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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Efeitos da senesc?ncia no folheto intergeniculado do t?lamo de ratos: an?lises morfol?gicas e neuroqu?micas

Fiuza, Felipe Porto 27 March 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-02-22T22:44:29Z No. of bitstreams: 1 FelipePortoFiuza_DISSERT.pdf: 2760660 bytes, checksum: a2d147e9d0481d5a91cfe15442490d40 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-02-25T22:05:52Z (GMT) No. of bitstreams: 1 FelipePortoFiuza_DISSERT.pdf: 2760660 bytes, checksum: a2d147e9d0481d5a91cfe15442490d40 (MD5) / Made available in DSpace on 2016-02-25T22:05:52Z (GMT). No. of bitstreams: 1 FelipePortoFiuza_DISSERT.pdf: 2760660 bytes, checksum: a2d147e9d0481d5a91cfe15442490d40 (MD5) Previous issue date: 2015-03-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / O Sistema de Temporiza??o Circadiana (STC), em roedores, ? composto por estruturas neurais interligadas como o n?cleo supraquiasm?tico (NSQ) do hipot?lamo, o folheto intergeniculado (FIG) do t?lamo, vias sincronizadoras e efetores comportamentais. O NSQ tem sido descrito como o principal marca-passo circadiano em diversas esp?cies de mam?feros enquanto que o FIG parece estar envolvido na integra??o de informa??es f?ticas e n?o-f?ticas retransmitindo-as ao NSQ. O STC, como um todo, permite que o organismo tenha uma organiza??o temporal interna ordenada, o que propicia a execu??o adequada dos mecanismos fisiol?gicos e comportamentais trazendo homeostasia para o organismo. No entanto, essa estabilidade ? alterada com o avan?o da idade ocorrendo desde perda de fun??es fisiol?gicas simples ? diminui??o no desempenho cognitivo. Tendo isso em vista, ? proposto nesse estudo verificar se h? mudan?as neuroqu?micas, citoarquitet?nicas e de afer?ncias retinianas no FIG com o envelhecimento e suas poss?veis implica??es morfofuncionais. Para isso, ratos Wistar foram divididos em 3 grupos: Jovem (3 meses); Meia Idade (13 meses); Idoso (23 meses). Esses animais foram submetidos a perfus?o transcard?aca de paraformalde?do (4%) para fixar seus tecidos. Posteriormente seu enc?falo foi removido e submetido ? microtomia (30 ?m) onde as sec??es foram coletadas em intervalos de 6. Essas sec??es foram processadas por colora??o de Nissl e imunoistoqu?micas para GFAP, GAD, ENK, NPY e CTb a fim de verificar as caracter?sticas do FIG. Observamos uma perda celular em animais de meia-idade e idosos na marca??o de Nissl, NPY e nas proje??es de CTb. Al?m disso, vimos um aumento de GFAP em animais de meia-idade quando comparados a jovens e idosos. N?o houve diferen?as na an?lise dos outros marcadores. Esses achados indicam que essa estrutura perde afer?ncias retinianas e neur?nios, em especial os produtores de NPY, existindo uma prov?vel gliog?nese compensat?ria. Isso aponta para uma correla??o entre os d?ficits de funcionamento do STC e deteriora??o anat?mica de seus componentes com o envelhecimento. / The circadian timing system (CTS), in rodents, consists of interconnected neural structures such as the suprachiasmatic nucleus (SCN) of the hypothalamus, Intergeniculate Leaflet (IGL) of the thalamus, synchronous pathways and behavioral effectors. The SCN has been described as the major circadian pacemaker in several species of mammals, while the IGL appears to be involved in integration of photic and non-photic clues relaying them to SCN. The CTS allows an ordered internal temporal organization to the organism, providing the proper execution of physiological and behavioral mechanisms, which brings homeostasis. However, this stability is disrupted with aging process causing numerous pathological disorders, ranging from simple loss of physiological functions to decreases in cognitive performance. Therefore, is fundamental understanding the effects of senescence in this system. In this context, is proposed in this study to check if there are changes in IGL cytoarchitecture, neurochemical and retinal afferent markers with aging and their possible morpho-functional implications. To achieve this goal wistar rats were divided into 3 groups: young (3 months); Middle Age (13 months); Old (23 months). They were submitted to paraformaldhyde (4%) transcardiac perfusion to tissue fixation. Then, they had their brain removed and sectioned in 30 ?m slices, which every sixth section were collected. This sections were processed by nissl method and immunostaining for GFAP, GAD, ENK, NPY and CTb in order to analyze the IGL features. It was observed a cell loss in middle age and old animals at Nissl, NPY and CTb stains. In addition, it was shown a increase in GFAP in middle aged animals compared to young and old ones. No differences were found in other neurochemichal stains. These data suggests IGL loss retinal afferents and neurons, in special the NPY-IR ones, likely having a compensatory gliogenesis. This supports the correlations between the CTS functional deficits and an anatomical deterioration of its components with the aging process.
2

