Dysfunction of the N-methyl-D-aspartate (NMDA) receptor is thought to contribute to the cognitive deficits of many neurodegenerative diseases and psychiatric disorders. Cognitive symptoms of Alzheimer's disease can be treated with NMDA receptor antagonists or drugs targeting the cholinergic system; however, there are no effective treatments for cognitive deficits of schizophrenia or Huntington's disease. With the discovery of a potent and selective allosteric modulator of the NMDA receptor, there is the possibility of new treatments based on NMDA receptor functional-enhancement through neuroactive steroids, closely related in structure to the endogenous neurosteroid, cerebrosterol. The aim of this thesis was to examine steroidal modulation of the NMDA receptor both in vitro and in vivo. In chapter 2, NMDA receptor enhancement of both the synthetic and endogenous neuroactive steroids was assessed in neurons maintained in cell culture using calcium imaging techniques. Sulphation of the steroids greatly increased the efficacy of NMDA receptor enhancement compared to the unsulphated steroids. Chapters 3 and 4 investigate the potential for neuroactive steroids to treat cognitive impairments of Huntington's disease. Using a mouse model, tests were selected that were analogous to those in which patients are impaired; however, no impairments were found in the mouse model. Chapter 5, therefore, used a different model of cognitive impairment – namely, rats with a set-shifting impairment, as is seen in many psychiatric and neurological disorders, including Huntington's disease – to assess the effect of the synthetic steroid administration. Unfortunately, the rats did not show the expected impairment. The lack of reliable animal models compromised testing the efficacy of these promising NMDA receptor positive allosteric modulators. Nevertheless, the promising in vitro results suggest that there could still be therapeutic potential. In addition, the compound is a useful research tool for exploring NMDA receptor function in health and disease.

Huntington's disease (HD) is an autosomal dominant hereditary neurodegenerative disease characterized by motor, cognitive and behavioral disorders. HD is caused by expansion of CAG triplet (cytosine-adenosine-guanine) located in a gene on the short arm of the fourth chromosome. This expansion encodes an aberrant polyglutamine chain in the protein huntingtin. Physiological and mutated huntingtin (in case of HD) are expressed in almost all tissues and influences many cellular functions. The prevalence of HD in population is about 1 per 10.000. The disease is currently incurable and its mechanisms are not sufficiently understood. Besides affecting the central nervous system HD also affects peripheral tissues, including skeletal muscles. HD disrupts mitochondrial function and damages oxidative phosphorylation system, which has the task of producing energy in the form of ATP in cells. Research of transgenic minipig model for HD could help elucidate the mechanisms of disease's pathogenesis and potential therapeutic strategy. In this diploma thesis, immunodetection with help of specific antibodies to detect changes in amount of 14 selected mitochondrial proteins in skeletal muscle tissue of three age groups of transgenic HD minipigs - 24, 36 and 48 months old was used. Gradual progression in reduced...

