Dissertations / Theses on the topic 'Neuronal NOS'
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Papale, Davide. "Oxygen activation during neuronal NOS reaction." Thesis, University of Edinburgh, 2008. http://hdl.handle.net/1842/12755.
Full textSobolewska-Stawiarz, Anna. "Probing the dynamics and conformational landscape of neuronal nitric oxide synthase." Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/probing-the-dynamics-and-conformational-landscape-of-neuronal-nitric-oxide-synthase(82903814-5474-42e3-9339-d9a7a98ead6d).html.
Full textNardi, Geisson Marcos. "Óxido nitrico proveniente da isoforma neuronal da enzima óxido nítrico sintase (NOS-1)." Florianópolis, SC, 2011. http://repositorio.ufsc.br/xmlui/handle/123456789/95541.
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Vários estudos demonstraram que produção excessiva de NO, relacionada com o aumento da expressão da NOS-2, contribui para as alterações hemodinâmicas observadas durante a sepse. No entanto, alguns trabalhos mostram que a inibição desta enzima não reverte a hipotensão, a hiporeatividade a agentes vasoconstritores e não influencia na sobrevivência de animais sépticos. Portanto, resolvemos investigar o papel do NO proveniente da isoforma neuronal da óxido nítrico sintase (NOS-1) sobre a reatividade a agentes vasoconstritores, e sua influência na progressão da sepse bem como o efeito de agonistas opióides sobre parâmetros comumente avaliados nesta doença. Nossos resultados demonstram que animais sépticos são sensíveis a analgesia com drogas opióides em modelo de dor por estímulo térmico e, além disso, os analgésicos opióides reduziram a hipotensão e hiporeatividade vascular induzidas pela sepse. Estes compostos quando administrados em doses baixas não interferiram na sobrevivência de animais sépticos, enquanto que doses maiores aumentam a mortalidade. A inibição da NOS-1 melhorou a reatividade vascular a agonistas e -adrenérgicos, tanto na fase inicial quanto na fase tardia da sepse. Tanto a NOS-1 quanto a guanilato ciclase solúvel tem sua expressão aumentada nas camadas de músculo liso vascular da aorta e do leito vascular mesentérico, e nos momentos mais tardios, ambas as enzimas interagem fisicamente no leito vascular mesentérico. Parte do mecanismo de reversão da hiporeatividade a agonistas -adrenérgicos, após inibição da NOS-1, se deve a redução na formação de GMPc. No entanto, a reversão da hiporeatividade vascular a agentes -adrenérgicos durante a sepse pelo 7-NI parece ser independente do aumento nos níveis de cAMP. As alterações promovidas pelo NO proveniente da NOS-1 no início da sepse estão relacionadas com a instalação da hipotensão, disfunção vascular, alterações na glicemia e nos níveis de leucócitos sanguíneos. A redução do conteúdo enzimático da NOS-1, reduz ou abole as alterações patológicas induzidas pela sepse. Nosso trabalho demonstra que o NO proveniente da NOS-1 participa ativamente na disfunção vascular promovida pela sepse.
Several studies have shown that overproduction of NO, associated with the increased expression of NOS-2, contributes to the hemodynamic changes observed in sepsis. However, inhibition of NOS-2 does not reverse hypotension, hyporesponsiveness to vasoconstrictor and does not influence the survival of septic animals. Therefore, we decided to investigate the role of NO derived from the neuronal isoform of nitric oxide synthase (NOS-1) on the reactivity to vasopressor agents and the progression of sepsis as well as the effect of opioid agonists on parameters commonly evaluated in this pathology. Our results demonstrate that septic animals are sensitive to analgesia with opioids in the pain model of thermal stimulation. In addition, opioids reduced the hypotension and vascular hyporesponsiveness induced by sepsis. When administered in low doses these drugs did not affect the survival of septic animals, whereas higher doses increased the mortality. The inhibition of NOS-1 improved the vascular reactivity to and -adrenergic agonists, both in early and late phase of sepsis. The expression of NOS-1 and soluble guanylate cyclase was increased in vascular smooth muscle layers of aorta and mesenteric vascular bed and both enzymes interact physically in the mesenteric vascular bed in late phase of sepsis. At least part of the mechanism of the recovery in the responsiveness to adrenergic agonists, after inhibition of NOS-1, is due to the reduced formation of cGMP. The changes promoted by NOS-1-derived NO in early sepsis are associated with the onset of hypotension, vascular dysfunction and changes in blood glucose levels and blood leukocytes. The reduction in the NOS-1 enzyme content reduces or abolishes the pathological changes induced by sepsis. Our work demonstrates that NOS-1-derived NO plays a role in promoting vascular dysfunction in sepsis.
Coelho, Camila Henriques. "Análise da inibição da óxido nítrico sintase neuronal (nNOS) na liberação de vasopressina durante sepse experimental." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/60/60135/tde-30102009-022744/.
Full textThe pathophysiology of sepsis is caracterized by hypotension accompanied by increase of vasopressin secretion (AVP) in early phase and decrease during late phase. This hypotension is due, in part, to the increase of nitric oxide (NO) production, that, like other mediators, shows high production during sepsis. Nitric oxide synthase (NOS) is responsible by synthesis of NO. The neuronal isoform of NOS is present in skeletic muscle, testicles, prostate, skin and vasopressinergics neurons of hypothalamus. The present work evaluated the participation of nitric oxide produced by neuronal NOS in temporal vasopressin secretion during experimental sepsis. Rats Wistar received intraperitoneal injection of 7-nitroindazole (50 or 80 mg/kg), an inhibitor of neuronal nitric oxide synthase activity, or DMSO 10% + sesame oil in the proportion 1:9 (vehicle) and after 30 minutes, they were submited to septic stimulus by cecal ligation and puncture (CLP) or to sham operation. In one of the groups, the survival rate was evaluated during 5 days. In other group, the animals were decapited 0, 4, 6, 18 and 24 hours after CLP and the blood was processed to determinate haematocrit, serum sodium, osmolality, proteins, glucose, creatinine, serum nitrate, and plasma AVP. Neurohypophysis was removed to determination of vasopressin content, and hypotalamus was dissected to determinate total NOS activity. Mortality observed after CLP was not affected by periferal injection of 7-nitroindazole (50 mg/kg) as well as haematocrit, glucose and nitrate increase. Serum sodium and plasma protein decreased after CLP and the treatment antecipated the loss protein, and delayed serum sodium decrease. CLP animals didn\'t show creatinine and osmolality alterations, but when treated with 7-nitroindazole, showed increase 6 and 18 hours, and decrease 4 hours, respectively. NOS activity in hypothalamus increased 4 and 24 hours after CLP, and was reduced with 7-NI pretreatment (50 and 80 mg/kg respectively). AVP neurohypophysis content diminished 4, 6 and 18 hours after CLP and 7-NI reduced the content just at 0 and 6 hours. Vasopressin plasma concentration increased just 6 hours after CLP and 7-NI pretreatment didn\'t alter this parameter. We concluded that NO produced by neuronal NOS doesn\'t have a substantial role in vasopressin secretion during experimental sepsis.
Kirsten, Gabriela Pena Chaves. "O receptor canabinóide CB1 nos núcleos da base e a sua participação no processo degenerativo em modelos da Doença de Parkinson." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/42/42137/tde-20092013-093533/.
Full textCannabinoid receptors CB1 are abundantly expressed in the basal ganglia (BG), suggesting the involvement of the cannabinoid system in Parkinson\'s disease (PD). The objectives of this study were to investigate the location of CB1 in BG of rats; evaluate the time course expression of CB1 and neuronal markers in an experimental model of PD in vivo, and evaluate the effects of treatment with cannabinoids compounds in experimental models of PD in vivo and in vitro. Our results showed that CB1 is predominantly expressed in GABAergic neurons in BG. The dopamine lesion produced distinct temporal changes in the expression of CB1 in BG structures. Treatment with the cannabinoid agonist ACEA aggravated the dopaminergic lesion and the motor behavioral performance. Moreover, the treatment with the antagonist AM 251, although have not generated neurochemical changes,it promoted improvements in behavioral tests. Finally, in our in vitro model, the treatment with Anandamide transport inhibitor AM 404 led to a slight reduction in the levels of cell death.