Estudo da organiza??o funcional do sistema circadiano por meio de ferramentas computacionais e matem?ticas / Gon?alves, bsb. study of the functional organization of the circadian system through computer modeling and analysis mathematics. Tese de doutorado em psicobiologia, ufrn, 137 p?ginas, 2013

Gon?alves, Bruno da Silva Brand?o 03 April 2013 (has links)
Made available in DSpace on 2014-12-17T15:36:40Z (GMT). No. of bitstreams: 1 BrunoSBG_DISSERT.pdf: 3965357 bytes, checksum: 7e3aabdd040d50db3f4557799b032b1d (MD5) Previous issue date: 2013-04-03 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Circadian rhythms are variations in physiological processes that help living beings to adapt to environmental cycles. These rhythms are generated and are synchronized to the dark light cycle through the suprachiasmatic nucleus. The integrity of circadian rhythmicity has great implication on human health. Currently it is known that disturbances in circadian rhythms are related to some problems of today such as obesity, propensity for certain types of cancer and mental disorders for example. The circadian rhythmicity can be studied through experiments with animal models and in humans directly. In this work we use computational models to gather experimental results from the literature and explain the results of our laboratory. Another focus of this study was to analyze data rhythms of activity and rest obtained experimentally. Here we made a review on the use of variables used to analyze these data and finally propose an update on how to calculate these variables. Our models were able to reproduce the main experimental results in the literature and provided explanations for the results of experiments performed in our laboratory. The new variables used to analyze the rhythm of activity and rest in humans were more efficient to describe the fragmentation and synchronization of this rhythm. Therefore, the work contributed improving existing tools for the study of circadian rhythms in mammals / Os ritmos circadianos s?o varia??es em processos fisiol?gicos que auxiliam os seres vivos na adapta??o aos ciclos ambientais. Esses ritmos s?o gerados e se sincronizam ao ciclo claro escuro por meio do n?cleo supraquiasm?tico. A integridade da ritmicidade circadiana tem grande implica??o na sa?de dos seres humanos. Atualmente sabe-se que dist?rbios nos ritmos circadianos est?o relacionados com alguns problemas da atualidade como a obesidade, propens?o a determinados tipos de c?ncer e transtornos mentais por exemplo. A ritmicidade circadiana pode ser estudada por meio de experimentos com modelos animais e diretamente nos seres humanos. Nesse trabalho utilizamos modelos computacionais para reunir resultados experimentais da literatura e explicar resultados de nosso laborat?rio. Outro foco desse trabalho foi na an?lise de dados de ritmos de atividade e repouso obtidos experimentalmente. Aqui fizemos uma revis?o sobre o uso de vari?veis utilizadas para analisar esses dados e por ?ltimo propomos uma atualiza??o na forma de calcular essas vari?veis. Os nossos modelos foram capazes de reproduzir os principais resultados experimentais da literatura e nos forneceram explica??es para resultados de experimentos realizados em nosso laborat?rio. As novas vari?veis utilizadas para analisar o ritmo de atividade e repouso em humanos se mostraram mais eficiente para descrever a fragmenta??o e sincroniza??o desse ritmo. Assim esse trabalho contribuiu aperfei?oando as ferramentas existentes para o estudo da ritmicidade circadiana nos mam?feros
3

Avalia??o do perfil de sono/vigilia em um modelo cr?nico de parkinsonismo em ratos

