Reduced CSF Aβ42 and Aβ42/Aβ40 ratio during early cerebral amyloid deposition in the App
NL‐F knock‐in mouse model of Alzheimer’s disease

The concentration of Aβ42 in cerebrospinal fluid (CSF) is decreased at least a decade before cognitive symptoms caused by Alzheimer’s disease (AD) manifest. This drop in concentration has been suggested to occur before abnormal levels of fibrillar Aβ in the brain are reached, but the underlying cause is not well understood. The present study aims to explore the translational potential of the App NL‐F knock‐in mouse model, and compare it to transgenic App‐overexpressing 3xTg mice, for investigation of the early events in Aβ pathology that associates with reduced CSF Aβ42 in preclinical AD.