Optically-based stimulation of target cells and modifications thereto

Abstract

Stimulation of target cells using light, e.g., in vivo or in vitro, is implemented using a variety of methods and devices. One example involves a vector for delivering a light-activated molecule comprising a nucleic acid sequence that codes for light-activated molecule. The light-activated molecule includes a modification to a location near the all- trans retinal Schiff base, e.g., to extends the duration time of the open state. Other aspects and embodiments are directed to systems, methods, kits, compositions of matter and molecules for ion channels or pumps or for controlling currents in a cell (e.g., in in vivo and in vitro environments).

1 .- 30 . (canceled) 
     
     
         31 . A method of modulating the activity of a mammalian neuron, the method comprising exposing the mammalian neuron to blue light, wherein the mammalian neuron expresses a light-responsive ion channel comprising an amino acid sequence having at least 90% amino acid sequence identity to the amino acid sequence set forth in SEQ ID NO:2, wherein the ion channel exhibits an extended conducting state after exposure to a light pulse, and wherein the ion channel comprises a substitution of a Cys residue at a position corresponding to amino acid residue 123 (C123) of SEQ ID NO:2 with a serine and a substitution of an Asp residue at a position corresponding to amino acid residue 151 (D151) of SEQ ID NO:2 with an alanine, wherein said exposing depolarizes the mammalian neuron, thereby activating the neuron. 
     
     
         32 . The method of  claim 31 , wherein the light-responsive ion channel comprises an amino acid sequence having at least 95% amino acid sequence identity to the amino acid sequence set forth in SEQ ID NO:2. 
     
     
         33 . The method of  claim 31 , wherein the mammalian neuron is in vivo. 
     
     
         34 . The method of  claim 31 , wherein the mammalian neuron expresses a hyperpolarizing light-activated chloride pump, wherein exposing the hyperpolarizing light-activated chloride pump to yellow light hyperpolarizes the mammalian neuron, thereby inhibiting the neuron. 
     
     
         35 . The method of  claim 34 , wherein the hyperpolarizing light-activated chloride pump comprises an amino having at least 90% amino acid sequence identity to the amino acid sequence set forth in SEQ ID NO:3. 
     
     
         36 . The method of  claim 31 , wherein the mammalian neuron is a hippocampal neuron. 
     
     
         37 . The method of  claim 31 , wherein the mammalian neuron is a cholinergic motoneuron. 
     
     
         38 . The method of  claim 31 , wherein the mammalian neuron is a GABAergic neuron. 
     
     
         39 . The method of  claim 31 , modulating the activity of the mammalian neuron comprises use of a system comprising:
 a) a delivery device, wherein the delivery device comprises:
 i) the light-responsive ion channel, or 
 ii) a nucleic acid encoding the light-responsive ion channel; 
   b) a light source; and   c) a control device.   
     
     
         40 . The method of  claim 39 , wherein the light source comprises a light-emitting diode. 
     
     
         41 . The method of  claim 39 , wherein the light source comprises a laser. 
     
     
         42 . The method of  claim 39 , wherein the nucleic acid is a gene transfer vector. 
     
     
         43 . The method of  claim 42 , wherein the gene transfer vector is a lentivirus vector. 
     
     
         44 . The method of  claim 39 , wherein the delivery device is implantable. 
     
     
         45 . The method of  claim 39 , wherein the nucleic acid is present in a dehydrated material or a water-soluble material. 
     
     
         46 . The method of  claim 45 , wherein the water-soluble material is a gelatin. 
     
     
         47 . The method of  claim 39 , wherein the nucleic acid is an expression vector. 
     
     
         48 . The method of  claim 47 , wherein the expression vector is an adeno-associated virus vector. 
     
     
         49 . The method of  claim 47 , wherein the expression vector is an adenovirus-based vector. 
     
     
         50 . The method of  claim 47 , wherein the expression vector is a herpes simplex virus-based vector.