Stroke is a widespread condition, which often leaves survivors with lasting deficits in motor function, however, physical rehabilitation is the only treatment available after the acute period. A large body of preclinical literature suggests dopamine-augmenting drugs, could enhance motor recovery following stroke. Unfortunately, mixed clinical results have prevented the implementation of such treatments, possibly due to the wide variety of G protein-coupled receptors these drugs can activate. Using a mouse photothrombosis stroke model and a battery of motor and sensorimotor behavioural tests, the current study aims to demonstrate proof of principle for the use of D1-class dopamine receptor agonists to enhance poststroke motor recovery and to evaluate the role of aerobic exercise rehabilitation in an asynchronous study design. The effect of light-dark cycle on behavioural outcome (horizontal ladder test, adhesive removal test, cylinder test) and histological outcome (infarct size) in photothrombotic stroke was evaluated in order to optimize the stroke model, but no there was no evidence of differences between strokes occurring during the light or dark period of a mouse’s circadian rhythm. A bioactive, suboptimal dose of D1-agonist dihydrexidine, was determined by evaluating its effect on locomotor activity and its ability to increase expression of immediate early gene c-fos. Using the determined dose, studies evaluating the efficacy of 7-days and 2-days of dihydrexidine administration on poststroke motor recovery, were performed, indicating efficacy of a 7-days, but not of a 2-days, course of treatment. The 7-days dihydrexidine treatment resulted in accelerated recovery as compared to a control group receiving saline. This work demonstrates, for the first time, proof of principle for the use of specific activation of D1-class dopamine receptors to enhance motor recovery following stroke.

abstract: Stroke remains the leading cause of adult disability in developed countries. Most survivors live with residual motor impairments that severely diminish independence and quality of life. After stroke, the only accepted treatment for these patients is motor rehabilitation. However, the amount and kind of rehabilitation required to induce clinically significant improvements in motor function is rarely given due to the constraints of our current health care system. Research reported in this dissertation contributes towards developing adjuvant therapies that may augment the impact of motor rehabilitation and improve functional outcome. These studies have demonstrated reorganization of maps within motor cortex as a function of experience in both healthy and brain-injured animals by using intracortical microstimulation technique. Furthermore, synaptic plasticity has been identified as a key neural mechanism in directing motor map plasticity, evidenced by restoration of movement representations within the spared cortical tissue accompanied by increase in synapse number translating into motor improvement after stroke. There is increasing evidence that brain-derived neurotrophic factor (BDNF) modulates synaptic and morphological plasticity in the developing and mature nervous system. Unfortunately, BDNF itself is a poor candidate because of its short half-life, low penetration through the blood brain barrier, and activating multiple receptor units, p75 and TrkB on the neuronal membrane. In order to circumvent this problem efficacy of two recently developed novel TrkB agonists, LM22A-4 and 7,8-dihydroxyflavone, that actively penetrate the blood brain barrier and enhance functional recovery. Findings from these dissertation studies indicate that administration of these pharmacological compounds, accompanied by motor rehabilitation provide a powerful therapeutic tool for stroke recovery. / Dissertation/Thesis / Ph.D. Neuroscience 2013

L’analyse de l’activité électromyographique (EMG) corrélative de l’imagerie motrice (IM) et l’effet de l’entraînement mental sur l’amélioration et le recouvrement de la force musculaire permettent de mieux comprendre les mécanismes nerveux de l’IM et l’importance du contenu de l’image mentale. Une activité EMG subliminale a en effet été enregistrée lors de l’IM, validant l’hypothèse d’une inhibition incomplète de la commande motrice. Elle était modulée selon l’intensité de l’effort mental et le régime de contraction, comme lors d’une contraction physique. Ces données renforcent l’équivalence physiologique entre IM et exécution réelle. Les programmes d’entraînement et de réhabilitation intégrant l’IM s’appuient sur ces données théoriques. L’amélioration de la force musculaire était significativement plus importante suite à un entraînement combinant répétitions physiques et mentales, comparativement à une pratique physique seule, même si l’effet ne concernait que certains groupes musculaires. Ce travail démontre également l’efficacité d’un entraînement par IM, lorsqu’il est associé à des soins de kinésithérapie, après rupture du ligament croisé antérieur ou brûlure de la main. L’IM jouerait un rôle prépondérant dans l’activation des programmes moteurs et faciliterait la récupération fonctionnelle. L’IM peut donc être considérée comme un complément bénéfique aux programmes d’entraînement et de réhabilitation dans le développement et le recouvrement des fonctions motrices / Analyzing the electromyographic (EMG) activity accompanying motor imagery (MI) as well as the imagery‐related effects on strength enhancement contributes to a better understanding of the neural mechanisms of MI. Accordingly, the subliminal EMG activity recorded during MI supports the hypothesis of an incomplete inhibition of the motor command during mental rehearsal. Interestingly, the pattern of EMG response was modulated by the mental effort and the imagined contraction type, in the same way as during physical movement. Furthermore, the data provided evidence that MI contributed both to increase muscle strength, though strength gains were not observed in all muscles. Finally, MI was found to facilitate motor recovery following anterior cruciate ligament tear as well as in burned patients. These results confirm that MI should be considered a reliable and costeffective technique to improve motor recovery and motor performance.

