Compared with sham mice, AD mice underwent splenectomy displayed less staining for markers of viable neurons (NeuN) and dendrites (Map2) (t = 2.89, p = 0.013 for NeuN; U = 9, p = 0.029 for Map2; Figure 5e) and more staining for an apoptosis‐related protein (activated caspase‐3) in the hippocampus (t = 2.21, p = 0.045; Figure 5e). Here, MAP2 is linked to Alzheimer disease.