Made available in DSpace on 2014-12-17T15:16:09Z (GMT). No. of bitstreams: 1 AdrianaJOB_DISSERT.pdf: 1566198 bytes, checksum: 766db20794ef85bc19aa4a81b03784d3 (MD5) Previous issue date: 2010-08-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / To the vertebrates, maintain body balance against the gravitational field and be able to orient themselves in the environment are fundamental aspects for survival, in which the participation of vestibular system is essential. As part of this system, the vestibular nuclear complex is the first central station that, by integrating many information (visual, proprioceptive), and the vestibular, assumes the lead role in maintaining balance. In this study, the vestibular nuclear complex was evaluated in relation to its cytoarchitecture and neurochemical content of cells and axon terminals, through the techniques of Nissl staining and immunohistochemistry for neuronal specific nuclear protein (NeuN), glutamate (Glu), substance P (SP), choline acetyltransferase (ChAT) (enzyme that synthesizes acetylcholine-Ach) and glutamic acid decarboxylase (GAD) (enzyme that synthesizes gamma-amino butyric acid-GABA). The common marmoset (Callithrix jacchus) was used as experimental animal, which is a small primate native from the Atlantic Forest in the Brazilian Northeast. As results, the Nissl technique, complemented by immunohistochemistry for NeuN allowed to delineate the vestibular nucleus superior, lateral, medial and inferior (or descending) in the brain of the common marmoset. Neurons and terminals immunoreactive to Glu and ChAT and only immunoreactive terminals to SP and GAD were seen in all nuclei, although in varying density. This study confirms the presence in the vestibular nuclei of the common marmoset, of Glu and SP in terminals, probably from the first order neurons of vestibular ganglion, and of GABA in terminals, presumably from Purkinge cells of the cerebellum. Second-order neurons of the vestibular nuclei seem to use Glu and Ach as neurotransmitters, judging by their expressive presence in the cell bodies of these nuclei in common marmosets, as reported in other species / Para os vertebrados, manter o equil?brio corporal contra o campo gravitacional e ser capaz de orientar-se no ambiente s?o aspectos fundamentais para a sobreviv?ncia, nos quais ? essencial a participa??o do sistema vestibular. Como parte deste sistema, o complexo nuclear vestibular ? a primeira esta??o central que, ao integrar v?rias informa??es (visual, proprioceptiva), al?m da vestibular, assume o papel principal na manuten??o do equil?brio. Neste estudo, o complexo nuclear vestibular do sagui foi avaliado com rela??o a sua citoarquitetura e conte?do neuroqu?mico de c?lulas e terminais ax?nicos, atrav?s das t?cnicas de colora??o de Nissl e imuno-histoqu?mica para prote?na neuronal nuclear espec?fica (NeuN), glutamato (Glu), subst?ncia P (SP), colina acetiltransferase (ChAT) (enzima de s?ntese da acetilcolina-Ach), e descarboxilase do ?cido glut?mico (GAD) (enzima de s?ntese do ?cido gama-amino-but?rico-GABA). Foi utilizado como animal experimental o sagui (Callithrix jacchus), um pequeno primata nativo da Mata Atl?ntica do Nordeste Brasileiro. Como resultados, a t?cnica de Nissl, complementada pela imuno-histoqu?mica para NeuN, permitiu delinear os n?cleos vestibulares superior, lateral, medial e inferior (ou descendente) no enc?falo do sagui. Neur?nios e terminais imunorreativos a Glu e ChAT e apenas terminais imunorreativos a SP e GAD foram vistos em todos os n?cleos, embora em densidade vari?vel. Este trabalho confirma a presen?a nos n?cleos vestibulares do sagui, de Glu e SP em terminais, provavelmente provenientes dos neur?nios de primeira ordem do g?nglio vestibular, e de GABA em terminais, supostamente provenientes das c?lulas de Purkinge do cerebelo. Neur?nios de segunda ordem dos n?cleos vestibulares parecem usar Glu e Ach como neurotransmissores, a julgar pela sua expressiva presen?a em peric?rios destes n?cleos no sag?i, como relatado em outras esp?cies

Ce travail a pour but de décrire les relations réciproques entre prise de perspective et informations vestibulaires. Une étude chez des patients avec un déficit vestibulaire bilatéral ancien et des sujets contrôles a montré que l’ancrage du soi sur le corps et la simulation implicite de la perspective visuo-spatiale d’autrui étaient similaires chez les deux groupes. Ainsi, une perte vestibulaire ancienne n’entraînerait pas de conflits multisensoriels, connus pour évoquer un sentiment de perspective désincarnée chez des patients avec des déficits vestibulaires aigus. Une étude chez des volontaires sains a combiné des stimulations vestibulaires naturelles sur fauteuil rotatoire à des tâches de prise de perspective dans un environnement virtuel embarqué. Les temps de prise de perspective étaient modulés en fonction de la direction de la rotation. Cette influence n’était pas présente pour la rotation mentale d’objets 3D. La contribution vestibulaire canalaire modulerait donc spécifiquement les rotations mentales du point de vue. Enfin, les modulations cognitives du traitement des informations vestibulaires ont été analysées par l’enregistrement de potentiels évoqués myogéniques