Condições músculo-esqueléticas como as desordens da articulação temporomandibular (ATM) são as principais causas de dor não odontogênica na região orofacial e incluem um grupo de condições usualmente acompanhadas de dor na região das ATMs e dos músculos mastigatórios, limitação da abertura bucal e dores de cabeça. Pacientes com desordens da articulação temporomandibular (DTM) também podem apresentar desordens relacionadas ao estresse caracterizadas por alterações somáticas e psicológicas como fadiga, distúrbios do sono, ansiedade e depressão. A causa exata das DTMs ainda não é completamente entendida, mas acredita-se que envolva fatores fisiológicos, comportamentais e ambientais. É possível que alguns sintomas de DTM e dor orofacial sejam apenas manifestações somáticas de estresse emocional. De fato, situações de estresse promovem uma série de mudanças fisiológicas e comportamentais que podem afetar os sistemas hormonais e de neurotransmissores. Estudos demonstraram que o CRF e seus receptores medeiam respostas comportamentais, endócrinas e autonômicas para o estresse, além de estar envolvidos em outras funções, como na modulação nociceptiva. O objetivo deste trabalho foi avaliar a nocicepção e o comportamento emocional em ratos com inflamação persistente nas ATMs, induzida por administração de adjuvante completo de Freund (CFA) em diferentes situações de estresse (agudo - EA, crônico repetido - ECR e crônico variado - ECV), bem como a ação do antidepressivo tricíclico (inibidor da recaptação de catecolaminas), imipramina, nessas respostas. Ainda, investigou-se o possível envolvimento de receptores CRF do núcleo central da amígdala (CEA) na modulação nociceptiva de animais com inflamação persistente das ATMs. Os resultados mostraram que a inflamação persistente das ATMs promoveu alodinia mecânica orofacial e hiperalgesia secundária. O EA per se promoveu analgesia nos animais sem inflamação das ATMs, além de reverter a alodinia mecânica e a hiperalgesia secundária induzidos pelo CFA intra-articular. Ainda, o ECV e o ECR promoveram per se hiperalgesia nos animais sem inflamação, mas não alteraram o efeito da administração intra-articular de CFA. Em adição, a inflamação persistente das ATMs promoveu alterações comportamentais com efeitos ansiogênicos significativos que não foram alterados pela exposição dos animais ao EA ou ECR. Em contrapartida, o ECV demonstrou efeito ansiogênico nos animais sem inflamação, porém não houve alterações nos animais com inflamação persistente nas ATMs. Em adição, a administração de imipramina reverteu a hiperalgesia, exercendo, dessa forma, efeito analgésico, e o efeito ansiogênico causado pelo CFA intra-articular. Com relação ao envolvimento de receptores para CRF no CEA verificamos que sua ativação promoveu analgesia nos animais sem inflamação das ATMs e ainda reverteu a hiperalgesia decorrente da administração intra-articular do CFA. Assim, nossos resultados sugerem que a inflamação persistente nas ATMs induzida por CFA produz efeitos ansiogênicos e aumenta a sensibilidade nociceptiva, bem como situações de estresse agudo e crônico podem modular essas alterações. Ainda, os efeitos da inflamação persistente podem ser revertidas pelo tratamento sistêmico com imipramina, e pela administração de agonista de receptores CRF no CEA. / Musculoskeletal conditions such as disorders of the temporomandibular joint (TMJ) are the main cause of non-odontogenic pain in the orofacial region and include a group of conditions usually accompanied by pain in TMJ region and masticatory muscles, limitation of mouth opening and headache. Patients with temporomandibular joint disorders (TMD) may also show related stress disorders characterized by somatic and psychological changes such as fatigue, sleep disturbances, anxiety and depression. The exact cause of TMD is not yet completely clarified, but is believed to involve physiological, behavioral and environmental factors. It is possible that some symptoms of TMD and orofacial pain are only somatic manifestations of emotional stress. In fact, stressful situations promote a series of physiological and behavioral changes that may affect hormonal and neurotransmitter systems. Studies have shown that CRF and its receptors mediate behavioral, endocrine and autonomic responses to stress, in addition to being involved in