Einführung. In der vorliegenden Studie untersuchten wir durch funktionelle Nahinfrarotspektroskopie (fNIRS) präfrontale Hirnoxygenierung während Ableistung von Sprachaufgaben. FNIRS weist über Bestimmung von Konzentrationsunterschieden von sauerstoffbeladenes (OxyHb) und sauerstofffreies Hämoglobin (DeoxyHb) regionale Blutflussänderungen nach und lässt somit validen Rückschluss auf Hirnaktivität zu. Bereits in früheren Studien konnte nachgewiesen werden, dass Patienten mit Alkoholkrankheit verminderte präfrontale Hirnaktivität zeigen. Teil 2 der Studie untersucht den im Untersuchungsgebiet liegenden Schläfenmuskel (musculus temporalis) auf Einflüsse auf die Methode fNIRS. Methoden. Wir verglichen 15 entgiftete Patienten mit Alkoholkrankheit (Patientengruppe, PG) mit passenden 15 gesunden Kontrollprobanden (Kontrollgruppe, KG)bezüglich deren Hirn- und Muskelaktivität während Ableistung Wortflüssigkeitsaufgabe (VFT; engl. Verbal Fluency Task). Bestimmte, insbesondere präfrontale Hirnareale wurden durch phonologische und semantische Testsaufgaben (TA´s), ebenso durch eine Kontrollaufgabe (KA), (Wochentag aufzählen) aktiviert. Durch EMG wurde während Durchführung der Aufgabe die Aktivität des musculus temporalis gemessen. Wir verwendeten zur Datenanalyse sowohl von fNIRS wie auch EMG eine 2x2x2x6 Varianzanalyse (ANOVA) mit Zwischensubjektfaktor „Gruppe“ und Innersubjektfaktoren „Bedingung“, „Seite“ und „Zeit“, gerechnet wurde dies für jeweils Oxy- und DeoxyHb sowie den phonologischen sowie semantischen Teil. Ergebnisse. Beide Gruppen lieferten eine vergleichbare Menge an Worten, Hirnaktivierung zeigte sich bei beiden Gruppen signifikant höher in den Testaufgaben (phonologisch > semantisch). Die PG zeigte verminderte Hirnaktivierung präfrontal im phonologischen, vergleichbare Hirnaktivität im semantischen Teil. Beide Gruppen zeigten vergleichbare Muskelaktivität, jeweils signifikant höher in den jeweiligen Testaufgaben. Es zeigten sich keine systematischen Assoziationen (Korrelation nach Pearson) zwischen fNIRS und EMG. Schlussfolgerungen. Insgesamt konnten vorherige Studien mit Nachweis niedrigerer präfrontaler Hirnoxygenierung bei entgifteten Patienten mit Alkoholkrankheit gegenüber gesunden Kontrollen bestätigt werden. Die Mehraktivierung beider Gruppen während phonologischer Aufgabe gründet in dem höheren intelektuellen Anspruch der Aufgabe, dies erklärt auch den Gruppenunterschied in speziell dieser Aufgabe. Durch eine vergleichbare Muskelaktivität der beiden Gruppen sowie fehlende Assoziationen zwischen fNIRS und EMG sehen wir keinen Einfluss von Muskelaktivität auf die Hirnaktivitätsmessung durch fNIRS. Auch eine valide Untersuchung von psychiatrisch kranken Probandengruppen wie Patienten mit Alkoholkrankheit ist hierdurch gut möglich. Die Studie befürwortet den künftigen Einsatz und weitere methodische Untersuchungen zur Messung mit fNIRS, einem validen, artefaktunempfindlichen, handlichen und relativ günstigen Messinstrument. / Introduction. In this study we examined prafrontal brain oxygenation using functional near infrared spectroscopy (fNIRS) while performing a speech test. Via changes of concentrations of oxygenated (OxyHb) and deoxygenated (DeoxyHb) hemoglobin fNIRS measures regional bloodflow mirroring brain activity. Former studies already showed that detoxified patients with alcohol dependency have lower prefrontal brain activity. In the second part of the study we investigate the temporal muscle, surfacing the measured prefrontal area, in reference to influence on the method fNIRS. Methods. We compared 15 detoxified patients with alcohol dependency (patient group, PG) with the same amount of 15 matching healthy controls (control Goup, CG) regarding their brain and muscle activity during performing a verbal fluency task (VFT). Spezific prefrontal brain areas were activated by executing a phonological and a semantical test task (TT), as comparison we led them perform a control task (CT), reciting weekdays. Via EMG we measured temporal muscle activity while passing the test. For data analysis for both measuring methods (fNIRS and EMG) we used a 2x2x2x6 Analysis of Variance (ANOVA) with the factors “group”, “condition”, “side” and “time”. We calculated these for both Oxy- and DeoxyHb as well as for phonological and semantical test. Results. Both groups announced a comparable amount of words, brain activity was significantly higher while performing th TT (phonological higher than semantical). The PG achieved less activity in prafrontal areas, only in the phonological part, not in the semantical. Both groups performed comparable muscle activity, however activated the temporal muscle more while performing the TT´s. Systematic correlations (Pearson) between fNIRS and EMG weren’t found. Discussion. Overall like in elder studies we could confirm lower prefrontal brain oxygenation on detoxified patients with alcohol dependency compared to matching controls. Reaching higher activity during the phonological task is defined by the exercises higher level of difficulty, which also explains the difference of group result in especially this test. As muscle activity was comparable between the two groups, we couldn’t find associations between fNIRS and EMG. Thus we don’t see muscle activity interfering with the measurement of brain activity using fNIRS. Also this method proofs reliable and valid being used in subjects with psychiatric illnesses like alcohol dependency. This study supports the future Use just like further methodical investigations of fNIRS, a method nonsensitive to artifacts.

