To test whether PB-AD neurons integrate into E/I networks alongside glutamatergic neurons, we co-cultured 3 DPI PB-AD neurons with 3 DPI glutamatergic NGN2 neurons in networks containing 100%, 30% (as found in the human cortex36–38) and 0% inhibitory neurons (Figure 2A–C). Here, NEUROG2 is linked to Alzheimer disease.