltungen führen. Sie ist die dritthäufigste Bewe-gungsstörung beim Menschen. Bisherige Befunde beim Menschen und Untersuchungen an Tier-modellen weisen u.a. auf eine besondere Bedeutung der Basalganglien-Thalamus-Schleife hin, die an der Kontrolle von willkürlichen und unwillkürlichen Bewegungen beteiligt ist. So konnten bei unterschiedlichen Tiermodellen Veränderungen im Striatum (STR), der Eingangsstruktur der Basalganglien, nachgewiesen werden. Beim dtsz Hamster, einem gut etablierten Tiermodell für die paroxysmale Dystonie, konnte neben vielen striatalen Veränderungen eine Reduktion der GABAergen Interneurone (IN), wie Parvalbumin-positive (PV+) IN, zum Zeitpunkt der maximalen Ausprägung der Dystonie gezeigt werden. Ziele der Untersuchung: Die Gründe für den Mangel an striatalen GABAergen IN bei der dtsz Hamstermutante sollten weiter untersucht werden, indem der Frage nachzugehen war, ob beim dtsz Hamster eine Migrations- oder Ausreifungsstörung der IN vorliegt. Dazu wurde das Homöodomänprotein Nkx 2.1, als Marker für aus dem medialen Ganglienhügel eingewanderte IN, im STR der dtsz Hamstermutante untersucht. Die Expression des Brain-derived neurotrophic factors (BDNF), des Kalium-Chlorid-Kotransporters 2 (KCC2) und die zytosolische Carboanhydrase vom Isotyp 7 (CAH7) wurden als Indikatoren für die Ausreifung von GABAergen IN herangezogen. Tiere, Material und Methoden: Die Untersuchungen wurden vergleichend an dtsz Hamstern und Kontrollhamstern durchgeführt. Beim dtsz Hamster zeigt die Dystonie einen altersabhängigen Verlauf (Beginn: ca. 16. Lebenstag (LT); Maximum: 30.-42. LT; Remission: 70. LT). Deshalb wurden als Untersuchungszeitpunkte der 18. LT und der 33. LT gewählt. Um die Migration der striatalen IN zu untersuchen, wurde im STR bei 33 Tage alten Hamsterns die Dichte der immun-histochemisch markierten Nkx 2.1-positiven Zellen stereologisch ermittelt. Der mRNA-Gehalt wurde relativ mittels „quantitativer Echtzeit-PCR“ (qPCR) bestimmt. Zusätzlich wurde die mRNA-Expression von Nkx 2.1 bei 18 Tage alten Tieren untersucht. Von KCC2 und CAH7 wurde die mRNA mittels qPCR bei 18 und 33 Tage alten Hamstern im STR untersucht. Die Expression von BDNF wurde mittels ELISA-System im Kortex (Cx), STR und im restlichen Gehirngewebe („R“) bei 33 und 18 Tage alten Tieren bestimmt. Der BDNF-mRNA Gehalt wurde im Cx (18. und 33. LT) und im STR (33. LT) untersucht. Des Weiteren sollte BDNF bei 33 Tage alten Hamstern mittels immunhistochemischer Markierung im Cx und STR untersucht werden. Die Untersuchung von BDNF im Cx ist deshalb wichtig, weil BDNF vom Cx in das STR trans-portiert wird. Zusätzlich wurde Parvalbumin (PV) zusammen mit Nkx 2.1 immunhistochemisch markiert und die mRNA-Expression von PV bei 18 und 33 Tage alten Tieren bestimmt. Ergebnisse: Für Nkx 2.1 konnte kein Unterschied in der Zelldichte zwischen dtsz- und Kontroll-hamstern gefunden werden. Ebenfalls gab es weder bei 18 noch bei 33 Tage alten Tieren einen Unterschied in der Nkx 2.1-mRNA-Expression. Unterschiede in der mRNA-Expression von KCC2 und CAH7 im STR (18. und 33. LT) lagen auch nicht vor. Die Expression der PV-mRNA im STR bei 33 Tage alten Tieren war jedoch erwartungsgemäß vermindert. Auf mRNA-Ebene konnte im Cx für BDNF kein Unterschied zwischen dtsz- und Kontrolltiergruppe gefunden wer-den. Bei beiden Tiergruppen wurde mittels ELISA im STR mehr BDNF nachgewiesen