Polycyclic aromatic hydrocarbons (PAHs) are widely distributed in the environment and are generated by many sources. Though the potential of PAH-rich mixtures to cause health effects has been known for almost a century, there are still unanswered questions about the levels of PAHs in the environment, the potential for human exposure to PAHs, the health effects associated with exposure, and how genetic susceptibility influences the extent of health effects in individuals. The first objective of this research was to quantify concentrations of PAHs in samples of settled house dust collected from homes in Azerbaijan, China, and Texas. The trends of PAH surface loadings and percentage of carcinogenic PAHs were China > Azerbaijan > Texas, indicating that the risk of health effects from exposure to PAHs in house dust is highest in the Chinese population and lowest in the Texas population. PAHs in China and Azerbaijan were derived mainly from combustion sources; Texas PAHs were derived from unburned fossil fuels such as petroleum. The second objective of this research was to investigate the effect of pregnane X receptor (PXR) on the genotoxicity of benzo[a]pyrene (BaP). BaP treatment resulted in significantly lower DNA adduct levels in PXR-transfected HepG2 cells than in parental HepG2 cells. Total GST enzymatic activity and mRNA levels of several metabolizing enyzmes were significantly higher in cells overexpressing PXR. These results suggest that PXR protects cells against DNA damage by PAHs such as BaP, possibly through a coordinated regulation of genes involved in xenobiotic metabolism. The third objective of this research was to investigate biomarkers of exposure in house mice (Mus musculus) exposed to PAH mixtures in situ. Mice and soil were collected near homes in Sumgayit and Khizi, Azerbaijan. Mean liver adduct levels were significantly higher in Khizi than in Sumgayit. Mean lung and kidney adduct levels were similar in the two regions. The DNA lesions detected may be a combination of environmentally-induced DNA adducts and naturally-occurring I-compounds. PAHs were present at background levels in soils from both Khizi and Sumgayit. It appears that health risks posed to rodents by soil-borne PAHs are low in these two areas.

Whole-genome studies of rates of protein evolution show that genes underlying reproduction and immunity tend to evolve faster than other genes, consistent with the frequent action of positive selection. The evolution of immunity has been well-studied at the interspecific level, but much remains unknown about the population-level dynamics of immunity. This project described genetic variation at immunity and non-immunity loci as well as variation among levels of infection for diverse pathogens in a natural population of mice from Tucson. Analysis of autosomal and X-linked loci in the native range of Mus domesticus, the species from which Tucson mice are primarily descended, revealed low levels of variation consistent with a recent population expansion, resulting in a slight excess of rare alleles across the genome. Genetic variation among a set of classical inbred strains represented a small fraction of wild variation. An overlapping set of genes sequenced in mice from Tucson revealed that there is significant introgression from Mus castaneus. After controlling for gene flow, Tucson mice showed evidence of a mild bottleneck that produced a slight excess of intermediate frequency alleles, but did not result in a dramatic loss of genetic variability. Most of the 15 pathogens and parasites studied in Tucson were found at low to intermediate frequency, and most mice had one to three infections, suggesting that there are many opportunities for host-pathogen coevolution, and a possible role for coinfection. A study of Fv-4, which confers resistance to murine leukemia viruses, confirmed that the resistance allele originated in M. castaneus and is now found at intermediate frequency in Tucson after introduction through gene flow. Finally, a study of the recently duplicated Ceacam1 and Ceacam2 genes, previously shown to be involved in resistance to mouse hepatitis virus (MHV), revealed that a gene conversion event moved a suite of mutations from Ceacam2 to Ceacam1. An elevated rate of protein evolution showed that Ceacam2 had experienced positive selection after duplication. Interestingly, there was no association between MHV antibody presence and Ceacam1 genotype in Tucson. This project showed that gene flow and gene conversion mediated resistance to infections in wild mice.