Mari, Renata de Britto. "Efeitos da alimentação com diferentes níveis calóricos nos neurônios mioentéricos do cólon de ratos Wistar durante o processo de envelhecimento." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/10/10132/tde-10082010-160611/.
Full textThe last years were characterized by a significant increase in the elderly population. For this reason, concern for the elderly is becoming a constant in our society, since the aging results in impairment of bodily function, or not accompanied by structural changes. In the gastrointestinal tract (GI), the aging process can cause significant morphological changes. The regulation of motility of the gut is controlled mainly by myenteric neurons of the enteric nervous system. The decrease in the density of neurons in the colon can lead to a reduction in the frequency and amplitude of contraction expressed as colonic constipation. The actions aimed at reducing the effects of aging on the GI system include those related to diet, among which stands out caloric restriction. Caloric restriction, and have a protective effect on the myenteric neurons during aging, is also responsible for the decrease of neuronal death by apoptosis, a process accentuated with aging. Thus, this study was to evaluate the effects of different levels of calorie restriction on the plasticity of myenteric neurons NADPH and acetylcholinesterase positive of the colon of rats during the aging process by means of ultrastructural (transmission electron microscopy) and morphoquantitative analysis. Therefore, we used 40 male Wistar rats (Rattus norvegicus), divided into four groups (n = 10): CI- animals six months; SR- animals 18 month fed a normal diet; RCI - animals 18 months fed a diet with 12% caloric restriction; RCII- animals 18 months fed a diet with 30% caloric restriction. At six months, the animals were transferred to the vivarium sector, where they remained up to 18 months under controlled conditions of temperature and light and water ad libitum. It was observed that the RC level of 30% effectively minimized the deleterious effects of aging on myenteric neurons, which may be adopted as an alternative against the common gastrointestinal disorders in the elderly.
Hajj, Glaucia Noeli Maroso. "A proteína prion celular e seus ligantes-vitronectina, STI1 e laminina - nos mecanismos de plasticidade neuronal." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/46/46131/tde-21122015-165320/.
Full textPrions are involved in numerous neurodegenerative diseases in humans and animals called transmissible spongiform encephalopathies. PrPsc, the infectious protein, is an isoform of a normal cellular protein named PrPc. PrPc functions are still under debate, among them Cu++ homeostase, protection against oxidative stress, cell survival signaling and neuritogenesis. PrPc interaction with laminin (Ln), an extracellular matrix protein, leads to neurite growth and maintenance. PrPc interaction with another extracellular matrix protein, vitronectin (Vn) is here demonstrated. This association leads to neurite growth in hippocampal and dorsal root ganglia cells. In dorsal root ganglia cells, PrPc ablation can be compensated by integrins, at least in the neuritogenesis phenomenon. PrPc is also a cellular ligand for STI1, a co-chaperone, mediating neuritogenesis or neuroprotection, depending on the activated cell signaling pathway. Vn and STI1 binding sites at the PrPc molecule are localized in contiguous domains what makes their binding to PrPc mutually exclusive. The first is more favorable, as observed in vitro and ex vivo. On the other hand, Ln binding site at PrPc is confined to a domain distinct from those where Vn or STI1 associate. Furthermore, laminin and STI1 have additive effects on neurite outgrowth. The importance of PrPc-Ln interaction is also observed in vivo, since the complex participates in memory consolidation mechanisms.
Carvalho, Altiere Araujo. "Estudo da plasticidade cruzada nos centros de fala e audição em pessoas ouvintes e surdas através de psicofísica e ressonância magnética funcional." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/47/47135/tde-26112009-151337/.
Full textIt is popularly said that when a person loses one sense, there is a compensation by the other remaining senses to suppress the loss. Throughout three Phsycophysic Experiments based on Inhibition of Return Posners Paradigm and Functional Magnetic Resonance (fMRI) Techniques, congenital deaf people were compared to normal hearing people in order to check if deaf people possess different attentional pattern compared to normal hearing people, and if the same cortical areas Wernicke and Brocas area and Hearing Cortex were activated in both groups. Experiment I consisted on pressing a button every time the presence of a big square (target) was detected by subjects while non-predictive small squares (cue) were also presented at the same or opposite side of the target. At Experiment I it was observed that both groups presented Posners Paradigm classical phenomena: Facilitation or Inhibition of Return, what suggested the possibility that attentional pattern may be similar to both groups. Therefore, it was observed that normal hearing people were faster than deaf people to respond to the task when time interval between cue and target was long (800 ms) when compared to the time they spent to respond when time interval between cue and target as short (100 ms). 24 Experiment I raised the hypotheses that possibly deaf people may present a temporal processing difference. At Experiment I every condition was randomly presented. Experiment II was elaborated to highlight MRT differences between short and long time intervals, so every time interval was presented on a fixed order. Comparison of Experiment I and II (Fixed Time Intervals) showed that normal hearing people presented shorter Manual Reaction Times (MRT), while deaf people kept the same averages despite the temporal advantage, what suggested that deaf people may present a deficit on temporal processing. Experiment III used Posners Paradigm while subjects were submitted to fMRI scanning in order to check if activated cortical regions could be similar in both groups. fMRI images demonstrate Wernicke and Brocas area and hearing cortex activations in both groups while executing the task, which, although did not have any explicit semantic content, had time as the main physical parameter on which subjects could be based to increase performance to respond to the task. Time is one of the oral language primary physical parameter, different of signed language which has visual and spatial parameters as primaries. Results suggest that cortical audition center activations may indicate a cross-modal plasticity at the deaf group. Yet, participation of hearing cortex on strategy elaboration to respond to a task which does not have any explicit semantic content possibly indicates the participation of hearing cortex on language processing.
Candemir, Esin [Verfasser], and Andreas [Gutachter] Reif. "Involvement of neuronal nitric oxide synthase (NOS-I) PDZ interactions in neuropsychiatric disorders / Esin Candemir ; Gutachter: Andreas Reif." Würzburg : Universität Würzburg, 2018. http://d-nb.info/1162444371/34.
Full textTajouri, Lotfi, and n/a. "Gene Expression Analysis and Genetic Studies in Multiple Sclerosis." Griffith University. School of Health Science, 2005. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20060111.123933.
Full textTajouri, Lotfi. "Gene Expression Analysis and Genetic Studies in Multiple Sclerosis." Thesis, Griffith University, 2005. http://hdl.handle.net/10072/366467.
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Doctor of Philosophy (PhD)
School of Health Sciences
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Filippini, Renata. "Eficácia do treinamento auditivo por meio do potencial evocado para sons complexos nos transtornos de audição e linguagem." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/5/5162/tde-19032012-114450/.
Full textDisorder (SLI) and Auditory Processing Disorder (APD) have been associated with disorders at neural decoding of acoustic complex sounds. These sounds perception depends on the integrity of decoding processes analyzed by the auditory nervous system, especially in challenging acoustic situations as in background noise. The Auditory Brainstem Response to complex sounds (c- ABR), investigate de neural representation of these sounds at subcortical levels because they reflect with fidelity the stimulus features, and it is altered in children with auditory, language and learning problems when compared to typical development children (TD). The formal Auditory training (AT) is a method to remediate some of these children difficulties, and its efficacy has been demonstrated using behavioral and electrophysiological assessments. Objective: Verify the efficacy of formal AT in children with hearing and language disorders through behavioral assessment and c-ABR, with and without background noise. Methods: Thirty children (aged 712 years and 11 months), were divided in four groups: TD(N=7), APD(N=9) underwent formal AT, SLIa (N=6) underwent formal AT - and SLIb(N=8) did not undergo formal AT. All had normal peripheral hearing and click-evoked ABR, and all underwent behavioral assessment of auditory processing and c-ABR with and without background noise. Only APD and SLIa groups underwent formal AT, although all children were reevaluated after 12 weeks from the initial assessment. Results: Groups APD, SLIa and SLIb showed worst behavioral performance than TD group, although only groups that underwent formal AT showed improvements at final assessment. To c-ABR in silence, no differences were observed among the groups concerning wave latencies, but APD group presented smaller amplitudes to transient portion of the response, and altered VA complex duration and slope, which did not change after AT. To c-ABR with background noise, SLIa group presented delayed latencies to all waves. This same group, after AT, presented significant improvements to wave latencies, balancing the responses among all studied groups. Conclusion: Formal AT seemed to be responsible for the behavioral performance changes seen in groups APD and SLIa. This study suggests that the c-ABR with background noise may be an effective tool to monitor the effects of formal AT
Marosti, Aline Rosa. "Análise morfoquantitativa e ultraestrutural dos componentes do plexo mioentérico do intestino delgado de ratos submetidos à dieta padrão de Moçambique nos períodos pré e pós-natal." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/5/5160/tde-08092016-095400/.
