Les pathologies du système somatosensoriel, appelées neuropathies sensitives périphériques, touchent environ 3 millions de personnes en France et causent des déficits sensoriels multiples. Parmi elles, les douleurs neuropathiques post traumatiques sont les plus fréquentes et sont souvent chroniques et résistantes aux traitements actuels. Une lésion nerveuse périphérique induit des réponses cellulaires permettant la survie et la régénération de ces neurones. Les ganglions rachidiens dorsaux (DRG) contiennent une variété de neurones sensitifs qui transmettent les stimuli somatiques. Suite à une blessure du nerf périphérique les neurones sensitifs s'adaptent à un nouvel environnement pour réussir leur élongation axonale. Parmi les mécanismes cellulaires conduisant à une croissance neuritique améliorée, il a été démontré qu'une lésion primaire in vivo du nerf augmente la régénération axonale suite à une deuxième lésion. In vitro, les neurones qui ont été conditionnés par le premier traumatisme montrent une croissance neuronale plus rapide et plus élonguée appelée croissance régénérative. L'élasticité est un paramètre déterminant des propriétés mécaniques de la membrane cellulaire. Elle donne des informations importantes sur la santé et la fonction de la cellule. Le microscope à force atomique (AFM) est devenu de nos jours un outil commun pour l'imagerie à haute résolution de matériaux biologiques puisque les cellules vivantes peuvent être imagées dans leurs conditions physiologiques. En plus du rôle des propriétés élastiques dans le processus de régénération, l'organisation structurale des tissus est en grande partie déterminante du degré et de la direction de croissance et du mouvement cellulaire. Le guidage de la croissance par la modification des surfaces ou « patterning » est possible avec la technique de « microcontact printing » qui permet la conception de circuits de protéines avec des géométries bien définies. Les protéines de la matrice extracellulaire. Dans la première partie de la thèse nous avons mis en évidence les propriétés mécaniques de la membrane de neurones sensitifs issus de DRG de souris adultes suite à une lésion du nerf sciatique gauche. Les neurones sensitifs conditionnés montrent un mode de croissance neuritique plus rapide et plus élonguée, moins de branchements neuritiques et plus de souplesse membranaire des somas et des cônes de croissance. Dans un deuxième volet du travail nous avons réussi à normaliser la pousse régénérative et l'activité électrique des neurones sensitifs et motoneurones spinaux en utilisant le patterning des protéines d'adhésion cellulaire (ECM) dans le but d'imiter la croissance longitudinale in vivo. / Peripheral nerve injuries lead to paralysis, anesthesia and lack of autonomic control of the affected body areas. The trauma results in loss of motor and sensory functions conveyed by the involved nerves. This process is referred to as Wallerian degeneration; it creates a microenviroment in the injury site that favors neurites regrowth. The increased intrinsic growth capacity of injured peripheral neurons is manifested experimentally by the conditioning lesion paradigm. Axotomy of a peripheral neuron previous to the test lesion, ‘‘primes'' the neuron, switches it on to a regenerative state and, thus, it will regenerate faster after receiving the second injury. Mechanical interactions play a key role in many processes associated with neuronal growth and development. Membrane cytoskeleton elasticity is a determining parameter of membrane mechanical properties and provides important information toward the health and function of the cell. For this reason the first objective of this thesis was to understand the conditioning injury effects on both morphology and rheological properties of live sensory neurons cell bodies and growth cones, using particularly the atomic force microscopy, and to correlate this to eventual modifications in the composition of the cytoskeletal proteins. In addition to the role of cell elastic properties and mechanical sensing in the regeneration process, the structural organization of tissues plays a major part in deciding the degree and direction of tissue growth and cell movement. The ability to guide cells and their outgrowth by modifying surfaces is possible with the microcontact printing technique which enables the design of protein pathways with experimentally defined geometries. Therefore, the second objective of the thesis was to modulate the regenerative growth of dorsal root ganglia sensory neurons and spinal motoneurons using cell adhesion proteins in order to physically mimic the in vivo longitudinal axonal growth. We used the extracellular matrix (ECM) proteins, ideal biomolecules for printing as they can guide in vitro the cellular adhesion, differentiation, migration. The patterning allowed us to normalize neurite elongation and electrical activity of sensory neurons before and after conditioning lesion.

