Elevated IL-6 in older animals is consistent with work indicating that IL-6 increases in the aged cortex (Prechel et al., 1996; Ye and Johnson, 1999; Campuzano et al., 2009; Scheinert et al., 2015), heightened levels of IL-6 are associated with cognitive impairments (Singh-Manoux et al., 2014; Puzianowska-Kuźnicka et al., 2016; Lin et al., 2018; Warren et al., 2018), and IL-6 influences prefrontal neuronal activity (Garcia-Oscos et al., 2015; Marsland et al., 2017). Here, IL6 is linked to Cognitive impairment.