This 2019 review highlights the central role of NAD⁺ in neuronal health, emphasizing its involvement in energy metabolism, DNA repair, mitochondrial function, and stress responses. The authors discuss how declining NAD⁺ levels with age contribute to neurodegenerative diseases such as Alzheimer's, Parkinson's, Huntington's, and ALS. NAD⁺-dependent enzymes, including sirtuins and