Full textIt is assumed that more than 40% of children are affected by chronic malnutrition in Mozambique (East Africa). The disease may be related, among other factors, the quality of diet that is offered to the population, since it is quite precarious, because it displays serious deficiencies of iron, fat and especially animal protein in their composition. This protein failure could result in damage to the development of the organism, as animal protein is considered a good source of essential amino acids, due to its higher digestibility and absorption in the small intestine when compared to vegetable sources. In this research has been reproduced in the laboratory, the staple diet of the population of Mozambique (DM), in order to evaluate its effects on components of the myenteric plexus and the mucosa of the small intestine segments of Wistar rats. For this, the animals were divided into control groups with AIN-93G diet with the addition of 20% casein (NN21 and NN42); Diet Mozambique (DM21 and DM42) and diet supplemented Mozambique, plus 20% casein (NM21 and NM42); and Refeeding group (RM42), consisting of the animals DM21 group, from the 22th day, given NM diet until they reached 42 days of life. The segments were collected and submitted to histochemical techniques of NADH-diaphorase and NADPH-diaphorase for disclosure of neurons of the myenteric plexus; histologic (HE, Sirius red, Weigert) for evaluation of the intestinal wall, mucosa, lymph nodes and its associated connective tissue; scanning electron microscopy (SEM) for observation of mucosal structure; and Transmission electron microscopy (TEM) ultrastructure to ganglion components. Statistically, body weight and length of the animals submitted to Mozambique diet were below the values found for control animals. Qualitative analysis showed the presence of elastic fibers, and elauninic oxytalan, and predominance of type I collagen fibers in the NN42 and DM42 groups, and type III in the NM42 and RM42 groups around the ganglia. The mucosa showed a smaller area in DM21 group recovery DM42, with a decrease in villus height in both groups. There have been changes in the organization of the rough endoplasmic reticulum and arrangement of fibrillar and granular materials nucleolus of DM animals. Under SEM the villi of the DM42 group showed smoother surface, with few boundaries between them. The density of reactive NADH decreased from 21 to 42 days in all groups; however, the DM21 and DM42 had a higher density. Reactive neurons to NADPH had decreased from 21 to 42 days density in DM and NM groups when compared to the control. Thus, it is concluded that vegetable diet Mozambique led to changes in the morphology of the mucosa, the intestinal wall and enteric neurons, as a way to adapt to the imposed diet
Silva, Liana Gouveia da [UNIFESP]. "Efeitos da inibição da óxido nítrico sintase neuronal sobre as respostas cardiovasculares causadas pela estimulação de receptores colinérgicos nos Núcleos do Tracto Solitário de ratos não anestesiados." Universidade Federal de São Paulo (UNIFESP), 2009. http://repositorio.unifesp.br/handle/11600/9400.
Full textO NTS é o sítio primário das terminações das aferências dos reflexos cardiovasculares no sistema nervoso central (SNC). A presença da acetilcolina (ACh) no NTS e sua participação na transmissão ou modulação central das funções neurovegetativas foi sugerida desde a década de 80 (Kobayashi et al., 1978; Simon et al., 1981; Criscione et al., 1983; Helke et al., 1983). Contudo, a maioria dos estudos da literatura foram realizados in vitro e não há evidências de estudos da transmissão colinérgica in vivo em animais não anestesiados. Estudos prévios de nosso laboratório mostraram que a microinjeção de ACh no NTS de ratos não anestesiados causa hipotensão e bradicardia dose-dependentes e estas respostas parecem ser mediadas ou moduladas em parte pela liberação de óxido nítrico derivado da isoforma neuronal da enzima óxido nítrico sintase (NOS). A queda de pressão arterial causada pela ACh não foi abolida após o bloqueio parassimpático com metilatropina, indicando que a ativação do sistema colinérgico no NTS causa redução significante do componente simpático. A fim de discriminar as respostas de pressão arterial média (PAM) e frequência cardíaca (FC) causadas pela estimulação dos receptores colinérgicos nicotínicos e muscarínicos no NTS, realizamos as curvas dose-resposta para os agonistas seletivos nicotina (NIC) e pilocarpina (PIL) microinjetados no NTS de ratos não anestesiados. Além disso, investigamos também os efeitos do bloqueio central da NOS neuronal (TRIM) sobre estas respostas. Ratos Wistar foram preparados de acordo com a técnina de implante crônico de cânulas guia em direção ao NTS e da metodologia para microinjeção de drogas em animais não anestesiados e registro de pressão arterial in vivo. A microinjeção unilateral do agonista colinérgico de receptor nicotínico (nicotina) no NTS de ratos não anestesiados causou significante hipotensão e bradicardia que se mostrou dosedependente. Com a microinjeção unilateral do agonista colinérgico de receptor muscarínico (pilocarpina) no NTS observamos significante hipotensão e bradicardia, onde as doses maiores que 1 nmol/100 nL causaram hipotensão seguida de aumento da pressão arterial e bradicardia. A microinjeção unilateral do inibidor da nNOS (TRIM 13,3 nmol/100 nL) no NTS reduziu significantemente a hipotensão e bradicardia causadas pela nicotina e pilocarpina no NTS. O bloqueio da nNOS também reduziu significantemente o aumento de pressão arterial média causado pela microinjeção de pilocarpina na dose de 5 nmol/100 nL. Os resultados são a primeira evidência funcional, em animais não anestesiados, da participação de ambos os subtipos de receptores colinérgicos (nicotínico e muscarínico) na resposta da ACh no NTS. As diferenças observadas com a estimulação seletiva dos receptores colinérgicos no NTS sugerem a participação de cada subtipo de receptor na modulação da transmissão de estímulos cardiovasculares distintos, e, a função do sistema colinérgico sofre influência, ainda por meios desconhecidos, do óxido nítrico de origem central.
The Nucleus of the Solitary Tract is the first sites of cardiovascular reflex afferent terminations in the central nervous system (CNS). Acetylcholine (ACh) is present within neurons and terminals in the NTS and its participation in modulation of neurovegetative function was suggested since the 80´s. However, most part of the studies in literature was performed in vitro and there were no evidences in nonanesthetized rats. Previous studies of our laboratory showed that ACh microinjection into the NTS of non-anesthetized rats elicits dose-dependent hypotension and bradicardia; and NO from nNOS may have a role in modulating these responses. Peripheral blockade of cholinergic muscarinic receptors (i.v. injection of methylatropine) did not alter hypotension induced by microinjection of ACh into the NTS of non-anesthetized rats, indicating that the activation of cholinergic system in the NTS elicits reduction of the sympathetic component. In order to discriminate cardiovascular responses elicited by cholinergic receptors stimulation in the NTS, we performed the dose-response curves for selective agonists nicotine (NIC) and pilocarpine (PIL) microinjected into the NTS of non-anesthetized rats. In addition, we investigated whether inhibition of the nNOS in the NTS affects the responses caused by cholinergic agonists. Male Wistar rats were prepared according to the methodology of guide cannulas implantation in the direction of the NTS for microinjection in freely-moving rats; and recording of blood pressure in nonanesthetized rats. Unilateral nicotine microinjection in the NTS of non-anesthetized rats caused dose-dependent hypotension and bradicardia. Microinjection of the muscarinic agonist (pilocarpine) in the NTS of non-anesthetized rats elicited significant hypotension and bradicardia, and with doses higher than 1nmol/ 100 nL it was observed hypotension followed by an increased in arterial pressure, and bradicardia. Blockade of neuronal nitric oxide syntase (nNOS) (TRIM 13.3 nmol/ 100 nL), in the NTS, significantly reduced responses elicited by nicotine and pilocarpine. Microinjection of TRIM also inhibited the increase in arterial pressure elicited by PIL 5 nmol/ 100 nL. These results are the first functional evidence in non-anesthetized rats of cholinergic receptors participation in ACh transmission s in the NTS. Differences observed with selective stimulation of cholinergic receptors in the NTS suggest the participation of each receptor subtype in modulation of distinct pathways of stimulus of cardiovascular integration to the NTS. Finally, the physiological effects of cholinergic transmission in the NTS are still unclear and NO modulation of this system remains to be elucidated.
