Evidence for age-related changes in the circadian activity rhythm of the diurnal primate Callithrix jacchus: a case report |
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| Authors: | Fabiana B Gonçalves Galileu R Borges Bruno S B Gonçalves Jeferson S Cavalcante Alexandre A L Menezes |
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| Institution: | 1. Laboratório de Cronobiologia, Departamento de Fisiologia, Universidade Federal do Rio Grande do Norte, Natal, Brazil;2. Escola Multicampi de Ciências Médicas do Rio Grande do Norte, Universidade Federal do Rio Grande do Norte, Caicó, Brazil;3. Laboratório Interdisciplinar de Neurociências Clínicas, Universidade Federal de, S?o Paulo, Brazil;4. Laboratório de Estudos Neuroquímicos, Departamento de Fisiologia, Universidade Federal do Rio Grande do Norte, Natal, Brazil |
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| Abstract: | 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 this 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 is associated with attenuation of photic synchronization and expression of CAR in LL in the marmoset. Further studies with a larger number of individuals are needed to confirm these findings. |
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| Keywords: | Aging synchronization ontogenesis non-human primates marmoset |
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