Long-term electrophysiological activity and pharmacological response of a human induced pluripotent stem cell-derived neuron and astrocyte co-culture

Abstract

Human induced pluripotent stem cell (hiPSC)-derived neurons may be effectively used for drug discovery and cell-based therapy. However, the immaturity of cultured human iPSC-derived neurons and the lack of established functional evaluation methods are problematic. We here used a multi-electrode array (MEA) system to investigate the effects of the co-culture of rat astrocytes with hiPSC-derived neurons on the long-term culture, spontaneous firing activity, and drug responsiveness effects. The co-culture facilitated the long-term culture of hiPSC-derived neurons for >3 months and long-term spontaneous firing activity was also observed. After >3 months of culture, we observed synchronous burst firing activity due to synapse transmission within neuronal networks. Compared with rat neurons, hiPSC-derived neurons required longer time to mature functionally. Furthermore, addition of the synapse antagonists bicuculline and 6-cyano-7-nitroquinoxaline-2,3-dione induced significant changes in the firing rate. In conclusion, we used a MEA system to demonstrate that the co-culture of hiPSC-derived neurons with rat astrocytes is an effective method for studying the function of human neuronal cells, which could be used for drug screening.

Is the time right for in vitro neurotoxicity testing using human iPSC-derived neurons?

“…These findings extend data from Dage et al (2014), who showed that iCell neurons respond with robust calcium transients in response to GABA and NMDA exposure up to DIV28. Nevertheless, it is important to characterize any iPSC-derived model and elucidate the receptor profile at different days in culture prior to neurotoxicity testing, as it has been shown that cellular properties can vary over time due to the maturation process of the cells (Odawara et al, 2014;Dage et al, 2014).…”

“…Nevertheless, future experiments using human iPSCs should focus on identification of culture conditions that allow bursting behavior and increase MSR as well as the percentage of active wells and the percentage of active electrodes. In this respect it should be noted that co-culturing human iPSC-derived neurons with astrocytes may enhance synaptic maturation and transmission (Clarke and Barres, 2013) as well as firing frequency and bursting behavior (Odawara et al, 2014).…”

“…Notably, our data on spontaneous network activity is derived from iCell and DOPA.4U neurons in the absence of (added) astrocytes. Future studies may therefore also need to focus on co-cultures of human iPSC-derived neurons with astrocytes, as it has been shown that this can enhance firing frequency and bursting levels (Odawara et al, 2014).…”

“…While it is long known that astrocytes can affect the vulnerability of primary cultures to toxic insults (e.g., Dugan et al, 1995), adding astrocytes to pure neuronal cultures may also alter neuronal development and enhance cell signaling (Clarke and Barres, 2013;Odawara et al, 2014). Moreover, addition of astrocytes may affect chemical sensitivity as it has been shown, using a mixed culture of NTERA-2 (NT2) cells, that astrocytes are more sensitive to, e.g., lead chloride and aluminum nitrate than neurons (Laurenza et al, 2013).…”

Rapid Neuronal Differentiation of Induced Pluripotent Stem Cells for Measuring Network Activity on Micro-electrode Arrays

“…Previously, protocols used for studying hiPSC-derived neuronal networks with MEAs relied on time-consuming differentiation procedures [13][14][15][16] . The protocol from Zhang et al (2013) provides a rapid alternative, and our modification removes a source of variability, which makes it now more feasible to use hiPSC-derived neurons in combination with MEA technology, especially in highthroughput or pharmacological studies.…”