SHANK3 and Alzheimer disease: Synaptic proteins including α3-Na/K-ATPase, synGap, and Shank3 did not show changes at early stages of AD in mice brains (data not shown), however oligomers of Aβ can significantly inhibit Na/K-ATPase activity in vitro (Figure 8) (60) and in vivo (65), which suggests that oligomers of Aβ may regulate Na/K-ATPase activity in AD brain.