Stroke is the leading cause of long-term disability costing the United States (US) health care system 34 billion dollars. However, stem cell based therapies have been shown to improve recovery after cortical injury by enhancing neural recovery and modulating immune responses (Lambertsen, Finsen, & Clausen, 2018; Orczykowski et al., 2018; Stonesifer et al., 2017). Specifically, reorganization of the motor circuit at the level of the spinal cord has been shown to improve functional recovery after injury (Christoph Wiessner; Weidner et al., 2001; Lee et al., 2004; Zai et al., 2009). In our study we used a non-human primate (NHP) model to study the neural recovery after cortical injury similar to damage from an ischemic stroke in the motor cortex with or without a systemic treatment of mesenchymal stem cell derived (MSCd) exosomes. We find a robust recovery in motor function within the first few weeks after injury including improved grasp patterns and faster retrieval times during behavioral tasks. Additionally, assessment of the cervical spinal cord (CSC) reveals decreased levels of sprouting axons from ipsilesional corticospinal tract (CST) and MAP2+ synapses in the contralesional ventral horn at 14 weeks post-injury, which correlates with improved retrieval latencies. We hypothesize that MSCd exosomes may encourage an earlier switch to anti-inflammatory and repair processes that reduces secondary damage in the cortex resulting in earlier pruning of axon collaterals and reducing the need for compensatory mechanisms of the spinal cord at 14 weeks post injury.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第18174号 / 医博第3894号 / 新制||医||1003(附属図書館) / 31032 / 京都大学大学院医学研究科医学専攻 / (主査)教授 金子 武嗣, 教授 髙橋 良輔, 教授 河野 憲二 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

L'hétérogénéité inter-patients des altérations motrices consécutives aux lésions cérébrales rend nécessaire le besoin d'individualiser la prise en charge du patient après AVC. Afin d'apporter une thérapie adaptée aux besoins du patient au moment opportun, il est nécessaire de prendre en compte plusieurs considérations théoriques afin de comprendre comment la rééducation influence la plasticité cérébrale. La récupération motrice est un phénomène complexe et non-linéaire, et identifier ses composantes caractéristiques est délicat. Au travers d'une étude observationnelle, nous avons investigué la récupération de la fonction motrice en condition unimanuelle (membre non-parétique, parétique) et bimanuelle chez des patients cérébro-lésés en phase subaigüe, sans interférer sur leur programme de rééducation classique. Nous avons d'abord validé l'analyse cinématique pour l'évaluation motrice des mouvements d'atteinte d'objets après AVC, en complément des tests cliniques. L'analyse cinématique permet de fournir des indicateurs de la récupération en temps réel de manière plus sensible que les échelles cliniques. En condition unimanuelle, la récupération du membre non-parétique progresse avant de se stabiliser après 9-10 semaines après AVC. En condition bimanuelle, la dynamique de récupération des coordinations bimanuelles change 6 semaines après AVC. Ces périodes pourraient être des fenêtres temporelles clés à prendre en compte en établissant des protocoles de rééducation. L'identification complète et précise de ces patterns naturels de récupération après AVC pourrait permettre de mieux comprendre les réseaux nerveux spécifiques qui sous-tendent les altérations du membre supérieur. A partir de ces indications cliniques prometteuses, proposer une rééducation adaptée au patient et au meilleur moment devient le challenge des travaux futurs. / Poststroke characteristics vary significantly between patients and over time, necessitating the introduction of individualized care. To provide to patients an appropriate and timely therapy, theoretical considerations must be taken into account to understand how a therapy may influence underlying neuroplasticity. Motor recovery is a nonlinear and complex function of time, and identifying its representative features remains intricate. Through observational analysis, we investigated in this thesis the time-related changes in unimanual (nonparetic, paretic upper-limb) and bimanual motor function in subacute poststroke patients, without interfering with standard rehabilitation. Overall, our results firstly validated the relevance of kinematics to assess recovery of reaching movements following stroke, in complement to clinical scores. Kinematics provides accurate real-time indicators of patients' recovery in a more sensitive way to current clinical scales. In unimanual reaching, motor function of nonparetic upper-limb recovered and then leveled off 9-10 weeks poststroke. In bimanual reaching, the dynamic of the recovery pattern of between-hands coordination changed after 6 weeks poststroke. These time-windows might be key periods to consider into designing rehabilitation protocols. Our results contribute to a better understanding of the natural pattern of motor recovery poststroke and could be of interest to understand specific neural network underlying upper-limb impairment. From these promising therapeutic guidelines, next challenge in future research includes tailoring rehabilitation training to patients at the most opportune time.

