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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Mecanismos de sincronia social no ritmo circadiano de atividade durante a coabita??o em casais de saguis (Callithrix jacchus)

Bessa, Zo?lia Camila Moura 08 June 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-14T20:51:44Z No. of bitstreams: 1 ZoeliaCamilaMouraBessa_DISSERT.pdf: 3791168 bytes, checksum: e624a66aeb2a2192f56727cc91e4cb75 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-17T20:49:25Z (GMT) No. of bitstreams: 1 ZoeliaCamilaMouraBessa_DISSERT.pdf: 3791168 bytes, checksum: e624a66aeb2a2192f56727cc91e4cb75 (MD5) / Made available in DSpace on 2016-06-17T20:49:25Z (GMT). No. of bitstreams: 1 ZoeliaCamilaMouraBessa_DISSERT.pdf: 3791168 bytes, checksum: e624a66aeb2a2192f56727cc91e4cb75 (MD5) Previous issue date: 2015-06-08 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Em saguis, foi observado que a sincronia entre os perfis circadianos de atividade dos animais que vivem em grupo ? mais forte entre os indiv?duos de uma mesma fam?lia do que entre fam?lias diferentes. Dentro do grupo ? mais forte entre juvenis do que entre juvenis e seus pais. No entanto, s?o desconhecidos os mecanismos envolvidos na sincronia social. Com o objetivo de investigar os mecanismos de sincroniza??o envolvidos na sincronia entre os perfis circadianos de atividade em casais de saguis, foi registrada continuamente a atividade motora por act?metros em 3 d?ades. Os casais foram submetidos a duas condi??es de ilumina??o: ciclo claro escuro CE 12:12 (CEJ I - 21 dias), e depois em claro constante (~350 lux). Em CC, os casais foram submetidos a 4 situa??es experimentais: 1. conv?vio completo (CCJ I - 24 dias), 2. remo??o de um membro do casal para outra sala com condi??es semelhantes (CCS I - 20 dias), 3. reintrodu??o do membro do casal na gaiola da 1? situa??o (CCJ II - 30 dias), e 4. remo??o do membro de cada casal para outra sala experimental (CCS II - 7 dias) para avaliar os mecanismos de sincroniza??o. Por fim, os membros do casal foram reintroduzidos na gaiola e submetidos ao ciclo CE 12:12 (CEJ II - 11 dias). Os casais entraram em livre curso na primeira condi??o em CC em conv?vio social, com per?odos id?nticos entre os membros do casal, semelhante ao observado na segunda condi??o. Nas etapas sem conv?vio social, apenas 2 f?meas entraram em livre curso na primeira etapa e 3 animais na segunda. Nas referidas condi??es, os ritmos dos animais de cada casal apresentaram diferentes per?odos end?genos. Al?m disso, nas condi??es com conv?vio social (CEJ e CCJ), os membros do casal apresentaram rela??o de fase est?vel entre si para o in?cio e fim da fase ativa, enquanto que nas etapas com separa??o entre o casal foi observada uma quebra de estabilidade nas rela??es de fase entre os perfis circadianos de atividade, com um aumento na diferen?a de ?ngulo de fase entre o casal. Ao entrar em livre curso, na transi??o entre CEJI e CCJI, todos os animais anteciparam progressivamente o in?cio e o fim da fase ativa em fase semelhante ? condi??o anterior, expressando sinal de arrastamento ao CE anterior. Enquanto que nas etapas seguintes isto foi observado em apenas 3 animais entre CCJI e CCSI, e entre CCJII e CCSII, demonstrando sinais de arrastamento ?s pistas sociais entre os membros dos casais. Por outro lado, 1 animal atrasou progressivamente entre CCJI e CCSI, 3 animais atrasaram entre CCSI e CCJII e 3 animais entre CCJII e CCSII, possivelmente por arrastamento aos animais da parte externa da col?nia. Processo semelhante foi observado em 4 animais entre CCSII e CEJII, indicando arrastamento ao CE. Na transi??o entre o CCSI e CCJII foram observados sinais de mascaramento no ritmo de uma f?mea em resposta ao macho e em outro casal no ritmo do macho em rela??o ao da f?mea. A correla??o geral e m?xima entre os perfis circadianos de atividade dos animais foi mais forte nas condi??es em conv?vio social em CE e CC do que na aus?ncia do conv?vio social em CC, evidenciando o efeito social. Os casais tiveram maiores valores para a correla??o m?xima em CE e CC juntos do que quando os perfis foram correlacionados com animais de gaiolas diferentes de mesmo ou diferente sexo. Resultados semelhantes foram observados na correla??o geral. Portanto, sugere-se que o conv?vio social favorece a