Banca de DEFESA: ROSANE MARIA SIMON LAMPERT DIAS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : ROSANE MARIA SIMON LAMPERT DIAS
DATA : 29/07/2016
HORA: 13:00
LOCAL: Sala RUTE do Hospital Universitário Onofre Lopes
TÍTULO:

Effect of wavelenght and intensity of light on circadian activity rhythm in marmosets (Callithrix jacchus)

PALAVRAS-CHAVES:

Lights wavelength; Photic entrainment; Diurnal primates; Callithrix jacchus.

PÁGINAS: 107
GRANDE ÁREA: Ciências Humanas
ÁREA: Psicologia
RESUMO:

Circadian entrainment depends on a complex interaction between light information and photoreceptor cells. The neurobehavioral circadian light effects are mediated primarily by retinal ganglion cells. Rods and cones operate in light detection and also interfere in the circadian timing system, but the mode of action of these photoreceptors in the control of circadian rhythms in diurnal non-human primates is unknown. Our study evaluated the effect of wavelength and intensity of light on parameters of the circadian activity rhythm in marmosets by analyzing the effect of short and long wavelengths of light in three light intensities. The locomotor activity was monitored by infrared sensors in 16 adult male marmosets, kept in controlled temperature and humidity in a light/dark cycle 12:12. The effect of two wavelengths in light phase were evaluated: short, with λmax 463 nm - in the spectral region of blue light, and long: with λmax 631 nm - in the spectral region of red light, in three light intensities: 200, 100 and 10 lux, in relation to control condition (fluorescent light). At the end of each stage, the marmosets were maintained in constant light (10 lux and 200) to analyze the mechanisms of synchronization involved. An interval lasting for 15 days (fluorescent light - 200 lux /lux 2) was done between the stages with different wavelengths. During the exposure to blue and red lights, the phase angle of the end of active phase was anticipated, and the duration of the active phase and the total daily activity were lower in relation to the control condition, with modulations at 10 lux. There was an increase in the power of circadian period in blue and red lights in LL under 200 lux. We also observed that the duration of the experiment modifies the expression of circadian activity rhythm, possibly affecting the photoreception mechanisms in adult marmosets. From these results it is suggested that: 1) the blue and red wavelengths modify the endogenous expression and the photic synchronization of the circadian activity rhythm in marmosets; 2) the animals respond differently to the blue and red wavelengths at the beginning and end of the active phase, with a larger advance the end of the active phase, reducing the length of the alpha and the total daily activity, probably due to a masking effect; 3) the effect of wavelength varies depending on the light intensity, with no difference between the intensities of 200 and 100 lux and a greater instability at 10 lux; 4) the duration of exposure of animals to the blue and red wavelengths is a factor to be considered in the construction of experimental protocols with this species.

MEMBROS DA BANCA:
Presidente - 1199136 - CAROLINA VIRGINIA MACEDO DE AZEVEDO
Externo à Instituição - CRHISTIANE ANDRESSA DA SILVA - UFPB
Externo à Instituição - GISELE AKEMI ODA - USP
Interno - 1216466 - JOHN FONTENELE ARAUJO
Interno - 2140860 - ROVENA CLARA GALVAO JANUÁRIO ENGELBERTH