We next asked whether human neurons would establish functional connections. Our system is designed to contain a large, open center well with room for a microscope objective and patch clamp apparatus (see Fig. 1,5a) or suitable to be used for functional analysis using an inverted microscope. Previous studies have shown the ability of compartmentalized systems to record inter-chamber communication using calcium imaging12,21. While our system has the capacity for calcium imaging, we designed the system to have an large open well to allow for electrophysiology, which measures high temporal resolution (in millisecond scale) neuronal firing or synaptic transmission. This aspect strengthens the relevance of our approach, as it enables more complex functional analyses of neurocircuitries. Whole-cell patch clamping experiments were performed on neurons cultured in the central chamber. These neurons are capable of firing spontaneous repetitive action potentials (Fig. 5b) as well as induced action potentials (Fig. 5c). Whole-cell current recordings under voltage clamp revealed both fast activating and inactivating sodium current responses as well as outward currents mediated by potassium channels (Fig. 5d). Finally, post synaptic currents could be