Die vorliegende Arbeit beschäftigt sich mit der Darstellung der plantaren Sprunggelenksregion des Pferdes im MRT. Das typische Signalverhalten des Musculus interosseus medius im MRT soll mit histologischen und sonographischen Untersuchungen abgeglichen werden. Weiterhin wird mit Hilfe des MRT geprüft, ob der charakteristische Binnenaufbau des Musculus interosseus medius einer Veränderung mit zunehmendem Alter der Tiere unterliegt. 27 Gliedmaßen von 22 orthopädisch gesunden Warmblutpferden im Alter von einem Monat bis 25 Jahren wurden magnetresonanztomographisch untersucht. Die MRT – Untersuchung wurde an einem 0,5 Tesla starken Gerät in fünf Sequenzen und drei Schnittebenen durchgeführt. Vergleichend wurde die plantare Sprunggelenksregion bei 14 Tieren ultrasonographisch dargestellt. Die Darstellung der Binnenstruktur des Musculus interosseus medius im MRT sollte deskriptiv erfasst werden. Nachfolgend wurden die Anteile der verschiedenen Gewebsanteile dieser Struktur alterskorrelierend, statistisch ausgewertet und den Signalintensitäten histologisch Gewebe zugeordnet. Grundsätzlich waren alle Strukturen der plantaren Sprunggelenksregion im MRT darstellbar. Unterschiede konnten abhängig von den Strukturen und deren Verlauf in den verschiedenen Schnittebenen festgestellt werden. Die verwendeten Sequenzen zeichneten sich als geeignet für die Weichteildiagnostik aus. In jeder Sequenz zeigte das gewebstypische Signalverhalten charakteristische Grauwertverteilungen. Signifikant am besten ließ sich der Musculus interosseus medius in transversalen Schnittebenen in protonengewichteter Sequenz abgrenzen. Der Binnenaufbau des Musculus interosseus medius konnte in jeder verwendeten Sequenz nachvollzogen werden. Es war keine signifikant feststellbare Korrelation zwischen dem Alter der Pferde und den prozentual ermittelten Gewebsanteilen nachzuweisen. Sonographisch konnte der Musculus interosseus medius weniger gut abgegrenzt werden, auch die Morphologie war nicht so genau nachzuvollziehen. Zur genauen Beurteilung dieser Struktur ist die MRT – Untersuchung der Sonographie überlegen. Den unterschiedlichen Signalverhalten des Musculus interosseus medius konnten histologisch verschiedene Gewebe zugeordnet werden. Dabei handelte es sich um größere Ansammlungen von Fett- und Muskelzellen, die in das sehnige Grundgewebe eingelagert waren. Die Magnetresonanztomographie hat sich als sehr geeignetes Verfahren erwiesen, die Weichteilgewebe der plantaren Sprunggelenksregion des Pferdes gut abgrenzbar darzustellen. Im histologischen Vergleich konnte der Magnetresonanztomographie eine sehr gute Sensitivität und Spezifität nachgewiesen werden.

Proefschrift Universiteit Maastricht. / Met bibliogr., lit. opg. - Met samenvatting in het Nederlands.

