Evidence for age-related changes in the circadian activity rhythm of the diurnal primate Callithrix jacchus: a case report

• Autor(a) principal: Gonçalves, Fabiana Barbosa
• Data de Publicação: 2016
• Outros Autores: Borges, Galileu R., Gonçalves, Bruno S. B., Cavalcante, Jeferson de Souza, Menezes, Alexandre A. L., Azevedo, Carolina Virginia Macedo de
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRN
• Texto Completo: https://repositorio.ufrn.br/handle/123456789/31020
• topic: Aging; Synchronization; Ontogenesis; Non-human primates; Marmoset

Many cross-sectional studies have shown that circadian rhythms change with age, but such age-related modifications are gradual and may be insufficiently described by cross- sectional studies. In the present case study, circadian activity rhythm (CAR) was evaluated longitudinally, in both LD (12:12) and LL conditions, on two occasions in a single male marmoset: when “adult” (3 y.o.) and when “old” (9 y.o.). When adult, the CAR synchronized with positive phase angles for the onset and offset of activity. In LL, the rhythm free-ran with τ < 24 h. When old, the animal showed a significant phase delay of its activity rhythm with respect to the LD cycle (t-test, p<0.01) and a reduction on total daily activity (t-test, p<0.01), with signs of lesser stability, greater fragmentation and some loss of photic synchronization. In LL, the period free-ran with τ > 24 h. We conclude that aging attenuates photic synchronization and the expression of a circadian activity rhythm in LL in the marmoset. Further studies with a larger number of individuals are needed to confirm these findings