other functions such as nociceptive modulation. The aim of this study was to evaluate emotional behavior and nociception in rats with persistent inflammation in TMJ induced by administration of complete Freund\'s adjuvant (CFA) in different stress situations (acute stress - AS, chronic restraint stress - CRS and unpredictable chronic stress - UCS) and the action of the tricyclic antidepressant (catecholamine reuptake inhibitor), imipramine, in these responses. In addition, we investigated the possible involvement of CRF receptors in the central nucleus of the amygdala (CEA) in nociceptive modulation in animals with persistent inflammation of the TMJs. The results have shown that persistent TMJ inflammation produced mechanical orofacial allodynia and widespread secondary hyperalgesia. AS induced analgesia in animals without TMJ inflammation and reversed both mechanical allodynia and secondary hyperalgesia induced by intra-articular CFA injection. In addition, CRS and UCS induced hyperalgesia in animals without inflammation, but did not alter the effect of intra-articular administration of CFA. Also, the persistent inflammation of the TMJ promoted behavioral changes with significant ansiogenic effects that were not altered by exposure of the animals to AS or CRS. In contrast, UCS showed ansiogenic effect in animals without inflammation, but no changes in animals with persistent TMJ inflammation. In addition, administration of imipramine had an ansiogenic and analgesic effect, reversing the hyperalgesia caused by intra-articular CFA administration. Regarding the involvement of CRF receptors in the CEA this study demonstrated that this activation promoted analgesia in animals without inflammation of the TMJ and was able to reverse the hyperalgesia caused by intra-articular CFA administration. Thus, our results suggest that persistent temporomandibular inflammation induced by CFA produces anxiogenic effects and decreases nociceptive sensitivity and situations of acute and chronic stress can modulate these changes. In addition, these changes can be reversed by systemic treatment with imipramine and by administration of CRF receptor agonist in CEA.

Condições músculo-esqueléticas como as desordens da articulação temporomandibular (ATM) são as principais causas de dor não odontogênica na região orofacial e incluem um grupo de condições usualmente acompanhadas de dor na região das ATMs e dos músculos mastigatórios, limitação da abertura bucal e dores de cabeça. Pacientes com desordens da articulação temporomandibular (DTM) também podem apresentar desordens relacionadas ao estresse caracterizadas por alterações somáticas e psicológicas como fadiga, distúrbios do sono, ansiedade e depressão. A causa exata das DTMs ainda não é completamente entendida, mas acredita-se que envolva fatores fisiológicos, comportamentais e ambientais. É possível que alguns sintomas de DTM e dor orofacial sejam apenas manifestações somáticas de estresse emocional. De fato, situações de estresse promovem uma série de mudanças fisiológicas e comportamentais que podem afetar os sistemas hormonais e de neurotransmissores. Estudos demonstraram que o CRF e seus receptores medeiam respostas comportamentais, endócrinas e autonômicas para o estresse, além de estar envolvidos em outras funções, como na modulação nociceptiva. O objetivo deste trabalho foi avaliar a nocicepção e o comportamento emocional em ratos com inflamação persistente nas ATMs, induzida por administração de adjuvante completo de Freund (CFA) em diferentes situações de estresse (agudo - EA, crônico repetido - ECR e crônico variado - ECV), bem como a ação do antidepressivo tricíclico (inibidor da recaptação de catecolaminas), imipramina, nessas respostas. Ainda, investigou-se o possível envolvimento de receptores CRF do núcleo central da amígdala (CEA) na modulação nociceptiva de animais com inflamação persistente das ATMs. Os resultados mostraram que a inflamação persistente das ATMs promoveu alodinia mecânica orofacial e hiperalgesia secundária. O EA per se promoveu analgesia nos animais sem inflamação das ATMs, além de reverter a alodinia mecânica e a hiperalgesia secundária induzidos pelo CFA intra-articular. Ainda, o ECV e o ECR promoveram per se hiperalgesia nos animais sem inflamação, mas não alteraram o efeito da administração intra-articular de