Whereas in low extracellular potassium solution, since tens of seconds after an SLE the GABAergic components switch their polarity from depolarizing to hyperpolarizing (Fujiwara-Tsukamoto et al., 2003), a rise in extracellular potassium in our experimental conditions slows down the process of chloride extrusion by means of inhibition or even reversal of the chloride extruder KCC2 (Thompson and Gähwiler, 1989; Jensen et al., 1993; Payne et al., 1996; DeFazio et al., 2000; Kakazu et al., 2000). This evidence concerns the gene SLC12A5 and systemic lupus erythematosus.