The status of cones in the rhodopsin mutant P23H-3 retina: Light-regulated damage and repair in parallel with rods

Vicki Chrysostomou, Jonathan Stone, Sally Stowe, Nigel L. Barnett, Krisztina Valter

Research output: Contribution to journalArticleResearchpeer-review

30 Citations (Scopus)

Abstract

PURPOSE. This study tests whether cones in the rhodopsinmutant transgenic P23H-3 retina are damaged by ambient light and whether subsequent light restriction allows repair of damaged cones. METHODS. P23H-3 rats were raised in scotopic cyclic (12 hours of 5 lux, 12 hours of dark) ambient light. At postnatal day 90 to 130, some were transferred to photopic conditions (12 hours of 300 lux, 12 hours of dark) for 1 week and then returned to scotopic conditions for up to 5 weeks. Photoreceptor function was assessed by the dark-adapted flash-evoked electroretinogram, using a two-flash paradigm to isolate the cone response. Outer-segment structure was demonstrated by immunohistochemistry for cone and rod opsins and by electron microscopy. RESULTS. Exposure for 1 week to photopic ambient light reduced the cone b-wave, the rod b-wave, and the rod a-wave by 40% to 60% and caused shortening and disorganization of cone and rod outer segments. Restoration of scotopic conditions for 2 to 5 weeks allowed partial recovery of the cone b-wave and the rod a- and b-waves, and regrowth of outer segments. CONCLUSIONS. Modest increases in ambient light cause rapid and significantly reversible loss of cone and rod function in the P23H-3 retina. The reduction and recovery of cone function are associated with shortening and regrowth of outer segments. Because the P23H mutation affects a protein expressed specifically in rods, this study emphasizes the close dependence of cones on rod function. It also demonstrates the capacity of cones and rods to repair their structure and regain function.

Original languageEnglish
Pages (from-to)1116-1125
Number of pages10
JournalInvestigative Ophthalmology and Visual Science
Volume49
Issue number3
DOIs
Publication statusPublished - 1 Mar 2008
Externally publishedYes

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Rhodopsin
Retina
Vertebrate Photoreceptor Cells
Light
Rod Opsins
Cone Opsins
Rod Cell Outer Segment
Recovery of Function
Electron Microscopy
Immunohistochemistry
Mutation
Proteins

Cite this

Chrysostomou, Vicki ; Stone, Jonathan ; Stowe, Sally ; Barnett, Nigel L. ; Valter, Krisztina. / The status of cones in the rhodopsin mutant P23H-3 retina : Light-regulated damage and repair in parallel with rods. In: Investigative Ophthalmology and Visual Science. 2008 ; Vol. 49, No. 3. pp. 1116-1125.
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title = "The status of cones in the rhodopsin mutant P23H-3 retina: Light-regulated damage and repair in parallel with rods",
abstract = "PURPOSE. This study tests whether cones in the rhodopsinmutant transgenic P23H-3 retina are damaged by ambient light and whether subsequent light restriction allows repair of damaged cones. METHODS. P23H-3 rats were raised in scotopic cyclic (12 hours of 5 lux, 12 hours of dark) ambient light. At postnatal day 90 to 130, some were transferred to photopic conditions (12 hours of 300 lux, 12 hours of dark) for 1 week and then returned to scotopic conditions for up to 5 weeks. Photoreceptor function was assessed by the dark-adapted flash-evoked electroretinogram, using a two-flash paradigm to isolate the cone response. Outer-segment structure was demonstrated by immunohistochemistry for cone and rod opsins and by electron microscopy. RESULTS. Exposure for 1 week to photopic ambient light reduced the cone b-wave, the rod b-wave, and the rod a-wave by 40{\%} to 60{\%} and caused shortening and disorganization of cone and rod outer segments. Restoration of scotopic conditions for 2 to 5 weeks allowed partial recovery of the cone b-wave and the rod a- and b-waves, and regrowth of outer segments. CONCLUSIONS. Modest increases in ambient light cause rapid and significantly reversible loss of cone and rod function in the P23H-3 retina. The reduction and recovery of cone function are associated with shortening and regrowth of outer segments. Because the P23H mutation affects a protein expressed specifically in rods, this study emphasizes the close dependence of cones on rod function. It also demonstrates the capacity of cones and rods to repair their structure and regain function.",
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The status of cones in the rhodopsin mutant P23H-3 retina : Light-regulated damage and repair in parallel with rods. / Chrysostomou, Vicki; Stone, Jonathan; Stowe, Sally; Barnett, Nigel L.; Valter, Krisztina.