als im Cx und im R (18. und 33. LT) nachweisbar. Entgegen der Hypothese war nach Analyse der Daten mittels Zwei-Wege ANOVA eine geringe Erhöhung der BDNF-Expression im Cx und STR bei 33 Tage alten dtsz Hamstern nachweisbar. Dies lag daran, dass die BDNF-Expression nur bei den Kontrolltieren am 33. LT im Vergleich zum 18. LT herunterreguliert war. Die Ergebnisse der BDNF-Immunhistologie waren in Hinblick auf die Spezifität zweifelhaft. Schlussfolgerung: Die Nkx 2.1 Daten lassen auf eine ungestörte Migration striataler IN bei der dtsz Mutante schließen. Wahrscheinlich ist eine Ausreifungsstörung für den Mangel an GABAer-gen IN verantwortlich. Die Ergebnisse von KCC2 und CAH7 zeigen, dass keine generelle Ausreifungsstörung von GABAergen Neuronen vorliegt, wobei dies für kleinere Subpopulationen nicht ausgeschlossen werden kann. Entgegen der Arbeitshypothese konnte keine Verringerung sondern eine leichte Erhöhung von BDNF zum 33. LT bei der dtsz Hamstermutante festgestellt werden. Eine mögliche Erklärung könnte sein, dass BDNF auf Grund der verzögert einsetzenden Entwicklung der IN nicht herunterreguliert wird. Die Gründe für diese Erhöhung wie auch weitere Marker für die neuronale Ausreifung werden durch weiterführende Studien untersucht.

The brain is a highly adaptable organ that is capable of converting sensory information into changes in neuronal function. This plasticity allows behavior to be accommodated to the environment, providing an important evolutionary advantage. Neurons convert environmental stimuli into long-lasting changes in their physiology in part through the synaptic activity-regulated transcription of new gene products. Since the neurotransmitter-dependent regulation of Fos transcription was first discovered nearly 25 years ago, a wealth of studies have enriched our understanding of the molecular pathways that mediate activity-regulated changes in gene transcription. These findings show that a broad range of signaling pathways and transcriptional regulators can be engaged by neuronal activity to sculpt complex programs of stimulus-regulated gene transcription. However, the shear scope of the transcriptional pathways engaged by neuronal activity raises the question of how specificity in the nature of the transcriptional response is achieved in order to encode physiologically relevant responses to divergent stimuli. Here we summarize the general paradigms by which neuronal activity regulates transcription while focusing on the molecular mechanisms that confer differential stimulus-, cell-type-, and developmental-specificity upon activity-regulated programs of neuronal gene transcription. In addition, we preview some of the new technologies that will advance our future understanding of the mechanisms and consequences of activity-regulated gene transcription in the brain. / Dissertation

BDNF/TrkB são descritos em diversas neoplasias onde iniciam sinais mitogênicos, facilitam o crescimento tumoral, previnem apoptose e regulam angiogênese e metástase. Outros fatores de crescimento também são importantes para tumorigênese, como GRP/GRPR e EGF/EGFR. O objetivo geral deste trabalho foi investigar o papel de BDNF/TrkB em câncer colorretal avaliando possíveis interações com GRPR e EGFR. Verificamos que BDNF e seu receptor, TrkB, estão presentes em amostras de pacientes com câncer colorretal esporádico, e os níveis de