MMP-9 levels are increased in brain lysates from MA-treated mice. Mice were killed at 6 h following a single intraperitoneal dose of 100 μL saline (control, n = 4), or MA dissolved in 100 μL saline (40 mg/kg, n = 4). Hippocampal and striatal lysates were then prepared as described (St Hillaire et al. 2005) and analyzed for total MMP-9 levels by ELISA (R & D Systems). Values were corrected for total protein concentration in the lysates (Qubit; Invitrogen) and ng MMP-9/mg total protein was graphed (mean + SEM). The difference between control and MA striatal samples was significant (*p < 0.5, Student’s t-test), and while the difference between hippocampal samples was not significant (p = 0.13, Student’s t-test), there was there was an appreciable trend towards increased MMP-9 in the hippocampal lysates from MA-treated animals.