Peripheral Rods Evade Light Damage in Albino Trout

Allen, Donald M.; Hendricks, Gordon C.; Hallows, Ted E.

doi:10.1007/978-1-4615-1355-1_31

Cited by 3 publications

(13 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…and embedded in epoxy resin as described previously~Allen & Hallows, 1997; Allen et al, 1999Allen et al, , 2001!. and embedded in epoxy resin as described previously~Allen & Hallows, 1997; Allen et al, 1999Allen et al, , 2001!.…”

Section: Histology and Labelingsupporting

confidence: 89%

“…Both TUNEL-positive and pyknotic nuclei were located in the vitread portion of the ONL, and were observed rarely in the peripheral regions of the retina, where light damage is less pronounced~current study, Allen et al, 2001!. In Series 1, TUNEL label was increased at all time-points, including a significant increase at 10 days of light damage. Observations during both experiments~Series 1 and 2!…”

supporting

confidence: 92%

“…degradation, there was no decrease in the number of ONL nuclei~Allen & Hallows, 1997; Allen et al, 1999Allen et al, , 2001!. degradation, there was no decrease in the number of ONL nuclei~Allen & Hallows, 1997; Allen et al, 1999Allen et al, , 2001!.…”

Section: Discussionmentioning

confidence: 99%

“…and normal retinal structure were maintained~Fig. This limited ONL loss had not been observed in albino trout during previous experiments Allen & Hallows, 1997;Allen et al, 1999Allen et al, , 2001! ROS were also maintained in albinos protected from sunlight~Fig.…”

Section: Histology Of Light-damaged Retinaementioning

confidence: 99%

See 3 more Smart Citations

Photic history modifies susceptibility to retinal damage in albino trout

Allison

Hallows²,

Johnson

et al. 2006

Vis Neurosci

Self Cite

View full text Add to dashboard Cite

Albino vertebrates exposed to intense light typically lose photoreceptors via apoptosis, and thus serve as useful models of retinal degeneration. In contrast, albino rainbow trout exposed to intense light maintain populations of rod and cone nuclei despite substantial damage to rod outer segments (ROS). The aim of this study was to differentiate between two hypotheses that could account for this divergent result: (1) trout rod nuclei remain intact during light damage, or (2) rod nuclei die but are replaced by cell proliferation. A further aim was to examine whether photic history modulates retinal damage, as in rodents. Albino and normally pigmented trout were moved from defined photic regimes into full daylight, while some were not moved to serve as protected controls. ROS were always maintained in pigmented fish and in albinos protected from full daylight. In albinos exposed to full daylight, ROS were removed over most of the central retina, whereas rod nuclei were maintained in the outer nuclear layer over 10 days. Pyknotic and TUNEL-labeled rod nuclei were abundant in affected albinos at all time-points tested. Rod death occurred without a decrease in the number of rod nuclei, confirming that proliferation must be replacing cells. Indeed a transient increase in proliferation was observed in retinal progenitors of albinos receiving 5 days of damaging light. This proliferative response was decreased with further damage. Cones remained intact even in areas where rod nuclei had degenerated. Pretreatment with light of moderate versus low intensity light affected the cell death and proliferative responses, and the ectopic localization of rod opsin. We conclude that apoptotic demise of rods, but not cones, occurred during light damage in retinas of albino trout and proliferative responses have a limited a capacity to replace lost rods.

show abstract

Section: Histology and Labelingsupporting

confidence: 89%

supporting

confidence: 92%

Section: Discussionmentioning

confidence: 99%

Section: Histology Of Light-damaged Retinaementioning

confidence: 99%

See 2 more Smart Citations

Photic history modifies susceptibility to retinal damage in albino trout

Allison

Hallows²,

Johnson

et al. 2006

Vis Neurosci

Self Cite

View full text Add to dashboard Cite

show abstract

“…Salmonids have various other features that facilitate a study of retinal development, such as light-induced degeneration of rod outer segments (Allen and Hallows, 1997;Allen et al, 2001) and disappearance of accessory corner cones (ACC) from their square cone mosaic. Because the loss of this cone type coincides with a decrease in visual sensitivity to ultraviolet (UV) light 1 the ACC have been putatively identified as UV wavelength-sensitive 2 (UVS) cones (Kunz, 1987).…”

mentioning

confidence: 99%

Ontogeny of ultraviolet‐sensitive cones in the retina of rainbow trout (Oncorhynchus mykiss)

Allison

Dann

Helvik

et al. 2003

J of Comparative Neurology

View full text Add to dashboard Cite

In order to facilitate emerging models of retinal development, we developed electroretinogram and in situ hybridization protocols to examine the ontogeny of photoreceptors in the retina of a land-locked salmonid, the rainbow trout (Oncorhynchus mykiss). We cloned cDNA fragments corresponding to the rod opsin and each of the four cone opsin gene families, which we utilized to produce riboprobes. We established the specificity of the in situ hybridization protocol by examining subcellular signal localization and through double-labeling experiments. We confirm the assumption that the accessory corner cones in the square mosaic are the ultraviolet wavelength-sensitive (UVS) cone photoreceptor (i.e., they express an SWS1 opsin) and observed UVS cones throughout the retina of small trout. Larger fish have a decrease in sensitivity to short wavelength light stimuli and the distribution of UVS cones in the mature retina is limited to the dorsal-temporal quadrant. These larger fish also possess differentiated UVS cones in the peripheral germinal zone (PGZ), including within areas peripheral to mature retina lacking UVS cones. These data are consistent with the loss of putative UVS cones from the PGZ of a migratory salmonid of another genus, and thus the disappearance of UVS cones appears to be general to the Family Salmonidae, regardless of life history strategy. The generation, differentiation, and subsequent loss of UVS cones in the smolt PGZ is a dramatic example of the supposition that the mechanisms of PGZ development recapitulate the retinal embryogenesis of that species.

show abstract