Striatal extracellular glutamate concentrations during Meth or saline treatment. Meth significantly increased glutamate release over time, and MLA completely blocked the Meth-induced increase in glutamate. *, p < 0.05, saline + Meth compared with saline + saline; #, p < 0.05; ##, p < 0.01, MLA + Meth compared with saline + Meth (n = 6–9 for each group). Large arrows indicate Meth or saline injections, and small arrows indicate MLA or saline pretreatment injections.