Bakgrund: Rektusdiastas är en delning av musculus rectus abdominis och är vanligt hos kvinnor som fött barn. Det kan ge besvär som instabilitet i bålen samt smärta i ländrygg och bäcken, men även oro och rädsla. Rektusdiastsen påverkar den vardagliga fysiska aktiviteten hos patientgruppen och fysioterapi rekommenderas i första hand som behandling. Evidensen är dock begränsad och svenska kliniska riktlinjer finns inte i dagsläget. Syfte: Syftet är att utforska fysioterapeuters erfarenheter av att arbeta med mödrar som har besvär av rektusdiastas efter förlossning till att få en mer fungerande fysisk aktiv vardag. Metod: En kvalitativ intervjustudie valdes där informanterna rekryterades genom ett ändamålsenligt urval samt snöbollsurval. En semistrukturerad intervjuguide nyttjades och datan analyserades genom en manifest kvalitativ innehållsanalys med en induktiv ansats. Resultat: Behandling för mödrar med besvär av rektusdiastas är främst att ge information och träning. För att hjälpa mödrarna med problematiska vardagsaktiviteter ges råd och strategier för att klara av dessa. Fysioterapeuter önskar kliniska riktlinjer och att kunskapen undervisas om redan på grundutbildningen. Slutsats: Behandling utifrån biopsykosociala faktorer är viktigt för patientgruppen. Fysioterapeuter kan hjälpa patientgruppen och det är viktigt att kunskapen sprids så alla får den vård de har rätt till. / Background: Diastasis recti is a split of the musculus rectus abdominis and is common among women who have given birth. It can lead to problems such as instability in the abdomen and pain in the lumbar region and pelvis, but also anxiety and fear. Diastasis recti affects the daily physical activity among this patient group, and to fix this physiotherapy is recommended. The evidence is limited and there are currently no Swedish clinical guidelines. Purpose: The purpose is to explore physiotherapists experience of working with mothers that are bothered by diastasis recti after childbirth to have a more functional physical activity everyday life. Method: A qualitative interview study where the informants were recruited through a purposive sampling and snowball sampling. The interviews were based on a semi-structured interview guide and analyzed through a manifest qualitative content analysis with an inductive approach. Result: Treatment for mothers with diastasis recti was mainly to provide information and exercises. To help mothers with problematic everyday activities, advice and strategies were given. Physiotherapist’s desire clinical guidelines and that knowledge about diastasis recti is a subject for education at university. Conclusion: Treatment based on biopsychosocial factors is important for this patient group. Physiotherapists can help this patient group and it is important that knowledge about the subject is spread so that everyone can receive the care they are entitled to.

O surgimento e a evolução da vida na terra foram possíveis graças ao desenvolvimento de mecanismos temporais precisos capazes de ajustar os processos fisiológicos que ocorriam no interior do organismo com os ciclos ambientais, promovendo assim, ganhos na capacidade adaptativa e reprodutiva dos indivíduos. Neste contexto, luz e temperatura são as duas pistas temporais mais relevantes para resetar o relógio endógeno e, aparentemente, esses dois zeitgebers trabalham juntos para manter os ritmos circadianos. Uma ampla gama de fotorreceptores e fotopigmentos evoluiu no sentido de perceber com alta sensibilidade a informação fótica fornecida pelo ambiente e, recentemente, foi demonstrado que a detecção de temperatura também pode ser exercida pelos fotopigmentos rodopsina e melanopsina, sendo mediada por canais TRP (Shen et al., 2011). Consideramos as células B16-F10 Per1::Luc como um modelo promissor para o estudo de luz e temperatura em relógios periféricos, uma vez que essa linhagem expressa os dois fotopigmentos apontados com função de termorreceptores em Drosophila. Nossos estudos nos permitiram verificar que a luz não atua como um agente sincronizador nessas células, que se mantiveram em livre curso mesmo após um pulso de 10 min de luz azul (650 lux). Por outro lado, um pulso de temperatura de 2,5º C acima da temperatura de manutenção por 1h atuou ajustando a expressão do gene Per1, imprimindo um ritmo circadiano, diferentemente do observado no controle. Com base nessas informações, hipotetizamos que a informação de luz, percebida via melanopsina na retina de mamíferos, levaria a regulação da temperatura circadiana pelo NSQ, e a temperatura corporal, por sua vez, poderia atuar como uma pista interna para a sincronização dos tecidos periféricos, tendo os canais TRP como mediadores. Para