Les Accidents Vasculaires Cérébraux (AVC) représentent la première cause de handicap moteur acquis chez l'adulte. La récupération s'appuie en grande partie sur des mécanismes de plasticité cérébrale. La rééducation a pour principal objectif d'optimiser ces mécanismes. Les travaux sur la plasticité cérébrale ont permis de développer de nouvelles techniques de modulation de la plasticité cérébrale à partir de stimulations cérébrales non-invasives (Non-invasive Brain Stimulation, NIBS) : la PAS (Paired Associative Stimulation) est une de ces techniques de stimulation permettant de moduler de façon la plasticité cérébrale. Le PAS consiste à coupler une stimulation électrique périphérique et une stimulation magnétique corticale de type TMS (Transcranial Magnetic Stimulation). Dans des études précédentes, nous avons montré, sur une session de 30 minutes, une facilitation durable (60mn) et spécifique du potentiel évoqué moteur (PEM) du long extenseur radial du carpe (ECRL) chez des patients hémiparétiques. Le protocole CIPASS (Chronic Interventional PAS in Stroke) a pour but d'étudier les effets d'une répétition quotidienne de sessions PAS (pendant 5 jours) et de prouver un effet durable (3 jours) de l'augmentation de la plasticité cérébrale pour le muscle ECRL chez le patient hémiparétique. Vingt-quatre patients ont été inclus dans une étude randomisée, en double-aveugle contre placebo. Aucune différence significative n'a été trouvée entre les groupes PAS et Sham, ni sur le plan électrophysiologique ni sur le plan moteur. Cependant, un sous-groupe de patients semble répondre à l'intervention ; la répétition de sessions PAS semble avoir un impact plus important chez les patients ayant un PEM initial (baseline) bas associé à une importante intensité de stimulation TMS. Cette étude est venue confirmer la variabilité des effets du PAS retrouvée chez le sujet sain et le patient victime d'AVC. Plusieurs études ont montré un effet adjuvant des NIBS lorsqu'elles sont associées à l'apprentissage d'une tâche motrice. Concernant le PAS, quelques études ont montré une facilitation plus importante lorsque celle-ci est associée à une contraction musculaire. L'imagerie motrice (IM) est le fait d'imaginer un mouvement sans le réaliser, elle partage des mécanismes similaires à ceux du mouvement réel. Cette technique a également montré ses effets en tant qu'adjuvant thérapeutique chez le patient hémiparétique, ils restent cependant moins importants que ceux obtenus après un entraînement moteur. L'utilisation de l'IM auprès de patients n'ayant aucune motricité en fait sa singularité et sa force. Le protocole MIPAS a quant à lui pour but d'étudier les effets de l'association du PAS à des exercices d'IM chez le patient hémiparétique et de démontrer l'intérêt thérapeutique de cette association. / Stroke represents the first cause of acquired disability in adults. Recovery relies mainly on brain plasticity mechanisms. The main goal of rehabilitation is to optimize those mechanisms. In recent decades, studies on brain plasticity have led to develop new techniques of noninvasive brain stimulation (NIBS) such as the Paired Associative Stimulation (PAS), which is a non-invasive brain stimulation method that modulates cortical plasticity. PAS consists of a combination of peripheral electrical stimulation and cortical TMS (Transcranial Magnetic Stimulation). In previous studies, we have shown that a session of 30 min targeting the extensor wrist muscles (ECRL) on stroke patient can lead to a motor evoked potential (MEP) specific facilitation of 60 min. The trial CIPASS (Chronic Interventional PAS in Stroke) is a new neuromodulation protocol where a PAS session targeting the extensor wrist muscles (ECRL) is performed on a daily basis during 5 days to hemiparetic patients with a stroke (less than 6 months). Our goal is to demonstrate a lasting increase (3 days) of motor cortical plasticity for ECRL muscle. Twenty-four patients were included in a double-blind, placebo-controlled trial and randomly assigned to one of two groups (PAS or sham). No significant difference was observed between the two groups on either electrophysiological or motor parameters. However, a patient profile appears to respond to the intervention; repetitive PAS sessions seems to have a more important impact on patients with a low initial MEP (baseline) associated to a high TMS intensity. This trial has confirmed the variability of PAS effects already found in healthy subjects and stroke patients. Moreover, many studies have shown the adjuvant effect of NIBS when associated to motor leaning. Regarding PAS, some studies have demonstrated an important facilitation when it was combined with muscle contraction. Motor imagery (MI) is the fact to imagine a movement without realising it; it relies on similar mechanisms to those of a real movement. This technique has also shown its interest as a therapeutic adjunct for stroke patients. Its use for patients with a severe paralysis makes it a very interesting technique. The protocol MIPAS (Motor Imagery and Paired Associative Stimulation) that combine PAS with motor imagery exercises for stroke patients aims to demonstrate the therapeutic interest of such an association for stroke patients.

