Early memory deficits precede plaque deposition in APPswe/PS1dE9 mice: Involvement of oxidative stress and cholinergic dysfunction

► APPswe/PS1dE9 mice exhibited spatial memory impairment at 3.5 months of age. ► APPswe/PS1dE9 mice had cholinergic dysfunction and oxidative damage at 3.5 months of age. ► Impaired memory correlated with cholinergic dysfunction and oxidative damage. ► Soluble Aβ correlated with ACh, ChAT, SOD, GSH-px, MDA, and protein carbonyls. ► Oxidative damage and cholinergic dysfunction are involved in early memory deficits.