In: Investigative Ophthalmology and Visual Science, Vol. 49, No. 3, 01.03.2008, p. 1116-1125.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - The status of cones in the rhodopsin mutant P23H-3 retina

T2 - Light-regulated damage and repair in parallel with rods

AU - Chrysostomou, Vicki

AU - Stone, Jonathan

AU - Stowe, Sally

AU - Barnett, Nigel L.

AU - Valter, Krisztina

PY - 2008/3/1

Y1 - 2008/3/1

N2 - PURPOSE. This study tests whether cones in the rhodopsinmutant transgenic P23H-3 retina are damaged by ambient light and whether subsequent light restriction allows repair of damaged cones. METHODS. P23H-3 rats were raised in scotopic cyclic (12 hours of 5 lux, 12 hours of dark) ambient light. At postnatal day 90 to 130, some were transferred to photopic conditions (12 hours of 300 lux, 12 hours of dark) for 1 week and then returned to scotopic conditions for up to 5 weeks. Photoreceptor function was assessed by the dark-adapted flash-evoked electroretinogram, using a two-flash paradigm to isolate the cone response. Outer-segment structure was demonstrated by immunohistochemistry for cone and rod opsins and by electron microscopy. RESULTS. Exposure for 1 week to photopic ambient light reduced the cone b-wave, the rod b-wave, and the rod a-wave by 40% to 60% and caused shortening and disorganization of cone and rod outer segments. Restoration of scotopic conditions for 2 to 5 weeks allowed partial recovery of the cone b-wave and the rod a- and b-waves, and regrowth of outer segments. CONCLUSIONS. Modest increases in ambient light cause rapid and significantly reversible loss of cone and rod function in the P23H-3 retina. The reduction and recovery of cone function are associated with shortening and regrowth of outer segments. Because the P23H mutation affects a protein expressed specifically in rods, this study emphasizes the close dependence of cones on rod function. It also demonstrates the capacity of cones and rods to repair their structure and regain function.

AB - PURPOSE. This study tests whether cones in the rhodopsinmutant transgenic P23H-3 retina are damaged by ambient light and whether subsequent light restriction allows repair of damaged cones. METHODS. P23H-3 rats were raised in scotopic cyclic (12 hours of 5 lux, 12 hours of dark) ambient light. At postnatal day 90 to 130, some were transferred to photopic conditions (12 hours of 300 lux, 12 hours of dark) for 1 week and then returned to scotopic conditions for up to 5 weeks. Photoreceptor function was assessed by the dark-adapted flash-evoked electroretinogram, using a two-flash paradigm to isolate the cone response. Outer-segment structure was demonstrated by immunohistochemistry for cone and rod opsins and by electron microscopy. RESULTS. Exposure for 1 week to photopic ambient light reduced the cone b-wave, the rod b-wave, and the rod a-wave by 40% to 60% and caused shortening and disorganization of cone and rod outer segments. Restoration of scotopic conditions for 2 to 5 weeks allowed partial recovery of the cone b-wave and the rod a- and b-waves, and regrowth of outer segments. CONCLUSIONS. Modest increases in ambient light cause rapid and significantly reversible loss of cone and rod function in the P23H-3 retina. The reduction and recovery of cone function are associated with shortening and regrowth of outer segments. Because the P23H mutation affects a protein expressed specifically in rods, this study emphasizes the close dependence of cones on rod function. It also demonstrates the capacity of cones and rods to repair their structure and regain function.

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U2 - 10.1167/iovs.07-1158

DO - 10.1167/iovs.07-1158

M3 - Article

VL - 49

SP - 1116

EP - 1125

JO - Investigative Ophthalmology

JF - Investigative Ophthalmology

SN - 0146-0404

IS - 3

ER -