Made available in DSpace on 2014-12-17T15:36:52Z (GMT). No. of bitstreams: 1 PaulaRMB.pdf: 735531 bytes, checksum: 6f97353cd0f92f620d3561920b75a484 (MD5) Previous issue date: 2008-06-05 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Most of ontogenetic studies on circadian timing system have been developed on infants, adults and elderly. The puberty has not been a stage of life few studied, except for researches in human adolescents, that presents phase delay in sleep-wake cycle. However, few studies have focused on the basis of this circadian change due to methodological difficulties. Thus, an animal model to study the sleep-wake cycle at puberty is essential. In the common marmoset, a social primate, the circadian activity periodicity stabilizes around 4 months (juvenile stage) and the 8h period component has a seasonal variation. Puberty stage of this species begins near the 8th month of age in males and near the 7th month in females with 7 months of duration. With the aim to characterize the circadian motor activity rhythm during puberty in marmosets (Callithrix jacchus) the motor activity was continuous registered by actiwatches in 6 animals between 5-12 months. Since the social factor influence the behavior of this specie, behavioral observations were realized in 30 minutes windows twice/week to a general evaluation of the influence social interactions dynamic across experiment. Determination of puberty onset was done by fecal progesterone and estrogens in females, and androgens in males. From the analysis of the multiple regression test was selected a model that evaluate age and seasonal variables effect on the activity rhythm according to the higher explanation coefficient. The total activity was the only parameter influenced by age. Moreover, the activity onset was the parameter more explained by the model, and the sunrise was the factor that most influenced it. After the puberty onset, 2 dyads advanced the activity onset. The activity total decreased in 1 dyad and increased in 2 dyads. This increase may be related to the birth of infants in these families. The motor activity circadian component stabilized later in 1 dyad, coinciding with the puberty onset of these animals, while bimodality, caused by the 8 h component, was modulated by seasonality. The agonistic behavior was not evaluated due to reduced number of events. There were changes across ages in affiliative behavior of contact in 1 dyad, grooming done in 1 animal and grooming received in 2 animals. Although there is evidence of puberty effect on the activity motor rhythm, the photoperiodic fluctuations influenced the rhythm. Therefore is not possible to affirm if the puberty modulate the activity rhythm in marmosets / A maioria dos estudos sobre o sistema de temporiza??o circadiana s?o desenvolvidos em animais adultos, infantes e idosos. A puberdade se tornou uma fase da vida pouco estudada, com exce??o dos trabalhos realizados em adolescentes humanos, que apresentam um atraso de fase no ciclo sono e vig?lia. No entanto, poucos estudos enfocam a base circadiana envolvida nesta mudan?a devido ?s dificuldades metodol?gicas. Dessa forma, um modelo animal para o estudo do ciclo sono e vig?lia na puberdade ? essencial. Em sag?is (Callithrix jacchus), um primata social, a periodicidade circadiana estabiliza em torno dos 4 meses (est?gio juvenil) e o componente ultradiano de 8 horas apresenta varia??o sazonal. A puberdade come?a pr?ximo dos 8 meses nos machos e dos 7 meses nas f?meas, com dura??o de aproximadamente 7 meses. Com o objetivo de caracterizar o ritmo de atividade motora em sag?is na puberdade foi registrada continuamente a atividade motora por act?metros em 6 animais dos 5 a 12 meses de idade. Como os fatores sociais podem influenciar os comportamentos desta esp?cie foram realizadas observa??es comportamentais em janelas de 30 minutos duas vezes/semana para uma avalia??o geral da influencia das intera??es sociais ao longo do experimento. A entrada na puberdade foi determinada a partir dos n?veis fecais de progesterona e estr?genos nas f?meas, e andr?genos nos machos. A partir da an?lise do teste de regress?o m?ltipla foi selecionado um modelo que avaliava o efeito da idade e de vari?veis sazonais sobre os par?metros do ritmo de acordo com o maior coeficiente de explica??o. O total da atividade foi o ?nico par?metro influenciado