Description:Neuronal NAD⁺ depletion via NMNAT2 loss reprograms brain metabolism toward fatty-acid oxidation, lipid depletion, and oxidative stress. Multi-omics profiling (untargeted metabolomics and lipidomics) of NMNAT2 conditional knockout and SARM1-deleted mouse cortex revealed coordinated changes in glycolysis, redox cofactors, and lipid pathways. Complete SARM1 deletion restored metabolic and lipid balance, supporting the NMNAT2–SARM1 axis as a key regulator of neuronal and glial metabolism.