Effects of beta-amyloid accumulation on neural function during encoding across the adult lifespan.

摘要: Limited functional imaging evidence suggests that increased beta-amyloid deposition is associated with alterations in brain function, even healthy older adults. However, the majority of these findings report on resting-state activity or connectivity adults over age 60. Much less known about impact neural activations during cognitive task performance, amyloid young and middle-aged The current study measured burden from PET using (18)Florbetapir, a large continuous sample highly-screened, (N=137; aged 30-89 years). same participants also underwent fMRI scanning, performing memory encoding task. Using both as predictors activity, we dose-response relationship load to beyond effects age. Specifically, individuals greater activation bilateral dorsolateral prefrontal cortex, region important for encoding, well reduced modulation areas default network activity: superior/medial frontal lateral temporal cortex. Importantly, this reduction suppression function was found across lifespan, young- individuals. Moreover, amyloid-reduced activation/suppression poorer processing speed, verbal fluency, fluid reasoning subgroup elevated amyloid, suggesting it detrimental, rather than compensatory nature.