Abstracts

Rationale: Functional evaluation assays using human induced pluripotent stem cell (hiPSC)-derived neurons are expected to predict the convulsion toxicity of new drugs and the neurological effects of antiepileptic drugs. However, differences in responsiveness depending on the convulsant type and the antiepileptic drugs, and an evaluation index possible to compare in vitro responses with in vivo responses are not well known. Methods: To evaluate the dynamics of epileptiform activities and the effect of anticonvulsant drug in cultured hiPSC-derived neurons, we used the high-throughput multielectrode array (MEA) system, where we simultaneously record extracellular potentials for 16 channels per well across 24-well plates. Human iPSC-derived cortical neurons were cultured on MEAs chip. Spike analyses were performed using Mobius software (Alpha Med Scientific) and MATLAB.  Results: We found the difference of synchronized burst pattern in the epileptiform activities induced by pentylenetetrazol (PTZ) and 4-aminopyridine (4-AP) with different action mechanisms using multi-electrode arrays (MEAs), and that 100 µM phenytoin suppressed epileptiform activities induced by PTZ, but increased those induced by 4-AP. In order to compare in vitro results with in vivo convulsive responses, frequency analysis of below 250 Hz, excluding the spike component, was performed. The in vivo convulsive firing enhancement of the high ? wave and ß wave component were observed remarkably in in vitro hiPSC-derived neurons with astrocytes in co-culture. Conclusions: MEA measurement of hiPSC-derived neuros in co-culture with astrocytes and our analysis methods including frequency analysis appear to be effective for the prediction of convulsion toxicity, side effects, and their mechanisms of action, as well as the comparison of convulsions induced in vivo. Funding: This study was supported by AMED Grant Number 17935517, Astellas a-cube, JSPS KAKENHI Grant Number 17K20111, 17K15577, 16J02472.