vestibulaires sur les muscles sternocléidomastoïdiens et trapèzes. L’amplitude des potentiels évoqués était significativement modulée par l’angle séparant le point de vue du participant et celui d’un avatar distant. Nos travaux théoriques et les résultats de cette série d’expériences démontrent la contribution des informations vestibulaires à la prise de perspective visuo-spatiale. / This thesis aims at describing the reciprocal relations between perspective taking and the vestibular system. A study in patients with bilateral vestibular deficits and controls showed that the anchoring of the self to the body and implicit visuo-spatial perspective taking were similar in both groups. Our negative findings offer insight into the multisensory mechanisms of embodiment: only acute peripheral vestibular disorders and neurological disorders in vestibular brain areas may evoke disembodied experiences. A second study, combined natural vestibular stimulation on a rotatory chair with virtual reality to test how vestibular signals are processed to simulate the view point of a distant avatar. While they were rotated, participants tossed a ball to a virtual character from the view point of a distant avatar. Our results showed that participants were faster when their physical body rotated in the same direction as the mental rotation needed to take the avatar's viewpoint. Altogether, these data indicate that vestibular signals have a direction-specific influence on visuo-spatial perspective taking, but not a general effect on mental imagery. Finally, cognitive modulations of vestibular information processing were analyzed by recording vestibular-evoked myogenic potentials on the sternocleidomastoid and trapeze muscles. The amplitude of evoked potentials was significantly modulated by the angle separating the participant’s viewpoint to that of a distant avatar. To conclude, our theoretical work, together with results from this series of experiments, demonstrate the contribution of vestibular information to visuo-spatial perspective taking.

Seules deux structures du système nerveux central adulte, la zone sous-granulaire et la zone sous-ventriculaire, produisent continuellement de nouveaux neurones et sont considérées comme neurogènes. En dehors de ces zones délimitées, le tissu nerveux ne possède pas de telles facultés. Leurs influences anti-neurogènes peuvent cependant être mises entre parenthèses dans certaines conditions. Cela se produit après neurectomie vestibulaire unilatérale (NVU) chez le chat adulte ; en effet, des études immunohistochimiques et comportementales nous ont permis de découvrir l'existence d'une neurogenèse réactionnelle de type GABAergique dans les noyaux vestibulaires désafférentés situés dans le tronc cérébral. Nos résultats témoignent de l'implication fonctionnelle de cette prolifération cellulaire dans la restauration des fonctions posturo-locomotrices suite à une NVU. Nous avons également mis en évidence que les caractéristiques et l'intensité de la désafférentation vestibulaire déterminent, non seulement, le décours temporel de la restauration des fonctions vestibulaires, mais aussi les différents mécanismes cellulaires post-lésionnels et le potentiel neurogène des noyaux vestibulaires. En outre, nous avons démontré que l'activation ou le blocage des récepteurs GABA de type A influence d'une part, les différentes étapes de la neurogenèse réactionnelle dans les noyaux vestibulaires, et détermine d'autre part le décours de la récupération comportementale des animaux. Ainsi, le système GABAergique joue-t-il un rôle important dans la régulation de la neurogenèse induite après NVU et de sa fonctionnalité. / Only two structures of the adult central nervous system: the subgranular zone and the subventricular zone, produce continuously new neurons and are considered as neurogenic. Outside these two delimited areas, nervous tissue does not have such faculties. The anti-neurogenic influences can however be removed under specific conditions. That is what happens after unilateral vestibular neurectomy (UVN) in the adult cat: behavioral and immunohistochemical studies have demonstrated the existence of a reactive GABAergic neurogenesis in the deafferented vestibular nuclei located in the brainstem. Our results demonstrate the functional role of the vestibular cell proliferation in the postural locomotor function recovery after UVN. We also demonstrated that characteristics and intensity of the vestibular lesion, not only determine the time course of recovery of vestibular function, but also the post-lesional cellular mechanisms and the neurogenic potential occurring in the vestibular nuclei. In addition, we showed that activation or blockade of GABA type A receptors influences the different steps of neurogenesis in the vestibular nuclei, and also determines the time course of behavioral recovery. Thus, the GABAergic system influences reactive neurogenesis that is benefic for vestibular compensation process. Finally, the results of a recent study demonstrated that vestibular-hippocampal relations exist, and that stress induced by vestibular deafferentation can modulate adult neurogenesis in both the vestibular nuclei and the dentate gyrus in the adult cat.

