Chunk #5 — Results — Human neuron/astrocyte co-culture in combination with simultaneous differentiation of NPCs improves synchronization of calcium oscillations and network activity
In addition to electrophysiological recordings on single cells we studied the development of neuronal connectivity on neuronal network level with live cell calcium imaging. Using an in-house optimized assay (Fig. 3a)16, functionality of differentiating hiPSC-derived neuronal networks was followed over a time course of 2–5 weeks after final plating. Neural precursor cells were plated with or without human astrocytes in the presence or absence of DAPT (Fig. 3b). We focused on the percentage of active neurons, bursting frequency and synchronicity (i.e. the mean Pearson’s correlation between calcium indicator traces of single cells16). All conditions were compared to the initial protocol, which is monoculture without DAPT (Fig. 3b). When neurons were co-cultured with primary human astrocytes in the presence of DAPT, the percentage of active neurons was significantly increased at all time points measured while bursting frequency and synchronicity were significantly higher from week 3 onwards compared to monocultures (Fig. 3b). All measured parameters reached a plateau 4 to 5 weeks after final plating and remained high at least up to week 8 (Fig. 3c). The individual contributions of DAPT treatment
