Fig. 4.

TPEN can both decrease and enhance methamphetamine toxicity. GFP-expressing PC12 cells were exposed to vehicle (CON), 300 µM methamphetamine (METH), and 300 µM methamphetamine in the presence of 3 µM TPEN (METH+TPEN) for 24 hr alone or in the presence of microglia. Note GFP-expressing cells in the METH+TPEN group is near control levels in the absence of microglia, but plummets when microglia are included in the treatment. Note also that not all PC12 cells are GFP positive (top-left panel). The quantification of the toxicity represented here is shown in Fig. 5.