Figure 2. Morphological changes in PC12 cells with different treatments. Cell morphology was examined under a phase contrast microscope 24 h after incubation with phosphate-buffered saline (A), 1-methyl-4-phenylpyridinium (MPP⁺) (B) and MPP⁺ plus 3-n-butylphthalide (NBP) (C). Twenty-four hours after MPP⁺ treatment, some of the PC12 cells died (arrows), leaving cells that appeared shrunken and with short processes (B). In contrast, in the NBP-treated groups the dendritic processes surrounding the cells were largely preserved (C), suggesting that NBP protected neuronal cells from MPP⁺-induced death.