Silva, Cinthya Montenegro de Vasconcelos 13 May 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-01-03T19:56:08Z No. of bitstreams: 1 CinthyaMontenegroDeVasconcelosSilva_DISSERT.pdf: 1465896 bytes, checksum: 0fbac94f7a38a84105e55f2ee7340731 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-01-05T22:10:42Z (GMT) No. of bitstreams: 1 CinthyaMontenegroDeVasconcelosSilva_DISSERT.pdf: 1465896 bytes, checksum: 0fbac94f7a38a84105e55f2ee7340731 (MD5) / Made available in DSpace on 2017-01-05T22:10:42Z (GMT). No. of bitstreams: 1 CinthyaMontenegroDeVasconcelosSilva_DISSERT.pdf: 1465896 bytes, checksum: 0fbac94f7a38a84105e55f2ee7340731 (MD5) Previous issue date: 2016-05-13 / A doen?a de Parkinson (DP) ? uma desordem neurodegenerativa e progressiva com espectro cl?nico variado. Al?m dos sintomas motores cl?ssicos tamb?m podem surgir complica??es n?o-motoras, destacando-se a? problemas cognitivos, psiqui?tricos e auton?micos. Evid?ncias demonstram que tais sintomas n?o-motores frequentemente precedem o aparecimento dos sinais motores e s?o extremamente relevantes, dado o impacto negativo que causam na qualidade de vida dos indiv?duos. Os sintomas n?o-motores podem apresentar m?ltiplas causas, dentre as quais uma poss?vel disfun??o do sistema circadiano. Dessa forma, diversos processos fisiol?gicos influenciados pelo sistema de temporiza??o circadiano (STC), como o ciclo sono/vig?lia podem se mostrar alterados em pacientes acometidos pela DP. O STC ? respons?vel pela gera??o e manuten??o dos ritmos circadianos, que s?o oscila??es end?genas manifestadas pelos seres vivos em diversos processos fisiol?gicos e comportamentais, com per?odo em torno de 24 horas. Assim, ? fundamental a compreens?o dos efeitos da progress?o do processo patog?nico da DP sobre o perfil circadiano do ciclo sono/vig?lia e tamb?m de componentes do STC, em particular no n?cleo supraquiasm?tico (NSQ), o principal marcapasso do sistema. No presente estudo, ratos wistar jovens (6 meses) e de meia-idade (10 meses) foram submetidos a um modelo animal cr?nico de DP com administra??o de reserpina durante 20 dias. Ao longo do tratamento foram realizadas an?lises comportamentais do sono, bem como a avalia??o motora dos animais. Ap?s o fim do tratamento, foram realizadas an?lises imunoistoqu?micas no NSQ dos animais. Nossos resultados mostraram que o tratamento cr?nico com reserpina promoveu comprometimento motor progressivo tanto nos animais jovens quanto nos de meia-idade. Al?m disso, as an?lises comportamentais revelaram perturba??es no ciclo sono/vig?lia dos animais tratados em compara??o aos indiv?duos controle, incluindo avan?o na fase de sono e aumento na fragmenta??o do sono. As an?lises imunistoqu?micas n?o permitiram observar efeitos significativos do tratamento com reserpina sobre a composi??o neuroqu?mica do NSQ, contudo novos estudos s?o necess?rios para a avalia??o neuroqu?mica e morfom?trica desse importante marcapasso circadiano na DP. / Parkinson?s disease (PD) is a neurodegenerative and progressive disorder with varied clinical spectrum. In addition to the classic motor symptoms may also emerge non-motor complications, highlighting cognitive, psychiatric and autonomic problems. Evidence shows that such non-motor symptoms often precede the onset of motor signs and are extremely relevant given the negative impact they have on the quality of life of the individuals. Non-motor symptoms may present multiple causes, among which a possible dysfunction of the circadian system. Therefore, many physiological processes influenced by the circadian timing system (CTS) as the sleep / wake cycle can show alterations in PD patients. In this study we sought to evaluate the profile of sleep/wake behavior in a chronic model of PD in rats compared with possible neurochemical changes in the suprachiasmatic nucleus(SCN), the main pacemaker of the CTS. To this end, young (6 months) and middle-age (10 months) wistar rats were subjected to a treatment with repeated administration of reserpine (0.1 mg / kg) for 20 days. During treatment sleep behavioral analysis were performed as well as the motor assessment of the individuals. After the end of treatment, immunohistochemical analyzes were performed in the SCN of the animals. Our results showed that chronic treatment with reserpine promoted progressive motor impairment both in young as in middle-age animals. It is noticed significant losses from the 12th day of treatment. Furthermore, the behavioral analyzes revealed disturbances in sleep / wake cycle of the treated animals compared to control subjects, including advanced sleep phase and increased sleep fragmentation. Such changes were observed from the 6th day of treatment, prior to the onset of motor symptoms. The immunohistochemical analysis not allowed to observe significant effects of treatment with reserpine on the neurochemical composition of the SCN. Thus, our data support the observation that non-motor symptoms precede the onset of motor symptoms in PD and are extremely important for early clinical diagnosis of the disease.
4

