CSF alterations correlate significantly with brain regional changes in App knock-in mice. CSF concentrations of all three synaptic proteins correlated with hippocampal concentrations of the respective proteins (C, B, C), moreover CSF concentrations of GluA3 further correlated with PFC concentrations (C) Pearson’s correlation was used to determine associations. Abbreviations: CSF, cerebrospinal fluid; PFC, prefrontal cortex.