Engineering circuits of human iPSC-derived neurons and rat primary glia

Abstract

Novel in vitro platforms based on human neurons are needed to improve early drug testing and address the stalling drug discovery in neurological disorders. Topologically controlled circuits of human induced pluripotent stem cell (iPSC)-derived neurons have the potential to become such a testing system. In this work, we build in vitro co-cultured circuits of human iPSC-derived neurons and rat primary glial cells using microfabricated polydimethylsiloxane (PDMS) structures on microelectrode arrays (MEAs). Our PDMS microstructures are designed in the shape of a stomach, which guides axons in one direction and thereby facilitates the unidirectional flow of information. Such circuits are created by seeding either dissociated cells or pre-aggregated spheroids at different neuron-to-glia ratios. Furthermore, an antifouling coating is developed to prevent axonal overgrowth in undesired locations of the microstructure. We assess the electrophysiological properties of different types of circuits over more than 50 days, including their stimulation-induced neural activity. Finally, we demonstrate the inhibitory effect of magnesium chloride on the electrical activity of our iPSC circuits as a proof-of-concept for screening of neuroactive compounds.

Driving electrochemical reactions at the microscale using CMOS microelectrode arrays

“…We observed that neurons avoided regions patterned with PMOXA and preferentially grew on locations with PLL. While this patterning approach on MEAs is less effective than the use of microstructures, 23,24,43,44 our results serve as a proof-of-concept that surface patterns on MEAs can be induced in situ to introduce neural guidance at unprecedented spatial resolutions in vitro . Microstructures excel in the guidance of neurons due to their three-dimensional physical confinement of neurons.…”