O n?cleo supraquiasm?tico e o folheto intergenicula do do morcego (Artibeus planirostris): proje??o retiniana e caracteriza??o neuroqu?mica

Santana, Nelyane Nayara Martins de 30 September 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-09T19:15:53Z No. of bitstreams: 1 NelyaneNayaraMartinsDeSantana_DISSERT.pdf: 5622573 bytes, checksum: c8393e8a0b4a684c098711fc1073bea4 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-05-09T22:05:08Z (GMT) No. of bitstreams: 1 NelyaneNayaraMartinsDeSantana_DISSERT.pdf: 5622573 bytes, checksum: c8393e8a0b4a684c098711fc1073bea4 (MD5) / Made available in DSpace on 2016-05-09T22:05:08Z (GMT). No. of bitstreams: 1 NelyaneNayaraMartinsDeSantana_DISSERT.pdf: 5622573 bytes, checksum: c8393e8a0b4a684c098711fc1073bea4 (MD5) Previous issue date: 2015-09-30 / O sistema de temporizac?a?o circadiana (STC) compreende um conjunto de estruturas neurais, que incluem vias aferentes, como projec?o?es retinianas, que permitem a sincronizac?a?o dos ritmos biolo?gicos aos ciclos ambientais; um marcapasso central que gera o sinal circadiano e vias eferentes, que conectam o marcapasso aos efetores comportamentais. Entre os componentes centrais do STC, destaca-se o nu?cleo supraquiasma?tico (NSQ), classicamente reconhecido como a estrutural neural que rege a ritmicidade biolo?gica, e o folheto intergeniculado (FIG) do complexo geniculado lateral do ta?lamo, modulador do marcapasso. Nesse estudo, ambos os centros circadianos foram avaliados quanto a sua citoarquitetura, padra?o de inervac?a?o retiniana e conteu?do neuroqui?mco por meio da te?cnica de Nissl, de trac?ador neural e te?cnicas imuno-histoqui?micas no morcego Artibeus planirostris, microquiro?ptero comum no territo?rio brasileiro. Com base nessas te?cnicas foi possi?vel observar que o NSQ, no ni?vel rostral, exibe um formato aproximadamante triangular e no ni?vel me?dio e caudal, assume uma forma arredondada, ale?m de apresentar inervac?a?o retiniana bilateral, com leve predomina?ncia contralateral. O NSQ do Artibeus planirostris e? dotado de ce?lulas imunorreativas a vasopressina (VP), polipepti?deo intestital vasoativo (VIP), calbindina (CB) e calretinina (CR); fibras/terminiais imunorreativos a neuropepti?deo Y (NPY) e serotonina (5-HT), ale?m de marcac?a?o para protei?na aci?dica fribilar glial (GFAP). O FIG recebe projec?a?o retiniana bilateral e nos ni?veis rostral e me?dio exibe a forma de um fino folheto interposto entre o GLD e o GLV e a ni?vel caudal expande-se medialmente contornando o GLV, ale?m de conter ce?lulas que expressam NPY, CB e CR; terminais imunorreativos a 5-HT e marcac?a?o para GFAP. Esse e? o primeiro estudo a examinar o STC dessa espe?cie de quiro?ptero. Os dados indicam que o NSQ e FIG no Artibeus planirostris apresenta afere?ncias retinianas e conteu?do neuroqui?mico similar a outras espe?cies de mami?feros. / The circadian timing system (CTS) comprises a set of neural structures that include input pathways, such retinal projections, which allow the synchronization of the biological rhythms to environmental cycles; a central circadian pacemaker, which generates the circadian signal and output pathways connecting the pacemaker to the behavioral effectors. Among the major components of the STC, highlight the suprachiasmatic nucleus (SCN), classically known as the neural structure that governs biological rhythmicity, and the intergeniculate leaflet (FIG) of the thalamic lateral geniculate complex, modulator pacemaker. In this study, both circadian centers were evaluated in respect to their cytoarchiteture, pattern of the retinal innervations and chemical content with a Nissl stain, neural tracer and imunohistochemical techniques in bat Artibeus planirostris, common microchiropteran in Brazil. Based on these techniques was observed in rostral sections, the SCN had an approximately triangular shape and in middle and caudal sections, this nucleus assumed an ellipsoidal contour. It receives bilateral retinal in nervations, with discrete contralateral predominance and contains vasopressin (VP), vasoactive intestinal polypeptide (VIP), calbindin (CB) e calretinin (CR) immunoreactive cell bodies; neuropeptide Y (NPY) and serotonin (5-HT) imunopositive fibers/ terminals, besides to glial fibrillary acidic protein (GFAP) labeling. The IGL contains NPY, CB and CR immunoreactive perikarya and receives a bilateral retinal projection. The rostral and middle IGL had a leaflet shape between the DLG and VLG. At a caudal level it had a descending portions which outlines de VLG medially. This is the first report examining the CTS of these species of chiropteran. The results indicate that retinal input and chemical content of the SCN and IGL in Artibeus planirostris are similar other mammalian species. In contrast, the SCN of these bat transcend the classical organizational schemes proposed in the scientific literature. Hodological and molecular studies are needed to stablish a specific division of this structure in these species of chiropteran.
5

