Michael Nestor

Director, Neural Stem Cell Research 

Investigator, Program in Neuroscience 

Hussman Institute for Autism


Characterization of multiple phenotypes in individuals with idiopathic autism using high-throughput screening of hiPSC-derived cortical organoids 

Individuals with Autism Spectrum Condition (ASC) exhibit a number of neurodevelopmental and behavioral challenges that are centered on repetitive behaviors, interests, and difficulties with social and emotional communication. These behaviors may have their basis in aberrant neurodevelopmental mechanisms in cortical networks conferred by a convergence of genes.  Although critical, gaining an understanding of phenotypic differences inherent in the neurons of autistic individuals remains a central challenge for the field. An emergent hypothesis in autism research is that the imbalance of excitatory and inhibitory (E/I) inputs within neural networks in autistic brains may account for some of the behavioral phenotypes observed in these individuals. The homeostatic regulation of the balance between E/I neurons and their synaptic inputs is required to maintain the narrow range of optimal neuronal spiking required for the transfer of information within the brain.  

To understand the role of E/I inputs in autism we employ a human induced pluripotent stem cell (hiPSC)-derived 3D organoid model system called a serum free embryoid body (SFEB). This system is an in vitro platform that may more accurately recapitulate human cortical development. SFEBs are used to test for potential differences in the morphology and network-level function that are specific to cortical neurons derived from ASC patient hiPSCs. We combine the use of SFEBs with high-throughput approaches to compensate for heterogeneity and variability inherent in 3D cultures. High-throughput screening using the ThermoFisher ArrayScan XTi platform was employed to quantify GABA+ and VGLUT+ cells in SFEBs and VGLUT+ neuron morphology in individuals with and without autism. Network-level activity was recorded from SFEBs using multi-electrode arrays. We observed fewer GABA+ cells and more spiking in a number of individuals with autism within our small cohort. These findings indicate that potential E/I deficits found in this ASC cohort can be detected using high-throughput approaches. 

 

Biography

Dr. Michael W. Nestor is the Director of Neural Stem Cell Research The Hussman Institute for Autism and Co-Chair, Neural Stem Cell Working Group, Center for Stem Cell Biology & Regenerative Medicine at the University of Maryland, School of Medicine. Dr. Nestor received his Ph.D. in Neuroscience from The University of Maryland, School of Medicine and completed postdoctoral fellowships at the National Institutes of Health, Rutgers University as an NIH IRACDA Fellow, and at The New York Stem Cell Foundation, where he was also a Staff Scientist. Dr. Nestor is an AAAS Executive Branch Science & Technology Policy Fellow and Adviser at The University of Maryland, Maryland Momentum Fund/UM Ventures-Department of Technology Transfer. Dr. Nestor is a neurophysiologist with 15 years of experience and a focus on electrophysiology, neural stem cell biology, genetics and project management. His laboratory works on assay development with an emphasis on cell based pre-clinical high throughput drug screens and phenotyping assays involving human iPSC-derived cortical organoids from individuals with autism.

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