BDNF encontram-se mais elevados no tecido neoplásico que no tecido adjacente ao tumor. O tratamento com RC- 3095, um antagonista de GRPR, na linhagem celular de câncer colorretal humana, HT-29, causa diminuição nos níveis de NGF secretados pelas células e aumento de BDNF em relação ao controle não tratado. RC-3095 inibe a proliferação e viabilidade celular das linhagens HT-29 (EGFR positiva) e SW-620 (EGFR negativa), embora apenas em HT-29 ocorra um aumento significativo na expressão de mRNA de BDNF. Por isso, um anticorpo monoclonal anti-EGFR, cetuximabe, foi combinado a RC-3095, nas células HT-29, sendo capaz de prevenir tal aumento, sugerindo que este efeito seja mediado por EGFR. Os tratamentos com um inibidor de Trks, K252a (1000 nM) ou com cetuximabe (10 nM) também inibem a proliferação celular. Entretanto, a combinação de BDNF a cetuximabe previne este efeito, enquanto que a combinação de doses não efetivas de K252a (10 nM) à cetuximabe (1 nM) inibe a proliferação celular de HT- 29. Além disso, cetuximabe também causa aumento na expressão de mRNA de TrkB e BDNF, após 600 minutos de tratamento. Nossos resultados sugerem que a inibição da proliferação celular in vitro ou do crescimento tumoral in vivo devem acontecer através do bloqueio combinado entre GRPR e TrkB em células de câncer colorretal EGFR positivas, e que BDNF também esteja envolvido em mecanismos de resistência a fármacos. Por isso, o bloqueio de BDNF / TrkB pode emergir como potencial alvo antitumoral. / BDNF / TrkB are described in various cancers where they participate in tumor growth, apoptosis, angiogenesis and metastasis. Furthermore, other growth factors are also important to tumorigenesis as GRP/GRPR and EGF/EGFR. Therefore, the aim of this study was to investigate the role of BDNF/TrkB in colorectal cancer evaluating the interactions with GRPR and EGFR. We found that BDNF and its receptor, TrkB, are present in samples from patients diagnosed with sporadic colorectal cancer, and BDNF levels were higher in tumor tissue compared to adjacent tumor tissue. Treatment with RC-3095, GRPR antagonist, in human colorectal cancer cell line, HT-29 caused a decrease in NGF levels secreted by cells, and generated increase of BDNF when compared to untreated control. RC-3095 inhibited the proliferation and cell viability in HT-29 (EGFR positive) and SW-620 (EGFR negative), but only HT-29 cells showed a significant increase in BDNF mRNA expression. Therefore, a monoclonal anti-EGFR antibody, cetuximab was combined with RC-3095 in HT-29 cells, and was able to prevent such an increase, suggesting that this effect is mediated by EGFR. The treatment with a Trk inhibitor, K252a (1000 nM) or cetuximab (10 nM), inhibited cell proliferation. However, the combination of BDNF with cetuximab prevented this effect, whereas the combination of ineffective doses of K252a (10 nM) with cetuximab (1 nM) still inhibited cell proliferation of HT-29. Furthermore, cetuximab also caused an increase in BDNF and TrkB mRNA expression, 600 minutes after treatment. In summary, our results suggest that inhibition of cell proliferation in vitro or tumor growth in vivo must occur between the combination of GRPR and TrkB in EGFR positive colorectal cancer cells, and that BDNF is also involved in drug resistance mechanisms. Therefore, blockage of BDNF / TrkB may emerge as potential antitumor target.