"O n?cleo supraquiasm?tico e o folheto intergeniculado do moc? (Kerodon rupestris): Proje??es retinianas e caracteriza??o imuno-histoqu?mica

Nascimento J?nior, Expedito Silva do 07 December 2007 (has links)
Made available in DSpace on 2014-12-17T15:36:32Z (GMT). No. of bitstreams: 1 ExpeditoSNJ.pdf: 2182833 bytes, checksum: 1d14b6b7f5a8b99dccd3ec09fd418133 (MD5) Previous issue date: 2007-12-07 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In this study, two circadian related centres, the suprachiasmatic nucleus (SCN) and the intergeniculate leaflet (IGL) were evaluated in respect to their cytoarchitecture, retinal afferents and chemical content of major cells and axon terminals with a tract tracer and immunohistochemical techniques in the rock cavy (Kerodon rupestris), a Brazilian caviidae rodent species. The rock cavy SCN is innervated in its ventral portion by terminals from the predominantly contralateral retina. It also contains neurophisin and vasoactive intestinal polypeptide immunoreactive cell bodies and neuropeptide Y and enkephalin immunopositive fibres and terminals and is marked by intense GFAP immunoreactivity. The IGL receives a predominantly contralateral retinal projection, contains neuropeptide Y and nitric oxide synthase producing neurons and enkephalin immunopositive terminals and is characterized by dense GFAP immunoreactivity. This is the first report examining the neural circadian system in a crepuscular rodent species for which circadian properties have been described. The results are discussed comparing with what has been described for other species and in the context of the functional significance of these centres / O sistema de temporiza??o circadiana compreende um conjunto de estruturas neurais diferenciadas, que incluem um marcapasso central, o qual produz ritmicidade na aus?ncia de est?mulos externos; vias de entrada, incluindo as afer?ncias retininas, que permitem a sincroniza??o dos ritmos aos ciclos ambientais; e vias de sa?da, que conectam o marca-passo aos efetores comportamentais. Entre os componentes centrais do sistema de temporiza??o circadiana de mam?feros, destaca-se o n?cleo supraquiasm?tico (NSQ) do hipot?lamo, at? o presente o ?nico marca-passo circadiano formalmente comprovado, e o folheto intergeniculado (FIG) do complexo geniculado lateral do t?lamo, que atua como modulador do marca-passo. Neste estudo, estes dois centros foram avaliados com rela??o a sua citoarquitetura, padr?o de inerva??o retiniana e conte?do neuroqu?mico de c?lulas e terminais ax?nicos, usando um tra?ador neural e t?cnicas imuno-histoqu?micas no moc? (Kerodon rupestris), um roedor nativo do Nordeste Brasileiro, cuja atividade locomotora exibe um padr?o circadiano predominantemente crepuscular. O NSQ do moc? ? inervado em sua por??o ventrolateral por terminais da retina predominantemente contralateral. O NSQ ? dotado de neur?nios contendo neurofisina (NPH) e polipept?deo intestinal vasoativo (VIP) e as prote?nas ligantes de c?lcio calbindina (CB) e cal-retinina (CR), terminais imunorreativos a neuropept?deo Y (NPY) e encefalina (ENK) e ? tamb?m marcado por imunorreatividade ? prote?na ac?dica fibrilar glial (GFAP). O FIG recebe uma proje??o retiniana predominantemente contralateral, cont?m neur?nios produtores de NPY, CB e CR, terminais positivos para ENK e ? marcado por imunorreatividade a GFAP. Este ? o primeiro trabalho a examinar o sistema de temporiza??o circadiana (STC) numa esp?cie de roedor crepuscular, para o qual as propriedades formais dos ritmos circadianos tenham sido descritas. Os resultados s?o comparados com resultados previamente descritos em outras esp?cies diurnas e noturnas e discutidos no seu contexto funcional

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