CSF glutamate levels are significantly increased in patients with Alzheimer’s disease compared to healthy controls in some (Pomara et al., 1992; Csernansky et al., 1996) but not all studies (Martinez et al., 1993; Kuiper et al., 2000), and a 3xTg-AD mouse model shows age-dependent progressive reduction in hippocampal GLT-1 levels (Zumkehr et al., 2015). This evidence concerns the gene SLC1A2 and Alzheimer disease.