Maintaining the appropriate balance of excitation (E) vs. inhibition (I) in the nervous system is essential for normal brain function, as disruptions in E/I balance are associated with disorders such as autism spectrum disorder (ASD), schizophrenia, and seizures. Development of therapeutics for ASD and schizophrenia has lagged due to their multifactorial etiology and challenges in modeling relevant biology in scalable in vitro assays. The Optopatch platform recently developed at Q-State Biosciences, which uses engineered optogenetic proteins, custom microscopes, and software, makes it possible to simultaneously stimulate (blue light) and record (red light) electrical activity from ~100 neurons with 1 millisecond temporal resolution, single-cell spatial resolution and high signal-to-noise ratio. In addition to measurements of intrinsic excitability, patterned blue light can be used to probe synaptic connections by stimulating a subset of neurons and recording postsynaptic potentials (PSPs) in all remaining cells. The Optopatch assays, which record signals in individual neurons, can be paired with fluorescent labels of inhibitory neurons to identify compounds that differentially affect signaling in excitatory and inhibitory cells and would be expected to shift the E/I balance. In Phase I of this project, we propose to 1) adapt the established Q-State assays for intrinsic excitability and synaptic transmission to measure the E/I balance and 2) validate these assays using tool compounds and gene knockdowns expected to shift the E/I balance. In Phase II, we propose to 3) screen annotated compound libraries, 4) confirm that proteins targeted by compounds in the library can modulate the E/I balance, and 5) validate that identified targets can also shift the E/I balance in human stem-cell derived neurons and in rodent brain slice. The identified protein targets will serve as a starting point for drug discovery, and identified FDA- approved compounds may be repurposed for new indications. The suite of tools developed here will pave a new path for developing E/I-modulating therapeutics for treating complex neurological disorders such as autism and schizophrenia.
Public Health Relevance Statement: Project Narrative The balance between excitatory (E) and inhibitory (I) signaling in the brain is essential for healthy brain function - disruptions in this delicate balance have been linked to multiple, poorly treated neurological disorders including depression, schizophrenia, autism, and epilepsy. Q-State has developed engineered proteins and custom microscopes that enable us to rapidly record excitatory and inhibitory signaling in thousands of neurons grown in a dish. We will screen a library of small molecules for compounds capable of tuning the E/I balance and characterize the compounds to determine their likelihood of being developed into effective therapeutics for neurological conditions.
Project Terms: Affect; Automation; Mental disorders; psychological disorder; psychiatric illness; mental illness; Psychiatric Disorder; Psychiatric Disease; Mental health disorders; Biological Assay; Biologic Assays; Bioassay; Assay; Biological Sciences; Life Sciences; Bioscience; Biologic Sciences; Biology; Brain; Encephalon; Brain Nervous System; Cell Body; Cells; depression; Mental Depression; Disorder; Disease; Dissection; drug/agent; Pharmaceutic Preparations; Medication; Drugs; Pharmaceutical Preparations; electrostimulation; Electrical Stimulation; Electric Stimulation; electrophysiological; Neurophysiology / Electrophysiology; Electrophysiology; Electrophysiology (science); Elements; Engineering; Environment; epileptogenic; epileptiform; epilepsia; Seizure Disorder; Epileptics; Epileptic Seizures; Epilepsy; balance function; balance; Equilibrium; Family; Foundations; Genes; Modern Man; Human; In Vitro; Industrialization; Internuncial Neuron; Internuncial Cell; Intercalated Neurons; Intercalary Neuron; Connector Neuron; Interneurons; Membrane Channels; Ionic Channels; Ion Channel; heavy metal lead; heavy metal Pb; Pb element; Lead; Libraries; Photoradiation; Light; Illumination; Lighting; muscular; Muscle Tissue; Muscle; Neurologic Organ System; Neurologic Body System; Nervous System; Nervous system structure; neurological disease; Neurological Disorders; Neurologic Disorders; Nervous System Diseases; nervous system disorder; Neural Transmission; Synaptic Transmission; neuronal; Neurocyte; Neural Cell; Nerve Unit; Nerve Cells; Neurons; Noise; optical; Optics; Patients; Perfusion; Pharmacology; Phenotype; protein design; genetic protein engineering; Protein Engineering; Proteins; Publishing; Ribonucleic Acid; RNA Gene Products; Non-Polyadenylated RNA; RNA; mRNA; Messenger RNA; Rodents Mammals; Rodentia; Rodent; schizophrenic; dementia praecox; Schizophrenic Disorders; Schizophrenia; Seizures; biological signal transduction; Signaling; Signal Transduction Systems; Intracellular Communication and Signaling; Cell Signaling; Cell Communication and Signaling; Signal Transduction; Software; Computer software; synapse; Synaptic; Synapses; Testing; Body Tissues; Tissues; Translating; Work; Measures; antisense oligo; anti-sense oligo; anti-sense agent; Antisense Agent; Anti-Sense Oligonucleotides; Antisense Oligonucleotides; Mediating; promotor; promoter; Custom; base; Label; Microscope; Acute; Phase; Physiological; Physiologic; Neurologic; Neurological; Link; Chemicals; Individual; Measurement; Therapeutic; tool; Life; millisecond; Msec; Complex; Protocols documentation; Protocol; cell type; Pattern; System; Country; Spinal; small molecule libraries; chemical library; voltage; neurotransmission; neuronal signaling; neural signaling; nerve signaling; glial signaling; glia signaling; axonal signaling; axon-glial signaling; axon signaling; Neuronal Transmission; Nerve Transmission; Nerve Impulse Transmission; G-Protein-Coupled Receptors; GPCR; G Protein-Coupled Receptor Genes; G Protein-Complex Receptor; Modeling; response; high throughput screening; High Throughput Assay; drug discovery; Pharmacological Substance; Pharmaceuticals; Pharmaceutical Agent; Pharmacologic Substance; Brain region; disease causation; causation; Causality; Etiology; small molecule; datamining; data mining; autism spectrum disorder; autistic spectrum disorder; Kanner's Syndrome; Infantile Autism; Early Infantile Autism; Autistic Disorder; Autism; Data; Resolution; in vitro Assay; Slice; Small Business Innovation Research Grant; Small Business Innovation Research; SBIR; Validation; Image; imaging; human stem cells; inhibitory neuron; knock-down; knockdown; design; designing; neuronal excitability; novel strategies; novel strategy; novel approaches; new approaches; Treatment Efficacy; therapy efficacy; therapeutically effective; therapeutic efficacy; intervention efficacy; aging brain; aged brain; induced pluripotent stem cell; iPSCs; iPSC; iPS; postsynaptic; therapeutic development; therapeutic agent development; FDA approved; optogenetics; screening; differential expression; transcriptional differences; differentially expressed; temporal measurement; time measurement; temporal resolution; Drug Screening; single-cell RNA sequencing; single cell RNA-seq; scRNA-seq; analysis pipeline; off-label use; off-label prescribing; off-label application