TEDE
BV UNIFESP: Teses e dissertações
Capitelli, Caroline Santos. "Efeito da manipulação do microambiente neuronal indiretamente através da pinealectomia ou transplante de células derivadas de medula óssea nos modelos animais da Doença de Parkinson induzido por neurotoxinas." reponame:Repositório Institucional da UFPR, 2014. http://hdl.handle.net/1884/36928.
Full textCo-orientadora : Profª Drª Valdo José Dias da Silva
Tese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Farmacologia. Defesa: Curitiba,17/09/2014
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Área de concentração: Farmacologia
Resumo: A Doença de Parkinson é uma doença neurodegenerativa caracterizada pela perda de neurônios dopaminérgicos na SNpc. O presente trabalho visou investigar em duas linhas distintas o papel do microambiente celular na neurodegeneração. Na primeira linha de investigação, os animais foram avaliados quanto ao efeito da pinealectomia sobre a neurodegeneração e estresse oxidativo induzido pela administração de MPTP e 6-OHDA. A administração dessas neurotoxinas resultou em comprometimento motor em ambos os grupos Sham e Px 24 h após a lesão no teste do campo aberto. Contudo, 7 e 14 dias após a cirurgia, os animais lesados pertencentes ao grupo Sham apresentavam recuperação motora, ao contrário dos grupos Px e lesados. No teste de natação forçada os animais lesados apresentavam menor tempo de natação em relação aos grupos controles, e ainda, os grupos Sham- 6-OHDA e Px-6-OHDA apresentaram maior tempo de imobilidade comparado aos controles. Corroborando com essas alterações, significativa degeneração dopaminérgica foi evidenciada nos animais lesados, e ainda, aumento na quantidade de células contendo ROS nesses grupos em relação aos grupos controles. Já no segundo estudo, o modelo do MPTP foi empregado para avaliar o efeito do transplante de BMMC ou BM-MSC em diferentes tempos, imediatamente e 24 h após a infusão da neurotoxina. A infusão de MPTP resultou em quebra da BHE e prejuízo motor 24 h após a infusão de MPTP, e o tratamento com BMMC imediatamente após a lesão aumentou significativamente a perda de células TH-ir nesses animais, ao contrário do tratamento com BM-MSCs. Por outro lado, o tratamento com BMMC 24 h após a infusão de MPTP resultou em similar perda de neurônios TH-ir comparado ao grupo MPTP-salina. No teste de natação forçada, o grupo MPTP-BMMC apresentou aumento no tempo de imobilidade comparado aos grupos Sham e MPTP, e ainda, aumento no número de células CD45+ e micróglia ativada nas secções estudadas. O presente estudo sugere que o transplante de BM-MSC em animais lesados com MPTP module positivamente o microambiente neuronal favorecendo a sobrevivência neuronal, enquanto que o transplante com BMMCs e a redução dos níveis fisiológicos de melatonina mostraram-se desfavorável ao microambiente neuronal. Palavras-chave: MPTP, 6-OHDA, BMMC, BM-MSC, pinealectomia e DP.
Abstract: Parkinson's disease (PD) is a neurodegenerative disease characterized by loss of dopaminergic neurons in the SNpc. This study aimed to investigate the role of cellular microenvironment on the neurodegenration in two distinct investigation lines. In the first line, the animals were evaluated for the effect of pinealectomy (Px) on neurodegeneration and oxidative stress induced by MPTP or 6-OHDA. The administration of these neurotoxins results in motor impairment in both sham and Px groups 24 h after injury in the open field test. However, 7 and 14th days after injury, the injured animals belonging to Sham group showed recovery of motor abnormalities, unlike injured animals of the Px-groups. In the forced swim test, the injured animals exhibited shorter swimming compared to control groups, and futher, Sham-6-OHDA and Px-6-OHDA groups showed a significant increase in immobility time compared to control groups. Supporting these alterations, significant dopaminergic loss in animals injured was observed in comparison to control groups, and futher, increased quantity of cellular ROS in these groups. In the second study, the MPTP model was used to evaluate the effect of BMMC and BM-MSCs at different times, immediately and 24 hours, after neurotoxins infusion. The MPTP infusion resulted in breakdown of bloodbrain barrier and motor impairment 24h after MPTP infusion, and the BMMC treatment immediately after lesion induced a significant increase loss of TH-ir neurons in these animals when compared to MPTP-saline group, in opposite to the BM-MSCs treatment. In the other hand, MPTP-lesioned rats treated with BMMCs 24 h after to neurotoxin infusion showed similar loss of dopaminergic neurons to MPTP-saline. In the forced swimming test, MPTP-BMMC treated group presented an increase in the immobility time compared to sham and MPTP-saline group, and futher increase in the number of CD45-labeled cells and activated microglial cells in the sections studied. This study suggests that the BM-MSCs transplantation in MPTP-lesioned rats positively modulate the microenvironment favoring neuronal neuronal survival, whereas transplantation BMMCs and the reduction of physiological levels of melatonin have proved unfavorable neuronal microenvironment. Keywords: MPTP, 6-OHDA, BMMC, BM-MSC, pinealectomy e PD.
Barreiro, Portela Esther. "Study of reactive oxygen species (ROS) and nitric oxide (NO) as molecular mediators of the sepsis-induced diaphragmatic contractile dysfunction : protective effect of heme oxygenases." Doctoral thesis, Universitat Pompeu Fabra, 2002. http://hdl.handle.net/10803/7066.
Full textEn un model de sepsi de disfunció diafragmàtica, s´ha avaluat el paper de les sintetases de l'òxid nítric (NOS) en la formació i localitzacio de 3-nitrotirosina, i l´expressió i significat biològic de les hemo oxigenases (HOs) (inhibidor de les HOs i estudis de contractilitat) davant l' estrès oxidatiu. La sepsi s'induí mitjançant injecció de 20 mg/kg del lipolisacàrid (LPS) d´Escherichia Coli a rates, i a ratolins deficients en les NOS induïble (iNOS), neuronal (nNOS) i endotelial (eNOS). Les proteïnes nitrificades i les HOs es van detectar amb anticossos específics. L' estrès oxidatiu s' avaluà mitjançant l' oxidació proteica, la peroxidació lipídica i el glutation muscular. Concloem que hi han proteïnes nitrificades en el múscul normal i aquestes s'incrementen durant la sepsi en les fraccions mitocondrial i membranar. L'isoforma iNOS és majorment responsable de la formació de nitrotirosina. Les HOs protegirien el múscul normal i sèptic dels efectes deleteris dels oxidants.
Bahri, Nesrine. "Une commande neuronale adaptative basée sur des émulateurs neuronal et multimodèle pour les systèmes non linéaires MIMO et SIMO." Thesis, Le Havre, 2015. http://www.theses.fr/2015LEHA0024/document.
Full textThe porosity of a composite plate in carbon / epoxy of type RTM is known by used of tomography X. A method of determination of this porosity by measure of the mitigation of the longitudinal waves through the thickness of this kind of plate is proposed. These measures are made on surfaces of different sizes (from some cm2 to some mm2) and allow the obtaining of cartographies. A correspondence porosity (tomo X) - Mitigation (US wave) is deducted and analyzed according to the structure of the composite material. In every case, we estimate the quality of the obtained relations and we deduct the limits of validity of the correspondence between porosity and mitigation. First results of acoustic tomography are obtained
Imbeault, Emilie. "Le rôle du récepteur NOD-like, Nlrx1 dans la neuroprotection et la mort cellulaire." Mémoire, Université de Sherbrooke, 2015. http://hdl.handle.net/11143/6937.