uma forte sincronia entre os perfis circadianos de atividade dos casais de sagui, que envolve sincroniza??o por arrastamento e mascaramento. Por?m, estudos adicionais s?o necess?rios para avaliar o efeito das pistas sociais na sincroniza??o do ritmo circadiano da atividade entre casais de saguis na aus?ncia de pistas sociais externas a fim de confirmar esta hip?tese. / In marmosets, it was observed that the synchrony among circadian activity profiles of animals that cohabite in family groups is stronger than those of the same sex and age of different families. Inside the group, it is stronger between the younger ones than between them and their parents. However, the mechanisms involved in the social synchrony are unknown. With the aim to investigate the synchronization mechanisms involved in the synchrony between the circadian activity profiles during cohabitation in pairs of marmosets, the motor activity was continuously registered by the use of actmeters on three dyads. The pairs were maintained in two different conditions of illumination: light-dark cycle LD 12:12 (LD cohabitation I ? 21 days), and thereafter in LL (~350 lux). Under LL, the pairs were submitted to four experimental situations: 1. Cohabitation (LLJ I ? 24 days), 2. Removal of one member of the pair to another room with similar conditions (LLS I ? 20 days), 3. Reintroduction of the separated member in the cage of the first situation (LLJ II ? 30 days) and 4. Removal of a member from each pair to another experimental room (LLS II ? 7 days), to evaluate the mechanisms of synchronization. Ultimately, the members of each pair were reintroduced in the cage and were kept in LD cycle 12:12 (LDJ II ? 11 days). The rhythms of pairs free-ran in LL, with identical periods between the members of each pair during the two stages of cohabitation. In the stages in which the animals were separated, only the rhythms of two females free-ran in the first stage and of three animals in the second one. In those conditions, the rhythms of animals of each pair showed different endogenous periods. Besides, during cohabitation in LD and LL, the members of each pair showed a stable phase relationship in the beginning of the active phase, while in the stages in which the animals were separated it was noticed a breaking in the stability in the phase relationships between the circadian activity profiles, with an increase in the difference in the phase angles between them. During cohabitation, at the transition between LD and LL, all animals showed free-running rhythms anticipating progressively the beginning and the end of the active phase in a phase similar to the previous condition, showing signs of entrainment to the previous LD. While in the posterior stages this was observed in only three animals between: LLT I and LLS I, and LLT II and LLS II, evidencing signs of entrainment to social cues between the members of each pair. On the other hand, one animal delayed progressively between LLT I and LLS I, three animals delayed between LLS I and LLT II, and three animals between LLT II and LLS II, perhaps by entrainment to the animals maintained outdoors in the colony. Similar process was observed in four animals between LLS II and LDT II, indicating entrainment to LD. In the transition between LLS I and LLT II, signs of masking was observed in the rhythm of a female in response to the male and in another pair in the rhythm of the male in regard to that of the female. The general and maximum correlations in the circadian activity profiles were stronger during cohabitation in LD and LL than in the absence of social contact in LL, evidencing the social effect. The cohabiting pairs had higher values of the maximum correlation in LD and LL than when the profiles were correlated to animals of different cages, with same or different sexes. Similar results were observed in the general correlation. Therefore, it is suggested that cohabitation induces a strong synchrony between circadian activity profiles in marmosets, which involves entrainment and masking. Nevertheless, additional studies are necessary to evaluate the effect of social cues on the synchronization of the circadian rhythm in pairs of marmosets in the absence of external social cues in order to confirm this hypothesis.

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