rhodopsin

These observations are consistent with our quantum mechanical model for the energetics of two-photon activation of rhodopsin.

Skin cells are not part of the nervous system, they apparently use rhodopsin just to regulate melanin.

Actually they did use transgenic GM mice, which allow the expression of rhodopsin in activated cells.

The virus did not deliver rhodopsin - but additional genes that allowed the cells of the rats to encode the optogenetic proteins.

And the mice were not genetically modified, the rhodopsin was delivered through a virus.

Your retinas are sensitive to light because light causes certain molecules (rhodopsin, I think) to change form and release energy.

Here are some absorption spectra [3] of crystals of various rhodopsin isomers.

Just a small bag of rhodopsin that triggers a nerve to depolarize.

Only 2 photosynthetic molecules are known so far in all branches of life, chlorophyll and rhodopsin, so the existence of another photosynthetic pathway is pretty surprising!

If the rhodopsin system is easy to retrofit, maybe we can install it into important crops to harvest more of incident light.

I think this is less due to the brain and more due to the chemical regeneration of rhodopsin, which takes time (minutes, even).

You could probably do the same thing with bacterio-rhodopsin.

However, if “rhodopsin becomes superfluous” then it won’t be a survival/reproduction factor.

Rhodopsin, used by phototrophic archea, evolved first and has a broad absorption peak in the green (giving it a purple colour).

Rhodopsin, for example, is a G-protein coupled receptor, which means that activation of the receptor triggers G-proteins inside the cell which can activate or inhibit any number of cellular processes.

Rhodopsin just like a photomultiplier detector has a certain noise level.