Interestingly, no drop of the synaptic density was detected close to plaques in APP/PSEN1/APOEnull mice (8.51 × 108 ± 76.51 × 107 PSD95 puncta/mm3 and 9.53 × 108 ± 7.03 × 107 synapsin positive puncta/mm3), which was significantly higher than the synaptic density measured in the vicinity of amyloid deposits in APP/PSEN1 mice (P = 0.0345), and comparable with wild-type and APOEnull animals. The gene discussed is APP; the disease is amyloidosis.