Ethanol worsens pathology and memory in the 5xFAD mouse model of
Alzheimer's disease
Abstract
Alzheimer’s disease (AD) is the most common age-related dementia.
Lifestyle factors, including alcohol use, can increase the risk of AD.
While human studies demonstrate that alcohol use can negatively impact
AD risk and disease progression, the underlying alcohol-dependent
mechanisms that increase neurodegeneration and Aβ burden remain elusive.
We have recently shown that alcohol can acutely affect microglial
dynamics, which are critical to microglial function, and many other
studies have reported inflammatory activation of microglia after
long-term alcohol exposure in both humans and animal models. Here, we
administered ethanol at dosages that mimic human binge drinking for 4
weeks to 2.5-month-old male 5xFAD mice, a common mouse model of AD.
After a two-week abstinence period, we performed behavior assays and
analyzed amyloid pathology and microglial morphology in the subiculum
where amyloid pathology develops earlier than in other brain regions. We
found that ethanol exposure facilitated amyloid pathology and worsened
cognitive function in 5xFAD mice, while microglial arborization and
phagocytosis appeared unchanged. Overall, our results suggest that
pronounced ethanol exposure, when started early in the disease before
amyloid pathology is established, can worsen AD progression in an
amyloidosis model.