Title: Rating postural stability in synchronized swimming Objectives: The aim of the diploma thesis is to detect, with a use of the system Gaitview ® AFA - 50 systém (Foot Scanner), if synchronized swimming has effect on postural stability of synchronized swimmers. Methods: Therotical part of diploma thesis is about synchronized swimming, influence of the aquatic environment, postural stability, stabilization and balance. A sample of 113 female athletes aged 6-35, who were long term synchronized swimmers at competition level, was chosen for this survey. Postural stability of athletes was tested while standing still with open and closed eyes by Gaitview ® AFA-50 system (Foot Scanner). Measured data were processed through Gaitview software, Microsoft Excel 2010 and anaylzed by statistical methods (average percentage, ratio, linear trend). Results: Results confirmed the effect of synchronized swimming on athletes postural stability. The longer are athletes dedicated to synchronized swimming the better is postural stability. From the age of 15 years and after 9 years of experience in synchronized swimming postural stability was shown to be better without access to visual information than with it. In the youngest category there is the biggest difference in postural stability while standing still with...

Le travail de recherche réalisé au cours de cette thèse s'intéresse à la nature des représentations spatiales formées par le cortex entorhinal médian (CEM). Tout d'abord, nous montrons que le CEM code spécifiquement une information de distance, l'une des composantes nécessaires pour que l'animal puisse réaliser un type de navigation reposant sur les informations idiothétiques, appelé intégration des trajets. Puis, nous observons que le système vestibulaire, une source importante d'informations idiothétiques, influence l'activité thêta du CEM et permet la modulation de ce rythme thêta par la vitesse de déplacement des animaux. Ensuite, nous montrons que l'activité du CEM est nécessaire à la stabilité de l'activité des cellules de lieu. Parallèlement, nous observons que l'activité des cellules grilles du CEM est modifiée par les informations contenues dans l'environnement (allothétiques).Dans leur ensemble, nos résultats montrent que le CEM traite et intègre des informations idiothétiques mais aussi des informations allothétiques. Ces données suggèrent que la carte spatiale du CEM ne fournit pas une métrique universelle reposant sur les informations idiothétiques, mais possède un certain degré de flexibilité en réponse aux changements environnementaux. De plus, cette carte spatiale entorhinale n'est pas requise pour la formation de l'activité spatiale des cellules de lieu, contrairement à ce que suggère l'hypothèse dominante. / The work conducted during my PhD thesis was aimed at understanding the nature of the spatial representation formed by the the medial entorhinal cortex (MEC). First, we show that the MEC codes specifically distance information which is necessary for a type of navigation based on idiothetic cues, called path integration. Then, we observe that the vestibular system, an important source of idiothetic information in the brain, influences the MEC theta rhythm and its modulation by the animal velocity. In addition, we show that MEC activity is necessary for the stability of place cells activity. Finally, we observe that entorhinal grid cells activity is modified by the information available in the environment (allothetic information).Together, our results show that the MEC processes and integrates idiothetic information as well as allothetic information. These data suggest that the entorhinal map is not a universal metric based on idiothetic information, but is flexible and dependant on the information present in the environment. In addition, the entorhinal map is not required for the generation of place cells activity, contrary to the dominant hypothesis.

