The involvement of corticotropin-releasing hormone (CRH) and neuropeptide Y (NPY) in the pathophysiology of anxiety and anxiety-related disorders is well established. The objective of this study is to explore the genetic variations in the CRH and NPY genes in a well-documented behavioral animal model, the vervet monkey (Chlorocebus aethiops sabaeus), in order to uncover a possible association between these polymorphisms and behavioral traits quantitatively extracted following analysis of social behavior and responses to novelty challenges. / The vervet CRH and NPY genes were amplified and sequenced; the priority was given to the regions expanding from -1kb upstream of the transcription initiation site (where most of the regulatory elements are found in both genes) through the second exon. / Polymorphism discovery analysis revealed the presence of 9 vervet CRH SNPs and 9 vervet NPY SNPs; the SNPs are relatively evenly distributed across the regions covered. An association between one intronic NPY SNP and "defensive aggression" was detected. / These results are coherent with other reports implicating NPY in defensive aggressive behavior, and support the notion that fear responses are fundamental behavioral traits for the dissection of anxiety.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / Härtill 6 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 6 uppsatser.

Thèses (Ph.D.)--Université de Sherbrooke (Canada), 2002. / Titre de l'écran-titre (visionné le 20 juin 2006). Publié aussi en version papier.

Thesis (Ph.D.)--University of Alberta, 2009. / A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy, Centre for Neuroscience. Title from pdf file main screen (viewed on October 31, 2009). Includes bibliographical references.

Thesis (Ph.D.)--Georgetown University, 2008. / Includes bibliographical references.

abstract: Externalizing behaviors are pervasive, widespread, and disruptive across a multitude of settings and developmental contexts. While the conventional diathesis-stress model typically measures the disordered end of the spectrum, studies that span the range of behavior, from externalizing to competence behaviors, are necessary to see the full picture. To that end, this study examined the additive and nonadditive relations of a dimension of parenting (ranging from warm to rejecting), and variants in dopamine, vasopressin, and neuropeptide-y receptor genes on externalizing/competence in a large sample of predominantly Caucasian twin children in toddlerhood, middle childhood, and early adolescence. Variants within each gene were hypothesized to increase biological susceptibility to both negative and positive environments. Consistent with prediction, warmth related to lower externalizing/higher competence at all ages. Earlier levels of externalizing/competence washed out the effect of parental warmth on future externalizing/competence with the exception of father warmth in toddlerhood marginally predicting change in externalizing/competence from toddlerhood to middle childhood. Warmth was a significant moderator of the heritability of behavior in middle childhood and early adolescence such that behavior was less heritable (mother report) and more heritable (father report) in low warmth environments. Interactions with warmth and the dopamine and vasopressin genes in middle childhood and early adolescence emphasize the moderational role gene variants play in relations between the rearing environment and child behavior. For dopamine, the long variant related to increased sensitivity to parent warmth such that the children displayed more externalizing behaviors when exposed to rejection but they also displayed more competence behaviors when exposed to high warmth. Vasopressin moderation was only present under conditions of parental warmth, not rejection. Interactions with neuropeptide-y and warmth were not significant. The picture that emerges is one of gene-environment interplay, wherein the influence of both parenting and child genotype each depend on the level of the other. As genetic research moves forward, gene variants previously implicated as conferring risk for disorder should be reexamined in conjunction with salient aspects of the environment on the full range of the behavioral outcome of interest. / Dissertation/Thesis / Ph.D. Psychology 2011

A elucidação dos mecanismos moleculares pelos quais tratamentos hormonais alteram o início da puberdade é de fundamental importância para o desenvolvimento de estratégias que reduzam a idade ao primeiro parto, e consequentemente a taxa de desfrute do rebanho Nelore. Foram investigados os efeitos do uso de dispositivos de progesterona, e do estradiol endógeno, sobre mecanismos moleculares controlando a obtenção da puberdade de novilhas Nelore peripúberes. Especificamente, como as diferenças na expressão de genes relativos à reprodução em duas áreas do hipotálamo. Trinta e cinco novilhas Nelores não púberes, e com idade entre 13 e 14 meses, foram divididas em quatro tratamentos experimentais (nove ou oito por tratamento): dispositivo de P4 sem estradiol (SP); dispositivo de P4 com estradiol (PE); sem dispositivo de P4 e sem estradiol (SS); e sem dispositivo de P4 e com estradiol (SE). As novilhas foram alimentadas no cocho pós desmame até atingirem 295 ± 11 kg, com fornecimento de água à vontade. Ao término do tratamento hormonal as novilhas foram abatidas e as porções de hipotálamo colhidas para processamento e armazenagem a -80 ºC. O RNA total do tecido hipotalâmico foi extraído, tratado com DNAse I e submetido à síntese de cDNA para estudo da expressão gênica por PCR em tempo real (qRT-PCR). Foram formados pools de RNA para a realização de um estudo abrangente da administração de progesterona e do efeito do estradiol endógeno e das diferenças entre áreas do hipotálamo, realizado por sequenciamento de nova geração (RNA-Seq), de forma a identificar possíveis genes candidatos no hipotálamo. Foram encontrados genes diferencialmente expressos alterados pelos tratamentos e entre as áreas do hipotálamo relativos à obtenção da puberdade. / The understanding of the molecular mechanisms by which nutrition, genetics and hormonal treatments affect the beginning of puberty is of great importance for developing strategies aiming to reduce the age at first calving, and therefore increase the slaughter rate in Nellore cattle. The effects of progesterone device and of endogenous estradiol on the molecular mechanisms controlling the attainment of puberty in Nellore heifers were investigated. Specifically, the molecular pathways of progesterone and estradiol were studied in the hypothalamus. Thirty five non-pubertal heifers, between 13 and 14 months of age, were divided into four treatment (nine or eight per treatment): P4 device without estradiol (SP), P4 device with estradiol (PE), without P4 device and without estradiol (SS), and without P4 device and with estradiol (SE). The heifers were fed after weaning until reach 295 ± 11 Kg, with water access. At the end of the hormonal treatments all heifers were slaughtered and the hypothalamus areas were harvested, processed and then also stored at -80°C. Total RNA of hypothalamus were extracted, treated with DNase I and submitted to cDNA synthesis for gene expression quantification by real time PCR (qRT-PCR). RNA samples were pooling to realize a comprehensive study of the effects of progesterone administration and endogenous estrogen on attainment of puberty by next-generation sequencing (RNA-Seq), in order to identify possible candidate genes in the hypothalamus. Genes diffentially expressed between hypothalamic areas and affected by treatments were found.

