In spite of the prevalence and severity of many neurological disorders, the development of new classes of drugs has been sluggish for decades. The lack of new therapeutics is due, in part, to challenges in replicating the relevant biology in robust, scalable in vitro assays. Synaptic dysfunction, in particular, has been implicated in a number of devastating neurological disorders including epilepsy, Alzheimers disease, Parkinsons disease, Autism Spectrum Disorder (ASD), schizophrenia, depression, ADHD and Huntingtons disease. Current approaches to measuring synaptic function suffer from the difficulty of stimulating the pre-synaptic cell and recording from the post-synaptic cell at a sufficient throughput for drug screening. The Optopatch platform recently developed at Q-State Biosciences, comprised of both engineered optogenetic proteins, custom microscopes, and software, makes it possible to simultaneously stimulate (blue light) and record (red light) electrical activity from around one hundred neurons with one millisecond temporal resolution, single cell spatial resolution and high signal-to-noise. Patterned blue light can be used to stimulate one or a larger subset of neurons while recording from all of the synaptic partners. Using a custom engineered channelrhodopsin for stimulation in combination with red fluorescent sensors of voltage, calcium and pH targeted to pre- and post-synaptic locations, we will develop a set of assays that span synaptic function. Furthermore, we will probe short- and long-term synaptic plasticity using different stimulus regimes. To validate the assays, we will test know pharmacological modulators of synaptic machinery. We will also test for an in vitro phenotype for knockout of a post-synaptic scaffolding protein, SHANK3, whose loss of function has been implicated in ASD and schizophrenia. We will use both mouse and human iPSC-based models of diseased neurons. These optical tools, which can scale to high throughput, have the potential to change the drug screening landscape for neurological disorders. We hope to open a new path to finding treatments for these devastating diseases.
Public Health Relevance Statement: Project Narrative Defective synaptic transmission, the signaling between neurons, is implicated in diverse disorders including epilepsy, Alzheimers, Parkinsons, autism, schizophrenia, depression, ADHD and Huntingtons disease. Progress on new classes of drugs to treat these diseases has been sluggish for decades, largely because of the difficulty of recording from both partners in a signaling pair. We propose to leverage Q-State Biosciences engineered optogenetic proteins and custom microscopes, which enable the simultaneous stimulation and recording of electrical activity from hundreds of neurons in parallel, to develop assays for rapidly screening compounds to treat these debilitating neurological disorders.
Project Terms: Alzheimer's Disease; AMPA Receptors; Attention deficit hyperactivity disorder; autism spectrum disorder; Autistic Disorder; base; Biological Assay; Biological Sciences; Biology; Calcium; Cells; Clustered Regularly Interspaced Short Palindromic Repeats; Computer software; Custom; Data; Devices; digital; Disease; drug discovery; Electrophysiology (science); Engineering; Enhancers; Epilepsy; Functional disorder; GABA Receptor; Genetic; genetic information; Genetic study; Goals; high throughput screening; Human; Huntington Disease; imaging system; improved; in vitro Assay; in vitro Model; in vitro testing; induced pluripotent stem cell; inhibitor/antagonist; instrumentation; Investigation; Kainic Acid Receptors; Knock-out; Knockout Mice; Lead; Light; Location; loss of function; Manuals; Measurement; Measures; Membrane Potentials; Mental Depression; Microscope; millisecond; Modeling; Molecular; Mus; N-Methyl-D-Aspartate Receptors; nervous system disorder; Neurodevelopmental Disorder; Neurons; Noise; novel drug class; novel therapeutics; Optics; optogenetics; Parkinson Disease; patch clamp; Pathway interactions; Pattern; Pharmacology; Phenotype; Physiological; Portraits; postsynaptic; Postsynaptic Membrane; Preclinical Drug Evaluation; presynaptic; Prevalence; Proteins; quasar; Reporter; Reproducibility; Resolution; response; Scaffolding Protein; Schizophrenia; screening; sensor; Severities; Signal Transduction; spatiotemporal; Speed; Staging; Stimulus; success; Synapses; synaptic function; Synaptic plasticity; Synaptic Transmission; Synaptic Vesicles; Technology; temporal measurement; Testing; Therapeutic; Time; tool; Translating; Validation; vesicular release; voltage