Delivery of a light-activated cation channel into the brain of a subject
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 into a brain of a subject, the method comprising: a) administering directly to a portion of a brain in a subject a viral vector comprising a nucleotide sequence encoding a light activated cation channel that comprises an amino acid sequence having at least about 95% amino acid sequence identity to the amino acid sequence set forth in SEQ ID NO: 1, wherein said nucleotide sequence is operably linked to a promoter that provides for expression of the light activated cation channel in a neuron in the portion of the brain, and wherein the portion of the brain is one or more of the anterior cingulate cortex, the subgenual anterior cingulate cortex, and the anterior limb of internal capsule; b) introducing a light source near the portion of the brain; and c) activating the light activated cation channel in the neuron using light from the light source.
2. 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 rate of at least about 20 Hz.
3. The method of claim 1 , wherein the neuron is in the anterior cingulate cortex of the brain.
4. The method of claim 1 , wherein the light activated cation channel protein is ChR2.
5. The method of claim 1 , wherein said activating comprises presenting a series of light pulses separated by less than about 50 milliseconds.
6. The method of claim 1 , wherein said promoter is a Thy1 promoter.
7. The method of claim 1 , wherein said light source is a light-emitting diode, a laser, or a fiber optic cable.
8. The method of claim 1 , wherein the light has an intensity of from 0.1 mW/mm 2 to 50 mW/mm 2 .
9. The method of claim 1 , wherein the light has a wavelength of from 440 nm to 590 nm.
10. The method of claim 1 , wherein the light has a wavelength of from 440 nm to 490 nm.