Introdução: Em crianças e adolescentes, o Transtorno de Humor Bipolar (THB) é associado a danos devastadores no desenvolvimento. O Transtorno de Déficit de Atenção/Hiperatividade (TDAH), caracterizado por sintomas de desatenção, hiperatividade e impulsividade também causa prejuízo funcional significativo. O diagnóstico diferencial entre os dois transtornos é puramente clínico e, até o momento, há poucos estudos avaliando diferenças neurobiológicas. Diversas pesquisas sugerem a participação do Fator Neurotrófico Derivado do Cérebro (BDNF), cujo papel não foi elucidado em crianças e adolescentes com THB e com TDAH. Apesar das altas taxas de comorbidade entre o THB e o TDAH, de uma pior resposta ao tratamento e de um pior funcionamento psicossocial quando da comorbidade, apenas dois estudos avaliaram a resposta ao tratamento especificamente neste grupo de pacientes. Objetivos: O objetivo principal deste trabalho é avançar no entendimento do papel do BDNF na psicopatologia do THB e do TDAH, visando sua diferenciação. O tratamento da comorbidade com estimulantes tambem foi estudado. Métodos: A transmissão do alelo Val66 do BDNF foi avaliada em famílias de crianças e adolescentes com THB e TDAH, assim como o efeito do gene no nível sérico da proteína do BDNF entre os grupos. Foi realizada a comparação dos níveis séricos entre pacientes com THB em comorbidade com TDAH e TDAH isolado. Um estudo clínico cruzado com estimulantes foi realizado em crianças e adolescentes com THB e TDAH em comorbidade que tinham apresentado remissão dos sintomas de humor com o uso de aripiprazol, mas persistência dos sintomas de TDAH. Os sintomas de mania, depressão, desatenção e hiperatividade foram acompanhados ao longo de quatro semanas de tratamento, duas com placebo ou metilfenidato e duas com o tratamento inverso. Resultados: Na investigação da transmissão do gene do BDNF em crianças e adolescentes não foi detectada diferença significativa na transmissão do alelo Val66. Tampouco foi observada diferença significativa nos níveis séricos da proteína do BDNF entre os pacientes com THB em comorbidade com TDAH, quando comparados aos pacientes com TDAH e controles. No estudo cruzado com crianças e adolescentes com THB em comorbidade com TDAH, não houve diferenças entre os grupos com placebo ou estimulantes na resposta ao tratamento nos sintomas de TDAH. Os sintomas de humor mantiveram-se estáveis a despeito do uso de metilfenidato. Conclusões: Os achados quanto ao gene do BDNF não sugerem sua participação na neurobiologia do THB ou no TDAH, ou que devido à herança poligênica característica dos transtornos mentais, sua participação seja pequena. O achado de diferença significativa entre os níveis séricos do BDNF de crianças e adolescentes com THB+TDAH e TDAH indica que esse tema deve ser mais estudado, e, caso seja também encontrado de forma consistente por outros grupos, possa vir a ser utilizado como marcador biológico na diferenciação diagnóstica entre essas condições. No estudo de tratamento da comorbidade entre THB e TDAH, a ausência de resposta ao metilfenidato nos sintomas de TDAH em pacientes que apresentam a comorbidade reforça a evidência de que há pior resposta ao tratamento neste grupo, dado o elevado tamanho de efeito do metilfenidato no tratamento do TDAH em isolado O estudo de fatores biológicos para um melhor entendimento da psicopatologia e conseqüente diferenciação dos transtornos mentais tem extrema relevância porque a identificação destes fatores pode auxiliar na elaboração de tratamentos mais precisos, urgentemente necessários devido às graves conseqüências do THB e do TDAH nas vidas dos pacientes e de suas famílias. A criação de um programa específico para Crianças e Adolescentes com Transtorno Bipolar (ProCAB) e de uma linha de pesquisa com foco na etiologia e tratamento possibilitam uma constante geração de conhecimento nesta área, onde poucos estudos estão disponíveis. / Introduction: Bipolar Disorder (BD) in children and adolescents is associated to devastating developmental deficits. Attention-Deficit/Hyperactivity Disorder (ADHD), characterized by inattention, hyperactivity, and impulsivity, also promotes significant impairment. Differential diagnosis between both conditions is purely clinical – currently, there are scarce investigations on neurobiological differences. Several studies suggest the participation of the Brain-Derived Neurotrophic Factor (BDNF) in these disorders, whose role has not been elucidated in BD and ADHD in children and adolescents. Despite high comorbidity rates between BD and ADHD, worse psychosocial functioning, and worse response to treatment, only two studies addressed treatment response specifically in this group of patients. Objectives: promote advances in understanding the role of BDNF in the psychopathology of BD and ADHD. The treatment of the comorbidity was also studied. Methods: Transmission of the Val66 allele at the BDNF was assessed in children and adolescents with BD and ADHD, as well as the effect of the gene on the serum levels of BDNF protein in both conditions. BDNF serum levels were compared between patients with BD comorbid with ADHD, and ADHD. A crossover clinical trial with stimulants and placebo was performed with children and adolescents preseting