starting the experiments. To record action potentials (in current clamp mode), cells were injected with current to maintain the cells at a holding potential of −65 mV. Steps of 50 pA were applied to evoke spiking within a range of −200 to 400 pA. Evoked responses were recorded from 4 time points (week 1: 7–12 days after final plating; week 2: 13–17 days after final plating; week 3: 21–24 days after final plating; week 4–5: 30–36 days after final plating), in order to monitor the progressive maturation of the neuronal culture.
