To further corroborate our functional results, the in vivo biochemical response of neurons to visual stimulation was verified in 6-month-old animals from three experimental groups (littermate wild-type, vehicle-treated Tg-AD, Tg-AD+mAb) by evaluating the synaptic alterations of the primary visual cortex in the experience-driven expression of the immediate early gene Arc (activity-regulated cytoskeleton protein). This evidence concerns the gene ARC and Alzheimer disease.