Optical tissue interface method and apparatus for stimulating cells
In one example, a system electrically stimulates target cells of a living animal using an elongated structure, a modulation circuit and a light pathway such as provided by an optical fiber arrangement. The elongated structure is for insertion into a narrow passageway in the animal such that an end of the elongated structure is sufficiently near the target cells to deliver stimulation thereto. The modulation circuit is for modulating the target cells while the elongated structure is in the narrow passageway, where the modulation circuit is adapted to deliver viral vectors through the elongated structure for expressing light responsive proteins in the target cells. The light pathway is used for stimulating the target cells by delivering light to the light-responsive proteins in the target cells.
1. A method for electrically stimulating a target cell of a living animal in vivo, the method comprising:
inserting an elongated structure, having a hollow portion, into a narrow passageway in the animal such that an end of the structure is sufficiently near the target cell to deliver stimulation thereto;
while the elongated structure is in the narrow passageway, delivering a viral vector through the hollow portion of the elongated structure, wherein the viral vector comprises a nucleotide sequence encoding a light-activatable polypeptide having at least 75% amino acid sequence identity to the ChR2 amino acid sequence set forth in SEQ ID NO:1, wherein the nucleotide sequence is operably linked to a target cell type-specific promoter, and wherein said delivering provides for expression of the light-activatable polypeptide selectively in the target cell;
after delivering the viral vector, inserting an optical fiber through the hollow portion of the elongated structure, and
stimulating the target cell by using the optical fiber to deliver light to the light-activatable polypeptide expressed in the target cell.
2. The method of claim 1 , further comprising securing the elongated structure to a skull of the animal.
3. The method of claim 1 , wherein the target cell is an excitable cell.
4. The method of claim 1 , wherein the target cell is a nerve cell, a heart cell, or a muscle cell.
5. A method comprising:
inserting an elongated structure that forms a lumen into a narrow passageway in an animal;
introducing, after insertion and through the lumen, a viral vector comprising a nucleotide sequence encoding a light-activatable polypeptide having at least at least 75% amino acid sequence identity to the ChR2 amino acid sequence set forth in SEQ ID NO:1, wherein said introducing provides for expression of the light-activatable polypeptide in the membrane of a target nerve cell located at a selected target site within the animal, and
introducing, into and through the lumen, an optical delivery arrangement configured for directing at least one flash of light upon the light-activatable polypeptide in the target nerve cell so as to modulate the function of the target nerve cell or surrounding cells.
6. The method of claim 5 , further comprising securing the elongated structure to the animal.
7. The method of claim 1 , wherein the elongated structure comprises multiple parallel optical fibers that terminate around the circumference of the elongated structure, and wherein stimulating the target cells includes activating less than all of the multiple parallel fibers.
8. The method of claim 1 , further comprising the step of measuring electrical properties of the target cell using a microelectrode.
9. The method of claim 1 , wherein the target cell is an electrically active cell of a sinoatrial node and wherein the stimulating of the target cell causes pacing of a heart.
10. The method of claim 1 , wherein the promoter is a CaMKIIα promoter.
11. The method of claim 1 , wherein the nucleotide sequence is optimized for expression in mammalian cells.
12. The method of claim 1 , wherein the light-activatable polypeptide has at least 85% amino acid sequence identity to amino acid sequence set forth in SEQ ID NO:1.
13. The method of claim 1 , wherein the light-activatable polypeptide has at least 95% amino acid sequence identity to amino acid sequence set forth in SEQ ID NO:1.
14. The method of claim 5 , wherein the light-activatable polypeptide has at least 85% amino acid sequence identity to the amino acid sequence set forth in SEQ ID NO: 1.
15. The method of claim 5 , wherein the light-activatable polypeptide has at least 95% amino acid sequence identity to the amino acid sequence set forth in SEQ ID NO:1.
16. The method of claim 1 , wherein the target cell is in the anterior cingulate, the prefrontal cortex, the posterior cingulate gyrus, or a Brodmann Area.
17. The method of claim 1 , wherein the viral vector is a lentiviral vector, an adenoassociated viral vector, a retroviral vector, or an adenoviral vector.
18. The method of claim 5 , wherein the viral vector is a lentiviral vector, an adenoassociated viral vector, a retroviral vector, or an adenoviral vector.
19. The method of claim 1 , wherein the animal is a mammal.
20. The method of claim 5 , wherein the animal is a mammal.