Full textAbstract : Neuronal cell death is a phenomenon that occurs during brain development as well as in pathological diseases. Depending on the environment in which the cells are; a poptosis or necrosis can contribute to neuronal cell death. Necrosis produces an environment that promotes inflammation and cytotoxicity and apoptosis is a highly organized process that maintains tissue homeostasis. A recently discovered NOD receptor, Nlrx1, is thought to play a role in regulation of inflammation and cell death during infection. Therefore, we hypothesize that Nlrx1 plays a neuroprotective role by controlling cell death in neurons. To determine the protective mechanism of Nlrx1 in vitro, a Knock-Down, a Knock-In and a Scrambled control of Nlrx1 in N2a cells was generated. LDH assays for cell death detection with staurosporine or oxidative stress, such as rotenone, MPP+ or H[subscript 2]O[subscript 2], have been done. After 24h treatment of staurosporine, N2a Knock-In cells showed higher cell death than N2a Knock-Down and Scrambled. When cells were treated with rotenone or H[subscript 2]O[subscript 2], N2a Knock-In cells had less cell death than Scrambled cells. N2a Knock-Down cells resulted in more cell death than Scrambled cells when treated with rotenone or MPP+.Western Blotting of HSP90 and HMGB1 as well as flow cytometry of cell death demonstrated N2a Knock-In cells to have less necrotic cells when treated with rotenone compared to Scrambled. The ratio of necrotic cells on apoptotic cells was also higher in N2a Knock-Down cells compared to Scrambled cells. Electron microscopy of control cells showed that Knock-In cells contains more mitochondria than Knock-Down and Scrambled cells. These results were confirmed by mitotracker staining by flow cytometry. Western blotting showed that there was an increased in Knock-In cells of active phosphorylated-DRP1 protein, a protein implicated in mitochondrial fission. Thus, it could explain the increased number of mitochondria seen in Knock-In cells. Immunoprecipitation showed that Nlrx1 protein interacts with DRP1 as well as active phosphorylated-DRP1. Adding Mdivi, a mitochondrial fission inhibitor, to rotenone or H[subscript 2]O[subscript 2] treatments, cell death was increased in Knock-In cells compared to Scrambled. Also, necrosis was also augmented in Knock-In cells to levels comparable to Scramble and Knoc k-Down cells. These results suggest an implication for Nlrx1 in regulating the balance of necrosis to apoptosis, permitting cells to survive. Nlrx1 could serve as a neuroprotective molecule in diseases mediated by oxidative stress.
Gendron, Judith. "Les longs ARN non codants, une nouvelle classe de régulateurs génomique tissu-spécifique : signature moléculaire spécifique des neurones dopaminergiques et sérotoninergiques." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066518.
Full textOnly 1.2% of the genome codes for proteins; 98.8% is thus non-coding, despite 93% of the human genome being actively transcribed, mostly in long non-coding RNA (lncRNA).These lncRNA constitute a new class of genomic regulator capable of acting at all levels of gene expression and their expression is highly tissue-specific,modulated during the time and under normal/pathological conditions.Thus, we propose that each specified cell expresses a specific repertoire of lncRNA correlated to open/active chromatin regions specifying its cellular identity.In this context, we isolated by FACS 2neural types involved in many pathologies: i) human dopaminergic neurons (nDA) differentiated from hiPS and ii) DA and serotoninergic (n5-HT) neurons. From these 2neural types, we identified 1,363 lncRNA in nDA (among which 989 new, whether 73%) constituting the repertoire of nDA, and 1,257 lncRNA (among which 719 new) constituting the repertoire of n5-HT. Moreover,their comparison has shown that only 194 lncRNA are common to both neural types:thus the majority of lncRNA is expressed either in nDA or in n5-HT, indicating a high degree of cell-specificity.In addition, 39% of open chromatin regions, potentially regulatory, were also not detected in the n5-HT.Thus, we have generated DA and 5-HT specific catalogues of non-coding elements of the genome, which constitute DA and 5-HT specific molecular signatures, that could participate in deepening our knowledge regarding nDA or n5-HT development and dysfunctions. With this in mind,these DA specific elements have been compared with the SNP described as Parkinson Disease risk variants and candidate lncRNA were selected to perform studies of function
Silva, Elizangela dos Anjos. "Avaliação morfológica e quantitativa dos neurônios do plexo mioentérico nas diferentes porções do ceco de ratos com seis e doze meses de idade, sedentários, e ratos submetidos à atividade física regular, com doze meses." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/10/10132/tde-25052007-152448/.
Full textThe arrangement of the myenteric plexus, the number of neurons, and the area of the profile of neuronal body (µm2) were studied in the different portions of the apical and basal regions of the cecum of rats. Thirty rats had been, equally, distributed in groups of six (G-6) and twelve months of age (G-12S), were sedentary, and a group with twelve months (G-12T), which was submitted to a program of physical activity of moderate intensity. They had been mounted whole mount preparation and were stained with the NADH-diaforase (NADH-d) and NADPH-diaforase (NADPH-d) histochemical techniques. The arrangement of the plexus and the number of neurons had been evaluated comparatively between the three groups, and the different portions of the regions of cecum. The neurons of the regions apical and basal had been distributed in class with intervals of 100µm2, and the averages of the measurements of the pairs were compared, considering the different ages and treatments. It was not observed alterations in the architecture of the myoenteric plexus in the portions of cecum, neither in the different studied groups. There was more NADH-d positive neurons than NADPH-d ones, in all the portions, of both the regions, of all the groups. The G-12T animals presented greater number of reactive NADH-d neurons than the sedentary ones, in all the portions of cecum, excepting the portion near to the cecal ampoule. The number of the positive NADPH-d neurons did not differ between G-6 and G-12T (p-value < 5%). The cellular profile area of the NADH-d and NADPH-d reactive neurons was bigger in the apical region than in the basal, in all groups, excepted of the NADPH-d neurons of animals G-12T. The NADH-d reactive neurons were more affected by the age of the animal and the physical exercise than the NADPH-d neurons. For the first time, the number of neurons of the myenteric plexus is reported in preset portions of ceco of rats. Our results reiterate the necessity of indication of the portion studied in this intestinal segment.
Brot, Sébastien. "Etude structurale et fonctionnelle de la « Collapsin Response Mediator Protein » CRMP5." Thesis, Lyon 1, 2010. http://www.theses.fr/2010LYO10264.
Full textThe purpose of this work is to focus on the study of CRMP5 during development of the central nervous system. We have demonstrated a direct interaction between CRMP5 and tubulin, leading to inhibition of neurite outgrowth in different cell lines, and inhibition of growth only at dendritic but not axonal level, in hippocampal neurons. Furthermore, we showed that CRMP5 could counteract the previously described CRMP2 effect on neurite outgrowth. The CRMP5 acted as a dominant signal to counteract CRMP2 outgrowth promotion and this function is also dependent on the tubulin-binding capacity of CRMP5.Unlike CRMP2, the CRMP5 expression being transient during neuronal differentiation, it would imply in the spatiotemporal regulation of the CRMP2 effect on neurite outgrowth, thereby regulating neuronal polarity. In another part, we also reported the presence of CRMP5 at mitochondrial level in vivo where it could play a role in mitochondrial autophagic process.Finally, we were interested in the study of CRMP5 expressed in pathological conditions, and we discovered a new nuclear localization of the protein in some cancer cells. Being localizedin several subcellular compartments and involved in different molecular mechanisms, this work describes CRMP5 as a "multi-functional" protein
Veltz, Romain. "Nonlinear analysis methods in neural field models." Thesis, Paris Est, 2011. http://www.theses.fr/2011PEST1056/document.
Full textThis thesis deals with mesoscopic models of cortex called neural fields. The neural field equations describe the activity of neuronal populations, with common anatomical / functional properties. They were introduced in the 1950s and are called the equations of Wilson and Cowan. Mathematically, they consist of integro-differential equations with delays, the delays modeling the signal propagation and the passage of signals across synapses and the dendritic tree. In the first part, we recall the biology necessary to understand this thesis and derive the main equations. Then, we study these equations with the theory of dynamical systems by characterizing their equilibrium points and dynamics in the second part. In the third part, we study these delayed equations in general by giving formulas for the bifurcation diagrams, by proving a center manifold theorem, and by calculating the principal normal forms. We apply these results to one-dimensional neural fields which allows a detailed study of the dynamics. Finally, in the last part, we study three models of visual cortex. The first two models are from the literature and describe respectively a hypercolumn, i.e. the basic element of the first visual area (V1) and a network of such hypercolumns. The latest model is a new model of V1 which generalizes the two previous models while allowing a detailed study of specific effects of delays
El, Achkar Roger. "Contribution à l'étude et à la validation expérimentale de commandes neuronales d'un palier magnétique actif." Compiègne, 2008. http://www.theses.fr/2008COMP1747.