responder esta questão, utilizamos camundongos WT e TrpV1 KO submetidos a diferentes protocolos de luz e avaliamos a expressão de genes do relógio Per1, Per2, Clock e Bmal1 e dos canais TrpV1 e TrpA1 em tecidos periféricos. Identificamos que a glândula suprarrenal, fígado e tecido adiposo marrom possuem uma maquinaria do relógio tipicamente ativa e acreditamos que a oscilação dos genes de relógio observada nesses tecidos é expressiva. Interessantemente, vimos também que o TrpV1, além de ser expresso nos tecidos analisados em animais WT, apresenta uma transcrição rítmica no fígado e tecido adiposo marrom de animais em LD, corroborando nossa hipótese de que canais TRP atuam como mediadores da informação de luz aos tecidos periféricos. Dadas as diferenças encontradas entre os animais WT e TrpV1 KO, sugerimos que a presença do canal TRPV1 pode ser essencial, embora seu grau de envolvimento varie de acordo com o tecido. No que diz respeito ao canal TRPA1, encontramos dois resultados que merecem ser destacados. Primeiramente, identificamos no fígado de camundongos TrpV1 KO mantidos em LD uma provável compensação da expressão de TrpA1 na ausência de TrpV1 e, curiosamente, que o tecido adiposo marrom não expressa o canal TrpA1. Considerando os resultados deste trabalho sobre o envolvimento dos canais TRP em resposta à luz e temperatura, acreditamos ter fortalecido nossa hipótese inicial, principalmente após demonstrarmos o papel do canal TRPV1 e que tecidos periféricos são sincronizados por alterações de temperatura. / The life emergence and evolution on Earth were made possible by the development of precise temporal mechanisms able to adjust the physiological processes within an organism with environmental cycles, thus promoting gains in the adaptive and reproductive capacity of the individuals. In this context, light and temperature are the two most relevant time cues to reset the endogenous clock; apparently these two zeitgebers work together to keep the circadian rhythms. A wide variety of photoreceptors and photopigments evolved in order to precisely perceive the photic information provided by the environment, and recently it has been shown that the temperature detection can also be exerted by the photopigments rhodopsin and melanopsin, being mediated by TRP channels (Shen et al., 2011). We have identified B16-F10 Per1::Luc cells as a promising model for the study of light and temperature effects on peripheral clocks, since this cell line expresses both photopigments pointed as thermoreceptors in Drosophila. Our studies allowed us to demonstrate that light does not act as a synchronizing agent on those cells, which remained in free running after a 10 min pulse of blue light (650 lux). On the other hand, a temperature pulse of 2.5º C above the maintenance temperature, for 1h, adjusted Per1 gene expression, imprinting a circadian rhythm, which was not observed in the control. Based on this information, we hypothesized that the light perceived via melanopsin by the mammalian retina would lead to the regulation of the circadian temperature by the SCN, and the body temperature, in turn, could act as an inner cue for the synchronization of the peripheral tissues, having the TRP channels as mediators. To answer this question, we have used WT and TrpV1 KO mice under different light protocols and evaluated the expression of clock genes Per1, Per2, Clock and Bmal1 and TrpV1 and TrpA1 channels in peripheral tissues. We found that the adrenal gland, liver and brown adipose tissue have a typically active clock machinery, and the oscillation of clock genes observed in these tissues is significant. Interestingly, we observed that TrpV1 is expressed in those tissues, and presents a rhythmic transcription in the liver and brown adipose tissue of LD maintained animals, confirming our hypothesis that TRP channels act as mediators of light information to peripheral tissues. In face of the differences between WT and trpV1 KO animals, we suggest that the presence of the TRPV1 channel may be essential, although its degree of involvement may vary according to the tissue. In terms of TRPA1 channel, we found two results that deserve to be highlighted. Firstly, we identified in the liver of TrpV1 KO mice maintained in LD a presumable compensation of TrpA1 expression in the absence of TrpV1 and, interestingly, the brown adipose tissue does not express TrpA1 channel. Considering the findings of this study on the participation of TRP channels in responses to light and temperature, we believe we have strengthened our initial hypothesis, especially after we have demonstrated the role of TRPV1 channel, and that peripheral tissues may be synchronized by temperature changes.

