In vitro microelectrode array (MEA) assessment using human induced pluripotent stem cell (iPSC)-derived neurons holds promise as a method of seizure and toxicity evaluation. However it is difficult to detect the response of drugs with different mechanisms of action with a single parameter, and the analysis method has become an issue. One effective way to solve this problem is to obtain more detailed information on neural network activity. Therefore, in this study, we cultured human iPS cell-derived cortical neurons on a 236,880-electrode CMOS-MEA and obtained precise single-neuron electrical activity.
As a result of acquiring spontaneous activity after 6 weeks of culture, an average of 296 ± 47 neurons (n = 9 wells) were identified, and network bursting was observed. There, 4-AP 10-30 µM, PTX 1-10 µM, AP5 25 µM, and CNQX 30 µM were administered, and in addition to conventional network burst analysis, we analyzed the burst activity of single-neuron and the synaptic connections between neurons that form networks. As a result of burst analysis, parameters with statistically significant changes were different between network burst and single burst, and the number of concentrations with significant differences also increased with single burst. In addition, in synaptic connections analysis, 4-AP showed no significant change, whereas PTX showed enhanced synaptic connections. CMOS-MEA, which can accurately acquire the electrical activity of single neurons, can increase the number of parameters that can be used to evaluate the effects of drugs, so it is effective as a method for predicting toxicity and the mechanism of action of compounds.