pela idade. Por outro lado, o in?cio da atividade foi o par?metro mais explicado pelo modelo, sendo o nascer do sol o fator que mais o influencia. Ap?s a entrada na puberdade, 2 d?ades iniciaram a atividade mais cedo. Em rela??o ao total da atividade, houve redu??o em 1 d?ade e aumento em 2 d?ades. Este aumento pode estar relacionado com o nascimento de filhotes nessas fam?lias. O componente circadiano da atividade motora estabilizou mais tarde em 1 d?ade, coincidindo com a entrada na puberdade desses animais. Enquanto que a bimodalidade, decorrente do componente ultradiano de 8 horas, sofreu uma modula??o sazonal. Os comportamentos agon?sticos n?o foram analisados em decorr?ncia do n?mero reduzido de eventos. Os comportamentos afiliativos de contato em 1 d?ade, de cata??o realizada em 1 animal e de cata??o recebida em 2 animais modificaram entre as idades. Embora existam evid?ncias do efeito da puberdade sobre o ritmo de atividade motora, as flutua??es fotoperi?dicas influenciaram o ritmo. Portanto, n?o ? poss?vel afirmar se a puberdade modula o ritmo de atividade motora em sag?is

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-07-14T15:47:32Z No. of bitstreams: 1 camilamendoncanettojobim.pdf: 1741926 bytes, checksum: 4e01cf9852d3df8c3d347e0e79055e6f (MD5) / Approved for entry into archive by Diamantino Mayra (mayra.diamantino@ufjf.edu.br) on 2016-07-19T15:31:18Z (GMT) No. of bitstreams: 1 camilamendoncanettojobim.pdf: 1741926 bytes, checksum: 4e01cf9852d3df8c3d347e0e79055e6f (MD5) / Made available in DSpace on 2016-07-19T15:31:18Z (GMT). No. of bitstreams: 1 camilamendoncanettojobim.pdf: 1741926 bytes, checksum: 4e01cf9852d3df8c3d347e0e79055e6f (MD5) Previous issue date: 2011-02-25 / Pela proximidade filogenética com os seres humanos os primatas não humanos são utilizados freqüentemente em estudos comparativos sobre o comportamento e como modelos experimentais na pesquisa biomédica. Contudo, o uso destes primatas implica numa série de questões éticas, incluindo as condições de seu cativeiro e os potenciais fatores da experimentação que podem acarretar dor, injúrias e estresse, interferindo diretamente no bem-estar do animal. O presente trabalho buscou avaliar as respostas comportamentais e endócrinas de sagüis-de-tufos-pretos (Callithrix penicillata) cativos, machos e fêmeas, frente à técnica de enriquecimento ambiental do tipo alimentar (tubo) e isolamento visual (barreira). As observações foram realizadas em uma amostra de seis fêmeas e seis machos adultos de C. penicillata mantidos no Centro de Biologia da Reprodução da Universidade Federal de Juiz de Fora, Minas Gerais, Brasil. As observações comportamentais foram realizadas antes, durante e depois da aplicação da técnica de enriquecimento, no período da manhã, iniciando entre 10 e 11 horas. A avaliação endócrina foi realizada através da mensuração dos níveis de cortisol presente nas amostras fecais dos animais. Tais análises foram realizadas no Laboratório de Dosagens Hormonais da Universidade Federal do Rio Grande do Norte. Para o enriquecimento alimentar foram encontradas alterações significativas que indicam que este foi eficaz reduzindo comportamentos de alimentação durante a exposição ao enriquecimento e reduzindo a agitação. Para este tipo de enriquecimento os machos se mostraram comportamentalmente mais reativos que as fêmeas e não houve diferença significativa para os níveis de cortisol. Com a utilização do enriquecimento social, foi verificado o conflito gerado com a proximidade entre indivíduos do mesmo sexo, sendo a fase com a barreira a que menos apresentou comportamentos indicativos de estresse, e as fêmeas apresentaram os menores valores para o cortisol. No confronto dos dados de machos e fêmeas, estas se mostraram mais reativas à presença de outras fêmeas, possivelmente pelo fato que sua estratégia reprodutiva ser reflexo do status social. Para os machos o isolamento foi um fator de estresse, uma vez que tiveram maior concentração de cortisol. / Non-human primates are often used in behavioral studies and in biomedical research as a model mainly because their phylogenic proximity to human beings. However, the use of non-human primates in researches implies in many ethical issues, including the captivity conditions and the potential aspects of the procedures that may cause pain, injuries and stress which can interfere with their