La mutagenèse chimique aléatoire par l’Ethyl-Nitroso-Urée (ENU), dont la puissance a été largement démontrée au cours de ces dernières décennies dans la création de modèles murins constitue un outil remarquable et essentiel en génomique fonctionnelle. Cette approche est en effet d’un apport considérable pour la compréhension de la fonction des gènes et de leur régulation et constitue un accélérateur pour identifier des éléments clés dans une voie de signalisation. Cette approche systématique, basée sur le criblage simultané d’un grand nombre de souris ne nécessite aucune connaissance préalable sur l’identité et la fonction des gènes étudiés. Les mutants sont identifiés au travers de cribles phénotypiques spécifiques, hiérarchisés et non-invasifs. L’identification du gène et de la mutation causale responsable du phénotype sont réalisés par un travail de cartographie génique en utilisant une série de marqueurs polymorphes ou par séquençage nouvelle génération. L’objectif de ma thèse a été de caractériser au niveau phénotypique et moléculaire, 3 lignées murines indépendantes issues de deux cribles ENU, un crible récessif et un crible dominant sensibilisé. Le premier crible visait à développer des modèles de pathologies humaines, à partir duquel a été isolée la lignée vdb, qui présente des défauts du système vestibulaire dus à une mutation dans le gène otog codant pour l’otogeline, et constitue un modèle de surdité chez l’homme. Le deuxième crible avait été mis en place dans le but d’approfondir nos connaissances fondamentales sur le développement du système squeletto-musculaire chez les mammifères, plus particulièrement chez l’homme et le bovin. Les analyses de deux lignées issues de ce crible, GMA24 et GMA06, ont permis d’identifier la mutation dans le gène Phex pour les souris GMA24 qui présentent un retard de croissance et constituent un modèle pour la maladie XLH (X-Linked Hypophosphatemic Rickets) chez l’homme. Pour les souris GMA06 présentant une hypermusculature, la mutation a été localisée sur le chromosome 2 et son identification est en cours. Ces trois modèles murins constituent des outils intéressants qui peuvent s’ajouter aux modèles déjà existants pour la surdité, la maladie XLH et les maladies type myopathies pour mieux appréhender les mécanismes moléculaires impliqués dans ces pathologies et les interactions génétiques mises en jeu dans l’objectif de tester de nouvelles thérapies. / The random chemical mutagenesis with the Ethyl-Nitroso-Urea (ENU), whose power has been widely demonstrated during these last decades in the murine models creation, is a remarkable and essential tool in functional genomics. This approach is indeed a significant contribution to the understanding of the genes’ function and regulation; it also establishes an accelerator to identify the key elements in a signaling pathway. This systematic approach, based on the simultaneous screening of a large number of mice, requires no prior knowledge on the identity and the function of the studied genes. The mutants are identified through specific, hierarchical and non-invasive phenotypic screens. The identification of the gene and the causal mutation responsible for the mutant phenotype are achieved by gene mapping by using a series of polymorphic markers or by new generation sequencing. The objective of my thesis has been to characterize at the phenotypic and molecular level 3 independent murine lines from two ENU screens, a recessive and a sensitized dominant one. The first screen aimed to develop models for human diseases, from which has been isolated the vbd murine line, presenting vestibular system defects due to a mutation in the Otog gene coding for the otogelin. This mouse line presents a model for human deafness. The second screen had been established in order to deepen our fundamental knowledge on the skeletto-muscular system development in mammals, more particularly in humans and cattle. Analyzes of two lines from this screen, GMA24 and GMA06, have allowed to identify the mutation in Phex gene for GMA24 mice showing a growth retardation and modeling XLH (X-linked Hypophosphatemic rickets) disease in humans. For the GMA06 mice presenting an increase muscle mass, the mutation has been localized on chromosome 2 and its identification is in progress. These three murine models are interesting added tools to the existing models for deafness, XLH and myopathies diseases for a better understanding of the molecular mechanisms and genetic interactions involved in these pathologies and so testing new therapies.

