Memory-impaired aging rats have elevated levels of serum Gro-KC and RANTES and hippocampal GM-CSF relative to elite agers (Scheinert et al., 2015) and long-term daily exercise can rejuvenate hippocampal neurogenesis and memory scores while modulating some systemic and central cytokines (Speisman et al., 2013a). This evidence concerns the gene CCL5 and memory impairment.