Eimeria falciformis ist ein Apicomplexa-Parasit, welcher das Blinddarmepithel der Maus befällt. Aufgrund des monoxenen Lebenszyklus in einem exzellent-erforschten Wirt, bietet sich E. falciformis als Modellorganismus an, um Wirts-Parasit-Interaktionen zu untersuchen. Im Rahmen dieser Arbeit wurden mit Hilfe von Genexpressionsanalysen bei E. falciformis-infizierten Zellen und Mäusen Wirtsfaktoren identifiziert, welche für die in vitro bzw. in vivo Entwicklung des Parasiten vonnöten sind. Der Transkriptionsfaktor c-FOS (FBJ osteosarcoma oncogene) zeigte eine erhöhte Expression bei der Infektion einer Epithelzelllinie mit E. falciformis. C-FOS ist ein Bestandteil des AP-1 (activator protein 1) Komplexes, welcher die Transkription zahlreicher Gene unterschiedlichster Funktion steuert. Unsere Ergebnisse zeigen, dass die Entwicklung von E. falciformis in Zellen, welche den Transkriptionsfaktor nicht besitzen (c-FOS knockout Zellen) beeinträchtigt war. Diese Beobachtung betont eine mögliche Ausbeutung des Transkriptionsfaktors des Wirtes durch den Parasiten. In E. falciformis-infizierten Mäusen war die Expression des Enzyms Indoleamin 2,3-Dioxygenase (IDO1) bemerkenswert induziert. IDO1 katalysiert die erste und geschwindigkeits-bestimmende Reaktion des Tryptophan-Abbaus innerhalb des Kynurenin-Stoffwechselweges. Wir zeigen in dieser Studie, dass in den E. falciformis-infizierten Epithelzellen IDO1 IFN-gamma abhängig induziert wird. Das Wachstum des Parasiten war zudem beeinträchtigt in IDO1-/- Mäusen sowie in Mäusen, in welchen zwei weiterer Enzyme des Kynurenin-Stoffwechselweges pharmakologisch inhibiert wurden. Bemerkenswerterweise konnte das Parasitenwachstum in IDO1-/- Mäusen durch Gabe von Xanthurensäure, ein Nebenprodukt des Tryptophan-Abbaus, auf Wildtyp-Niveau angehoben werden. Diese Daten demonstrieren, dass sich der intrazelluläre Parasit E. falciformis die wirtseigenen Verteidigungsmechanismen (IFN-gamma, IDO1) für seine eigene Entwicklung zu Nutze macht. / Eimeria falciformis is a highly host- and tissue-specific parasite of murine caecum epithelium. Its monoxenous life cycle in a well-investigated host makes it an excellent model to examine parasite-host interactions. To identify the host determinants of the parasite infection, this work involved the comparative in vitro and in vivo analyses of mouse gene modulation by E. falciformis. The in vitro microarray analyses identified the transcription factor FBJ osteosarcoma oncogene (c-FOS) as highly induced during E. falciformis infection. C-FOS is part of the activator protein 1 (AP-1) complex, which controls the transcription of genes involved in various biological processes. We show that infection of c-FOS-deficient mouse cells results in an impaired development of E. falciformis, highlighting an exploitation of the host transcription factor by an apicomplexan parasite. Our ex vivo gene expression analyses using mouse caecum cells revealed a substantial modulation of the host transcriptome. The indoleamine 2,3-dioxygenase 1 (IDO1), the first and rate-limiting enzyme of tryptophan catabolism in the kynurenine pathway, was one of the most up-regulated epithelial transcripts. Induction of IDO1 supposedly depletes tryptophan in host cells, which is proposed to inhibit the in vitro growth of pathogens auxotrophic for this essential amino acid. We show that E. falciformis induces IDO1 in the epithelial cells in an IFN-gamma-dependent manner. The absence or inhibition of IDO1 and two downstream enzymes of the pathway in the mouse impairs parasite growth. Noticeably, the parasite development was entirely rescued by xanthurenic acid, a by-product of tryptophan catabolism. These data demonstrate contrasting roles of IFN-gamma signaling and a conceptual subversion of the host defense (IFN-gamma, IDO1) by an intracellular pathogen for progression of its natural life cycle.

