NEFL and Alzheimer disease: In the current study, we aimed to gain a better understanding of synaptic dysfunction in AD by studying a panel of synaptic proteins (including SNAP-25, SYT1, NPTX1 and -2, β- and γ-synuclein, 14-3-3 proteins) and NfL, in a longitudinal design, by use of serial CSF sampling in a cohort of memory clinic patients.25