CFA. Em adição, a inflamação persistente das ATMs promoveu alterações comportamentais com efeitos ansiogênicos significativos que não foram alterados pela exposição dos animais ao EA ou ECR. Em contrapartida, o ECV demonstrou efeito ansiogênico nos animais sem inflamação, porém não houve alterações nos animais com inflamação persistente nas ATMs. Em adição, a administração de imipramina reverteu a hiperalgesia, exercendo, dessa forma, efeito analgésico, e o efeito ansiogênico causado pelo CFA intra-articular. Com relação ao envolvimento de receptores para CRF no CEA verificamos que sua ativação promoveu analgesia nos animais sem inflamação das ATMs e ainda reverteu a hiperalgesia decorrente da administração intra-articular do CFA. Assim, nossos resultados sugerem que a inflamação persistente nas ATMs induzida por CFA produz efeitos ansiogênicos e aumenta a sensibilidade nociceptiva, bem como situações de estresse agudo e crônico podem modular essas alterações. Ainda, os efeitos da inflamação persistente podem ser revertidas pelo tratamento sistêmico com imipramina, e pela administração de agonista de receptores CRF no CEA. / Musculoskeletal conditions such as disorders of the temporomandibular joint (TMJ) are the main cause of non-odontogenic pain in the orofacial region and include a group of conditions usually accompanied by pain in TMJ region and masticatory muscles, limitation of mouth opening and headache. Patients with temporomandibular joint disorders (TMD) may also show related stress disorders characterized by somatic and psychological changes such as fatigue, sleep disturbances, anxiety and depression. The exact cause of TMD is not yet completely clarified, but is believed to involve physiological, behavioral and environmental factors. It is possible that some symptoms of TMD and orofacial pain are only somatic manifestations of emotional stress. In fact, stressful situations promote a series of physiological and behavioral changes that may affect hormonal and neurotransmitter systems. Studies have shown that CRF and its receptors mediate behavioral, endocrine and autonomic responses to stress, in addition to being involved in other functions such as nociceptive modulation. The aim of this study was to evaluate emotional behavior and nociception in rats with persistent inflammation in TMJ induced by administration of complete Freund\'s adjuvant (CFA) in different stress situations (acute stress - AS, chronic restraint stress - CRS and unpredictable chronic stress - UCS) and the action of the tricyclic antidepressant (catecholamine reuptake inhibitor), imipramine, in these responses. In addition, we investigated the possible involvement of CRF receptors in the central nucleus of the amygdala (CEA) in nociceptive modulation in animals with persistent inflammation of the TMJs. The results have shown that persistent TMJ inflammation produced mechanical orofacial allodynia and widespread secondary hyperalgesia. AS induced analgesia in animals without TMJ inflammation and reversed both mechanical allodynia and secondary hyperalgesia induced by intra-articular CFA injection. In addition, CRS and UCS induced hyperalgesia in animals without inflammation, but did not alter the effect of intra-articular administration of CFA. Also, the persistent inflammation of the TMJ promoted behavioral changes with significant ansiogenic effects that were not altered by exposure of the animals to AS or CRS. In contrast, UCS showed ansiogenic effect in animals without inflammation, but no changes in animals with persistent TMJ inflammation. In addition, administration of imipramine had an ansiogenic and analgesic effect, reversing the hyperalgesia caused by intra-articular CFA administration. Regarding the involvement of CRF receptors in the CEA this study demonstrated that this activation promoted analgesia in animals without inflammation of the TMJ and was able to reverse the hyperalgesia caused by intra-articular CFA administration. Thus, our results suggest that persistent temporomandibular inflammation induced by CFA produces anxiogenic effects and decreases nociceptive sensitivity and situations of acute and chronic stress can modulate these changes. In addition, these changes can be reversed by systemic treatment with imipramine and by administration of CRF receptor agonist in CEA.