Full textThe active magnetic bearing (AMB) presents a solution for technical proble since it ensures the total levitation of a body in space eliminating any mechanical contact between the rotor and the stator. The goal of o work is to show that the control of the AMB by Multilayer perceptions (MLP) involves an improvement of the responses compared to the non linear control of the AMB by classical controllers. Two methods with MLP were developed to control the AMB. The first consists in adding the MLP in order to stabilize the system around the desired answers. This method is also used to reduce the value of the unbalance. In the second method, the MLP controls the parameters of the PID in order to minimize the oscillations of the answers obtained with the previous method. This tuning, by neural network, of the parameters of the PID controller reduces the consumption of the energy used by the AMB. The last section is devoted to the simulation of these two methods and the implementation of the MLP in real time application on an active magnetic bearing at the Heudiasyc laboratory of the UTC
Jönsson, Maria. "The neuronal and non-neuronal substance P, VIP and cholinergic systems in the colon in ulcerative colitis." Doctoral thesis, Umeå universitet, Anatomi, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-19946.
Full textBARJAUD, PASCAL. "Etude d'un protocole d'utilisation dans la determination de la nse et du rapport nse/nne pour le suivi des cancers anaplasiques a petites cellules du poumon." Clermont-Ferrand 1, 1992. http://www.theses.fr/1992CLF13051.
Full textCorson, Nathalie. "Dynamique d'un modèle neuronal, synchronisation et complexité." Phd thesis, Université du Havre, 2009. http://tel.archives-ouvertes.fr/tel-00453912.
Full textLoyer, Xavier. "Expression, rôle et régulation de l'isoforme neuronale NOS dans le myocarde sain et pathologique." Paris 7, 2007. http://www.theses.fr/2007PA077072.
Full textHypertrophy is crucial in the development of heart failure (HF). In failing hearts, NOS1 expression and activity are increased in cardiomyocytes,. However, the role of NOS1 in the setting of myocardial hypertrophy is unclear. Thus, the goals of the study were to 1- determine the pattern of NOS1 expression and 2- define its role in LVH. Using pressure overload-induced LVH in rats, we demonstrated that NOS1 expression and activity increased early in males and latter on in females, these regulations being only dependent on biomechanical stress. In vitro, the direct prohypertrophic role of NOS1 was confirmed on cultured cardiomyocyte, using RNA interference approach. In vivo, using a transgenic mouse with cardiac-specific overexpression of NOS1, we demonstrated that NOS1 protects against maladaptive remodeling and contractile dysfunction in response to pressure overload- Analyses of both in vivo and in vitro intracellular pathways showed that NO SI directly regulated the cardiac hypertrophic response through modulation of the calcineurin signalling pathway. Mechanistically, we showed that NOS 1 overexpression is beneficial in preventing the transition toward HF through the preservation of cardiomyocyte calcium cycling and contractility. In conclusion, our results suggest that targeting endogenous NOS1 could provide a useful strategy against adverse remodeling and functional deterioration during chronic pressure overload
Chavy, Cyril. "Codeur neuronal prédictif : application au codage de phonèmes." Paris 6, 2004. http://www.theses.fr/2004PA066526.
Full textFerreira, Brigham Marco Paulo. "Nonstationary Stochastic Dynamics of Neuronal Membranes." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066111/document.
Full textNeurons interact through their membrane potential that generally has a complex time evolution due to numerous irregular synaptic inputs received. This complex time evolution is best described in probabilistic terms due to this irregular or "noisy" activity. The time evolution of the membrane potential is therefore both stochastic and deterministic: it is stochastic since it is driven by random input arrival times, but also deterministic, since subjecting a biological neuron to the same sequence of input arrival times often results in very similar membrane potential traces. In this thesis, we investigated key statistical properties of a simplified neuron model under nonstationary input from other neurons that results in nonstationary evolution of membrane potential statistics. We considered a passive neuron model without spiking mechanism that is driven by input currents or conductances in the form of shot noise processes. Under such input, membrane potential fluctuations can be modeled as filtered shot noise currents or conductances. We analyzed the statistical properties of these filtered processes in the framework of Poisson Point Processes transformations. The key idea is to express filtered shot noise as a transformation of random input arrival times and to apply the properties of these transformations to derive its nonstationary statistics. Using this formalism we derive exact analytical expressions, and useful approximations, for the mean and joint cumulants of the filtered process in the general case of variable input rate. This work opens many perspectives for analyzing neurons under in vivo conditions, in the presence of intense and noisy synaptic inputs
Selmi, Foued. "Réponse excitable et propriétés neuromimétiques de micropiliers lasers à absorbant saturable." Thesis, Paris 11, 2015. http://www.theses.fr/2015PA112158/document.
Full textExcitability is a well known property of biological neurons. In excitable systems, the response to a perturbation above the excitable threshold is of all-or-none type. Other properties exist in neurons such as the refractory periods and temporal or spatial summation of input stimuli.Excitability has been demonstrated in many III-V semiconductor material devices. Thanks to their nonlinear properties it could be possible to realize neuromimetic and all-optical signal processing with high speed and low energy consumption. Thanks to progress in fabrication techniques it is possible to fabricate high quality micropillar laser with saturable absorber. Thus, using micropillars it could be possible to realize neural photonic networks analog to neural networks.In this thesis work, I studied neuron-like properties of a micropillar laser with a saturable absorber. My main results are : 1) fabrication of micropillars has been improved leading to an increase of their robustness and a reduction of the laser threshold. 2) well known properties of biological neurons, such as excitability, existence of refractory periods, temporal summation, have been demonstrated experimentally and have been numerically analyzed with the Yamada model. 3) propagation effects of excitations have been demonstrated in one-dimensional structures : wire lasers and chains of coupled micropillars.The demonstration of neuromimetic properties in micropillar lasers with saturable absorber and the evidence of propagation of excitations pave the way to neuromorphic networks based on coupled micropillars for neuromimetic signal processing like information encoding with excitable pulses and realization of optical memories
Ebrahimian, Talin. "Expression et fonction de la NOS neuronale dans les cellules musculaires lisses de la paroi vasculaire." Paris 7, 2003. http://www.theses.fr/2003PA077155.
Full textLairi, Mostafa. "Identification et commande neuronales de systèmes non-linéaires : application à un système de sustentation magnétique." Nancy 1, 1998. http://www.theses.fr/1998NAN10156.
Full textJurzik, Lars. "Veränderung der neuronalen Vasoregulation im mesenterialen Gefässbett bei portaler Hypertension mit besonderem Fokus auf die neuronale Stickstoffmonoxyd-Synthase (nNOS)-vermittelte Vasorelaxation und die Neuropeptid-Y-(NPY)-induzierte Vasokonstriktion /." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=973326840.
Full textJúnior, André Oliveira Mota. "Caracterização molecular do gene ncsA de Aspergillus fumigatus." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/17/17136/tde-05012009-123104/.
Full textHere, we characterize the A. fumigatus Neuronal Calcium Sensor, ncsA homologue. We showed that ncsA is not an essential gene and ncsA growth was decreased in the presence of EGTA and SDS. Furthermore, the ncsA mutant is more resistant to calcium chloride. NcsA:mRFP localizes to the cytoplasm that its cellular localization is not affected by the cellular response to calcium chloride. The ncsA mutant strain is more sensitive to voriconazole, itraconazole, and the ergosterol intercalating agent, amphotericin. Polar growth in the DncsA mutant strain was also considerably more affected by lovastatin than in the wild type mutant strain. The Spitzenkörper cannot be visualized in the DncsA mutant, and there is a significant decrease of the endosome/vacuole structures. NcsA supports pmcA and pmcB expression therefore reduced expression of these ion pumps, and also of other genes involved in the response to calcium in A. fumigatus. The ncsA inactivation mutation is not causing loss of virulence in a low dose murine infection when compared to the corresponding wild type strain.
