System for optical stimulation of target cells

Abstract

Various systems and methods are implemented for controlling stimulus of a cell. One such method is implemented for optical stimulation of a cell expressing an NpHR ion pump. The method includes the step of providing a sequence of stimuli to the cell. Each stimulus increases the probability of depolarization events occurring in the cell. Light is provided to the cell to activate the expressed NpHR ion pump, thereby decreasing the probability of depolarization events occurring in the cell.

1 .- 10 . (canceled) 
     
     
         11 . An apparatus for optical stimulation of a mammalian cell expressing a light-driven chloride ion pump from  Natronobacterium pharaonis  (NpHR), the apparatus comprising:
 an optical source that provides an optical stimulus comprising yellow light to the cell to activate the expressed NpHR ion pump, thereby inhibiting activity of the cell.   
     
     
         12 . The apparatus of  claim 11 , wherein the optical stimulus provided by the optical source hyperpolarizes the cell. 
     
     
         13 . The apparatus of  claim 11 , wherein the optical source comprises an optical switch. 
     
     
         14 . The apparatus of  claim 13 , wherein the optical source further comprises a dichroic mirror. 
     
     
         15 . The apparatus of  claim 11 , wherein the optical source comprises an array of light emitting diodes (LEDs). 
     
     
         16 . The apparatus of  claim 11 , wherein the cell also expresses a channelrhodopsin-2 ion channel and the optical source is configured to provide an optical stimulus comprising blue light. 
     
     
         17 . The apparatus of  claim 11 , wherein the optical source emits light at a wavelength of about 470 nm. 
     
     
         18 . The apparatus of  claim 11 , wherein the optical source emits light at a wavelength of about 560 nm. 
     
     
         19 . The apparatus of  claim 11 , further comprising a detector for detecting changes in voltage across a cell membrane of the cell. 
     
     
         20 . The apparatus of  claim 11 , wherein the apparatus further comprises a fluorescence detector, and the cell also includes a fluorescent calcium-sensitive dye or a fluorescent voltage-sensitive dye. 
     
     
         21 . The apparatus of  claim 11 , wherein the optical source provides a light pulse at a millisecond time scale. 
     
     
         22 . The apparatus of  claim 11 , wherein the cell is a neuron. 
     
     
         23 . The apparatus of  claim 11 , wherein the apparatus is configured to stimulate the cell in vitro. 
     
     
         24 . The apparatus of  claim 11 , wherein the apparatus is configured to stimulate the cell in vivo. 
     
     
         25 . The apparatus of  claim 11 , wherein the apparatus is a head-mounted apparatus. 
     
     
         26 . The apparatus of  claim 11 , wherein the apparatus is an implantable apparatus. 
     
     
         27 . The apparatus of  claim 26 , wherein the implantable apparatus further comprises an inductor and is configured as a remotely-powered implantable apparatus.