Systems, methods and compositions for optical stimulation of target cells
Methods, systems and devices are implemented in connection with light-responsive ion channel molecules. One such method is implemented using a light-activated ion channel molecule that responds to a light stimulus. The method includes engineering the light-activated ion channel molecule in a cell; and activating the ion channel molecule, in response to light stimulus that is provided to the ion channel molecule and that has properties that do not activate a ChR2 ion channel, to allow ions to pass through the light-activated ion channel molecule.
1. A method for modulating the activity of a cell engineered to express a Volvox carteri light-responsive ion channel protein (VChR1), the method comprising:
activating the light-responsive VChR1 protein with light.
2. The method of claim 1 , wherein the cell is a stem cell.
3. The method of claim 1 , wherein the light-responsive VChR1 protein is activated by light having a wavelength in a range of from 535 nm to 589 nm.
4. The method of claim 1 , wherein the light-responsive VChR1 protein comprises the amino acid sequence set forth in SEQ ID NO:3.
5. The method of claim 1 , wherein the cell is a neuronal cell.
6. The method of claim 5 , wherein the light-responsive VChR1 protein is encoded by a nucleotide sequence operably linked to an alpha-CaMKII promoter.
7. The method of claim 1 , wherein the light-responsive VChR1 protein is encoded by a nucleotide sequence that is optimized for expression in a mammalian cell.
8. The method of claim 1 , wherein the light-responsive VChR1 protein is encoded by an expression vector.
9. The method of claim 8 , wherein the expression vector is a viral vector.
10. The method of claim 9 , wherein the viral vector is a lentiviral vector or an adenoassociated virus (AAV) vector.
11. The method of claim 1 , wherein the cell is further engineered to express a light-responsive ChR2 protein from Chlamydomonas reinhardtii.
12. The method of claim 11 , wherein the ChR2 protein comprises the amino acid sequence set forth in SEQ ID NO:2.
13. The method of claim 1 , wherein the cell is further engineered to express a light-responsive NpHR protein from Natromonas pharaonis.
14. The method of claim 1 , wherein the ChR2 protein is activated by light having a wavelength of 589 nm