Diagnostic methods for neural disorders

Abstract

The invention generally relates to optical methods for the diagnosis of neuronal condition by converting a cell from a patient into a neuron and optically evaluating action potentials of that cell in vitro. The cell is transformed with an optical reporter and exhibits an optical signature in response to neural stimulation. Using genome-editing, a control cell can be made that is isogenic but-for a known mutation and a control signature obtained from the control cell. Thus, methods of the invention reveal potential neurodegenerative effects of a mutation as manifested in a patient's genetic context. The optical signature of the cell, or the difference between the signature and the control signature, is correlated to a diagnosis of the neurodegenerative disease

1 - 31 . (canceled) 
     
     
         32 . A method of diagnosing schizophrenia, the method comprising:
 obtaining an cell from a person suspected of having schizophrenia;   causing the cell to express an optical reporter of electrical activity;   observing a signature generated by the optical reporter in response to a stimulation of the cell; and   comparing the observed signature to an expected signature, wherein a difference between the observed signature and the expected signature corresponds to a positive diagnosis of schizophrenia.   
     
     
         33 . The method of  claim 32 , further comprising causing the cell to express an optical actuator that initiates an action potential in response to optical stimulation. 
     
     
         34 . The method of  claim 33 , wherein the stimulation of the cell comprises illuminating the optical actuator. 
     
     
         35 . The method of  claim 32 , wherein obtaining the cell comprises obtaining a somatic cell from the subject and converting the somatic cell into an electrically active cell type. 
     
     
         36 . The method of  claim 35 , wherein the somatic cell is converted into a neuron. 
     
     
         37 . The method of  claim 35 , wherein converting the somatic cell into an electrically active cell type comprises one selected from the list consisting of: direct lineage conversion; and through an iPS intermediary. 
     
     
         38 . The method of  claim 35 , further comprising obtaining the expected signal by obtaining a control cell suspected of not having the condition and observing a control signal generated by a control optical reporter in the control cell. 
     
     
         39 . The method of  claim 38 , wherein obtaining the control cell comprises editing a genome from the subject such that the control cell and the cell are isogenic but for a mutation. 
     
     
         40 . The method of  claim 32 , wherein causing the cell to express the optical reporter comprises transforming the cell with a vector bearing a genetically encoded fluorescent voltage reporter. 
     
     
         41 . The method of  claim 40 , wherein the vector also comprises a genetically encoded optical voltage actuator. 
     
     
         42 . The method of  claim 32 , wherein observing the signal comprises observing a cluster of different cells with a microscope and using a computer to isolate the signal generated by the optical reporter from a plurality of signals from the different cells. 
     
     
         43 . The method of  claim 42 , wherein the computer isolates the signal by performing an independent component analysis and identifying a spike train associated with the cell. 
     
     
         44 . The method of  claim 32 , wherein the difference between the observed signal and the expected signal comprises a modified probability of a voltage spike in response to the stimulation of the cell relative to a control. 
     
     
         45 . The method of  claim 32 , wherein the difference between the observed signal and the expected signal comprises a decreased probability of a voltage spike in response to the stimulation of the cell relative to a control and an increased probability of a voltage spike during periods of no stimulation of the cell relative to a control 
     
     
         46 . A method for determining an effect of a compound for treatment of schizophrenia, the method comprising:
 presenting a compound to a sample comprising a neuron that expresses an optical reporter of membrane electrical potential;   receiving, via a microscopy system, an optical signal generated by the optical reporter in response to optical stimulation of a light gated ion channel in the sample following presentation of said compound; and   identifying the compound as a candidate for treatment of schizophrenia based on said optical signal.   
     
     
         47 . The method of  claim 46 , wherein a plurality of samples are exposed to a plurality of different compounds. 
     
     
         48 . The method of  claim 46 , wherein the light gated ion channel comprises an algal channelrhodopsin being expressed by a second neuron in synaptic communication with the neuron, and the optical reporter of membrane potential comprises a microbial rhodopsin with between 1 and 10 amino acid substitutions relative to a wild type form of the microbial rhodopsin. 
     
     
         49 . The method of  claim 48 , wherein the neuron also expresses a genetically-encoded indicator of intracellular calcium level. 
     
     
         50 . The method of  claim 46 , wherein the neuron is caused to express both the optical reporter of membrane electrical potential and the light gated ion channel. 
     
     
         51 . The method of  claim 50 , further comprising transforming the neuron with a vector that includes a nucleic acid encoding the optical reporter of membrane electrical potential and the light gated ion channel. 
     
     
         52 . The method of  claim 46 , further comprising performing the steps on a control sample, wherein the neuron in the sample is isogenic with cells in the control sample but for a mutation. 
     
     
         53 . The method of  claim 46 , wherein receiving the optical signal comprises observing a cluster of cells with a microscope and using a computer to isolate a signal generated by the optical reporter from among a plurality of signals from the cluster of cells. 
     
     
         54 . The method of  claim 53 , wherein the computer isolates the signal by performing an independent component analysis and identifying a spike train produced by the neuron. 
     
     
         55 . The method of  claim 54 , further comprising using the microscopy system to obtain an image of a plurality of clusters of cells.