Submitted by Lara Oliveira (lara@ufersa.edu.br) on 2017-08-08T21:28:55Z No. of bitstreams: 1 EdigleyceLC_DISSERT.pdf: 1495589 bytes, checksum: 331e814fbf35fd0903ce95ef191653df (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-08-17T22:39:03Z (GMT) No. of bitstreams: 1 EdigleyceLC_DISSERT.pdf: 1495589 bytes, checksum: 331e814fbf35fd0903ce95ef191653df (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-08-17T22:41:07Z (GMT) No. of bitstreams: 1 EdigleyceLC_DISSERT.pdf: 1495589 bytes, checksum: 331e814fbf35fd0903ce95ef191653df (MD5) / Made available in DSpace on 2017-08-17T22:41:14Z (GMT). No. of bitstreams: 1 EdigleyceLC_DISSERT.pdf: 1495589 bytes, checksum: 331e814fbf35fd0903ce95ef191653df (MD5) Previous issue date: 2015-02-12 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The Aspidosperma pyrifolium Mart species. it is used in feed for farm ani-mals. However, there are few studies on the toxicity of this plant. This study aimed to iden-tify the existence of toxic effect, cytotoxic and mutagenic leaves of A. pyrifolium the test system Allium cepa and mice. It was made growth analysis of roots, inhibition relative and mitotic index with the Allium cepa test. For the LD50 they were used of groups mice were observed for 14 days to determine the number of dead and surviving animals. For the mi-cronucleus test and binucleated cells was done extracting bone marrow of animals. Bioas-says performed with the Allium cepa revealed that the aqueous extract of dried leaves showed no toxic effects, however, stimulated cell division in a concentration of 50 mg/L, is indicative of formation of tumor cells. The fresh leaves were toxic at the concentration of 300 mg/L and had a effect toxic sublethal on concentration of 5 mg/L.. In mice, the median lethal dose was 750.63 mg/kg with the aqueous extract of fresh leaves, and lethal concen-trations tested from the concentration 900 mg/kg in males and females. The evaluated ani-mals showed behavioral changes in the nervous system and change in average total weight. The concentrations tested indicated are not mutagenic or not cytotoxic in the overall analy-sis of micronucleus frequency and binucleated cells, respectively. But, this work provides data toxicity; cytotoxicity and mutagenicity still have not investigated for the species A. pyrifolium / A espécie Aspidosperma pyrifolium Mart. é utilizada na alimentação por animais de produção. No entanto, são escassos os estudos sobre a toxicidade dessa planta. Este trabalho objetivou identificar a existência de efeito tóxico, citotóxico e mutagênico de folhas de A. pyrifolium no sistema teste Allium cepa e em camundongos. Foi feita a análise de crescimento de raízes, inibição relativa e índice mitótico com o teste Allium cepa. Para a DL50 foram utilizados grupos de camundongos, observados por 14 dias para determinar a quantidade de mortos, doentes e sobreviventes. Para o teste de micronúcleo e células binucleadas foi feita a extração da medula óssea dos animais. Os bioensaios com o Allium cepa realizados revelaram que o extrato aquoso das folhas secas não mostrou efeito tóxico, contudo, estimulou a divisão celular na concentração de 50 mg/L, sendo indicativo de formação de células tumorais. As folhas frescas foram tóxicas na concentração de 300 mg/L e teve efeito tóxico subletal na concentração de 5 mg/L. Nos camundongos, a dose letal mediana foi de 750,63 mg/Kg com o extrato aquoso de folhas frescas, sendo letal nas concentrações testadas a partir da concentração de 900 mg/Kg em machos e fêmeas. Os animais avaliados apresentaram alterações comportamentais no sistema nervoso e alteração no peso médio total. As concentrações testadas indicaram não serem mutagênicas e nem citotóxicas na análise geral das frequências de micronúcleo e células binucleadas, respectivamente. Mas, este trabalho fornece dados de toxicidade, citotoxicidade e mutagenicidade ainda não investigados para a espécie A. pyrifolium / 2017-08-08

O surgimento e a evolução da vida na terra foram possíveis graças ao desenvolvimento de mecanismos temporais precisos capazes de ajustar os processos fisiológicos que ocorriam no interior do organismo com os ciclos ambientais, promovendo assim, ganhos na capacidade adaptativa e reprodutiva dos indivíduos. Neste contexto, luz e temperatura são as duas pistas temporais mais relevantes para resetar o relógio endógeno e, aparentemente, esses dois zeitgebers trabalham juntos para manter os ritmos circadianos. Uma ampla gama de fotorreceptores e fotopigmentos evoluiu no sentido de perceber com alta sensibilidade a informação fótica fornecida pelo ambiente e, recentemente, foi demonstrado que a detecção de temperatura também pode ser exercida pelos fotopigmentos rodopsina e melanopsina, sendo mediada por canais TRP (Shen et al., 2011). Consideramos as células B16-F10 Per1::Luc como um modelo promissor para o estudo de luz e temperatura em relógios periféricos, uma vez que essa linhagem expressa os dois fotopigmentos apontados com função de termorreceptores em Drosophila. Nossos estudos nos permitiram verificar que a luz não atua como um agente sincronizador nessas células, que se mantiveram em livre curso mesmo após um pulso de 10 min de luz azul (650 lux). Por outro