O labirinto em cruz elevado é um teste comportamental sensível à iluminação ambiental. Na ausência de luz, ratos testados neste modelo exibem aumento da exploração dos braços abertos, quando comparados com animais testados em ambientes iluminados. No presente trabalho investigou-se a expressão da proteína Fos em cérebro de ratos expostos ao labirinto em cruz elevado na presença e ausência de iluminação. Duas horas depois do teste no labirinto em cruz elevado, ratos foram perfundidos com paraformaldeído juntamente com outros que somente permaneceram em uma gaiola enquanto os primeiros eram testados no labirinto. Para cada par (labirinto e gaiola) manteve-se a mesma condição de iluminação: claro ou escuro. Ainda, ratos de um terceiro grupo que permanecia no biotério eram perfundidos juntamente com cada dupla. Os cérebros foram retirados e preparados para inicio do procedimento imunoistoquímico da marcação da proteína Fos e posterior contagem de células marcadas. De um modo geral, animais expostos ao labirinto em cruz elevado sem iluminação, exibiram aumento na porcentagem de entradas e tempo de permanência nos braços abertos, assim como aumento da expressão de Fos em diferentes regiões do cérebro. A comparação entre os grupos sugere que a lâmina intergeniculada se relaciona provavelmente com a detecção de iluminação. A exploração de ambientes novos ou familiares envolve a participação do córtex cingulado e do locus coeruleus. Animais testados no labirinto em cruz elevado no escuro exibiram aumentos significativos na expressão de Fos nos núcleos da amígdala lateral, basolateral e medial, núcleos do hipotálamo lateral anterior e dorsomedial, quando comparados com os animais testados no mesmo modelo na presença de luz e com os que somente permaneceram na gaiola no escuro. Além disso, na ausência de luz, correlações significativas entre medidas comportamentais no labirinto em cruz elevado e número de neurônios marcados por Fos mostraram uma relação entre o aumento da exploração dos braços abertos e ativação de neurônios pertencentes à maioria dos núcleos descritos. Os resultados sugerem que a detecção de luminosidade em ambientes novos inibe a ativação neuronal e comportamental inicial. Esse processo induziria uma diminuição do número de neurônios ativos e comportamentos relacionados com ansiedade. A ausência de luz, pelo contrario, manteria a ativação inicial gerada pela novidade e envolveria comportamentos de exploração subjacentes ao aumento da expressão de Fos sobretudo no complexo amigdalóide e córtex piriforme. / The elevated plus-maze is a behavioral test sensitive to environmental illumination. In the absence of light, rats tested in with this model exhibit increases in the exploration of the open arms, when compared to animals tested in illuminated environments. The present work investigated Fos protein expression in the brain of rats exposed to the elevated plus-maze in the presence and absence of illumination. Two hours after the test in the plus-maze, the rats were perfused with paraformaldehyde together with others that just remained in a cage while the first were tested in the maze. For each pair (maze and cage) the same illumination condition was maintained: light or dark. Also, rats from a third group that only remained in the vivarium were perfused together with each pair. The brains were removed and prepared for the procedure of immunohistochemical staining for Fos followed by cell counting. In general, rats exposed to the elevated plus-maze in the dark exhibited increases in the percentage of entries and time spent in the open arms, as well as increases in Fos expression in different brain areas. Comparisons among groups suggests that intergeniculate leaflet is probably related to illumination detection. The exploration of novel of familiar environments involves the cingulate cortex and the locus coeruleus. Rats tested inn the elevated plus-maze in the dark exhibited significant increases in Fos expression in the lateral, basolateral, medial and central amygdala nuclei, lateral anterior and dorsomedial hypothalamic nuclei when compared to rats tested in this model under illumination and rats that remained in the cage in the dark. Besides, in the dark, significant correlations between behavioral measurements in the maze and amount of Fos-stained cells indicates a relationship between open arm exploration and neuron activation in most of the studied nuclei. The results suggest that light detection in novel environments inhibits the initial neuronal and behavioral activation. This process induces a decrease in the number of active neurons and behaviors related to anxiety. The absence of light, on the other hand, keeps the initial activation generated by novelty and involves the exploratory behaviors subserved by the increases in the expression of Fos protein, mainly in the amygdaloid complex and piriform cortex.