Indiana University-Purdue University Indianapolis (IUPUI) / Huntington’s Disease (HD) is an inherited, autosomal dominant, neurodegenerative disorder. There is no cure for HD and the existing therapies only alleviate HD symptoms without eliminating the cause of this neuropathology. HD is linked to a mutation in the huntingtin gene, which results in an elongation of the poly-glutamine stretch in the huntingtin protein (Htt). A major hypothesis is that mutant Htt (mHtt) leads to aberrant Ca2+ homeostasis in affected neurons. This may be caused by increased Ca2+ influx into the cell via the N-methyl-Daspartate (NMDA)-subtype of glutamate receptors. The contribution of two major Ca2+ removal mechanisms, mitochondria and plasmalemmal Na+/Ca2+ exchangers (NCX), in neuronal injury in HD remains unclear. We investigated Ca2+ uptake capacity in isolated synaptic (neuronal) and nonsynaptic mitochondria from the YAC128 mouse model of HD. We found that both Htt and mHtt bind to brain mitochondria and the amount of mitochondriabound mHtt correlates with increased mitochondrial Ca2+ uptake capacity. Mitochondrial Ca2+ accumulation was not impaired in striatal neurons from YAC128 mice. We also found that expression of the NCX1 isoform is increased with age in striatum from YAC128 mice compared to striatum from wild-type mice. Interestingly, mHtt and Htt bind to the NCX3 isoform but not to NCX1. NCX3 expression remains unchanged. To further investigate Ca2+ homeostasis modulation, we examined the role of collapsin response mediator protein 2 (CRMP2) in wild-type neurons. CRMP2 is viewed as an axon guidance protein, but has been found to be involved in Ca2+ signaling. We found that CRMP2 interacts with NMDA receptors (NMDAR) and disrupting this interaction decreases NMDAR activity. CRMP2 also interacts with and regulates NCX3, resulting in NCX3 internalization and decreased activity. Augmented mitochondrial Ca2+ uptake capacity and an increased expression of NCX1 in the presence of mHtt suggest a compensatory reaction in response to increased Ca2+ influx into the cell. The role of NCX warrants further investigation in HD. The novel interactions of CRMP2 with NMDAR and NCX3 provide additional insight into the complexity of Ca2+ homeostasis regulation in neurons and may also be important in HD neuropathology.

Huntington's Disease (HD) is a rare condition that has been under-researched by the medical professions and psychologists alike. There is a clear lack of psychological literature on the subject of HD and furthermore, there are no adequate QoL scales available for use by spousal carers. The development of a HD specific QoL scale (HDQoL-C) for this special population, brings together theoretical constructs and practical application in order to produce a user-friendly QoL measurement for spousal carers of HD patients.

Bakgrund: Huntingtons sjukdom innebär ofta såväl motoriska, kognitiva som psykiatriska symtom. Chorea är ett tidigt motoriskt symtom och innebär överrörelser som kan förekomma i hela kroppen. Få studier beskriver den subjektiva upplevelsen av chorea.   Syfte: Att undersöka upplevelser av chorea hos fem personer med Huntingtons sjukdom samt att undersöka hur chorean påverkade deras förmåga till fysisk aktivitet.    Design och metod: Explorativ kvalitativ design. Semistrukturerade intervjuer med fem personer med Huntingtons sjukdom. En kvalitativ innehållsanalys användes för databearbetning.   Resultat: Utifrån studiens två frågeställningar identifierades tre teman: Att finna sin plats i tillvaron; Att finna sig i förändring; Att omvärdera rörelse. Dessa teman består av nio kategorier: Oro; Vardagliga hinder; En kropp som inte lyder; Förståelse från andra; Ett accepterande förhållningssätt; Omgivning; Att möta motgångar; Hitta rätt tillvägagångssätt; Att inse sina begränsningar.   Konklusion: För vissa av informanterna rådde en omedvetenhet kring chorea, medan den för andra låg till grund för stort lidande. De påtalade även hur chorea på olika sätt utgjorde en fysisk begränsning. Detta bör fungera som ett incitament för personcentrering i mötet med personer med Huntingtons sjukdom. / Background: Huntington's disease results in a combination of motor, cognitive and psychiatric symptoms. Chorea is an early symptom which entails involuntary movements that can affect various body parts. There are few studies addressing the subjective experiences of having chorea.   Purpose: To investigate experiences of having chorea in five people with Huntington's disease and to investigate how the chorea affected their ability to be physically active.   Design and method: Explorative qualitative design. Semi-structured interviews of five people with Huntington's disease. A qualitative content analysis was conducted. Results: Based on the two questions of the study, three themes were identified: Finding your place; Finding yourself in change; Revaluating movement. These themes consist of nine categories: Concern; Everyday obstacles; A disobedient body; Comprehension from others; An accepting approach; Surroundings; Facing setbacks; Finding the right strategies; Realizing your limitations.   Conclusion: Some of the informants were unaware of their chorea while in others it caused a great suffering. They also underlined how chorea in different ways could imply a physical limitation. This could function as an incentive for person-centered care when meeting people with Huntington's disease.

