Made available in DSpace on 2014-12-17T15:36:51Z (GMT). No. of bitstreams: 1 CrhistianeAS.pdf: 3837481 bytes, checksum: 1e934fe40afea6283d1a23747a0954ea (MD5) Previous issue date: 2007-09-06 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The principal zeitgeber for most of species is the light-dark photocycle (LD), though other environment factors as food availability, temperature and social cues may act. Daily adjustment of the circadian pacemaker may result from integration of environmental photic and non-photic cues with homeostatic cues. Characterization of non-photic effects on circadian timing system in diurnal mammals is scarce in relation to nocturnal, especially for ecologically significant cues. Thus, we analyzed the effect of conspecific vocalizations and darkness on circadian activity rhythm (CAR) in the diurnal primate Callithirx jacchus. With this objective 7 male adults were isolated in a room with controlled illumination, temperature (26,8 ? 0,2?C) and humidity (81,6 ? 3,6%), and partial acoustic isolation. Initially they were under LD 12:12 (~300:2 lux), and subsequently under constant illumination (~2 lux). Two pulses of conspecific vocalizations were applied in total darkness, separated by 22 days, at 7:30 h (external time) during 1 h. They induced phase delays at circadian times (CTs) 1 and 10 and predominantly phase advances at CTs 9 and 15. After that, two dark pulses were applied, separated by 14 days, during 1 h at 7:30 h (external time). These pulses induced phase delays at CTs 2, 3 and 18, predominantly phase advances at CTs 8, 10 and 19, and no change at CT 14. However, marmosets CAR showed oscillations in endogenous period and active phase duration influenced by vocalizations from animals outside the experimental room, which interfered on the phase responses to pulses. Furthermore, social masking and relative coordination with colony were observed. Therefore, phase responses obtained in this work cannot be attributed only to pulses. Afterwards, pulses of conspecific vocalizations were applied in total darkness at 19:00 h (external time), during 1 h for 5 consecutive days, and after 21 days, for 30 consecutive days, on attempt to synchronize the CAR. No animal was synchronized by these daily pulses, although oscillations in endogenous period were observed for all. This result may be due to habituation. Other possibility is the absence of social significance of the vocalizations for the animals due to random reproduction, since each vocalization has a function that could be lost by a mixture of sounds. In conclusion, conspecific vocalizations induce social masking and relative coordination in marmosets CAR, acting as weak zeitgeber / O principal zeitgeber para a maioria das esp?cies ? o ciclo claro-escuro (CE), por?m outros fatores ambientais como disponibilidade de alimento, temperatura e pistas sociais podem atuar. O ajuste di?rio do marcapasso circadiano deve resultar da integra??o de pistas ambientais, f?ticas e n?o-f?ticas, com pistas homeost?ticas. Como a caracteriza??o do efeito de est?mulos n?o-f?ticos sobre o sistema de temporiza??o circadiano em mam?feros diurnos ? escassa em rela??o aos noturnos, principalmente em rela??o a pistas com significado ecol?gico, analisamos o efeito de vocaliza??es de co-espec?ficos e do escuro sobre o ritmo circadiano de atividade motora (RCA) do primata diurno Callithrix jacchus. Com esse objetivo, foram isolados 7 machos adultos em uma sala com ilumina??o, temperatura (26,8 ? 0,2?C) e umidade (81,6 ? 3,6%) controladas e isolamento ac?stico parcial. Inicialmente os animais ficaram sob CE 12:12 (~300:2 lux) e posteriormente sob claro constante (~2 lux). Foram aplicados dois pulsos de vocaliza??es de co-espec?ficos em escuro total, com um intervalo de 22 dias, ?s 7:30 h (hor?rio local) durante 1 h. Esses pulsos desencadearam atrasos de fase nas horas circadianas (HCs) 1 e 10 e predominantemente avan?os de fase nas HCs 9 e 15. Depois foram aplicados dois pulsos de escuro, com um intervalo de 14 dias, ?s 7:30 h (hor?rio local) durante 1 h. Esses pulsos desencadearam atrasos de fase nas HCs 2, 3 e 18, predominantemente avan?os de fase nas HCs 8, 10 e 19, e nenhuma resposta na HC 14. Contudo, o RCA dos sag?is apresentou modula??es no per?odo end?geno e na dura??o da fase ativa por influ?ncia de vocaliza??es emitidas pelos animais de fora da sala, que interferiram nas respostas aos pulsos. Inclusive, foram observados mascaramento social positivo e coordena??o relativa com a col?nia. Portanto, as respostas de fase obtidas nesse trabalho n?o podem ser atribu?das apenas aos pulsos. Posteriormente foram aplicados pulsos de vocaliza??es de co-espec?ficos em escuro total ?s 19 h (hor?rio local), durante 1 h por 5 dias consecutivos, e ap?s 21 dias, por 30 dias consecutivos, para sincronizar o RCA. Nenhum animal sincronizou o RCA aos pulsos di?rios, embora tenham ocorrido modula??es no per?odo end?geno de todos. Esse resultado pode ter sido decorrente de habitua??o ao est?mulo. Outra possibilidade ? a falta de significado social para os animais devido ? reprodu??o aleat?ria das vocaliza??es, visto que cada vocaliza??o tem uma fun??o que pode ter sido perdida com a mistura dos sons. Concluindo, vocaliza??es de co-espec?ficos induzem mascaramento social e coordena??o relativa no RCA de sag?is, atuando como zeitgebers fracos