Investigou-se o efeito da leptina exógena e do maior consumo de energia, sobre o padrão da expressão de genes no hipotálamo de novilhas zebuínas; de modo a elucidar o mecanismo de sinalização da leptina no hipotálamo e os genes responsáveis pela obtenção da puberdade. Trinta e seis novilhas não púberes, e com idade entre 18 e 20 meses, foram divididas em três grupos experimentais: baixa energia (BAIXA), alta energia (ALTA), baixa energia com administração de leptina recombinante ovina (BAIXA+LEP), totalizando 56 dias de tratamento. Vinte e quatro novilhas foram abatidas ao apresentar sinais de puberdade, sendo eles: concentração de progesterona no soro superior a 1 ng/mL por duas amostras seguidas e presença de corpo lúteo detectável por ultra-sonografia. O hipotálamo foi colhido e armazenado a -80ºC. As amostras foram submetidas à extração do RNA total, tratadas com DNAse I e submetidas à síntese de cDNA. A quantificação relativa de quatro genes candidatos reconhecidamente envolvidos com a sinalização hipotalâmica da leptina em bovinos: NPY, NPY-Y1, NPY-Y4 e SOCS-3, foi feita através de PCR quantitativo (tempo real). Não houve efeito da administração de leptina sobre a expressão do NPY (P=0,70), ou de seus receptores: NPY-Y1 (P=0,27) e NPY-Y4 (P=0,92) no início da puberdade. A expressão de SOCS-3 foi reduzida (P=0,05) no hipotálamo de novilhas tratadas com leptina, o que sugere menor ação inibitória sobre a leptina. Em novilhas alimentadas com dieta de alta energia, a expressão do NPY-Y1 foi reduzida (P=0,04), o que indica que o hipotálamo estaria menos sensível à ação do NPY, permitindo a entrada precoce em puberdade. Nos demais genes estudados, NPY (P=0,75), NPY-Y4 (P=0,92) e SOCS-3 (P=0,24), a dieta não alterou significativamente suas expressões hipotalâmicas. Estudo mais abrangente do efeito da nutrição e da administração de leptina foi realizado através de hibridização em microarranjos de DNA, objetivando a identificação de possíveis genes candidatos, expressos no hipotálamo, que influenciam na obtenção da puberdade em novilhas Nelore tratadas com leptina ou submetidas à dieta de alta energia. Foram encontrados 78 genes cuja expressão foi alterada pela densidade energética da dieta (P=0,05) no hipotálamo das novilhas Nelore, destes foram selecionados os que apresentaram razões de expressão da ordem de 1,4 ou mais, totalizando 20 genes. Entre esses se destaca o gene da &beta;-arrestina 1 (ARRB1), que foi 1,40 vezes mais expresso (P=0,04) em novilhas submetidas à dieta de alta energia, pois atua na mediação da dessensibilização dos receptores acoplados à proteína-G-(GPCRs)1, como os receptores de NPY. Foram encontrados 134 genes diferencialmente expressos (P=0,05) devido a aplicação de leptina. Dentre os 80 genes que apresentaram razões superiores a 1,4, 18 genes tiveram a expressão reduzida, e 62 tiveram a expressão aumentada pela aplicação de leptina. Destes, alguns estão envolvidos na regulação da sinalização da leptina. O gene SRC foi menos expresso (1,64 vezes; P=0,04) em novilhas tratadas com leptina, o que sugere menor ação inibitória pela SHP-2. A proteína SOCS-2 foi 1,43 vezes (P=0,01) mais expressa no hipotálamo de novilhas tratadas com leptina. Sabe-se que, ao contrário de SOCS-1 e SOCS-3, CIS e SOCS-2 não se ligam, ou inibem, as janus kinases. O STAT-3 foi 2,14 vezes (P=0,03) mais expresso em novilhas tratadas com leptina, e sua ativação possibilita a ligação hipotalâmica da leptina com seu receptor (Ob-Rb). As IGFPB-1 e -2 foram mais expressas no hipotálamo de novilhas tratadas com leptina que em novilhas não tratadas, sendo IGFPB-1 1,78 vezes (P=0,04) mais expressa e IGFPB-2 1,89 vezes (P=0,05). As IGFPBs podem desempenhar função de potencialização da ação do IGF-1, ou exercer ação inibitória. Conclui-se que tanto o consumo de energia quanto a aplicação com leptina influenciaram o padrão de expressão gênica no hipotálamo de novilhas Nelore. A modulação da quantidade do receptor do NPY, NPY-Y1, no hipotálamo pode ser uma via importante pela qual a nutrição afeta o início da puberdade em novilhas. E ainda que estudos mais aprofundados de expressão dos genes encontrados nas hibridizações por microarranjo poderão revelar interações mais concisas entre os genes, a nutrição e a leptina