In 1982, I published a review about ultraviolet (UV) visual
sensitivity. Since that time, there have been many reports contradicting
the earlier dogma that vertebrate animals do not see UV. I pursued
this work in collaboration with De-Mao Chen working in my laboratory.
We showed, using electrophysiology, that the juvenile goldfish
is sensitive to UV light while the adult is not. We obtained evidence
that there is a diminution with aging of a UV cone mechanism.
When Guangjun Dong, an EM specialist, came for one year's fellowship
in my laboratory from the Institute of Microbiology in Beijing,
we pursued this topic into the realm of UV light damage. Widespread
cone damage by UV, transmitted through the eye's optics, suggests
a mechanism independent of visual pigment absorbance. It seem
as though the primary site of damage is to mitochondria, which
fits with a growing literature on mitochondrial involvement in
light damage. Surprisingly, UV light was more damaging to double
cones than to UV cones. Protection by retinoic acid adds to a
growing literature on its relevance to visual system.
Paper on UV vision in the goldfish:
Chen, D.-M., Stark, W. S. Electroretinographic analysis of ultraviolet sensitivity in juvenile and adult goldfish retinas, Vision Research, 1994, 34, 2941-2944. PubMed
Chen, D.-M., Dong, G, Stark, W. S. Ultraviolet light damage and reversalby retinoic acid in juvenile goldfish. In Retinal Degenerative Diseasesand Experimental Therapy (eds. J. G. Hollyfield, R. E. Anderson, M. M. LaVail),New York, Plenum, 1999, 325-336.
Spectral sensitivity of Juvenile and adult goldfish (from Chen and Stark, 1994)
A UV cone survives [with normal mitochondria (M)]12 days of light exposure surrounded by damaged double cones with displaced mitochondria (middle of figure). Rods survive (upper right).
The mosaic of a juvenile goldfish shows Double cones (D), Long single cones (Lc), Short single cones (Sc), and ultraviolet cones (uv).
An high magnification electron micrograph of the inner- outer-segment area of a fish cone before light damage
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This page was last updated July 27, 2005