lado, um pulso de temperatura de 2,5º C acima da temperatura de manutenção por 1h atuou ajustando a expressão do gene Per1, imprimindo um ritmo circadiano, diferentemente do observado no controle. Com base nessas informações, hipotetizamos que a informação de luz, percebida via melanopsina na retina de mamíferos, levaria a regulação da temperatura circadiana pelo NSQ, e a temperatura corporal, por sua vez, poderia atuar como uma pista interna para a sincronização dos tecidos periféricos, tendo os canais TRP como mediadores. Para responder esta questão, utilizamos camundongos WT e TrpV1 KO submetidos a diferentes protocolos de luz e avaliamos a expressão de genes do relógio Per1, Per2, Clock e Bmal1 e dos canais TrpV1 e TrpA1 em tecidos periféricos. Identificamos que a glândula suprarrenal, fígado e tecido adiposo marrom possuem uma maquinaria do relógio tipicamente ativa e acreditamos que a oscilação dos genes de relógio observada nesses tecidos é expressiva. Interessantemente, vimos também que o TrpV1, além de ser expresso nos tecidos analisados em animais WT, apresenta uma transcrição rítmica no fígado e tecido adiposo marrom de animais em LD, corroborando nossa hipótese de que canais TRP atuam como mediadores da informação de luz aos tecidos periféricos. Dadas as diferenças encontradas entre os animais WT e TrpV1 KO, sugerimos que a presença do canal TRPV1 pode ser essencial, embora seu grau de envolvimento varie de acordo com o tecido. No que diz respeito ao canal TRPA1, encontramos dois resultados que merecem ser destacados. Primeiramente, identificamos no fígado de camundongos TrpV1 KO mantidos em LD uma provável compensação da expressão de TrpA1 na ausência de TrpV1 e, curiosamente, que o tecido adiposo marrom não expressa o canal TrpA1. Considerando os resultados deste trabalho sobre o envolvimento dos canais TRP em resposta à luz e temperatura, acreditamos ter fortalecido nossa hipótese inicial, principalmente após demonstrarmos o papel do canal TRPV1 e que tecidos periféricos são sincronizados por alterações de temperatura. / The life emergence and evolution on Earth were made possible by the development of precise temporal mechanisms able to adjust the physiological processes within an organism with environmental cycles, thus promoting gains in the adaptive and reproductive capacity of the individuals. In this context, light and temperature are the two most relevant time cues to reset the endogenous clock; apparently these two zeitgebers work together to keep the circadian rhythms. A wide variety of photoreceptors and photopigments evolved in order to precisely perceive the photic information provided by the environment, and recently it has been shown that the temperature detection can also be exerted by the photopigments rhodopsin and melanopsin, being mediated by TRP channels (Shen et al., 2011). We have identified B16-F10 Per1::Luc cells as a promising model for the study of light and temperature effects on peripheral clocks, since this cell line expresses both photopigments pointed as thermoreceptors in Drosophila. Our studies allowed us to demonstrate that light does not act as a synchronizing agent on those cells, which remained in free running after a 10 min pulse of blue light (650 lux). On the other hand, a temperature pulse of 2.5º C above the maintenance temperature, for 1h, adjusted Per1 gene expression, imprinting a circadian rhythm, which was not observed in the control. Based on this information, we hypothesized that the light perceived via melanopsin by the mammalian retina would lead to the regulation of the circadian temperature by the SCN, and the body temperature, in turn, could act as an inner cue for the synchronization of the peripheral tissues, having the TRP channels as mediators. To answer this question, we have used WT and TrpV1 KO mice under different light protocols and evaluated the expression of clock genes Per1, Per2, Clock and Bmal1 and TrpV1 and TrpA1 channels in peripheral tissues. We found that the adrenal gland, liver and brown adipose tissue have a typically active clock machinery, and the oscillation of clock genes observed in these tissues is significant. Interestingly, we observed that TrpV1 is expressed in those tissues, and presents a rhythmic transcription in the liver and brown adipose tissue of LD maintained animals, confirming our hypothesis that TRP channels act as mediators of light information to peripheral tissues. In face of the differences between WT and trpV1 KO animals, we suggest that the presence of the TRPV1 channel may be essential, although its degree of involvement may vary according to the tissue. In terms of TRPA1 channel, we found two results that deserve to be highlighted. Firstly, we identified in the liver of TrpV1 KO mice maintained in LD a presumable compensation of TrpA1 expression in the absence of TrpV1 and, interestingly, the brown adipose tissue does not express TrpA1 channel. Considering the findings of this study on the participation of TRP channels in responses to light and temperature, we believe we have strengthened our initial hypothesis, especially after we have demonstrated the role of TRPV1 channel, and that peripheral tissues may be synchronized by temperature changes.

