In contrast to no detectable general cytotoxicity (Fig 4B), KCl-induced depolarization (Fig 5G) demonstrates various degree of calcium influx dysregulation in SH-SY5Y inoculated 3 days with individual AD brain-derived tau seeds (S6A,S6B, S6D, and S6E Fig), likely linked to excitotoxicity [65,66], with the most significant impact of AD brain-derived conformers with structurally exposed R1 domain (P = 0.006) (Fig 5H). This evidence concerns the gene MAPT and Alzheimer disease.