Environmental pollution by pharmaceuticals is an issue of concern that is currently attracting attention around the world. Although environmental effects of pharmaceutical contaminants are not yet well documented, studies have shown that these substances may have the potential to disrupt the biotic component of an ecosystem. Particularly worrisome contaminants are the neuroactive pharmaceuticals which have the potentiality to induce behavioral modifications in non-target species. In the present study, I examined the effects of a benzodiazepine anxiolytic pharmaceutical (oxazepam) on the behavior of Atlantic salmon (Salmo salar) juveniles (fry). The hypothesis of this study was that oxazepam reduces the anxiety-like behavior of the Atlantic salmon juveniles. To test the hypothesis and assess the impact of oxazepam exposure on Atlantic salmons fry behavior, two different concentrations of this drug; a low-level (1.9 ug L-1) and a high-level concentration (1000 ug L-1) were used. Exposures lasted for 48 hours and afterwards, the fish were recorded to evaluate their behavioral responses. The results of this study reveal that oxazepam in a high concentration (1000 ug L-1 ) alters specific behavioral endpoints related to the fitness (feeding/predator avoidance) of Atlantic salmons fry. Individuals exposed to the high oxazepam concentration exhibited significant lower average speed and acceleration as well as they traveled a shorter mean distance compared to the unexposed (control) individuals. These findings confirm the hypothesis and show that psychotropic pharmaceutical contaminants modify animal behaviors, which can ultimately lead to ecological consequences. However, the concentration that generated behavioral effects in this study was three magnitudes higher than concentrations measured in the environment and thus, should not be viewed representative for oxazepam contaminated ecosystems.

Schizophrenia is a severe psychiatric disorder with unsatisfactory treatment options and poorly under- stood etiology. Genetic models are a suitable tool for studying this disorder with its high heritability. However, currently available animal models do not cover the broad range of schizophrenia symptoms and are not disorder-specific. Ribonucleic acid binding motif protein 12 gene (RBM12), a novel, high- risk gene for schizophrenia, was recently identified. This thesis aimed to assess the social behavior of schizophrenia-like phenotype in RBM12 zebrafish mutants. The social behavior of mutated adult zebrafish was assessed during free-swimming. Trajectories of each zebrafish were obtained from recordings by the usage of idtracker.ai. Parameters selected to quantify the social behavior of the zebrafish were chosen based on common symptoms of humans with schizophrenia. Inter-fish distance was examined as an indicator of preferred personal space since humans diagnosed with schizophre- nia have an increased need for a greater personal space compared to mentally healthy individuals. Wall-hugging, increased speed and bottom-dwelling were studied as indicators of anxiety, a common comorbid symptom of schizophrenia. The RBM12 mutants exhibited a greater inter-fish distance than their wild-type siblings during three-dimensional recordings. They however, did not demonstrate an increased inter-fish distance during two-dimensional recordings. The mutated zebrafish displayed a higher average speed and greater wall-hugging, indicating anxiety. It can be concluded that RBM12 mutation produces partial symptomatology consistent with humans diagnosed with schizophrenia, providing a promising animal model. The current work provided novel insight into the neural substrates of schizophrenia and for potential drug screening for this disorder. Further research is needed to fully characterise schizophrenia-like symptoms in this RBM12 animal model.