na obtenção da puberdade. / It was investigated the effect of exogenous leptin and the high energy intake on gene expression pattern in the hypothalamus of zebuine heifers; in a way to elucidate the mechanism of leptin signaling in hypothalamus and the responsible genes for puberty. Thirty six heifers not in puberty at 18 and 20 months of age were divided in three experimental groups: low energy diet (LOW), high energy diet (HIGH), low energy diet with administration of recombinant ovine leptin (LOW+LEP), totalizing 56 days of treatment. Twenty four heifers were slaughtered when presented the signals of puberty: progesterone serum concentration above 1 ng/mL for two followed weeks and the presence of detectable corpus luteum by ultrasonography. The hypothalamus was collected and stored at -80ºC. Samples were submitted to total RNA extraction, treated with DNAse I and submitted to cDNA synthesis. The relative quantification of four candidate genes admittedly involved with hypothalamic leptin signaling in bovine: NPY, NPY-Y1, NPY-Y4 and SOCS-3, was evaluated through quantitative PCR (real time). There was no effect of leptin administration on NPY expression (P=0.70), or on its receptors: NPY-Y1 (P=0.27) and NPY-Y4 (P=0.92) in the onset of puberty. The expression of SOCS-3 was reduced (P=0.05) in the hypothalamus of heifers treated with leptin, what suggests lower inhibitory action over leptin. In heifers fed high energy diets, the expression of NPY-Y1 was reduced (P=0.04), which indicates that the hypothalamus would be less sensitive to the action of NPY, allowing the precocious onset of puberty. In other studied genes, NPY (P=0.75), NPY-Y4 (P=0.92) and SOCS-3 (P=0.24), the diet did not significantly altered their hypothalamic expressions. A more comprehensive study regarding the effect of nutrition and leptin administration was performed through the hybridization in DNA microarrangements, aiming the identification of possible candidate genes, expressed in hypothalamus that influence in the onset of puberty in Nelore heifers treated with leptin or submitted to high energy diets. It was found 78 genes whose expression was altered by the energy density of the diet (P<0.05) in the hypothalamus of Nelore heifers. From them, it was selected those genes which presented rates of expression in the order of 1.4 or more, totalizing 20 genes. From them, the highlight gene was &beta;-arrestin 1 (ARRB1) which was 1.40 more expressed (P=0.04) in heifers fed high energy diet due to its action in the mediation of receptors desensibilization coupled to protein-G-(GPCRs)1, as the receptors of NPY. It was found 134 genes differently expressed (P<0.05) due to leptin administration. From the 80 genes that presented rates of expression higher than 1.4, 18 genes had their expression reduced and 62 had their expression increased by leptin administration. Some of these 62 genes are involved in the regulation of leptin signaling. The gene SRC was the less expressed (1.64 times; P=0.04) in heifers treated with leptin what suggests lower inhibitory action by SHP-2. The protein SOCS-2 was 1.43 times (P=0.01) more expressed in the hypothalamus of heifers treated with leptin. It is known that on the contrary of SOCS-1 and SOCS-3, CIS and SOCS-2 do not bind or inhibit, as janus kinases. The STAT-3 was 2.14 times (P=0.03) more expressed in heifers treated with leptin and its activation enables the hypothalamic binding of leptin and its receptor (Ob-Rb). The IGFPB-1 and -2 were more expressed in the hypothalamus of heifers treated with leptin than the animals not treated, being the IGFPB-1 1.78 times (P=0.04) more expressed and the IGFPB-2 1.89 times (P=0.05). The IGFPBs could play a function of IGF-1 action enhancer or exert an inhibitory action. It is concluded that both energy intake and leptin administration influenced gene expression pattern in the hypothalamus of Nelore heifers. The modulation of the receptor quantity of NPY, NPY-Y1 in hypothalamus could be an important route in which nutrition affects the onset of puberty in heifers. Moreover, more detailed studies regarding gene expression in hybridization by microarrangement could reveal more concise interactions between genes, nutrition and leptin in the onset of puberty.