welfare. The present research intended to analyze the behavioral and endocrine responses of six males and six females of captive black-tuffed marmosets (Callithrix penicillata) to a feeding (tube) and a visual isolation (barrier) environmental enrichment techniques. The animals belong to the colony maintained by Centro de Biologia da Reprodução of Universidade Federal de Juiz de Fora, in Juiz de Fora, Minas Gerais state, in Brazil. The behavior and hormonal data were collected before, during and after the exposure to environmental enrichment. The hormonal analysis of fecal cortisol was performed in the Laboratorio de Dosagens Hormonais of the Universidade Federal do Rio Grande do Norte. During the exposure to the feeding enrichment technique – FASE II, it was observed a decrease in movement and in ingestion of the regular diet by the animals. Besides, in this experiment, the male marmosets were more reactive than the females and no significant differences on cortisol levels were detected. Using the social enrichment (a visual barrier between the cages), it was verified the existence of conflicts between close same-sex animals, which decreased cortisol when the barrier was used. In this case, the marmoset females were more reactive to the enrichment probably because they compete to reproductive as a consequence of social dominance. For males the isolation seems to be a stressful situation since they increase cortisol on this situation.

No description available.

A seizure is defined as an abnormal electrical discharge from the brain that results in the affected area losing its normal function and reacting uncontrollably. A particular subset of seizures, known as absence seizures, are characterized by brief, paroxysmal losses of consciousness that are associated with bilaterally synchronous 3 Hz spike and wave discharges (SWDs) on electroencephalography (EEG). The optimal way to understand any disease state is to study it within the human. Unfortunately, well controlled experiments in humans are difficult due to small patient populations, treatment medications which alter the seizure, and the ethical problems associated with invasive experimental procedures. Animal models of absence seizures provide a means of avoiding the above difficulties but the model should mimic, as closely as possible, the human condition. The goal of this thesis was to develop an animal model of absence epilepsy that could be used to explore, non-invasively, the underlying mechanisms of absence seizures. Functional magnetic resonance imaging (fMRI) was used to non-invasively monitor brain activity during absence seizures in various animal models. In this dissertation I report the development of a pharmacological rat model of absence seizures for use in fMRI investigations. Imaging was performed after absence seizure induction using γ-butyrolactone (GBL) and it was found that the cortico-thalamic circuitry, critical for the formation of SWDs, showed robust signal changes consistent with electroencephalographic recordings in the same animals. Since a major disadvantage of the GBL rat model is that it produces acute, drug-induced seizures, a genetic rat model with spontaneous absence seizures was subsequently developed for fMRI. EEG-triggered fMRI was used to identify areas of brain activation during spontaneous SWDs in the epileptic WAG/Rij rat strain under awake conditions. Significant signal changes were apparent in several areas of the cortex and several important nuclei of the thalamus. These results draw an anatomical correlation between areas in which there is increased fMRI signal and those where SWDs have been previously recorded using electrophysiologic techniques. One way in which absences differ between humans and both of these rat models is that the SWD frequency in humans is classically 3 Hz while in rats it varies from 7 to 11 Hz. Marmoset monkeys were found to model the human absence seizure condition better than other animals because GBL administration in these non-human primates results in the formation of 3 Hz SWDs. This monkey model was developed for awake functional imaging and changes in signal intensity in the thalamus and sensorimotor cortex correlated with the onset of 3 Hz SWDs. The change in BOLD signal intensity was bilateral but heterogeneous, affecting some brain areas more than others.

No description available.