INVESTIGADORES
VALDEZ Diego Javier
artículos
Título:
A nonmammalian vertebrate model of blindness reveals functional photoreceptors in the inner retina.
Autor/es:
VALDEZ D J; NIETO PS; GARBARINO-PICO E; AVALLE LB; DÍAZ-FAJRELDINES H; SCHURRER C; CHENG KM; GUIDO ME
Revista:
FASEB JOURNAL
Editorial:
FEDERATION AMER SOC EXP BIOL
Referencias:
Año: 2009 vol. 23 p. 1186 - 1195
ISSN:
0892-6638
Resumen:
ABSTRACT In mammals, photoreceptors located in
the inner retina convey photic information to the brain,
regulating diverse non-image-forming tasks such as
pupillary light reflexes and photic synchronization (entrainment)
of daily activity rhythms. In nonmammalian
vertebrates, the retina, deep brain photoreceptors, and
pineal organ may be photoreceptive. Here we investigated
light perception in the absence of functional cone
and rod photoreceptors using GUCY1* chickens, birds
carrying a null mutation that causes blindness at hatch.
They showed light responses in both the pupillary light
reflex and the entrainment of feeding rhythms to a
12:12 h light-dark cycle. Light responses persisted even
when the extraretinal photoperception was abolished,
but they were lost after enucleation; this strongly indicates
the essential role played by the inner retina. A
sensitivity spectrum study for the pupillary reflex that
combined pupil responses to different monochromatic
lights of various intensities demonstrated that a single
opsin/vitamin A-based photopigment peaking at 484
nm drives photic responses; the best fit (lowest sum of
squares, R2 0.9622) was attained with an opsin:vitamin
A2 template. The results are the first characterization
of functional inner retinal photoreceptors participating
in the regulation of non-image-forming activities in
nonmammalian vertebrates.?Valdez, D. J., Nieto,
P. S., Garbarino-Pico, E., Avalle, L. B., Díaz-Fajreldines,
H., Schurrer, C., Cheng, K. M., Guido, M. E. A nonmammalian
vertebrate model of blindness reveals functional
photoreceptors in the inner retina. FASEB J. 23,
000?000 (2009)