DKK1 and Alzheimer disease: Twenty-Four hours after treatment, neuronal cultures were fixed, and non-direct immunofluorescence against synaptic proteins was used to examine pre- and post-synaptic puncta Cortico-hippocampal cultures from 3xTg-AD mice transfected with miR-431 prior to treatment with Dkk1 showed a significantly higher number of presynaptic sites (70.14 ± 3.097, n = 41) in comparison to cultures treated with Dkk1 and transfected with a negative miRNA mimic control (52.32 ± 3.343, n = 37, p < 0.005) (Figure 3A).