We performed a study of gene expression changes that occur during mouse aging in the striatum and cortex in specific neuronal populations. Using translating ribosome afifnity purificaiton, we captured cell type-specific mRNAs from Drd1a-expressing cortical neurons, Drd1a-expressing striatal neurons, Drd2-expressing cortical neurons, and Drd2-expressing striatal neurons. Overall design: 31 total samples were anlayzed. We generated the followinf pairwise comparisons: Old (2 years) vs young (6 weeks) Drd1a expressing cortical cells; old (2 years) vs young (6 weeks) Drd2 expressing cortical cells; old (2 years) vs young (6 weeks) Drd1a expressing striatal cells; old (2 years) vs young (6 weeks) Drd2 expressing striatal cells. We used a restriction of Benjamini-Hochberg FDR <0.05, and a fold-change restriction of 1.2-fold.