Sustained synchronized neuronal network activity in a human astrocyte co-culture system

Abstract

Impaired neuronal network function is a hallmark of neurodevelopmental and neurodegenerative disorders such as autism, schizophrenia, and Alzheimer's disease and is typically studied using genetically modified cellular and animal models. Weak predictive capacity and poor translational value of these models urge for better human derived in vitro models. The implementation of human induced pluripotent stem cells (hiPSCs) allows studying pathologies in differentiated disease-relevant and patient-derived neuronal cells. However, the differentiation process and growth conditions of hiPSC-derived neurons are non-trivial. In order to study neuronal network formation and (mal) function in a fully humanized system, we have established an in vitro co-culture model of hiPSC-derived cortical neurons and human primary astrocytes that recapitulates neuronal network synchronization and connectivity within three to four weeks after final plating. Live cell calcium imaging, electrophysiology and high content image analyses revealed an increased maturation of network functionality and synchronicity over time for co-cultures compared to neuronal monocultures. The cells express GABAergic and glutamatergic markers and respond to inhibitors of both neurotransmitter pathways in a functional assay. The combination of this co-culture model with quantitative imaging of network morphofunction is amenable to high throughput screening for lead discovery and drug optimization for neurological diseases. ; The research leading to these results has received support from the Innovative Medicines Initiative Joint Undertaking under grant agreement no. 115439, resources of which are composed of financial contribution from the European Union's Seventh Framework Programme (FP7/2007-2013) and EFPIA companies in kind contribution. This publication reflects only the author's views and neither the IMI JU nor EFPIA nor the European Commission are liable for any use that may be made of the information contained therein. This work was supported by the University of Antwerp (WDV: TTBOF 29267), the Institute for the Promotion of Innovation by Science and Technology (IWT) (JK GM PV BB: no. 120511; JD WDV: no. 140775; PV WDV: no. 150003), by the Fonds Wetenschappelijk Onderzoek (FWO) (MV: no. 11ZF116N) in Flanders and by the 7th Framework Program of the European Commission Marie Curie NAMASEN Network Grant no. 264872 (TO). The authors thank the Janssen Neuroscience department for scientific advice and helpful discussions and Andreas Ebneth for critical review of the manuscript.