Magno, Luiz Alexandre Viana. "Fármacos estabilizadores do humor regulam a expressão do sensor neuronal de cálcio 1 (NCS-1)." Universidade Federal de Minas Gerais, 2012. http://hdl.handle.net/1843/BUOS-96LGMM.
Full textOs fármacos estabilizadores do humor (FEHs) são uma classe de medicamentos empregados na terapia do transtorno afetivo bipolar (TAB) cujo mecanismo de ação responsável pelas suas ações terapêuticas ainda não é bem esclarecido. Neste estudo, nós investigamos pela primeira vez o efeito dos FEHs lítio (Li), valproato (VPA), lamotrigina (LTG) e carbamazepina (CBZ) sobre a regulação da expressão do sensor neuronal de cálcio tipo 1 (Ncs-1), uma proteína multifuncional desregulada em transtornos psiquiátricos e associada com a sobrevivência e a sinalização dopaminérgica. Além disso, o impacto biológico e farmacológico da deleção genética in vivo do Ncs-1 também foi investigado em camundongos e Caenorhabditis elegans. Através de diferentes modelos experimentais e regimes de tratamento farmacológico in vitro e in vivo, os resultados do estudo mostraram que a expressão do Ncs-1 é induzida por Li e VPA em células PC12 e córtex frontal de camundongos após tratamento crônico. Interessantemente, este efeito foi abolido em animais nocautes de Arr2 (beta arrestina 2) e D2R (receptor de dopamina tipo 2). A inibição das vias de sinalização de Gsk3 e Erk, as quais são alvos em comum de Li e VPA, mas não a inibição de histonas deacetilases, induziu a expressão o gene NCS-1 in vitro e in vivo, enquanto que a superexpressão de Gsk3reduziu drasticamente os níveis de RNAm deste gene. O efeito mediado pela inibição de Gsk3 ou Erk sobre o gene NCS-1 mostrou-se fundamental para a elevação dos níveis intracelulares de Ncs-1 pois a inibição da tradução impediu tal aumento observado. Com a finalidade de compreender como a expressão do gene NCS-1 é regulada, sequências candidatas a promotor foram clonadas em um sistema de gene repórter, porém, nenhuma atividade significante dessas sequências foi detectada em células transfectadas. Além disso, os diferentes modelos experimentais empregados pelo estudo mostraram que animais nocautes de Ncs-1 são caracterizados por alterações no estresse oxidativo e metabolismo energético cerebral, memória e perda de resposta hiperlocomotora induzida por anfetamina. Um modelo experimental de mania aguda induzida por anfetamina que foi caracterizado por níveis reduzidos de Ncs-1 especificamente no córtex frontal, foi tratado com VPA e obteve normalização dos níveis de Ncs-1. Até o momento, poucos alvos moleculares em comum relacionados com a ação farmacológica dos FEHs foram identificados. Desta forma, as evidências apresentadas por este estudo apontam a proteína multifuncional Ncs-1 como o mais novo alvo celular em comum regulado por Li, VPA, Gsk3 e Erk. Estes resultados inéditos, além de prover novos conhecimentos neurobiológicos, abrem uma janela de oportunidades para novas explorações que investiguem o papel celular do Ncs-1 através da inibição de Gsk3 e Erk na mediação dos efeitos terapêuticos e/ou adversos do tratamento com fármacos estabilizadores do humor.
Niksic, Laurent. "La vasopressine module l'expression de l'isoforme neuronale de la "Nitric oxyde synthetase" (NOS) dans la medulla du rat /." Genève : [s.n.], 2005. http://www.unige.ch/cyberdocuments/theses2005/NiksicL/these.pdf.
Full textSéjourné, Julien. "Dynamique des phases de mémoire et réseaux neuronaux chez Drosophila melanogaster." Phd thesis, Paris 6, 2009. http://pastel.archives-ouvertes.fr/pastel-00567093.
Full textCheung, Nathan Yiutung. "Serotonin receptor and neuronal nitric oxide synthase expression in the rat brain : implications for MDMA toxicity." Thesis, King's College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368095.
Full textJouffroy, Guillaume. "Contrôle oscillatoire par réseau de neurones récurrents." Paris 8, 2008. http://www.theses.fr/2008PA082918.
Full textIn the control field, most of the applications need a non-oscillatory continuous control. This work focuses instead on controllers with recurrent neural networks (RNN) which generate a periodic oscillatory control. The purpose of the present work is to study stochastic optimisation methods which can be used to discover the parameters of a network so that it generates a cyclic input. First we take a look at the knowledge about biological oscillators. Tthen we describe the mathematical tools to be able to guarantee the stability oscillators. The potential of RNN, especially applied to dynamical systems being still poorly used, we propose for each method, a general detailed matrix formalization and we precise the computational complexity of the methods. We validate each method using a simple example of oscillator, and we demonstrate analytically the stability of the resulting oscillator, but also how it is robust to parameters perturbations. We then compare these different methods with these criteria and the speed of convergence. We finish this thesis with an illustration, where we take all the steps of the construction of an oscillatory neural controller, to control the axis of direction of a particular vehicle. This will let us discuss how realistic is the use of recurrent neural networks in the field of control, and propose interesting questions
Leber, Werner. "Characterisation of a bifunctional plasmodium falciparum phosphatidylinositol 4-phosphate 5-kinase/neuronal calcium sensor (PfPip5K/NCS)." Thesis, London School of Hygiene and Tropical Medicine (University of London), 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.502463.
Full textGuimaraes, Melissa Monteiro. "Envolvimento da proteína neuronal sensora de cálcio-1 (NCS-1) na sinalização muscarínica em células PC12." Universidade Federal de Minas Gerais, 2007. http://hdl.handle.net/1843/BUOS-9R6HWA.
Full textA proteína Neuronal Sensora de Cálcio-1 (NCS-1) pertence à superfamília de proteínas apresentando domínios EF-hand com afinidade ao Ca2+. É expressa em neurônios e células neuroendócrinas onde modula a transmissão sináptica e plasticidade celular. Trabalhos descritos mostraram aumento da expressão da proteína NCS-1 no córtex pre-frontal de pacientes esquizofrênicos a partir de análises pós-morte sugerindo o envolvimento de NCS-1 nos mecanismos moleculares de regulação da transmissão dopaminérgica associados aos transtornos mentais. Entretanto, pouco se sabe a respeito da participação de NCS-1 na regulação da via de sinalização muscarínica. Neste trabalho foram verificados efeitos da superexpressão da NCS-1 em células PC12 (PC12- NCS-1) nos processos de liberação de glutamato, níveis de Ca2+ e dinâmica de fosfoinositídeos provocados pela ativação da via muscarínica. Foi observado que o estímulo com carbacol (CCH) (300mM) induziu liberação de glutamato tanto nas células PC12 selvagens (PC12-wt) quanto nas células PC12-NCS-1. Entretanto a liberação de glutamato foi maior nas células PC12-NCS-1 em comparação às células PC12-wt respectivamente (14.4 ± 1.8 e 8.3 ± 0.9 nmol/mg de proteína). Níveis aumentados de glutamato liberado pelas células PC12-NCS-1 estimuladas com CCH foram observados tanto na presença quanto na ausência do influxo de Ca2+. Além disso, níveis aumentados de InsP3 (663,0 ± 63,0 e 310.0 ± 39.0 % de fluorescência em U.A. ± EPM) e na [Ca2+]i (766.35 ± 35.0 e 687.8 ± 37.0 em nM ± EPM) foram observados nas células PC12-NCS-1 em comparação às células PC12-wt estimuladas com CCH (300mM) respectivamente. Padrões distintos na dinâmica intracelular de Ca2+ foram observados após o estímulo das células com CCH. Nas células PC12-NCS-1 foi observado um aumento na [Ca2+]i seguido de um decaimento rápido. Nas células PC12-wt foi observado um decaimento lento na [Ca2+]i característico de um platô. Tanto o aumento na formação de InsP3 quanto na liberação de glutamato foram bloqueados pela atropina (10mM) nas células PC12-NCS-1 estimuladas com CCH. Esses resultados indicam que o aumento da expressão de NCS-1 nas células PC12 induz facilitação da dinâmica de formação de segundos mensageiros e da liberação de glutamato dependente da ativação muscarínica. Essas evidências sugerem que a proteína NCS-1 poderia estar envolvida na amplificação de processos adaptativos da sinalização muscarínica associados a patofisiologia dos transtornos neurais.