Neurodegeneration is a chronic, progressive and debilitating condition that affects majority of the World's elderly population who are at greater risk. Numerous scientific studies suggest that there could be a common underlying molecular mechanism that promotes the degeneration and the subsequent neuronal loss, however so far the progress in this direction is rather limited. Abnormal protein misfoldings, as well as protein plaque formations in the brain, are some of the hallmark characteristic features of neurodegenerative disorders (NDDs). Genetic and environmental factors, oxidative stress, excessive reactive oxygen species formation, mitochondrial dysfunction, energy depletion and autophagy disruption etc. are some of the widely suspected mechanisms that manifest the cognitive, motor and emotional symptoms of these NDDs. Motivated by some molecular traits found in common in several NDDs, network-based systems biology tools and techniques were used in this study to identify critical molecular players and underlying biological processes that are common for Parkinson's, Alzheimer's and Huntington's disease. Utilizing multiple microarray gene expression datasets, several biomolecular networks such as direct interaction, shortest path, and microRNA regulatory networks were constructed and analyzed for each of the disease conditions. The network-based analysis revealed 26 genes of potential interest in Parkinson's, 16 in Alzheimer's and 30 in Huntington's disease. Many new microRNA-target regulatory interactions were identified. For each disorder, several routes for possible disease initiation and protection scenarios were uncovered. A unified neurodegeneration mechanism network was constructed by utilizing the significantly differentially expressed genes found in common in Parkinson's, Alzheimer's and Huntington's microarray datasets. In this integrated network many key molecular partakers and several biological processes that were significantly affected in all three NDDs were uncovered. The integrated network also revealed complex dual-level interactions that occur between disease contributing and protecting entities. Possibilities of microRNA-target interactions were explored and many such pairs of potential interest in NDDs were suggested. Investigating the integrated network mechanism, we have identified several routes for disease initiating, as well as alleviating ones that could be utilized in common for Parkinson's, Alzheimer's and Huntington's disease. Finding such crucial and universal molecular players in addition to maintaining a delicate balance between neurodegeneration promoters and protectors is vital for restoring the homeostasis in the three NDDs.

600 out of every 100,000 people in the United States today suffer from some form of cerebellar disease that causes major abnormalities in the equilibrium and aligned, coordinated movement of the body. Hence it becomes essential to diagnose the extent of the movement and gait disorder and provide required therapy to the patients. Various developments have been made in the designing and application of interactive software system for body positioning. Object oriented design techniques are used in the field of software engineering for interactive geometric representation of system behavior. Motion analysis of the upper and lower extremities of the body could be beneficial in the diagnosis and therapy of numerous orthopedic and neurological ailments. Mathematical models of neuro-musculoskeletal dynamics establish a scientific basis for movement analysis. As mentioned above, an interactive geometric representation of the system behavior is an important diagnostic tool in orthopedic therapy. This realistic depiction of the human body with respect to the model is a very effective diagnostic tool for clinicians. There are existing biomechanical modeling tools like Visual 3-D etc, that are used for motion analysis. Visual 3-D was developed by the movement disorders laboratory at NIH. The preferred method is to place markers on the segments and calculate the joint center locations using a rigid-body assumption. However studies have shown that markers on the joint centers are subject to artifact (skin movement). Moreover, very few details are provided on the algorithm used by Visual 3-D, and no "fixes" are provided for marker dropout. This project aims at testing the accuracy of existing biomechanical movement analysis software Visual 3D by calculating the rigid body motion from the spatial co-ordinates of the markers clusters on the subject's upper extremities. This project tries to emulate their approach in a simple and effective manner and at the same time validate the approach by testing it by three different methods by calculating the elbow and wrist locations during a forward reaching motion of the subject. A mathematical model is developed by determining a relationship between the projections of a particular point in two different planes or on a single plane in two different directions [Kinzel, G.L. et. al. 1972]. The computer simulations are performed using MATLAB to calculate the lunematical parameters from the co-ordinates of projections of markers placed on the upper extremities of the subject's body. This relation will aid in quantitative motion analysis of the upper extremities in the rehabilitation setting. This can be extended to in-depth gait analysis of the lower extremities too. This type of biomechanical movement analysis allows us to understand the dynamic implications of a particular impairment, such as spasticity or weakness, in a particular muscle group.