BD and comorbid ADHD. Manic, depressive, inatention and hyperactivity symptoms were assessed along a 4-week treatment, 2 weeks in each treatment arm (placebo or stimulants). Results: There was no significant transmission of the Val66 allele at the BDNF gene in children and adolescents with BD or ADHD. A significant difference in BDNF protein serum levels between BD+ADHD when compared to ADHD alone and controls. In the crossover trial with children and adolescents with BD and comorbid ADHD, we did not observe differences between the placebo and stimulant treatment groups in the response of ADHD symptoms. Mood symptoms remained stable despite the use of methylphenidate. Conclusions: our results regarding the BDNF gene do not suggest its participation in the neurobiology of BD or ADHD, or that due to the polygenic characteristic of mental disorders, that this gene confers a only a small risk, undetectable in our sample. The finding of a significant difference in BDNF serum levels between BD comorbid with ADHD, and ADHD alone warrants further investigation, and in case replication studies with larger samples from other groups are positive, BDNF serum levels might be used as a biological marker in the diagnostic difference between these conditions. In the investigation of the treatment of the comorbidity between BD and ADHD, the absence of different responses between placebo and methylphenidate in ADHD symptoms strengthens the evidence that there is a worse response to treatment in this group, given the large effect size of methylphenidate response in the treatment of ADHD alone. The quest for biological markers for a better understanding of the psychopathology and subsequent differentiation of mental disorders is extremely relevant. The identification of these factors may facilitate the creation of more accurate treatment regimens, urgently needed due to the severe developmental consequences of BD and ADHD in the patients’ and families’ lives. In this sense, the creation of a specific outpatient program for children and adolescent BD (ProCAB), a research line with focus on risk factors and treatment, will enable a Constant generation of knowledge in this área, where scarce data is available.

Progressive degeneration in the central nervous system (CNS) of Huntington’s disease (HD) patients is a relentless debilitating process, resulting from the inheritance of a single gene mutation. With limited knowledge of the underlying pathological molecular mechanisms, pharmaceutical intervention has to-date not provided any effective clinical treatment strategies to attenuate or compensate the neuronal cell death. Attention has therefore turned to biotherapeutic molecules and novel treatment approaches to promote restoration and protection of selectively vulnerable populations of neurons in the HD brain. Rapid advances in vectorology and gene-based medicine over the past decade have opened the way for safe and efficient delivery of biotherapeutics to the CNS. With numerous factors known to regulate the development, plasticity and maintenance of the mammalian nervous system many proteins have emerged as potential therapeutic agents to alleviate HD progression. This investigative study utilised gene delivery vectors derived from the non-pathogenic adeno-associated virus (AAV) to direct high-level expression of brain-derived neurotrophic factor (BDNF), glial cell-line derived neurotrophic factor (GDNF), Bcl-xL or X-linked inhibitor of apoptosis protein (XIAP) within the rodent striatum. Maintenance of the basal ganglia and functional behaviour deficits were assessed following excitotoxic insult of the striatum by quinolinic acid (QA), a neurotoxic model of HD pathology. Enhanced striatal expression of BDNF prior to QA-induced lesioning provided maintenance of the striosome-matrix organisation of the striatum, attenuating impairments of sensorimotor behaviour with a 36-38% increase in the maintenance of DARPP-32 / krox-24 expressing striatal neurons, reduced striatal atrophy and increased maintenance of striatonigral projections. Higher levels of BDNF however induced seizures and weight-loss highlighting the need to provide regulatable control over biotherapeutic protein expression. Continuous high-expression of BDNF or GDNF resulted in a downregulation of intracellular signal mediating proteins including DARPP-32, with AAV-GDNF not found to enhance the overall maintenance of striatal neurons. Neither of the anti-apoptotic factors provided significant protection of transduced striatal neurons but tended towards ameliorating QA-induced behavioural deficits, displaying behaviour – pathology correlations with the survival of parvalbumin-expressing neurons in the globus pallidus. The results of this thesis suggest BDNF as a promising putative biotherapeutic for HD, but emphasises the requirement to control expression following gene delivery, and for further elucidation of the physiological impact that enhanced expression of endogenous factors has on the host cells. Additionally the maintenance of neural networks beyond the caudate-putamen will be vital to ensuring efficient clinical outcomes for HD. / Auckland Medical Research Foundation. Foundation for Research, Science and Technology. The University of Auckland.