Dans ce travail de thèse, nous avons évalué les effets neurotoxiques multigénérationnels de l’exposition des mères F0 gestantes et allaitantes aux polychlorobiphényles non-dioxin-like indicateurs (PCB-NDLi), à un profil mimant l'exposition humaine à partir de poissons contaminés, sur le développement et le comportement, y compris les réponses émotionnelles et les interactions sociales, des deux générations F1 et F2 des souris mâles et femelles, à différentes phases de leur ontogenèse. Deux faibles doses des PCB-NDLi : (i) la DJT, qui est de 10 ng/kg/j, et (ii) une dose environnementale de 1000 ng/kg/j, ont été administrés par accès libre aux souris mères F0. En fonction de la modalité d’exposition des parents F1 aux PCB, 4 groupes de génération F2 ont été obtenus, en croisant (i) des pères F1 exposés à des mères F1 non exposées, (ii) des mères F1 exposées à des pères F1 non exposés, (iii) des deux parents F1 exposés, ou (iv) des deux parents F1 non exposés (témoins), aux PCB en période périnatale. Nos résultats ont montré que les mâles adultes de la génération F1 ont manifesté un comportement dépressif-like ; alors que les mâles F2, issus uniquement des pères F1 exposés aux PCB, ont exhibé un comportement anti-dépressif-like, ce que suggère que l’exposition périnatale des souris F1 aux PCB-NDLi a induit une altération multigénérationnelle d’origine parentale du comportement de la résignation, et ce d’une façon sexe dépendante. De même, une altération sexe-dépendante de l’anxiété, a été détectée chez la génération F1 exposées durant la période périnatale aux PCB-NDLi comme uniquement les souris mâles d’âge moyen F1 ont développé un phénotype anxieux qui a été transmis aux souris mâles d’âge moyen F2, via leurs pères F1. En outre, une altération multigénérationnelle du comportement social a été détectée chez les souris mâles et femelles F1 et F2. D’une façon remarquable, chez la génération F2, des altérations comportementales dépendantes à la fois du sexe et de la dose, ont été trouvées, malgré l’absence d’effets chez leurs parents F1, effets qui dépendaient également de l’origine parentale, tels que la diminution significative du niveau de la préférence pour la nouveauté sociale chez les souris mâles F2, issues uniquement des mères F1 périnatallement exposées à la dose 10 ng/kg de PCB. Le dosage des biomarqueurs chez les souris d’âge moyen de la génération F1 a révélé une altération de nombreux paramètres biochimiques, y compris une augmentation du niveau de corticostérone et de l’activité de l’acétylcholinestérase / In this study, we evaluated the multigenerational neurotoxic effects of gestational and lactational exposure of F0 female mice to a representative mixture of the six indicator non-dioxin-like-polychlorinated biphenyls (NDL-PCBs) at environmentally low doses, a profile that closely mimics human exposure to contaminated fish. The tolerable day intake (TDI) of 10 ng/kg/day and a higher environmental dose of 1000 ng/kg/day were administered by free access to F0 mothers during pregnancy and lactation. Afterwards, the development and behavior, including emotional responses and social interactions, of the two F1 and F2 generations of Swiss male and female mice at different phases of their ontogenesis, were assessed. Depending on the mode of exposure of F1 parents to PCBs, four F2 generation groups were obtained by crossing (i) F1 fathers perinatally exposed with unexposed F1 mothers, (ii) F1 mothers perinatally exposed with unexposed F1 fathers, (iii) both F1 parents perinatally exposed, or (iv) both F1 parents perinatally unexposed (controls), to PCBs. Our results showed that F1 adult males showed depressive-like behavior whereas F2 adult males, coming from F1 mothers, perinatally exposed to PCBs, exhibited anti-depressive-like behavior. This result suggested an induction of a multigenerational alteration that was of parental origin, on the resignation behavior in a sex-dependent manner. Similarly, sex-selective anxious behavior was detected in F1 middle-aged males perinatally exposed to PCBs, which was transmissible to F2 middle-aged males, via their F1 fathers. Furthermore, a multigenerational alteration of social behavior was found in F1 and F2 male and female mice. Remarkably, some behavioral alterations in F2 generation were found, despite of the absence of effects in their F1 parents, such as a significant decrease in the level of preference for social novelty in F2 male mice, coming from F1 mothers perinataly exposed to 10 ng/kg of NDL-PCBs. The biomarker assays in F1 middle-aged mice revealed an alteration in many biochemical markers, including increased corticosterone levels and acetylcholinesterase activity in male as well as females.