La Maladie de Huntington (MH) reste à ce jour une pathologie neurodégénérative dévastatrice pour laquelle aucun traitement n'est disponible. L'agrégation de la Huntingtine Mutante (Htt PolyQ) joue un rôle majeur dans les processus pathologiques. Dans ce contexte, des études récentes ont démontré que la partie N-terminale de la Huntingtine Humaine (Htt wt) ou de son Homologue drosophile (dHtt) sont toutes deux capables de réduire l'agrégation et la toxicité de Htt PolyQ. En se basant sur cette observation, le travail de thèse décrit dans ce manuscrit a mis au point un découpage du fragment N-terminal de Htt wt de manière à isoler en son sein, une courte séquence de 23 acides aminés (nommée P42), capable d'inhiber spécifiquement l'agrégation de Htt PolyQ en modèle cellulaire. L'effet protecteur de ce peptide a été confirmé in vivo, sur un modèle drosophile de la MH. Le potentiel thérapeutique que représente P42 a servi de point de départ à une étude menée sur le modèle murin R6/2 de la MH. L'effet de P42 a été potentialisé par l'ajout du peptide de transduction TAT de manière à faciliter son entrée dans les cellules cibles. Puis, la protéine fusion P42-TAT a été vectorisée sous forme de microémulsion de manière à assurer à la fois une administration simple de la molécule, et un accès au système nerveux central. Ce protocole original a permis d'observer des bénéfices sans précédent sur les phénotypes comportementaux, histologiques et moléculaires que présentent les souris R6/2.Au-delà de son aspect thérapeutique, P42 est avant tout une séquence méconnue située dans une région cruciale de la Huntingtine. L'étude du rôle physiologique de ce site, a mené à une meilleure compréhension de la fonction sauvage de la protéine toute entière. En outre, une analyse biochimique a montré la capacité du fragment N-terminal de Htt wt à se lier aux microtubules. Cette interaction avec le cytosquelette dépend de plusieurs processus (clivages, dimérisation) et semble affilier la Huntingtine à la grande famille des MAP.L'identification de P42 ouvre donc une voie nouvelle vers la compréhension du rôle physiologique de la Huntingtine, mais représente surtout un espoir thérapeutique captivant. / Huntington's disease (HD) is a devastating and incurable neurodegenerative disorder. Aggregation processes of mutant Huntingtin (Htt PolyQ) play a central part in the pathology onset. In this context, recent studies pointed out the capacities of wild-type Huntingtin N-terminus to reduce both aggregation and toxicity associated with Htt PolyQ. The drosophila Homologue shares the sames properties. Basing on these observations, the present work realised a cut of human Huntingtin N-terminus in order to identify the region responsible for therapeutic benefits. This screen highlighted a 23 amino-acid sequence (noted P42), that inhibits Htt PolyQ aggregation in a HeLa cells model. Then, the protective effect of this peptide was confirmed in vivo, in a HD drosophila model.P42 therapeutic potential was explored in the R6/2 HD mouse model. The entry of the peptide into cells, was potentialised by grafting to P42, the transduction sequence of TAT. Then, the fusion protein P42-TAT was vectorised in microemulsion, in order to enhance the delivery of the peptide to the brain by resorting to a non-invasive administration way. This original protocol exhibited highly-significant rescues on behavioural, histological and molecular R6/2 phenotypes..Over the therapeutic aspect, P42 also represents an important region of Huntingtin. The study of this site led to a better understanding of Huntingtin physiological function. Biochemestrial experiments underlined the binding of Htt N-terminus on microtubules networks. This interaction depends on a range of complex processes (dimerization, cleavage) and suggests that the Huntingtin belongs to the family of Structual MAPs.In summary, the identification of P42 enhances the knowledge about Huntingtin function, and opens a new promising therapeutical avenue for HD.