Orientador: Fausto Viterbo / Resumo: INTRODUÇÃO: Os nervos periféricos, assim como os demais tecidos do organismo, estão sujeitos a doenças inflamatórias, traumáticas, metabólicas, tóxicas, genéticas e neoplásicas. Estas doenças levam a diferentes tipos e graus de lesões. As lesões nervosas são bem conhecidas pela redução da capacidade funcional e diminuição da qualidade de vida dos pacientes, essas lesões induzem altos gastos socioeconômicos devido à reabilitação prolongada e absenteísmo dos jovens vítimas de trauma. Questiona-se se a Estimulação Elétrica (EE) e a terapia por Laser de Baixa Potência (LBP) teriam capacidade de melhorar a recuperação muscular e nervosa pós - neurorrafia látero - terminal (NLT). OBJETIVO: Analisar a eficiência da EE e da terapia por LBP na manutenção do músculo tibial cranial (MTC) e regeneração do nervo fibular comum pós NLT. MÉTODO: Trabalho aprovado pelo CEUA FMB - UNESP Nº 1154/2015. Foram utilizados 100 ratos da linhagem Wistar, machos, com massa média de 384,33 g e aproximadamente 9 semanas de vida. Os animais foram divididos em seis grupos experimentais. Grupo Controle, Grupo Desnervado, Grupo com Neurorrafia Látero -Terminal (NLT), Grupo com NLT e Estimulação Elétrica (EE), Grupo com NLT e LASER de baixa potência (LBP) e Grupo com NLT e combinação de EE e LBP (LBP+EE). O tratamento foi realizado durante 180 dias. Foram realizados testes funcionais e histológicos. Análise Estatística: Quando comparados os grupos, foi utilizado predominantemente teste Kruskal Wallis e método... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: INTRODUCTION: Peripheral nerves, as well as other tissues of the body, are subject to inflammatory, traumatic, metabolic, toxic, genetic and neoplastic diseases. These diseases lead to different types and degrees of injury. Nerve injuries are well known for reducing functional capacity and decreasing patients' quality of life. These injuries induce high socioeconomic costs due to prolonged rehabilitation and absenteeism of young trauma victims.It is questioned whether Electric Stimulation (ES) and Low Power Laser Therapy (LPLT) would have the capacity to improve muscle and nerve recovery after end to side neurorrhaphy (SEN). OBJECTIVE: To analyze the efficiency of ES and LPLT in the maintenance of cranial tibial muscle (CTM) and regeneration of the common fibular nerve post SEN. METHOD: Work approved by certificate No. 1154/2015 CEUA FMB - UNESP. One hundred Wistar rats, male, with a mean mass of 384.33 g and approximately 9 weeks of life, were used. The animals were divided into six experimental groups. Control group, denervated group, group with neurorrhaphy. Grupo Controle, Grupo Desnervado, Group with SEN, Group with SEN and Electrical Stimulation (ES), Group with SEN and low power LASER (LPL) and Group with SEN and combination of ES and LPL (LPL + ES). The treatment was performed for 180 days. Functional and histological tests were performed. Statistical analysis: When comparing the groups, were used predominantly, the Kruskal Wallis test followed by Dunn´s method and AN... (Complete abstract click electronic access below) / Doutor

Orientador: Eliana Aparecida de Resende Duek / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-09T22:07:51Z (GMT). No. of bitstreams: 1 Barauna_GrazielledosSantos_M.pdf: 1217156 bytes, checksum: ded7e97c7818fe0c3d87cb97d8c8f8aa (MD5) Previous issue date: 2007 / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica