Phototransuction, Degeneration, Rescue Flashcards
What photopigment is expressed in Rods
Rhodopsin
What is the function of the retina
To transduce light into an electrical signal that is transmitted to the brain
What compound do rods and cones exploit
11-cis-retinal
What is 11-cis-retinal bound to
Opsin signaling protein
What happens to 11-cis-retinal in the presence of light
Isomerized to all-trans-retinal
What causes the inability to se at night after passing an oncoming cars bright lights
Depletion of 11-cis retinal in rods
How is more 11-cigs-retinal made
All trans-retinal is converted back to 11-cis-retinal through a series of enzymatic steps (visual cycle)
- 11-cis-retinal is hit by light and isomerized to all-trans-retinal
- Conformation change in opsin GPCR to signal transduction cascades which causes closure of the cGMP gated cation channels
Photoreceptor is hyperpolarized - After opsin is released, the all-trans-retinal is reduced to all-trans-retinOL
- All-trans-retinOL is transported back to RPE
- 11-CIA retinOL is oxidized and transported back to photoreceptor outer segment
Know this
Look at slide 6-7
Know them!!
What is an ERG
Electroretinogram
What does an ERG measure
Electrical act yet generate d by neural and non-neural cells in the retina in response to light stimulus
Can be used to monitor progression of retinal
What is retinal remodeling
See slide 10 (very complex)
What is RP
Retinal degeneration disease Inherited Defect in rods 1:4000 P23H mutation is most common Irreversible blindess
What is curcumin? What affect does it have on RP
A compound of curry.
It works as a natural neural protectant
What are some therapeutic strategies to restore vision
Gene therapy Viral vectors Retinal prosthesis Stem cell therapy Neurotrophic factors
