Summary
This thesis investigates the molecular basis of melanopsin-driven light sensitivity by silencing OPN4 in rod/cone-deficient mice, establishing a reproducible in vivo model using pupillometry as a functional readout. The work has implications for future therapies aimed at restoring residual light sensitivity in blind patients by leveraging or augmenting the ipRGC/melanopsin pathway.
Key Findings
- siRNA-mediated knockdown achieved >85% silencing of melanopsin (OPN4) protein in Neuro2A cells as confirmed by immunolabelling.
- Intravitreal siRNA injection in rd and rd/rd cl mice inhibited pupil light responses in vivo, functionally confirming Opn4 silencing detected by RT-PCR and molecular analysis.
- The study established a novel reproducible in vivo model linking siRNA-induced melanopsin pathway silencing to measurable pupillometric and molecular endpoints across multiple timepoints.
Categories
The Science of Light: Investigates the molecular mechanisms of melanopsin (OPN4)-mediated phototransduction using siRNA knockdown in mouse models, directly probing ipRGC photoreceptor biology.
Eye Health & Vision: Explores therapeutic potential of OPN4 ectopic expression for restoring light sensitivity in degenerate retinas with complete photoreceptor loss.
Author(s)
AN Vachtsevanos
Publication Year
2012
Related Publications
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
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