Aging and Neurodegenerative Diseases

Aging is recognized as the most important risk factor for the development of neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, and Huntington’s disease. This chapter explores the neurobiological mechanisms that predispose the aging brain to neurodegenerative disorders. It discusses different interconnected cellular and molecular processes such as mitochondrial dysfunction(definition), impaired protein homeostasis, chronic inflammation, epigenetic alterations, genomic instability, and stem cell exhaustion that collectively decrease neuronal resilience and accelerate disease progression. By analyzing how these mechanisms interact and augment one another, the chapter provides a foundation for understanding the pathophysiology of age-related cognitive decline. It further emphasizes therapeutic and regenerative interventions aimed at addressing the fundamental drivers of aging, underscoring the need for a transition from symptom-oriented management to upstream, preventive strategies with the potential to delay or attenuate neurodegenerative pathology.