Different research groups have already shown that rodent astrocytes improve the maturation of hiPSC-derived neurons2931. Hence, in order to reduce cell clustering and detachment of hiPSC-derived cortical neuronal networks, we established co-cultures with primary human fetal astrocytes provided by ScienCell™. Immunocytochemistry and microarray data (Supplementary Fig. S1) on different passage numbers of these human primary astrocytes revealed that the expression of astrocyte markers GFAP and S100B (mRNA and protein) decreased with increasing passage numbers. Therefore, only astrocytes passaged for a maximum of 3 times were used for co-cultures. These neuron/astrocyte co-cultures effectively reduced neuronal clumping and detachment in vitro (Fig. 2b).