Abstracts in Afrikaans and English / Inklusiewe onderrig ondersteun die insluiting van alle leerders met verskillende behoeftes en vaardighede in klaskamers, wat baie keer te groot, of te verskillend vir doeltreffende onderrig is. Beweging as deel van ‘n vroeë leerervaring is noodsaaklik vir optimale neurale ontwikkeling. Dit beïnvloed organisasie en stimuleer die spesifieke neurologiese sisteme nodig vir optimale funksionering en ontwikkeling van die brein. Sensoriese integrasie disfunksie word gesien as die wortel van baie leerprobleme. Die vestibulêre sisteem is direk verbind met die sensoriese en motoriese sisteme. ‘n Sensoriese integrasie disfunksie het ‘n duidelike invloed op die vestibulêre sisteem. Die vestibulêre sisteem het baie interkonneksies met baie dele in die brein, byvoorbeeld propriosepsie en die tassisteem. Doeltreffende funksionering van die sensoriese, motoriese en vestibulêre sisteme word verlang vir ‘n hoë vlak van prestasieverrigting in sport en akademie. Wanneer die vestibulêre sisteem gestimuleer word, het dit ‘n direkte positiewe invloed op die sensoriese en motoriese ontwikkeling van leerders. Die doel van hierdie studie was om te bepaal wat die persepsie van grondslagfase-onderwysers en ouers is oor die rol en voordele wat vestibulêre oefeninge te weeg kan bring in die motoriese en sensoriese ontwikkeling van leerders. Leerders in graad 1 van ‘n privaatskool, asook van grade 2 en 3 van ‘n plaasskool is gekies as deelnemers in die studie. Die keuse van leerders was op grond van die bereidwilligheid van hulle en hul ouers om aan die studie deel te neem. Leerders het ‘n vestibulêre oefenprogram drie maal per week gedoen vir die tydperk van agt weke. Observasie-vraelyste is deur onderwysers en ouers ingevul na afloop van die derde sessie elke week. Vir die vraelys het ouers en onderwysers gekyk na die verbetering in aandagspan, konsentrasie, luistervaardigheid, oogkontak, sosiale interaksie en samewerking. Onderhoude is met ouers en onderwysers gedoen na aanleiding van die observasievraelyste wat vir die agt weke voltooi is. Transkripsies van die onderhoude is gedoen en afleidings is gemaak deur analise van die observasie-vraelyste en die getranskribeerde onderhoude. Al ses die ontwikkelingsareas by beide skole het verbetering getoon oor die agt weke. Dit dui daarop dat vestibulêre oefeninge wel ‘n invloed op die sensoriese en motoriese ontwikkeling het. / Inclusive education promotes the inclusion of learners with different needs and capabilities in classes which are often too big and diverse for effective teaching. Movement as an early learning experience is necessary for optimal neural development. It influences organisation and stimulates the specific neurological systems required for optimal functioning and development of the brain. Sensory integrative dysfunction is believed to be at the root of many learning disorders. The vestibular system is directly connected with the sensory and motor systems. The vestibular system will be directly affected when a sensory integrations dysfunction presents. In fact, the vestibular system has many interconnections with almost every other part of the brain like proprioception and the tactile system. Proper functioning of the sensory, motor and vestibular systems is required for higher level performance in sport and academics. When the vestibular system is stimulated, it will result in a positive influence on the sensory and motor development of learners. The aim of this study is to determine the perceptions of foundation phase teachers and parents regarding the role or benefits of vestibular exercises in promoting learners’ motor and sensory development. Learners in Grade 1 of a private school and Grade 2 and 3 learners of a farm school in the northern Free State were selected as participants in the research. Learners were selected on the basis of the willingness of them and their parents to participate in the research. The participants did exercise sessions three times a week for thirty minutes over a period of eight weeks. Observation sheets were completed for all eight weeks, for the duration of the exercise program, by teachers and parents. These sheets were completed weekly after the third sessions in that week. The observation sheets listed concentration, attention span, listening, eye contact, cooperation, social interaction and self-esteem as developmental areas. Interviews were done after the period of eight weeks with the parents and teachers. The interviews conducted with both parties were taped and meticulously transcribed. This helped the researcher to get a better understanding of the study and to analise data and draw conclusions.All six areas of development showed improvement at both schools over the period of eight weeks. This indicates that stimulating the vestibular system promotes sensory and motor development. / Inclusive Education / M. Ed. (Inklusiewe Onderwys)