O hormônio adrenocorticotrópico, ACTH, regula função (esteroidogênese) e proliferação das células da córtex das glândulas adrenais através de um único receptor específico, ACTHR, que pertence à superfamília GPCR (G-protein coupled receptors). Embora o ACTHR tenha sido clonado há 8 anos, os mecanismos moleculares das ações mitogênica e anti-mitogênica de ACTH permanecem obscuros, cuja elucidação é objeto de estudo deste trabalho. A abordagem experimental consistiu na clonagem do ACTHR de células adrenocorticais Y-1 de camundongo e expressão funcional em fibroblastos 3T3 e células AR-1. Clones transfectantes, expressando estavelmente ACTHR, mostraram-se responsivos a ACTH através de: a) ativação de adenilato ciclase e b) indução de genes das famílias fos e jun. Por outro lado, medidas de síntese de DNA e proliferação celular indicam que ACTH não tem nenhum efeito mitogênico ou anti-mitogênico nos transfectantes ACTHR. O gene c-fos foi usado como alvo para testar vias de transdução de sinal ativadas por ACTH nos transfectantes 3T3 ACTHR. Estes testes mostraram que PKA, PKC e MAPK tem pouca ou nenhuma participação na indução de c-fos por ACTH nos clones 3T3 ACTHR, sugerindo que ACTHR pode ativar vias ainda não identificadas e motivando a busca de novas vias ativadas por ACTH nas células Y-1. Verificou-se que células Y-1 apresentam níveis constitutivamente elevados de AKT/PKB ativada (fosforilada), dependentes de PI3K e SRC, e que ACTH promove rápida desfosforilação de AKT via Gs/Adenilato Ciclase/cAMP/PKA. Ao promover a inativação de AKT, ACTH promove simultaneamente a indução da proteína p27'IND.Kip1', um mecanismo que contribui para a atividade anti-mitogênica de ACTH. / The adrenocorticotropic hormone, ACTH, regulates both function and proliferation of adrenocortical cells binding to a specific receptor, ACTHR, which belongs to superfamily of GPCR (G-protein coupled receptors). ACTHR was cloned a few years ago, but the molecular mechanisms underlying the mitogenic and anti-mitogenic actions of ACTH remain unknown, whose elucidation is aim of this project. The experimental approach was to clone the ACTHR from mouse Y-1 adrenocortical cells and to express the functional receptor in Balb 3T3 fibroblasts and AR-1 cells. Transfectant clones stably expressing the ACTHR respond to ACTH treatments by: a) adenylate cyclase activation and b) induction of fos and jun genes. On the other hand, experiments of DNA synthesis and cellular proliferation showed that ACTH has not mitogenic or anti-mitogenic effects in ACTHR transfectants. c-fos gene was used as a target to test signal transduction pathways activated by ACTH into 3T3 ACTHR transfectants. The results showed that PKA, PKC and MAPK have no relevant contribution on the ACTH c-fos induction in 3T3 ACTHR transfectants suggesting that ACTHR can activate signal transduction pathways still not identified. This conclusion prompted us to search for another signal transduction pathways triggered by ACTHR in Y-1 adrenocortical cells. This search led to the detection of high constitutive levels of activated AKT/PKB in Y-1 adrenocortical cells, which are dependent on PI3K and SRC. ACTH causes a strong and rapid downregulation of activated AKT in a Gs/Adenylate Cyclase/cAMP/PKA dependent manner. Apparently, dephosphorylation of AKT promoted by ACTH releases transcription factors that induce p27'IND.Kip1', a likely mechanism underlying ACTH anti-mitogenic effects in adrenocortical cells.

Os tumores de glândula salivar compreendem em torno de 2 a 6,5% dos tumores de cabeça e pescoço. Entre os tumores de glândula salivar, o adenoma pleomórfico é benigno e o mais comum. O carcinoma adenoide cístico e adenocarcinoma polimorfo de baixo grau encontram-se entre os mais frequentes malignos. Jab1 é uma de muitas proteínas que afetam diversos estágios da tumorigênese sendo importante na regulação variadas vias de sinalização e/ou proteínas como p27 e AP-1, a última composta por c-jun e c-fos, que são principalmente relacionadas com o ciclo celular e proliferação celular. O objetivo desse trabalho foi avaliar a expressão imuno-histoquímica das proteínas Jab1, p27, c-jun e c-fos no adenoma pleomórfico, adenocarcinoma polimorfo de baixo grau e carcinoma adenoide cístico das glândulas salivares. Foi realizada análise imuno-histoquímica semi-quantitativa das células marcadas nos tumores de glândula salivar e glândula salivar normal de acordo com o escore 0 (células sem expressão), 1(> 0 <= 5% de células marcadas), 2 (> 5 <= 50%) and 3 (> 50%). Para Jab1, c-jun e c-fos foi considerado apenas marcação nuclear e para p27, nuclear e citoplasmática, separadamente. Os resultados foram analisados utilizando-se os testes de Kruskal-Wallis, de Mann-Whitney, do Qui-quadrado e o teste de correlação de Spearman, cujo nível de significância foi de p<0,05 e processados com o auxílio do software GraphPad Prisma 5.0. A análise estatística revelou que a expressão de Jab1 foi significante no adenoma pleomórfico e no carcinoma adenoide cístico em relação aos ductos e no adenocarcinoma polimorfo de baixo grau em relação ao carcinoma adenoide cístico (p=0,0136, 0,0001 e 0,0344, respectivamente); a expressão de p27 nuclear foi significante no adenoma pleomórfico e no adenocarcinoma polimorfo de baixo grau quando comparados ao carcinoma adenoide cístico (p=0,0074 e 0,0004, respectivamente) e a expressão citoplasmática em todos os grupos quando comparados aos ácinos; c-fos, a expressão foi significativa nos ductos ao compará-los ao adenoma pleomórfico, adenocarcinoma polimorfo de baixo grau e carcinoma adenoide cístico (p=0,0002, 0,0048 e 0,0352, respectivamente). O teste de correlação de Spearman de Jab1, p27, c-jun e c-fos em cada lesão separadamente revelou que no adenoma pleomórfico houve correlação significativa entre Jab1 e p27 (r=0,371; p=0,020) e entre c-jun e c-fos (r=0,452; p=0,004). No adenocarcinoma