Figure 2.

Pilocarpine-induced SE elicits cell death in the hilus. A, Mice were given injections of either pilocarpine (325 mg/kg, i.p.) or saline (control), and brain sections were stained with Fluoro-Jade B, a fluorescent marker of dead and dying cells. Mice were killed 6 h after SE onset. Fluoro-Jade B labeling was observed specifically in the hilus (Hil). In contrast, cell death was not observed in the GCL. Boxed regions are shown magnified on the right. Arrows denote dead/dying cells. B, Double labeling revealed that Fluoro-Jade B (FJB) -labeled cells in the hilus express STEP. In stratum oriens of CA1, cell death was specifically observed in STEP-positive cells. CC, Corpus callosum; SO, stratum oriens. Scale bars, 20 μm. C, Results of double labeling in the hilus for STEP and TUNEL, a marker of apoptotic cell death, were consistent with the Fluoro-Jade B staining data; TUNEL-labeled cells were STEP positive. For TUNEL labeling, animals were killed 3 d after SE. Scale bars: A, 100 μm (low-magnification image) and 25 μm (high-magnification image); B, 20 μm; C, 10 μm.