A lesão medular (LM) promove uma condição devastadora que resulta em déficits sensorial e motor, impedindo o desempenho funcional do indivíduo. Modelos experimentais de lesão medular têm sido utilizados na investigação do funcionamento do sistema sensório-motor e da reorganização promovida por meio de tratamentos, podendo corroborar com aplicações clínicas atuais e futuras. Este trabalho tem como objetivos verificar a recuperação funcional e a dinâmica da reorganização cortical do sistema sensório-motor de ratos Wistar lesados medulares submetidos a treinamento motor. 17 ratos foram divididos aleatoriamente em três grupos: treinado (n = 6), controle (n = 7) e sham (n = 4). Todos os animais receberam um implante de matriz de 32 micro-elétrodos no córtex sensório-motor. Os animais do grupo treinado e controle foram submetidos à LM contusa e os do grupo sham somente ao procedimento cirúrgico sem a LM. Foram realizadas as avaliações comportamentais motoras, de dor neuropática (alodínea e hiperalgesia mecânica), de dor térmica e eletrofisiológica antes da LM e nos 1º, 3º, 5º, 7º, 14º, 21º, 28º, 35º, 42º, 49º e 56º dias pós-operatórios (dPO) da lesão. O grupo treinado realizou treinamento motor em uma esteira com velocidade controlada, tendo início no 5º dPO e foi realizado por 15 minutos, cinco vezes na semana até o final do experimento. Os outros dois grupos ficaram sem treinamento. No 57º dPO, os animais foram sacrificados, e as medulas espinhais e os encéfalos foram coletados para análise histológica. Os resultados mostraram melhora motora significativa do grupo treinado em relação ao controle. Ao final do experimento, os animais treinados foram capazes de realizar passos plantares coordenados consistentes de forma independente. Ambos os grupos lesados apresentaram alodínea após a LM, mas somente o controle apresentou aumento da dor mecânica. Os dados eletrofisiológicos revelaram alterações na atividade cortical sensório-motora no 1º dPO e ao longo do tempo. Foi identificado que o aumento da potência da banda beta contribuiu para a melhora motora do grupo treinado e o aumento da potência delta contribuiu para a recuperação motora limitada do grupo controle. Na análise histológica os grupos não diferiram em relação ao tamanho da lesão, mas foi identificada uma diminuição significativa dos neurônios do corno ventral da medula espinhal, no segmento caudal à lesão para os animais controles. O treinamento na esteira potencializou a recuperação funcional e parece ter facilitado a reorganização do córtex sensório-motor após a lesão. Esses resultados podem servir de base para futuras aplicações clínicas em pacientes lesados medulares / Spinal cord injury (SCI) results in a devastating condition, which leads to motor and sensory deficits that impair the injured person functional performance. Spinal cord injury experimental models are used in sensory-motor functioning and reorganization or plasticity promoted by trainings investigation. Thus, these studies can corroborate with current and future clinical approaches. This work aims to verify the functional recovery and the sensorimotor cortical reorganization dynamics in Wistar rats with spinal cord injury submitted to motor training. 17 rats were randomly divided into 3 groups: trained (n = 6), control (n = 7) and sham (n = 4). All animals received a 32 microelectrodes array in the sensorimotor cortex. Control and trained animals were submitted to contusive SCI and the sham group only to the surgical procedure without the contusion. Motor behavior, neuropathic pain (allodynia and mechanical hyperalgesia), thermal pain and electrophysiological assessments were accomplished before SCI and on the 1st, 3rd, 5th, 7th, 14th, 21st, 28th, 35th, 42nd, 49th and 56th post-operative days (POd). The trained group performed the motor training on a treadmill with controlled speed, starting on the 5th post-operative day and it was done for 15 minutes, five times per week till the end of the experiment. The other two groups did not receive any training. Soon after SCI the animals completely lost the hindlimbs movements. On the 57th POd, the animals were sacrificed and the spinal cords and brains were collected for histological