Neuronal Activity Characterization via MEA

NPCs of each line were plated at a density of 10,000 cells/well in six wells of a 96-well multielectrode array activity (MEA) plate coated with poly-l-ornithine and laminin for neuronal differentiation as described before [16 (link)]. Recordings were performed in a Maestro MEA system and AxIS software (Axion Biosystems) using a bandwidth with a filter for 200 Hz to 3 kHz cutoff frequencies. Spike detection was performed using an adaptive threshold set to 5.5 times the standard deviation of the estimated noise on each electrode. Each plate was acclimatized for 10 min in the Maestro Instrument and recorded for 10 min for quantification. Recordings were performed before media change. Multi-electrode data analysis was performed using the Axion Biosystems Neural Metrics Tool and the mean spontaneous neuronal bursts (spontaneous neuronal activity) value was determined in each well. Averages of wells with at least one active electrode were considered for the analysis presented per each cell line. An electrode was considered active at a threshold of five spikes/min. An average of 14–16 electrodes were active per line, with some variations. Only the wells that exhibited activity were included in the analysis. Neuronal firing synchrony per well was not evaluated for these experiments.