This is in keeping with previous analysis reporting no alterations in synapse density or synapse contact area in 13-month-old 3xTg-AD mice.37 Interestingly, when synaptosome preparations were immunoblotted with antibodies against tau and APP, the results suggested a transient trend towards upregulation of tau in the synaptic compartment in young (1–2-month-old) mice that was lost with aging (Figure 3b). This evidence concerns the gene APP and Alzheimer disease.