We found that application of LiCl for 4 h to 3xTg-AD brain slice cultures at 28 days daysin vitro (DIV) resulted in significantly reduced tau phosphorylation at the Ser396/404 and Ser202/Thr205 epitopes, in addition to causing a subtle reduction in total tau amounts when compared to slices treated with control (NaCl). The gene discussed is MAPT; the disease is Alzheimer disease.