Les invasions biologiques sont de plus en plus fréquentes, avec des conséquences importantes sur la biodiversité et la santé humaine. Étudier les mécanismes qui les expliquent permet simultanément (i) d’envisager des stratégies efficaces de contrôle et de prévention et (ii) d’étudier divers processus écologiques et évolutifs sur des échelles de temps contemporaines. Plusieurs hypothèses basées sur le parasitisme et l’immunité des hôtes sont proposées pour expliquer le succès des espèces envahissantes. Ainsi, au cours de l’invasion, les hôtes exotiques (1) perdraient leurs parasites naturels (Enemy Release, ER), (2) transfèreraient leurs parasites exotiques aux hôtes natifs (Spill-Over, SO) et/ou (3) amplifieraient les cycles des parasites natifs au sein des hôtes locaux (Spill-Back, SB). En relation avec ces changements dans les interactions hôtes-parasites, l’hypothèse EICA (Evolution of Increased Competitive Ability) prédit une modulation des ressources de l’hôte envahissant via un investissement moins important dans les réponses immunitaires coûteuses (inflammation) au profit de réponses immunitaires beaucoup moins coûteuses (réponses médiées par les anticorps) et de capacités de reproduction et de dispersion des populations sur le front d’invasion. Le but de ma thèse est de tester ces prédictions dans le cadre de deux invasions actuellement en cours au Sénégal : celles du rat noir Rattus rattus et de la souris domestique Mus musculus domesticus, deux espèces envahissantes majeures tant par leurs impacts (économique, sanitaire, écologique) que par leur distribution quasiment mondiale. Mes travaux se basent sur un dispositif d’échantillonnage en populations naturelles et sur le développement d’approches comparatives le long d’un gradient d’invasion pour chacune des deux espèces exotiques. Les patrons de structure (prévalence, abondance, richesse) de deux communautés de parasites (helminthes gastro-intestinaux, bactéries pathogènes) et les profils immunitaires (réponses médiées par les anticorps naturels, inflammation) des rongeurs commensaux exotiques (M. m. domesticus, R. rattus) et/ou natifs (Mastomys spp.) ont été comparés pour des localités situées dans des régions anciennement envahies (depuis plus de 100 ans), récemment envahies (depuis moins de 30 an : front d’invasion), et non envahies. Mes résultats montrent des variations dans la structure des communautés de parasites et les réponses immunitaires des hôtes natifs et exotiques. Les tendances observées, aussi bien pour les communautés de parasites que pour les composantes immunitaires étudiées le long des deux routes d’invasion, attestent de patrons globalement plus complexes qu’attendu sous les hypothèses de départ, suggérant l’existence de relations complexes entre caractéristiques des communautés d’hôtes et de parasites, investissement immunitaire, conditions environnementales et invasions biologiques. Des approches expérimentales doivent être envisagées afin de déterminer les conséquences et les mécanismes sous-jacents aux différents phénomènes observés. / Biological invasions are increasingly phenomenon worldwide having deleterious impacts on biodiversity and human health. Studying the mechanisms explaining them allows both (i) to define efficient strategies for controlling and preventing invaders and (ii) to study ecological and evolutionary processes at contemporary scales. Some major hypotheses rely on parasitism and host immunity to explain invasion success. Thus, exotic host populations (1) may benefit of an " Enemy Release " (ER) through impoverishment of their original parasite communities, and may affect native hosts by (2) transferring exotic parasites (Spill-Over, SO) and/or (3) by increasing transmission risk of native parasites (Spill-Back, SB). In turn, according to the refined “Evolution of Increased Competitive Ability” (EICA) theory, invasive populations should experience immune trade-offs by favouring less expensive antibody-mediated responses over costly inflammation, to increase their competitive ability (dispersion, reproduction). The aim of my thesis is to test these predictions along the invasion routes of two commensal exotic species in Senegal, the domestic mouse (Mus musculus domesticus) and the black rat (Rattus rattus). These rodent species are considered to be major invasive species worldwide inducing high economic, sanitary and ecological damages. My research is based on comparative analyses along one invasion route for each invasive species. We focused on gastrointestinal helminths and pathogenic bacteria as parasite communities, and inflammation and natural antibody-mediated responses as immune estimates. Comparisons were performed for invasive and/or native (Mastomys spp.) rodents between localities of long-established invasion (100-200 years ago), recent invasion (10-30 years ago; invasion front), and non-invaded localities. My findings showed variations along both invasion routes in parasite community structure and immune patterns, but in a more complex way than expected under the initial predictions. The heterogeneity of changes observed highlights the existence of particular relations between host and parasite traits, host immune investment, environmental conditions and biological invasions. Further experimental works are needed to assess the consequences and mechanisms underlying the changes observed along both invasion routes.