Les hydrocarbures aromatiques polycycliques (HAP) sont des polluants organiques persistants qui sont présents en mélange complexe dans l’environnement et notamment dans les milieux aquatiques. Ils s’adsorbent sur les particules en suspension, s’accumulent dans les sédiments et dans les premiers maillons de la chaîne trophique. L’objectif de cette étude était de mesurer les effets à long terme d’une contamination par des HAP chez un modèle de vertébrés : le poisson zèbre. Dans un premier temps, des embryons ont été exposés pendant les 4 premiers jours de leur développement sur du sédiment naturel enrobé de 3 HAP individuel (phénanthrène, pyrène et benzo[a]pyrène) puis transférés et élevés en eau propre. Dans un deuxième temps, des poissons ont été exposés par voie alimentaire tout au long du cycle de vie et dès le premier repas à 3 fractions de HAP à doses environnementales enrobées sur les aliments : une fraction pyrolytique (PY) extraite d’un sédiment échantillonné dans la Seine et deux fractions pétrogéniques (un fuel lourd (HO) provenant de l’Erika et un pétrole brut type Arabian light (LO)). Les effets à long terme sur la croissance, la survie, la reproduction et le comportement ont été évalués à différents âges. Ces effets ont pu être observés à plusieurs échelles, i.e. de la molécule, aux tissus et organes puis à l’échelle de l’individu. Globalement, chez les poissons contaminés, la croissance est ralentie, la survie larvaire diminuée chez les HO, la fonction reproduction est altérée fortement à la fois au niveau hormonal, tissulaire et phénotypique ainsi que les réponses comportementales léthargiques ou hyper-réactives selon les cas. L’exposition par voie sédimentaire a révélé des effets visibles lorsque les individus atteignaient 6 mois soulignant l’existence d’effets tardifs, notamment sur les réponses comportementales, d’une exposition très précoce y compris chez la descendance. Quant à l’exposition par voie alimentaire, elle a montré une gradation des effets. Toutes fonctions confondues, les résultats obtenus permettent d'établir une hiérarchie dans la toxicité des fractions étudiées : PY < LO ≈ HO. L'approche multi-échelle utilisée dans ce travail a permis, en partant d'informations acquises au niveau moléculaire, tissulaire et individuel, d'aboutir à une compréhension intégrée des conséquences qu'une exposition à des HAP peut avoir sur l'aptitude à la survie des poissons dans leur milieu naturel ainsi qu'à leur capacité à participer au renouvellement des générations futures. / Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants (POPs) which are found in complex mixtures in the environment including aquatic ecosystems. They adsorb on particles, accumulate in sediment and in the first link of the food web. The aim of this study was to measure long term effects of PAHs contamination on a vertebrate model : the zebrafish. In a first study, embryos were exposed on natural sediment spiked with 3 individual PAH (phenanthrene, pyrene and benzo[a]pyrene) during the first four days of their development. In a second study, to evaluate the consequences of long-term chronic exposure to PAHs, zebrafish were exposed, from their first meal (5 days post fertilisation) until they became reproducing adults, to diets spiked with three PAHs fractions at environmentally relevant concentrations (0.3X, 1X and 3X; with the 1X concentration being in the range of 4.6-6.7 μg.g-1 for total quantified PAHs). The fractions used were representative of PAHs of pyrolytic (PY) origin or of two different oils of differing compositions (a heavy fuel (HO) and a light crude oil (LO)). Long term effects on growth, survival, reproduction and behavior were evaluated at different ages. Effects were observed at molecule, tissue, organ and individual scales. In general, for contaminated fish, growth was reduced, larval survival decreased in HO, and reproduction was strongly impaired at hormonal, tissue and phenotypic levels, and behavioral responses were lethargic or hyperactive depending on fractions and stages. Sediment exposure still revealed visible effects when fish were 6 month old. These results hereby showed significant late effects, especially in behavioral responses after an early exposure, including in larvae issued from contaminated fish. In spiked diets contaminated fish, we observed a gradation of effects. Combining all functions, we established of hierarchy in toxicity in the studied fractions: PY < LO ≈ HO. Finally, our results gathered at a multiscale from molecule, to tissue and individuals, indicate that PAH mixtures of different compositions, representative of situations encountered in the wild, can promote lethal and sublethal effects which are likely to be detrimental for fish survival and recruitment into future generations.