ABSTRACT
Alzheimer's disease is a neurodegenerative disorder which contributes to millions of cases of dementia worldwide. The dominant theoretical models of Alzheimer's disease propose that the brain passively succumbs to disruptions in proteostasis, neuronal dysfunction, inflammatory and other processes, ultimately leading to neurodegeneration and dementia. However, an emerging body of evidence suggests that the adult brain is endowed with endogenous mechanisms of resilience which may enable individuals to remain cognitively intact for years despite underlying pathology. In this brief review, we discuss evidence from basic neuroscience and clinical research which demonstrates the existence of endogenous molecular signaling pathways that can promote resilience to neurodegeneration. The p75 neurotrophin receptor provides one such pathway of resilience due to its role as a fundamental signaling switch which determines neuronal survival or degeneration. We highlight a series of preclinical studies targeting the p75 neurotrophin receptor in mouse models which demonstrate resilience to amyloid. We briefly discuss the design and goals of a recent clinical trial of p75 neurotrophin receptor modulation in patients with mild to moderate Alzheimer's disease. Unique challenges for developing therapeutics and biomarkers which are optimized for targeting and detecting endogenous mechanisms of resilience are also discussed. Altogether, this review motivates further trial work of therapeutics modulating the p75 neurotrophin receptor and other deep biology targets.