analysis. Results showed significant motor improvement of the trained group. In the end of the experiment, these animals were able to perform consistent coordinated plantar steps on their own. Both injured groups showed allodynia after the SCI, but only the control group presented increased mechanical pain. Electrophysiological data revealed sensorimotor cortical activity changes on the 1st POd and over time. It was indentified that an increase in beta power contributed to the trained group motor improvement and that an increase in delta power contributed to the limited motor recovery of the control group. In the histological analysis the groups did not differ concerning the lesion size, but a significant spinal cord ventral horn neurons decrease in the lesion caudal segment compared to the controlled animals was identified. The treadmill training enhanced functional recovery and seemed to facilitate sensorimotor reorganization after injury. These results can be applied for future clinical interventions in spinal cord injured patients. Spinal cord injury (SCI) results in a devastating condition, which leads to motor and sensory deficits that impair the injured person functional performance. Spinal cord injury experimental models are used in sensory-motor functioning and reorganization or plasticity promoted by trainings investigation. Thus, these studies can corroborate with current and future clinical approaches. This work aims to verify the functional recovery and the sensorimotor cortical reorganization dynamics in Wistar rats with spinal cord injury submitted to motor training. 17 rats were randomly divided into 3 groups: trained (n = 6), control (n = 7) and sham (n = 4). All animals received a 32 microelectrodes array in the sensorimotor cortex. Control and trained animals were submitted to contusive SCI and the sham group only to the surgical procedure without the contusion. Motor behavior, neuropathic pain (allodynia and mechanical hyperalgesia), thermal pain and electrophysiological assessments were accomplished before SCI and on the 1st, 3rd, 5th, 7th, 14th, 21st, 28th, 35th, 42nd, 49th and 56th post-operative days (POd). The trained group performed the motor training on a treadmill with controlled speed, starting on the 5th post-operative day and it was done for 15 minutes, five times per week till the end of the experiment. The other two groups did not receive any training. Soon after SCI the animals completely lost the hindlimbs movements. On the 57th POd, the animals were sacrificed and the spinal cords and brains were collected for histological analysis. Results showed significant motor improvement of the trained group. In the end of the experiment, these animals were able to perform consistent coordinated plantar steps on their own. Both injured groups showed allodynia after the SCI, but only the control group presented increased mechanical pain. Electrophysiological data revealed sensorimotor cortical activity changes on the 1st POd and over time. It was indentified that an increase in beta power contributed to the trained group motor improvement and that an increase in delta power contributed to the limited motor recovery of the control group. In the histological analysis the groups did not differ concerning the lesion size, but a significant spinal cord ventral horn neurons decrease in the lesion caudal segment compared to the controlled animals was identified. The treadmill training enhanced functional recovery and seemed to facilitate sensorimotor reorganization after injury. These results can be applied for future clinical interventions in spinal cord injured patients

La récupération fonctionnelle des patients victimes d’un accident vasculaire cérébral (AVC) ischémique est largement sous-tendue par les propriétés plastiques du cerveau et plus précisément par sa capacité à remodeler les réseaux de neurones épargnés par l’infarctus. Les études réalisées sur différents modèles animaux d’infarctus cérébral s’accordent à montrer que ces changements plastiques sont induits par le BDNF (Brain-Derived Neurotrophic Factor). Aussi, augmenter les taux cérébraux de BDNF est considéré comme une stratégie thérapeutique prometteuse de réduction des déficiences post-AVC. Dans ce contexte, notre travail avait 2 objectifs : 1) chez le rat, identifier les cellules impliquées dans la surproduction de BDNF et évaluer la pertinence de la mesure des taux circulants de BDNF pour estimer les taux de BDNF présents dans le cerveau, 2) chez le patient victime d’un infarctus cérébral, étudier l’efficacité de la fluoxétine sur la récupération motrice à 3 mois, la fluoxétine étant un inhibiteur spécifique de la recapture de la sérotonine commercialisé comme