polimorfo de baixo grau, houve correlação entre Jab1 e p27 (r=0,494; p=0,044) e no carcinoma adenoide cístico, entre p27 e c-fos (r=0,513; p=0,035). Foi concluído que a tumorigênese do adenoma pleomórfico, adenocarcinoma polimorfo de baixo grau e carcinoma adenoide cístico parece estar associada à expressão de Jab1 e p27. / Salivary gland tumors comprise about 2 to 6.5% of the head and neck tumors. Among the salivary gland tumors, pleomorphic adenoma is the most common and benign tumor. Adenoid cystic carcinoma and polymorphous low-grade adenocarcinoma are the most frequent malignant tumors. Jab1 is one of many proteins which affects many stages of the tumorigenesis and regulates positively and negatively several pathways and/or proteins such as p27 and AP-1, the latter composed by c-jun and c-fos, which are mostly related to cell cycle and cell proliferation. The aim of this study was to evaluate the immunoexpression of the proteins Jab1, p27, c-jun and c-fos in pleomorphic adenoma, polymorphous low-grade adenocarcinoma and adenoid cystic carcinoma of the salivary glands. The semi-quantitative immunohistochemical analysis was performed in salivary gland tumors and in normal salivary gland according to the score 0 (no stained cells), 1 (> 0 <= 5% of stained cells), 2 (> 5 <= 50%) and 3 (> 50%). Nuclear immunostaining alone was considered for Jab1, c-jun and c-fos proteins and cytoplasmic and nuclear staining for p27. Results were analyzed in GraphPad Prisma 5.0 software using Kruskal-Wallis, Mann-Whitney and Chi-square tests and Spearman correlation test in which significancy level was p<0,05. Statistical analysis revealed that Jab1 expression was significant in pleomorphic adenoma and adenoid cystic carcinoma in relation to ducts and in polymorphous low-grade adenocarcinoma in relation to adenoid cystic carcinoma (p=0,0136, 0,0001 e 0,0344, respectively); the p27 nuclear expression was significant in pleomorphic adenoma and in polymorphous low-grade adenocarcinoma when compared to adenoid cystic carcinoma (p=0,0074 e 0,0004, respectively) and cytoplasmic immunostaining was significant in all groups when compared to acini; c-fos expression was significant in ducts if compared to pleomorphic adenoma, polymorphous low-grade adenocarcinoma and adenoid cystic carcinoma (p=0,0002, 0,0048 e 0,0352, respectively). Spearman correlation test to Jab1, p27, c-jun and c-fos in each lesion separately revealed significant correlation between Jab1 and p27 (r=0,371; p=0,020) and c-jun and c-fos (r=0,452; p=0,004) in pleomorphic adenoma. There was correlation between Jab1 and p27 (r=0,494; p=0,044) in polymorphous low-grade adenocarcinoma and between p27 and c-fos (r=0,513; p=0,035) in adenoid cystic carcinoma. In conclusion, tumorigenesis in pleomorphic adenoma, polymorphous low-grade adenocarcinoma and adenoid cystic carcinoma seems to be associated to expression of Jab1 and p27.

Os tumores de glândula salivar compreendem em torno de 2 a 6,5% dos tumores de cabeça e pescoço. Entre os tumores de glândula salivar, o adenoma pleomórfico é benigno e o mais comum. O carcinoma adenoide cístico e adenocarcinoma polimorfo de baixo grau encontram-se entre os mais frequentes malignos. Jab1 é uma de muitas proteínas que afetam diversos estágios da tumorigênese sendo importante na regulação variadas vias de sinalização e/ou proteínas como p27 e AP-1, a última composta por c-jun e c-fos, que são principalmente relacionadas com o ciclo celular e proliferação celular. O objetivo desse trabalho foi avaliar a expressão imuno-histoquímica das proteínas Jab1, p27, c-jun e c-fos no adenoma pleomórfico, adenocarcinoma polimorfo de baixo grau e carcinoma adenoide cístico das glândulas salivares. Foi realizada análise imuno-histoquímica semi-quantitativa das células marcadas nos tumores de glândula salivar e glândula salivar normal de acordo com o escore 0 (células sem expressão), 1(> 0 <= 5% de células marcadas), 2 (> 5 <= 50%) and 3 (> 50%). Para Jab1, c-jun e c-fos foi considerado apenas marcação nuclear e para p27, nuclear e citoplasmática, separadamente. Os resultados foram analisados utilizando-se os testes de Kruskal-Wallis, de Mann-Whitney, do Qui-quadrado e o teste de correlação de Spearman, cujo nível de significância foi de p<0,05 e processados com o auxílio do software GraphPad Prisma 5.0. A análise estatística revelou que a expressão de Jab1 foi significante no adenoma pleomórfico e no carcinoma adenoide cístico em relação aos ductos e no adenocarcinoma polimorfo de baixo grau em relação ao carcinoma adenoide cístico (p=0,0136, 0,0001 e 0,0344, respectivamente); a expressão de p27 nuclear foi significante no adenoma pleomórfico e no adenocarcinoma polimorfo de baixo grau quando comparados ao carcinoma adenoide cístico (p=0,0074 e 0,0004, respectivamente) e a expressão citoplasmática em todos os grupos quando comparados aos ácinos; c-fos, a expressão foi significativa nos ductos ao compará-los ao adenoma pleomórfico, adenocarcinoma polimorfo de baixo grau e carcinoma adenoide cístico (p=0,0002, 0,0048 e 0,0352, respectivamente). O teste de correlação de Spearman de Jab1, p27, c-jun e c-fos em cada lesão separadamente revelou que no adenoma pleomórfico houve correlação significativa entre Jab1 e p27 (r=0,371; p=0,020) e entre c-jun e c-fos (r=0,452; p=0,004). No adenocarcinoma polimorfo de baixo grau, houve correlação entre Jab1 e p27 (r=0,494; p=0,044) e no carcinoma adenoide cístico, entre p27 e c-fos (r=0,513; p=0,035). Foi concluído que a tumorigênese do adenoma pleomórfico, adenocarcinoma polimorfo de baixo grau e carcinoma adenoide cístico parece estar associada à expressão de Jab1 e p27. / Salivary gland tumors comprise about 2 to 6.5% of the head and neck tumors. Among the salivary gland tumors, pleomorphic adenoma is the most common and benign tumor. Adenoid cystic carcinoma and polymorphous low-grade adenocarcinoma are the most frequent malignant tumors. Jab1 is one of many proteins which affects many stages of the tumorigenesis and regulates positively and negatively several pathways and/or proteins such as p27 and AP-1, the latter composed by c-jun and c-fos, which are mostly related to cell cycle and cell proliferation. The aim of this study was to evaluate the immunoexpression of the proteins Jab1, p27, c-jun and c-fos in pleomorphic adenoma, polymorphous low-grade adenocarcinoma and adenoid cystic carcinoma of the salivary glands. The semi-quantitative immunohistochemical analysis was performed in salivary gland tumors and in normal salivary gland according to the score 0 (no stained cells), 1 (> 0 <= 5% of stained cells), 2 (> 5 <= 50%) and 3 (> 50%). Nuclear immunostaining alone was considered for Jab1, c-jun and c-fos proteins and cytoplasmic and nuclear staining for p27. Results were analyzed in GraphPad Prisma 5.0 software using Kruskal-Wallis, Mann-Whitney and Chi-square tests and Spearman correlation test in which significancy level was p<0,05. Statistical analysis revealed that Jab1 expression was significant in pleomorphic adenoma and adenoid cystic carcinoma in relation to ducts and in polymorphous low-grade adenocarcinoma in relation to adenoid cystic carcinoma (p=0,0136, 0,0001 e 0,0344, respectively); the p27 nuclear expression was significant in pleomorphic adenoma and in polymorphous low-grade adenocarcinoma when compared to adenoid cystic carcinoma (p=0,0074 e 0,0004, respectively) and cytoplasmic immunostaining was significant in all groups when compared to acini; c-fos expression was significant in ducts if compared to pleomorphic adenoma, polymorphous low-grade adenocarcinoma and adenoid cystic carcinoma (p=0,0002, 0,0048 e 0,0352, respectively). Spearman correlation test to Jab1, p27, c-jun and c-fos in each lesion separately revealed significant correlation between Jab1 and p27 (r=0,371; p=0,020) and c-jun and c-fos (r=0,452; p=0,004) in pleomorphic adenoma. There was correlation between Jab1 and p27 (r=0,494; p=0,044) in polymorphous low-grade adenocarcinoma and between p27 and c-fos (r=0,513; p=0,035) in adenoid cystic carcinoma. In conclusion, tumorigenesis in pleomorphic adenoma, polymorphous low-grade adenocarcinoma and adenoid cystic carcinoma seems to be associated to expression of Jab1 and p27.

Made available in DSpace on 2014-12-17T15:36:53Z (GMT). No. of bitstreams: 1 RuthnaldoRML.pdf: 3880208 bytes, checksum: 7da0684594a4d62a80785416490983fa (MD5) Previous issue date: 2008-04-30 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / In rodents, the suprachiasmatic nucleus (SCN) and the intergeniculate leaflet (IGL) are the main components of the circadian system. The SCN is considerate the site of an endogenous biological clock because can to generate rhythm and to synchronize to the environmental cues (zeitgebers) and IGL has been related as one of the main areas that modulate the action of SCN. Both receive projections of ganglion cells of retina and this projection to SCN is called retinohypothalamic tract (RHT). Moreover, the IGL is connected with SCN through of geniculohypothalamic tract (GHT). In primates (include humans) was not still demonstrated the presence of a homologous structure to the IGL. It is believed that the pregeniculate nucleus (PGN) can be the answer, but nothing it was still proven. Trying to answer that question, the objective of our study is to do a comparative analysis among PGN and IGL through of techniques immunohystochemicals, neural tracers and FOS expression after dark pulses. For this, we used as experimental model a primate of the new world, the common marmoset (Callithrix jacchus). Ours results may contribute to the elucidation of this lacuna in the circadian system once that the IGL is responsible for the transmission of nonphotic information to SCN and participate in the integration between photic and nonphotic stimulus to adjust the function of the SCN. In this way to find a same structure in primates represent an important achieve in the understanding of the biological rhythms in those animals / O sistema de temporiza??o circadiana (STC) ? respons?vel pela gera??o e modula??o dos ritmos circadianos que s?o oscila??es end?genas manifestadas pelos seres vivos para a maioria das fun??es e comportamentos, com per?odo em torno de 24 horas. Estes ritmos s?o sincronizados principalmente ao ciclo claro-escuro di?rio. O STC ? constitu?do por um conjunto de estruturas neurais interligadas, incluindo na sua composi??o um marca-passo encarregado da gera??o do ritmo, vias sincronizadoras e de sa?da aos efetores comportamentais. O n?cleo supraquiasm?tico do hipot?lamo (NSQ) ? tido como principal marcapasso circadiano. A les?o desse conjunto de c?lulas deixa o animal arr?tmico para algumas fun??es circadianas. A principal via direta de sincroniza??o ? o tracto retinohipotal?mico (TRH), que leva informa??o f?tica ambiental da retina ao NSQ. Uma segunda via, tida como de sincroniza??o indireta para o NSQ, ? o tracto gen?culohipotal?mico (TGH), que se origina das c?lulas produtoras de neuropept?deo Y (NPY) do folheto intergeniculado (FIG) do complexo geniculado lateral do t?lamo de roedores. Essas c?lulas tamb?m recebem proje??o direta da retina. Em primatas essa estrutura ainda n?o foi identificada. No entanto, um conjunto de c?lulas medial ao n?cleo geniculado lateral dorsal (GLD) do t?lamo, denominado de n?cleo pr?geniculado (NPG), se apresenta como poss?vel estrutura hom?loga ao FIG dos roedores, j? que algumas c?lulas do NPG apresentam imunorreatividade ao anticorpo contra NPY em diversos primatas estudados. Sabe-se que o sistema FIG-TGH al?m de estar relacionado ? modula??o f?tica do NSQ, parece tamb?m estar fortemente envolvido na sincroniza??o n?o-f?tica desse sistema. Ainda, as c?lulas imunorreativas a NPY est?o claramente mais envolvidas na sincroniza??o n?o-f?tica, comprovado pela marca??o da atividade metab?lica envolvendo o gene c-fos (gene de express?o imediata). Considerando este aspecto funcional e a dificuldade de identificar com precis?o uma estrutura hom?loga ao FIG em primatas, realizamos a caracteriza??o neuroqu?mica, analisamos o padr?o da proje??o retiniana e a express?o da prote?na do gene c-fos ap?s pulso de escuro, para melhor definir o papel do NPG dentro do STC. Para isso, usamos como modelo experimental um primata do novo mundo, o Callitrhix jacchus, conhecido popularmente como sag?i. Nossos dados confirmaram a hip?tese inicial de que o NPG, ou parte dele, seria hom?logo ao FIG de roedores. Encontramos, em toda extens?o do NPG do sag?i, neur?nios imunorreativos a NPY e uma densa proje??o retiniana em uma regi?o localizada mais pr?xima ao GLD. Conclu?mos que esta ?rea situada mais internamente, em rela??o ao complexo geniculado lateral do t?lamo, corresponde ao FIG e a por??o mais externa ao n?cleo geniculado lateral ventral dos roedores

O labirinto em cruz elevado é um teste comportamental sensível à iluminação ambiental. Na ausência de luz, ratos testados neste modelo exibem aumento da exploração dos braços abertos, quando comparados com animais testados em ambientes iluminados. No presente trabalho investigou-se a expressão da proteína Fos em cérebro de ratos expostos ao labirinto em cruz elevado na presença e ausência de iluminação. Duas horas depois do teste no labirinto em cruz elevado, ratos foram perfundidos com paraformaldeído juntamente com outros que somente permaneceram em uma gaiola enquanto os primeiros eram testados no labirinto. Para cada par (labirinto e gaiola) manteve-se a mesma condição de iluminação: claro ou escuro. Ainda, ratos de um terceiro grupo que permanecia no biotério eram perfundidos juntamente com cada dupla. Os cérebros foram retirados e preparados para inicio do procedimento imunoistoquímico da marcação da proteína Fos e posterior contagem de células marcadas. De um modo geral, animais expostos ao labirinto em cruz elevado sem iluminação, exibiram aumento na porcentagem de entradas e tempo de permanência nos braços abertos, assim como aumento da expressão de Fos em diferentes regiões do cérebro. A comparação entre os grupos sugere que a lâmina intergeniculada se relaciona provavelmente com a detecção de iluminação. A exploração de ambientes novos ou familiares envolve a participação do córtex cingulado e do locus coeruleus. Animais testados no labirinto em cruz elevado no escuro exibiram aumentos significativos na expressão de Fos nos núcleos da amígdala lateral, basolateral e medial, núcleos do hipotálamo lateral anterior e dorsomedial, quando comparados com os animais testados no mesmo modelo na presença de luz e com os que somente permaneceram na gaiola no escuro. Além disso, na ausência de luz, correlações significativas entre medidas comportamentais no labirinto em cruz elevado e número de neurônios marcados por Fos mostraram uma relação entre o aumento da exploração dos braços abertos e ativação de neurônios pertencentes à maioria dos núcleos descritos. Os resultados sugerem que a detecção de luminosidade em ambientes novos inibe a ativação neuronal e comportamental inicial. Esse processo induziria uma diminuição do número de neurônios ativos e comportamentos relacionados com ansiedade. A ausência de luz, pelo contrario, manteria a ativação inicial gerada pela novidade e envolveria comportamentos de exploração subjacentes ao aumento da expressão de Fos sobretudo no complexo amigdalóide e córtex piriforme. / The elevated plus-maze is a behavioral test sensitive to environmental illumination. In the absence of light, rats tested in with this model exhibit increases in the exploration of the open arms, when compared to animals tested in illuminated environments. The present work investigated Fos protein expression in the brain of rats exposed to the elevated plus-maze in the presence and absence of illumination. Two hours after the test in the plus-maze, the rats were perfused with paraformaldehyde together with others that just remained in a cage while the first were tested in the maze. For each pair (maze and cage) the same illumination condition was maintained: light or dark. Also, rats from a third group that only remained in the vivarium were perfused together with each pair. The brains were removed and prepared