Alzheimer’s Disease: Beyond the Neuron

This chapter describes the various systems beyond the central nervous system that are associated with Alzheimer’s disease (AD). There is strong evidence to believe that while AD has symptoms of memory and cognitive impairment—undoubtedly domains of the central nervous system—the primary insult that causes this condition may arise systemi-cally. We describe associations with the immune system, gut microbiome, and endocrine abnormalities that may be at play. Our goal is to incorporate a multi-system approach to understand the pathogenesis of AD. Our body does not function as soloed organ sys- tems, and we hypothesize that the mechanisms described herein are similarly contribut-ing to the progression of cognitive impairment in AD.