Indeed, we found that at 2 weeks in culture, the PS1 mutant AD neurons (M146V/WT and ΔE9/WT) manifested greater sodium and potassium current densities, increased electrical capacitance, and increased synaptic density measured histologically compared to their gene-corrected isogenic WT counterparts (Figure 3A–E, Figure 3—figure supplement 1A–D, Figure 3—figure supplement 2A,B). Here, PSEN1 is linked to Alzheimer disease.