Neurodevelopmental origins of neurodegeneration: a lifespan perspective on brain vulnerability.

Neurodegenerative disorders-including Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis-are increasingly understood to have origins in early neurodevelopmental disturbances. This review examines how genetic, epigenetic, and environmental factors impact brain development during critical periods, predisposing individuals to neurodegeneration later in life. Prenatal and early-life exposures such as maternal stress, malnutrition, infection, and environmental toxins can alter key developmental processes, leading to long-term vulnerability. Mechanistic pathways linking early-life disruptions to neurodegenerative outcomes include persistent mitochondrial dysfunction, chronic neuroinflammation, increased oxidative stress, and aberrant synaptic pruning, all of which contribute to progressive neuronal damage and dysfunction. The gut-brain axis is also discussed as a key intermediary, where early microbiota dysbiosis alters neuroimmune signaling and inflammatory responses, modulating susceptibility to age-related neurological disorders. In this context, the review highlights emerging molecular and imaging biomarkers capable of detecting subtle neurodevelopmental deviations that may precede clinical symptoms by decades. The paper emphasizes the need for early-life interventions, including maternal nutritional optimization, management of prenatal stress, and microbiome-targeted strategies, as potential tools to reduce long-term neurological risk. Furthermore, it proposes the integration of precision medicine approaches aimed at individualized risk assessment and therapeutic targeting of developmental pathways. Adopting a lifespan perspective, this review argues for a paradigm shift from reactive to preventive strategies in neurology. Understanding the developmental roots of neurodegeneration opens new avenues for research and intervention, enabling resilience and reducing disease burden through early diagnostics and tailored therapeutics across the lifespan.