Visual functional effects of constant blue light in a retinal degenerate rat model.
Retinal degenerative conditions increase susceptibility to light damage, but rapid retinal degeneration (RD) models show less susceptibility to cyclic dim light. We investigated whether constant blue light (BL) exposure can eliminate the residual visual responses in a comparatively rapid RD rat model. Pigmented rhodopsin mutant S334ter line-3 rat pups (21 days old) were exposed for 5-6 consecutive days to constant BL. Visual behavior was evaluated with an optokinetic head tracking apparatus. Electrophysiological recordings were made from the superior colliculus (SC). S-antigen, red-green opsin and rhodopsin immunoreactive residual photoreceptors were counted. Following BL exposure, head tracking was significantly reduced at 0.25 cycles degree(-1) in 38-day-old line 3 rats. With a 0.125 cycles degree(-1) stimulus, the head tracking performance of 80-day-old BL rats were similar to that of 220-day-old no-BL-treated line-3 rats. SC recordings also revealed a significant decrease in the residual photoreceptor activity. Histological evaluation showed reduction of the rod population in the central area of the light-damaged retina. Exposure to constant BL considerably reduces the residual visual responses in a rapid degenerating RD rat model.
Thomas
Biju B
BB
Doheny Retina Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA.
Seiler
Magdalene J
MJ
Aramant
Robert B
RB
Samant
Deedar
D
Qiu
Guanting
G
Vyas
Neil
N
Arai
Shinichi
S
Chen
Zhenhai
Z
Sadda
SriniVas R
SR
D000367:Age Factors; D000818:Animals; D004594:Electrophysiology; D008027:Light / Q000009:adverse effects*; D023421:Models, Animal; D009154:Mutation; D020419:Photoreceptor Cells, Vertebrate; D051381:Rats; D012162:Retinal Degeneration / Q000209:etiology* / Q000503:physiopathology; D017948:Retinal Rod Photoreceptor Cells / Q000473:pathology; D012243:Rhodopsin / Q000235:genetics
D012243:Rhodopsin