We intend to analyze a single-cell RNA sequencing dataset from our lab. The research question is whether or not astrocytes show differential gene expression between old and young animals. Our data includes 6 samples, from 3 young and 3 old animals (rats). Aim 1: As none currently exist in the literature, we must first establish a recommendation for the cut-off for the percentage of reads mapping to mitochondrial (MT) data for this cell type, which is extremely metabolically active. We will do this by taking 2-3 other publicly available datasets, starting with the raw counts data, and examining the average MT reads in clusters identified as astrocytes. Aim 2: On our own data, and starting from the FastQ file from the sequencing facility, run the cellranger pipeline and conduct the downstream analysis in the R package Seurat. We will then use the outputs to draw conclusions regarding gene expression in astrocytes.