antidépresseur et capable non seulement d’augmenter la production cérébrale de BDNF mais aussi de stimuler la plasticité post-lésionnelle.Les études précliniques ont été réalisées chez le rat soumis à l’embolisation unilatérale du cerveau par un nombre variable de microsphères (en carbone et calibrées à 50 µm) afin de reproduire le large panel de souffrance cérébrale rencontré en clinique. Le BDNF a été mesuré dans le cerveau et dans le sang (plasma et sérum par technique ELISA) avant et après (4, 24h et 8j) embolisation. Nos résultats montrent :- que la production de BDNF est plus intense et plus durable dans l’hémisphère embolisé que dans l’hémisphère non embolisé et que cette production est indépendante du degré d’embolisation, marqueur indirect de la souffrance cérébrale. - que les cellules non-neuronales deviennent une source non négligeable de BDNF en cas d’ischémie, notamment les cellules endothéliales et microgliales avant 24h et les astrocytes au temps 8j.- que les taux circulants et cérébraux de BDNF ne sont pas corrélés mais qu’il existe une corrélation entre le BDNF plasmatique mesuré au temps 4h et le degré d’embolisation.L’étude clinique correspond à un essai randomisé contrôlé en double aveugle comparant la fluoxétine (20mg/j, voie orale, pendant 3 mois et débutée entre 5 et 10j après les premiers symptômes) au placebo chez des patients présentant un déficit moteur modéré à sévère sur l’échelle motrice de Fugl-Meyer (n=59 dans chaque groupe). Nos résultats montrent que l’amélioration de la fonction motrice est meilleure sous fluoxétine que placebo. En conclusion, notre travail montre l’intérêt des médicaments capables d’augmenter le BDNF et la plasticité post-lésionnelle pour améliorer le pronostic clinique de l’AVC et identifie pour la première fois les cellules endothéliales cérébrales comme une cible potentielle de ces médicaments. Il remet également en cause l’idée largement répandue selon laquelle les taux circulants de BDNF varient dans le même sens que les taux cérébraux. / Functional recovery after ischemic stroke largely involves brain plasticity and more accurately its ability to reorganize the neuronal networks spared by the infarct. Studies conducted on animals using different ischemic stroke models have demonstrated that plastic changes are induced by BDNF (Brain-Derived Neurotrophic Factor). Hence, increasing levels of BDNF in the brain is considered a promising therapeutic strategy to reduce post-stroke impairments. In this context, our work had 2 aims: 1) In a rat model, to identify cells involved in the over-production of BDNF and to evaluate the pertinence of the measurement of circulating BDNF levels to estimate brain BDNF levels; 2) In ischemic stroke patients, to study the effectiveness of fluoxetin on 3-month motor recovery. This drug is a selective serotonin-reuptake inhibitor commercialized as an antidepressant treatment that is not only able to increase brain production of BDNF, but also to stimulate post-lesion plasticity. Animal studies were performed on rats that underwent unilateral embolization of the brain with various amounts of carbonized calibrated (50 µm) micropsheres in order to mimick the large panel of brain injury observed in humans. BDNF levels were measured in the brain and the blood (plasma and serum, ELISA method) before and after (4, 24h, and 8d) embolization. Our results show that:- The production of BDNF was more intense and longer lasting in the embolized than in the non-embolized hemisphere, and this production was independent of the degree of embolization, an indirect marker of brain injury.- Several non-neuronal cells become a non-negligible source of BDNF after ischemia, particularly endothelial cells and microglia before 24h, and astrocytes at 8d.- Brain and circulating levels of BDNF did not correlate, but a correlation between plasma BDNF at 4h and the degree of embolization was noted.Our clinical study was a randomized placebo-controlled trial that evaluated the efficacy of fluoxetine (20mg/d, oral route, over 3 months, and starting between 5 and 10d after stroke onset) in patients with moderate to severe motor impairment measured by the Fugl-Meyer motor scale (n=59 in each group). Our results showed a greater improvement in motor recovery under fluoxetin than placebo.To conclude, our work underlines the fact that treatments able to increase BDNF levels and post-lesion brain plasticity are of interest to improve the prognosis after stroke. We have shown, for the first time, that endothelial cells are a potential target for these treatments. Our study also calls into question the widespread idea according to which circulating levels of BDNF vary in the same way as levels of BDNF in the brain.