Este trabalho teve como objetivo analisar os efeitos comportamentais e morfológicos da exposição ao campo magnético contínuo em um modelo experimental de doença de Huntington. Foram utilizados 68 ratos Wistar, machos, divididos em 6 grupos: GC (controle, n=12), GS (sham, n=12), GSM (sham magnético, n=8), GL (lesão, n=12), GEPS (polo sul, n=12) e GEPN (polo norte, n=12). O animais passaram por habituação ao Rota Rod durante 3 dias pré-cirúrgicos e por habituação ao monitor de atividade 24 horas antes da cirurgia. Após procedimentos cirúrgicos adequados, os GL, GEPS e GEPN receberam administração de ácido quinolínico (120nmol/2L) no núcleo estriado esquerdo. Os GS e GSM receberam administração de 2L de salina na mesma região. Ainda, nos GEPS e GEPN foi implantado no crânio de cada animal um magneto circular de neodímio (8x3mm) com potência de 3200 Gauss e no GSM foi realizado implante do mesmo material, sem estar magnetizado. No 7º dia pós-cirúrgico, os animais foram avaliados em relação à atividade motora espontânea no monitor de atividades, após 5 minutos da injeção subcutânea de apomorfina (2,5 mg/Kg), sendo que os animais do GC não receberam esta injeção, e atividade motora forçada no Rota Rod. Posteriormente aos experimentos os animais foram perfundidos e os encéfalos retirados para histologia. Os resultados da avaliação comportamental espontânea evidenciaram, para o comportamento de distância percorrida, um aumento significativo do GEPS em relação aos GC, GL e GEPN, e também do GSM e GS em relação ao GC, GL e GEPN. Observamos também uma diminuição significativa do GEPN em relação aos GS, GSM, GL e GEPS [F(5,62) = 3,19; p0,05]. Para o tempo de atividade, um aumento significativo do GEPS em relação aos GC e GEPN, e também do GSM e GS em relação ao GC, GL e GEPN. Observamos também uma diminuição significativa do GEPN em relação aos GS, GSM, GL e GEPS [F(5,62) = 5,46; p0,05]. Para o comportamento de cruzamentos, um aumento significativo do GEPS em relação aos GC e GEPN e também do GSM e GS em relação ao GC, GL e GEPN. Observamos também uma diminuição significativa do GEPN em relação aos GS, GSM, GL, e GEPS [F(5,62) = 3,31; p0,05]. E para o comportamento de giros anti-horários (ipsilaterais a lesão) um aumento significativo dos GL, GEPS e GEPN em relação aos GC, GS e GSM. Observamos também uma diminuição significativa dos GEPN e GEPS em relação ao GL e ainda uma diminuição do GEPN em relação ao GEPS [F(5,62) = 16,01; p0,05]. Os resultados referentes ao Rota Rod (atividade motora forçada) revelaram diminuição significativa do tempo de permanência no aparato do GL em relação aos demais GC, GS, GSM, GEPS e GEPN [(F(5,62) = 5,46; p0,05)]. A análise histológica revelou uma perda significativa de neurônios no núcleo estriado esquerdo do GL em relação aos demais GC, GS, GSM, GEPS e GEPN [(F(5,66) = 5,13; p0,05)]. Dessa forma, os resultados obtidos sugerem que a estimulação magnética exerce efeito neuroprotetor, com reversão das alterações comportamentais e morfológicas promovidas pelo ácido quinolínico. / The aim of this study was to analyze the behavioral and morphologic effects of the static magnetic field exposition in an animal model of Huntingtons disease. Sixty- eight male Wistar rats were used, placed in 6 groups: GC (control group, n=12), GS (sham group, n=12), GSM (sham magnetic group, n=8), GL (lesion group, n=12), GEPS (south pole stimulated group, n=12) and GEPN (north pole stimulated group, n=12). The animals passed through habituation to Rota Rod, during the 3 days pre-surgical, and