Graphs showing the SAS area of asymmetric synapses in the stratum pyramidale (str pyr) and radiatum (str rad) of CA1 in control and Alzheimer’s disease cases. (A and B) Frequency distributions of the SAS areas of asymmetric synapses in controls (green line) and Alzheimer’s disease cases (grey line) in stratum pyramidale (A) and stratum radiatum (B). (C and D) Frequency distributions of the SAS areas of axospinous asymmetric synapses in controls and Alzheimer’s disease cases in stratum pyramidale (C) and stratum radiatum (D). (E and F) Frequency distributions of the SAS areas of macular asymmetric synapses in controls and Alzheimer’s disease cases in stratum pyramidale (E) and stratum radiatum (F). Asymmetric synapses with the largest areas are less frequent in Alzheimer disease cases (see text for further details). Alzheimer = Alzheimer’s disease; Asym = asymmetric synapses. Statistical significance is represented by asterisks (***P < 0.001).