for the procedure of immunohistochemical staining for Fos followed by cell counting. In general, rats exposed to the elevated plus-maze in the dark exhibited increases in the percentage of entries and time spent in the open arms, as well as increases in Fos expression in different brain areas. Comparisons among groups suggests that intergeniculate leaflet is probably related to illumination detection. The exploration of novel of familiar environments involves the cingulate cortex and the locus coeruleus. Rats tested inn the elevated plus-maze in the dark exhibited significant increases in Fos expression in the lateral, basolateral, medial and central amygdala nuclei, lateral anterior and dorsomedial hypothalamic nuclei when compared to rats tested in this model under illumination and rats that remained in the cage in the dark. Besides, in the dark, significant correlations between behavioral measurements in the maze and amount of Fos-stained cells indicates a relationship between open arm exploration and neuron activation in most of the studied nuclei. The results suggest that light detection in novel environments inhibits the initial neuronal and behavioral activation. This process induces a decrease in the number of active neurons and behaviors related to anxiety. The absence of light, on the other hand, keeps the initial activation generated by novelty and involves the exploratory behaviors subserved by the increases in the expression of Fos protein, mainly in the amygdaloid complex and piriform cortex.

Des études récentes ont montré le rôle clé de la ligne médiane ventrale du thalamus (noyaux Reuniens et Rhomboïde; ReRh) dans la persistance d’une mémoire spatiale chez le Rat qui nécessite un dialogue hippocampo-préfrontal pour une consolidation au niveau des systèmes. Etant donné que l’environnement enrichi (EE) favorise la récupération d’une mémoire de type déclarative après une lésion diencéphalique (thalamus antérieur) et augmente la plasticité neuronale, nous avons évalué son impact sur la consolidation/rappel d'une mémoire spatiale ancienne en piscine de Morris (25 jours post-acquisition) chez le rat après une lésion des noyaux ReRh. Pour cela, nous avons exposé les animaux pendant 40 jours à un environnement enrichi débutant 2 semaines après la lésion excitotoxique thalamique. En outre, l’expression du gène précoce, c-fos, a été cartographiée en immunohistochimie comme marqueur de l'activité neuronale dans l'hippocampe dorsal, le cortex préfrontal médian (mPFC), les noyaux intralaminaires du thalamus et l’amygdale. L’EE a permis la récupération des capacités de persistance d’une mémoire spatiale chez les rats lésés ReRh, accompagnée d’effets bénéfiques sur l'anxiété et l'habituation à un nouvel environnement. L’immunohistochimie de la protéine Fos a montré un recrutement plus élevé des neurones du mPFC associé à la récupération fonctionnelle chez les rats ReRh enrichis, alors que les rats ReRh élevés en condition standard ont présenté un défaut d’activation dans cette région associé à une altération des performances de mémoire. De plus, l’hyperactivité de l’amygdale induite par la lésion chez les rats ReRh standard à la fois en condition basale et après le rappel d’une mémoire a été significativement atténuée dans le groupe ReRh enrichi. Ainsi, nous avons suggéré que l'amygdale pourrait être impliquée dans les effets de la lésion ReRh sur la perte des capacités de rappel d’une mémoire ancienne, mais aussi dans la récupération fonctionnelle associée à la restauration de l’activité du mPFC au rappel de cette mémoire chez les rats lésés enrichis. / Recent studies have shown the key role of the ventral midline thalamus (Reuniens and Rhomboid nuclei; ReRh) in spatial memory persistence in rats, which requires a hippocampo- prefrontal dialogue for consolidation at the systems-level. As enriched environment (EE) promotes the recovery of declarative-like memories after diencephalic (anterior thalamus) lesion, and enhances neuronal plasticity, we tested its impact on the effects of the ReRh lesion upon the consolidation/retrieval of a remote spatial memory in a Morris water maze (i.e. 25 post-acquisition days). For this purpose, we exposed rats for 40 days to an enriched environment beginning 2 weeks after fiber-sparing excitotoxic thalamic lesions. In addition, the expression of the immediate early gene, c-fos, was mapped by immunohistochemistry as a marker of functional activity in the dorsal hippocampus, the median prefrontal cortex (mPFC), the intralaminar thalamic nuclei and the amygdala. Enriched housing allows the recovery of spatial memory persistence capacities in ReRh rats, with additional beneficial effects on anxiety and habituation to a novel environment. Immunohistochemistry of the Fos protein showed a higher recruitment of the mPFC, concomitant with memory capacities recovery in enriched ReRh rats, while in standard ReRh rats, Fos expression in the mPFC was significantly decreased together with the alteration of memory performance. The lesion-induced amygdala hyperactivity in basal and memory conditions was significantly attenuated in the ReRh enriched group. We suggested that amygdala might be involved in the effect of ReRh lesion on memory persistence, and also in the functional recovery associated with the restoration of the mPFC activity during remote memory retrieval in enriched ReRh rats.