Lu, Chieh-Ju. "Neuronal nitric oxide synthase-CAPON regulation of cardiac sympathetic activity in the development of hypertension." Thesis, University of Oxford, 2015. http://ora.ox.ac.uk/objects/uuid:1204dec9-9f09-458d-b361-c8d14589fcd1.
Full textDaachi, Boubaker. "Observateurs et commande neuronale adaptative pour systèmes robotisés." Versailles-St Quentin en Yvelines, 2000. http://www.theses.fr/2000VERS0020.
Full textAmmar, Adel. "Restitution de la salinité de surface de l'océan à partir des mesures SMOS : une approche neuronale?" Toulouse 3, 2008. http://thesesups.ups-tlse.fr/475/.
Full textUsing neural networks to retrieve the sea surface salinity from the observed Soil Moisture and Ocean Salinity (SMOS) brightness temperatures (TBs) is an empirical approach that offers the possibility of being independent from any theoretical emissivity model. We prove that this approach is applicable to all pixels over ocean, by designing a set of neural networks with different inputs. Besides, we demonstrate that a judicious distribution of the geophysical parameters in the learning database allows to markedly reduce the systematic regional biases of the retrieved SSS, which are due to the high noise on the TBs. An equalization of the distribution of the geophysical parameters, followed by a new technique for boosting the learning process, makes the regional biases almost disappear for latitudes between 40°S and 40°N, while the global standard deviation remains between 0. 6 psu (at the center of the swath) and 1 psu (at the edges)
McNamara, Tanner. "ENOS and nNOS contribution to reflex cutaneous vasodilation during dynamic exercise in humans." Thesis, Kansas State University, 2012. http://hdl.handle.net/2097/13788.
Full textDepartment of Kinesiology
B.J. Wong
Recent data suggests nNOS mediates the NO-component of reflex cutaneous vasodilation with passive heat stress. Our hypothesis was nNOS, but not eNOS, inhibition would attenuate reflex cutaneous vasodilation during dynamic exercise. Protocol 1: subjects performed a VO[subscript]2 peak test on a supine cycle ergometer. Protocol 2: with experimental arm at heart level subjects cycled in supine posture at 60% VO[subscript]2 peak to raise core temperature (Tc) 0.8-1.0°C (35-45 min). In protocol 2 subjects were equipped with 4 microdialysis fibers on the forearm and each randomly assigned as: 1) lactated Ringer’s (control); 2) 5mM NPLA (nNOS inhibition); 3) 10mM L-NIO (eNOS inhibition); and 4) 20mM L-NAME (non- selective NOS inhibition). At the end of protocol 2 all sites were locally heated to 43°C and infused with SNP to elicit maximal dilation. Mean arterial pressure (MAP), skin blood flow via laser- Doppler flowmetry (LDF), and Tc via ingestible telemetric pill were measured; cutaneous vascular conductance (CVC) was calculated as LDF/MAP and normalized to maximum. In protocol 2 there was no significant difference between control (62±5 %CVCmax) and NPLA (61±6 %CVCmax). L-NIO (38±4 %CVCmax) and L-NAME (41±7 %CVCmax) significantly attenuated CVC compared to control and NPLA (p<0.001 all conditions). There was no difference between L-NIO and L- NAME. We conclude eNOS, not nNOS, contributes to reflex cutaneous vasodilation during dynamic exercise.
Cherruel, Gildas. "Etude de commandes neuronales en environnement synchrone SIGNAL." Brest, 1996. http://www.theses.fr/1996BRES2011.
Full textDumont, Grégory. "Analyse de modèles de population de neurones : cas des neurones à réponse postsynaptique par saut de potentiel." Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14601/document.
Full textThis thesis concerns the mathematical modelling and the study of the behavior of a population of neurons. In this work we will mainly consider a population of excitatory neurons whe reall the cells of the network follow the integrate-and-fire model. Nonetheless, we will tackle in a chapter the modelling of an inhibitory population of neurons, and we will discuss in the lastchapter the modelling of a population of neurons that follows the Ermentrout-Koppell model.The point of view of this thesis is given by the population density approach that has beenintroduced more than a decade ago in order to facilitate the simulation of a large assembly ofneurons. More precisely, this approach gives a partial differential equation that describes thedensity of neurons in the state space that is the set of all admissible potential of a neuron. We will assume that when receiving an action potential, the potential of the neuron makes a small jump. As we will see this partial differential equation is non linear (due to the coupling betweenneurons) and non-local (due to the potential jump). If this idea is complicated and abstract, itallows to simulate easily a large neural network.First of all, the thesis gives a mathematical framework for the equations that arise from thisthe population density approach. Then we will discuss the existence and the possible blow upin finite time of the solution. We will discuss how the consideration of more realistic modellingassumptions, as the refractory period and the delay between the emission and the reception ofan action potential can stop the blow up of the solution and give a well posed model.We will also try to caracterise the occurence of synchronization of the neural network. Twodifferent ways of seeing the synchronization will be describe. One relates the blow up in finitetime of the solution to the occurence of a Dirac mass in the firing rate of the population.Nonetheless, taking into account the delays, this kind of blow up will not be observed anymore.Nonetheless, as we will see, with this additional features the model will generate some periodicalsolutions that can also be related to the synchronization of the population
Wira, Patrice. "Approches neuromimétiques pour l'identification et la commande." Habilitation à diriger des recherches, Université de Haute Alsace - Mulhouse, 2009. http://tel.archives-ouvertes.fr/tel-00605218.
Full textZerkaoui, Salem. "Commande neuronale adaptative des systèmes non linéaires." Le Havre, 2007. http://www.theses.fr/2007LEHA0010.
Full textThe main contribution of this work is to propose a robust stable self-adaptive InDirect neural Network Control "IDNC" to control a broad variety of unknown linear, nonlinear, SISO and MIMO systems. The control scheme is made of an adaptive instantaneous neural model, a neural controller and an on-line parameter updating law. The IDNC parameters start at zero initial conditions which ensure that the performances do not depend on the initialization phase. Closed loop performances as well as sufficient conditions for asymptotic stability and robustness are derived from the Lyapunov approach. The simulations and experimental tests are carried out in order to validate the performances of the proposed approach. In particular, our contribution is used for the control of the Tennessee Eastman Challenge Process and a medical robot. Also, the proposed structure can easily be implemented in several practical applications
Glazar, Petar. "Expression and possible functions of circular RNAs." Doctoral thesis, Humboldt-Universität zu Berlin, 2020. http://dx.doi.org/10.18452/21396.
Full textcircular RNAs (circRNAs) are a large class of endogenous RNAs present in organisms that process RNA transcripts by splicing. They are products of backsplicing - alternative splicing reactions where the 3’ end of an exon is spliced to an upstream 5’ splice site. Despite their abundance and tissue- and developmental-stage-specific expression patterns, their in vivo functions are largely unknown. We systematized the existing knowledge on circRNAs and made it freely available by developing circBase - an online database where circRNA datasets can be accessed, downloaded and browsed within the genomic context. Another technical challenge was addressed by developing ciRcus - a software package for working with high-throughput circRNA data, which allowed us to routinely handle, explore, annotate, quantify and integrate circRNA data with the external sources of biological data. To learn more about circRNA expression and potential functions, we have explored the expression patterns of circRNAs in the mammalian brain. Using own and public RNA-seq data, we discovered thousands of neural circRNAs in human and mouse. circRNAs were upregulated during neuronal differentiation and maturation, enriched in synapses, and often differentially expressed compared to their host mRNAs. Many circRNAs were conserved between human and mouse. Finally, we explored in vivo functions of Cdr1as - a conserved circRNA known to be highly expressed in the brain, heavily bound by microRNA (miRNA) effector complexes, and harbouring many binding sites for miR-7, as well as a single binding site for miR-671. Upon deleting the Cdr1as locus, knockout animals displayed impaired sensorimotor gating and dysfunctional synaptic transmission. Expression of miR-7 and miR-671 was deregulated in different brain regions of Cdr1as knockout animals. Expression of immediate early genes, some of which are miR-7 targets, was increased, providing a possible molecular link to the behavioral phenotype.