Light-activated cation channel and uses thereof
The present invention provides compositions and methods for light-activated cation channel proteins and their uses within cell membranes and subcellular regions. The invention provides for proteins, nucleic acids, vectors and methods for genetically targeted expression of light-activated cation channels to specific cells or defined cell populations. In particular the invention provides millisecond-timescale temporal control of cation channels using moderate light intensities in cells, cell lines, transgenic animals, and humans. The invention provides for optically generating electrical spikes in nerve cells and other excitable cells useful for driving neuronal networks, drug screening, and therapy.
1. A method of delivering a light-activated cation channel protein into a subject, the method comprising:
a) administering to the subject an implantable prosthetic device comprising a cell expressing the light-activated cation channel protein, wherein the light-activated cation channel protein comprises an amino acid sequence having at least 95% amino acid sequence identity to the amino acid sequence set forth in SEQ ID NO:1;
b) introducing to the subject a light source near the implantable prosthetic device; and
c) activating the light activated cation channel protein expressed in the cell using light from the light source.
2. The method of claim 1 , wherein the light-activated cation channel protein is ChR2.
3. The method of claim 2 , wherein said activation of the light-activated cation channel protein expressed in the cell causes a release of a peptide by the cell expressing the light-activated cation channel protein.
4. The method of claim 3 , wherein said peptide is insulin, leptin, neuropeptide Y, substance P, human growth hormone, secretin, glucagon, endorphin, oxytocin, vasopressin, orexinlhypocretin, or a combination thereof.
5. The method of claim 2 , wherein said activation of the light-activated cation channel protein expressed in the cell causes a synaptic event, wherein the synaptic event comprises a release of a small molecule neuromodulator by the cell expressing the light-activated cation channel protein.
6. The method of claim 5 , wherein the small molecule comprises nitric oxide or a cannabinoid.
7. The method of claim 1 , wherein the nucleotide sequence comprises the sequence of SEQ ID NO:2 or SEQ ID NO:3.
8. The method of claim 1 , wherein the step of activating the light activated cation channel protein includes presenting a series of light pulses at a frequency rate of about 5 Hz or more, about 10 Hz or more, or about 20 Hz or more.
9. The method of claim 1 , wherein the cell is selected from the group consisting of: a retinal cell, a spiral ganglion cell, and a neuron.
10. The method of claim 9 , wherein the cell is a pain pathway neuron, a peripheral neuron, a neuron of the anterior cingulate cortex, or a neuron of the subgenual cingulate cortex.
11. The method of claim 1 , wherein said administering comprises administering the implantable prosthetic device under the skin, under the skull, or in the brain of the subject.
12. The method of claim 1 , wherein the method further comprises detecting a sound with a microphone of the implantable prosthetic device.
13. The method of claim 12 , wherein the method further comprises analyzing the frequency components of the sound and converting the frequency components of the sound to light-emitting diode (LED) signals.
14. The method of claim 13 , wherein the light from the light source is emitted in a spatially patterned fashion.
15. The method of claim 1 , wherein the light activated cation channel protein is encoded by a nucleotide sequence present in a viral vector, wherein the light activated cation channel protein-encoding nucleotide sequence is operably linked to a cell-specific promoter.
16. The method of claim 15 , wherein the cell-specific promoter is a somatostatin promoter, a parvalbumin promoter, a GABA-6 promoter, a calbindin promoter, or an EF1-alpha promoter.
17. The method of claim 1 , wherein the light source is an implantable light source.