Figure 2

Electrophysiological properties of neurons in cerebral spheroids. (a) Upper trace: representative trace in current clamp mode showing spontaneous action potentials. Lower trace: representative trace in voltage-clamp mode showing spontaneous putative sEPSCs. (b) Input–output curves as a measure of excitability in spheroids at different times of culture. Neurons in spheroids show a maximum action potential frequency around 50–100 pA of injected current after which a depolarization block is observed. Data represents mean ± SEM of excitable cells described in Table 1. No statistical difference observed between day 70–80 and day 115–120. (c) Example of a burst of action potentials in a putative mature neuron triggered by100 pA of injected current. (d) Example of a depolarization block in a putative immature neuron.