to habituation to the activity monitor, 24 hours before surgery. After appropriate surgical procedures GL, GEPS and GEPN received administration of quinolinic acid (120nmol/ 2L) in the left striatum. The GS and GSM received administration of 2L of saline in the same region. Also, in GEPS and GEPN was implanted, on the skull of each animal, a circular neodymium magnet (8x3mm) with a power of 3200 gauss, the GSM was performed the implant of the same material, without being magnetized. On the seventh after surgery day, the animals were evaluated referring to spontaneous motor activity in the activity monitor, 5 minutes after subcutaneous injection of apomorphine (2.5 mg / kg), whereas the animals of the CG did not receive this injection, and forced motor activity in Rota Rod. Subsequently the experiments the animals were perfused and their brains removed for histology. The results showed to spontaneous behavioral assessment, related to the behavior of distance travelled, significant increase in GEPS compared to GC, GL e GEPN, and also in GSM and GS compared to GC, GL, and GEPN, and a decrease in GEPN compared to GC, GS, GSM, GL e GEPS [F (5,62) = 3.19, p 0.05]; for time of activity, a significant increase in GEPS compared to GC and GEPN, and also in GSM and GS compared to GC, GL and GEPN, and a decrease in GEPN compared to GS, GSM, GL e GEPS [F (5,62) = 5.46, p 0.05]; for the behavior of crossings, a significant increase in GEPS compared to GC and GEPN, and also in GSM and GS compared to GC, GL and GEPN, and a decrease in GEPN compared to GS, GSM, GL, e GEPS [F (5,62) = 3.31, p 0.05]; and to the behavior of anti hourly rotations, significant increase in GL, GEPS and GEPN compared to GC, GS, GSM, significant decrease in GEPN and GEPS compared to GL and also a decrease in GEPN compared to GEPS [F (5 , 62) = 16.01, p 0.05]. The results for the Rota Rod indicated a significant decrease in the permanency time on apparatus to GL compared to GC, GS, GSM, GEPS and GEPN [(F (5, 62) = 5.46, p 0.05)]. The histological analysis revealed a significant reduction in the number of neurons in the animals of GL compared to the others groups [F (5, 66) = 5, 13, p 0.05]. Therefore, the results suggest that magnetic stimulation exerts neuroprotective effect, with reversal of behavioral and morphological changes caused by quinolinic acid.

Huntington's disease (HD) is caused by an expanded plyglutamine repeat in the huntingtin protein. In this study, I focused on the effect of the mutant huntingtin protein (mhtt) on the subcellular localization of glutamic acid decarboxylase (GAD), the enzyme responsible for synthesizing gama-aminobutyric acid (GABA). Subcellular distribution of GAD65 is significantly altered in two neuronal cell lines that express either the N-terminus or full length mhtt. GAD65 is predominantly associated with the Golgi membrane in cells expressing normal huntingtin (Htt). However, it diffuses in the cytosol of cells expressing mhtt. Palmitoylation of GAD65 is required for GAD65 trafficking, and I demonstrated the palmitoylation of GAD65 is reduced in the HD model. Overexpression of huntingtin-interacting protein 14 (HIP14), the enzyme that palmitoylates GAD65, rescues GAD65 palmitoylation and vesicle-associated trafficking. This data suggests that impairment of GAD65 palmitoylation by mhtt may alter its localization and lead to altered inhibitory neurotransmission in HD. / by Daniel Rush. / Thesis (M.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2012. Mode of access: World Wide Web.