Made available in DSpace on 2016-12-12T17:32:59Z (GMT). No. of bitstreams: 1 resumo ANAMARIA.pdf: 111799 bytes, checksum: 1fd65c3285e10d1c7098ccfa70716c7e (MD5) Previous issue date: 2015-07-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Background. Training aimed at restoring and / or improving motor impairments after a spinal cord injury have shown importance in the neurofunctional rehabilitation process, as well as the relationship with biochemical markers involved in neuroplasticity. Objective. verify the effects of two training protocols in sensorimotor recovery and neural plasticity in an experimental model of incomplete LME Methods: 32 adult Wistar rats divided into four groups: Sham, NT, BCT and GT, subject to weekly reviews of locomotor and sensory-motor recovery of the hind limbs. Brain structures and lumbar spinal cord were dissected and processed for biochemical analysis quantification of the expression of BDNF, MAP-2 and Synaptophysin. Results: In the motor cortex, for synaptophysin the NT showed lower rates compared to the sham group. The BCT showed higher rates compared to the GT and NT group. For MAP-2 NT showed lower rates compared to the sham group and BCT showed higher rates compared to the NT group. For BDNF, BCT and GT groups showed higher rates compared to the NT and SHAM group. In the cerebellum for synaptophysin GT group showed higher rates compared to the NT and SHAM group, BCT showed higher rates compared to the NT. For MAP-2 the BCT group showed higher rates compared to the NT. In the SC, for synaptophysin the NT, BCT and GT showed lower rates compared to the sham group.Conclusions. Gait training played key role in sensory-motor recovery of the hind limbs. And both training modulate synaptic and structural proteins, playing an important role in exercise dependent plasticity after experimental spinal cord injury. / O treinamento motor tem sido utilizado para restabelecer e/ou melhorar deficiências após uma lesão medular e têm mostrado importância no processo de reabilitação neurofuncional, bem como a sua relação com os marcadores bioquímicos envolvidos na neuroplasticidade. Objetivo: verificar os efeitos de dois protocolos de treinamento na recuperação funcional e plasticidade neural em um modelo lesão medular incompleta. Métodos: 32 ratas Wistar adultos divididos em quatro grupos: Controle da lesão (Sham), Não-treinado (NT), Balance and coordenation trainning (BCT) e o grupo gait trainning (GT), sujeitos a avaliações semanais de recuperação locomotora e coordenação sensório-motora dos membros posteriores. O córtex motor, cerebelo e medula espinal lombar foram dissecados e processados para análise da quantificação bioquímica da expressão do BDNF, MAP-2 e sinaptofisina. Resultados: No córtex motor, para sinaptofisina o NT mostrou valores menores em comparação com o grupo Sham. O BCT mostraram níveis mais elevadas em comparação com o grupo GT e NT. Para MAP-2, NT mostrou menores níveis em comparação com o grupo Sham e BCT mostraram níveis mais elevados em comparação com o grupo NT. Para BDNF, grupos BCT e GT mostraram maiores níveis em comparação ao grupo SHAM e NT. No cerebelo para sinaptofisina, o grupo GT mostrou maiores níveis em comparação com o grupo NT e SHAM, BCT mostrou taxas mais elevadas em comparação com o NT. Para MAP-2 do grupo BCT mostraram taxas mais elevadas em comparação com o NT. Na medula, para sinaptofisina o NT, BCT e GT mostraram menores em comparação com os grupo Sham. Conclusão: Treino de marcha exerceu papel fundamental na recuperação sensório-motora dos membros posteriores. E ambos os treinamentos modularam a expressão de proteínas sinápticas e estruturais, desempenhando um importante papel na plasticidade exercício-dependente após lesão medular experimental.