Summary
This thesis explores two aspects of photoreceptor biology: restoring light sensitivity in degenerated cone photoreceptors using halorhodopsin (a potential therapy for retinitis pigmentosa), and characterizing microRNA turnover regulated by light adaptation in the retina. While primarily basic science, the findings have implications for understanding retinal light-processing mechanisms and developing vision-restoration therapies relevant to patients with hereditary blindness.
Key Findings
- Halorhodopsin expression in light-insensitive cones restored light sensitivity in mouse models of retinitis pigmentosa, reactivating retinal cone pathways, cortical circuits, and visually guided behaviors.
- Human ex vivo retinas could be reactivated using halorhodopsin, and blind patients with persisting light-insensitive cones were identified as candidates for this therapy.
- miR-183/96/182 cluster, miR-204, and miR-211 levels were down-regulated during dark adaptation and up-regulated in light-adapted mouse retinas, with rapid decay and increased transcription driving these changes.
- MicroRNA turnover in retinal, hippocampal, and cortical neurons was substantially faster than in non-neuronal cells, with neuronal activity (glutamate stimulation) accelerating and activity blockade reducing turnover rates.
Categories
Eye Health & Vision: The thesis directly addresses retinal photoreceptor dysfunction, retinitis pigmentosa, and therapeutic restoration of light sensitivity in cone photoreceptors.
The Science of Light: The second project investigates microRNA regulation by light levels in the retina, revealing molecular mechanisms of light adaptation in photoreceptor cells.
Author(s)
V Busskamp
Publication Year
2010
Related Publications
Eye Health & Vision
- Diminished pupillary light reflex at high irradiances in melanopsin-knockout mice
- Genetic reactivation of cone photoreceptors restores visual responses in retinitis pigmentosa
- Melanopsin and rod–cone photoreceptors play different roles in mediating pupillary light responses during exposure to continuous light in humans
- Characteristic patterns of dendritic remodeling in early-stage glaucoma: evidence from genetically identified retinal ganglion cell types
- Intrinsically photosensitive melanopsin retinal ganglion cell contributions to the pupillary light reflex and circadian rhythm
The Science of Light
- Phototransduction by retinal ganglion cells that set the circadian clock
- Color appearance models
- The mammalian circadian timing system: organization and coordination of central and peripheral clocks
- Diminished pupillary light reflex at high irradiances in melanopsin-knockout mice
- Melanopsin is required for non-image-forming photic responses in blind mice