Differential regulation of feeding rhythms through a multiple-photoreceptor system in an avian model of blindness.

VALDEZ DJ; NIETO PS; DÍAZ NM; GARBARINO PICO E; GUIDO ME

FEDERATION AMER SOC EXP BIOL

Lugar: Nueva York; Año: 2013 vol. 27 p. 2702 - 2702

ll organisms have evolved photodetection systems to synchronize their physiology and behaviorwith the external light-dark (LD) cycles. In nonmammalian vertebrates, the retina, the pineal organ, and the deep brain can be photoreceptive. Inner retinal photoreceptors transmit photic information to the brain and regulate diverse nonvisual tasks. We previously reported that even after preventing extraretinal photoreception, blind GUCY1* chickens lacking functional visual photoreceptors could perceive light that modulates physiology and behavior. Here we investigated the contribution of different photoreceptive system components (retinal/pineal and deep brain photoreceptors) to the photic entrainment of feeding rhythms. Wild-type (WT) and GUCY1* birds with head occlusion to avoid extraocular light detection synchronized their feeding rhythms to a LD cycle with light >12 lux, whereas at lower intensities blind birds free-ran with a period of >24 h. When released to constant light, both