<p>Amyotrophic lateral sclerosis is a fatal, progressive neurodegenerative disease with unknown ethiology. The aim of this study was to increase understanding of the pathophysiological mechanisms of dying motor neurons and wasting muscle tissue in this particular disorder.</p><p>Quantitative receptor autoradiographic methodology was applied on cervical spinal cord sections from patients with ALS to evaluate the specific binding of the acetylcholine transporter ³H-vesamicol in motor neurons. Despite a significant reduction of the number of ventral motor neurons in ALS, the ³H-vesamicol binding was not reduced in ALS compared to control cases, which suggests an increased metabolic activity in remaining motor neurons.</p><p>Motor neurons dying in ALS might go through apoptosis (programmed cell death), so immunohistochemical and TUNEL techniques were applied on thoracic spinal cord from ALS patients to evaluate the possibility of an apoptotic process. The increased Bax expression indicates an apoptotic process and further, motor neurons were TUNEL-positive, indicating DNA degradation caused by programmed cell death.</p><p>Muscle biopsies were obtained from ALS patients, and mRNA levels for the neurotrophic factors GDNF and BDNF were measured and compared to control subjects. GDNF levels were increased in muscle tissue in ALS whereas BDNF levels were unaltered.</p><p>Levels of GDNF and BDNF were also measured in cerebrospinal fluid from ALS patients and controls using ELISA methodology. Levels of BDNF were unaltered in ALS cornpared to controls. GDNF however was not detectable in controls whereas 12 out of 15 ALS patients had measurab1e levels of GDNW. A marked upregulation of endogenous GDNF and GDNF mRNA in ALS CSF and muscle respectively is of special interest in relation to clinical trials where GDNF is administered to this group of patients.</p>

Amyotrophic lateral sclerosis is a fatal, progressive neurodegenerative disease with unknown ethiology. The aim of this study was to increase understanding of the pathophysiological mechanisms of dying motor neurons and wasting muscle tissue in this particular disorder. Quantitative receptor autoradiographic methodology was applied on cervical spinal cord sections from patients with ALS to evaluate the specific binding of the acetylcholine transporter 3H-vesamicol in motor neurons. Despite a significant reduction of the number of ventral motor neurons in ALS, the 3H-vesamicol binding was not reduced in ALS compared to control cases, which suggests an increased metabolic activity in remaining motor neurons. Motor neurons dying in ALS might go through apoptosis (programmed cell death), so immunohistochemical and TUNEL techniques were applied on thoracic spinal cord from ALS patients to evaluate the possibility of an apoptotic process. The increased Bax expression indicates an apoptotic process and further, motor neurons were TUNEL-positive, indicating DNA degradation caused by programmed cell death. Muscle biopsies were obtained from ALS patients, and mRNA levels for the neurotrophic factors GDNF and BDNF were measured and compared to control subjects. GDNF levels were increased in muscle tissue in ALS whereas BDNF levels were unaltered. Levels of GDNF and BDNF were also measured in cerebrospinal fluid from ALS patients and controls using ELISA methodology. Levels of BDNF were unaltered in ALS cornpared to controls. GDNF however was not detectable in controls whereas 12 out of 15 ALS patients had measurab1e levels of GDNW. A marked upregulation of endogenous GDNF and GDNF mRNA in ALS CSF and muscle respectively is of special interest in relation to clinical trials where GDNF is administered to this group of patients.