SLC12A5 and temporal lobe epilepsy: Consistent with their opposing roles in maintaining chloride homeostasis and GABA-shift, whereas NKCC1 protein levels were observed to be increased in patients with temporal lobe epilepsy (TLE) (Sen et al., 2007), SLC12A5 (KCC2) mRNA expression was found to be downregulated (Huberfeld et al., 2007).