SLC1A2 and opiate dependence: For example, heroin self‐administration and withdrawal reduces the levels and activity of GLT‐1 and system Xc− and promotes an increase of glutamate spillover to the extracellular space in the NAc, opposite to the reduced spillover observed in the present study, an effect that also contributed to opioid dependence as the normalization of glutamate transporters levels reduced heroin reinstatement.31