Dans cette thèse, nous présentons un modèle d’analyse du discours économique et commercial à différents niveaux : énonciatif, lexical, syntaxique, sémantique, pragmatique et sociolinguistique. L’analyse détaillée du corpus spécialisé dans le domaine de l’économie peut grandement contribuer à la définition des caractéristiques spécifiques du discours économique et commercial. En fonction des résultats nous proposons des moyens pour l’application des résultats d’analyse à la didactique de la langue française en proposant les tâches à effectuer dans une perspective actionnelle. Notre hypothèse part du principe qu’en améliorant et en modernisant les méthodes d’apprentissage/enseignement de la langue française, nous répondrons aux demandes et aux besoins langagiers contemporains des apprenants, des entreprises et des institutions en Serbie. L’apprentissage des langues étrangères représente une des grandes priorités pour l’Union européenne dans le cadre de la stratégie Europe 2020. Chaque entreprise, qui veut être plus efficace, plus performante et plus compétitive sur le marché mondial, a besoin d’un personnel parlant la langue du client ou du partenaire d’affaires. Par conséquent, cela nécessite l’adaptation de l’enseignement de la langue française ou plus précisément le français sur objectif spécifique (FOS) ou le français de spécialité (FS) aux conditions socio-économiques actuelles en Serbie. À cet effet, nous consacrons une attention particulière au rôle de la langue dans le travail, à la description des enjeux de la communication professionnelle et aux relations économiques entre la Serbie et la France ainsi qu’avec le monde francophone. / In this paper, we present the analytical model of economic and commercial speech on different levels: expository, lexical, syntactic, semantic, pragmatic, and sociolinguistic. Detailed analysis specified in the area of economics can greatly contribute to defining the particularities of economic and commercial speech. According to the results, we offer some ways for involvement of the analyzed results to the teaching of the French language, suggesting various tasks, which would be done in action-oriented perspective.Our hypothesis represents the idea that while enriching and modernizing current methods of learning French language, we actually respond to requests and needs of a contemporary language to ones who learn it, to enterprises, and institutions in Serbia. Learning foreign languages presents one of the biggest priorities for European Union in means of their strategy called EU 2020. Every enterprise which has a goal to become more efficient, more successful, and more competitive on the world’s market, needs a person who speaks the language of a customer, or a business partner. According to that, it demands the adjustment of learning French language, and more precisely said, French language for specific purposes, or French language for personal communication under current socio-economic conditions in Serbia. In that purpose, we pay special attention to the role of language in work, in describing parts in professional communication and economic relations between Serbia and France, as well as the relations between Francophone countries.

The reinforcing properties of nicotine depend partly on cholinergic projections from the pedunculopontine tegmental (PPTg) and laterodorsal tegmental (LDTg) nuclei to midbrain dopamine neurons in the ventral tegmental area (VTA) and substantia nigra pars compacta (SNc). Neuronal activation was investigated using Fos expression in these areas following acute (0, 0.1, 0.4, 0.8mg/kg) or chronic systemic nicotine (0, 0.1, 0.4, 0.8, 1.0mg/kg given once per day for 5 days). We also examined co-localization of Fos expression in bNOS and TH positive neurons to determine what populations of neurons were activated by nicotine. Acute nicotine resulted in dose related Fos expression, with the biggest increase seen after 0.4mg/kg nicotine, but no co-localization occurred with bNOS in the PPTg/LDTg. Surprisingly, nicotine also failed to activate midbrain dopamine neurons. After animals were sensitized to nicotine there was a similar dose response curve in Fos expression, but the biggest increase was seen after 0.8mg/kg nicotine. Chronic nicotine, like acute, also preferentially activated non-cholinergic neurons in the LDTg and PPTg and non-dopamine neurons in the SNc and VTA. Further experiments looked at the mechanisms of Fos expression after nicotine administration. Fos expression in the LDTg/PPTg and SNc/VTA was suppressed after d-amphetamine, despite an increase in locomotor activity, suggesting that the increased Fos expression after chronic nicotine was not simply due to the locomotor activating effects of sensitized nicotine. Blocking autoreceptors in the dopaminergic midbrain by haloperidol pre-treatment did not increase Fos expression in dopamine neurons indicating that the inhibitory mechanism was not dependent on local autoreceptors. Novel methods of visualising and lesioning GABA neurons in the mesopontine tegmentum and midbrain were also examined. The data suggest that the mechanisms by which dopamine is involved in the pharmacological actions of passively administered nicotine are more complex than was first thought and that the role of non-dopamine neurons in the VTA (possibly GABA or glutamate containing) are also important.