Animals.

The Slc13a5^−/− (1) and Slc13a5 floxed mice, both in C57BL/6 background, were generously provided by Dr. Rafael de Cabo (National Institute on Aging, Baltimore, MD). Zinc transporter (Zip1) KO mice were generated in our laboratory with the support of National Institute of Neurological Disorders and Stroke-Johns Hopkins University (NINDS JHU) Center for Neuroscience Research, Murine Mutagenesis Core (NS050274), using the CRISPR-Cas9 technique, which caused a 171-bp insertion that induced a frameshift and a premature stop codon (TAA) in exon 2. mTmG mice (B6.129(Cg)-Gt(ROSA)26Sor^{tm4(ACTB-tdTomato-EGFP)Luo}/J) were purchased from The Jackson Laboratory. Details on the breeding scheme, generation of Zip1 KO mice, and genotyping can be found in SI Appendix, Materials and Methods.