K_v channel blockers ameliorated Tat-induced microglia neurotoxicity in rat hippocampus slices.

<p>Rat hippocampus slices were pretreated with MgTx (5 nM), PAP (10 nM), or 4-AP (1 mM) for 30 min before addition of Tat (200 ng/ml). Immunohistochemistry or TUNEL staining was performed 24 hr later. <b>A</b>: Tat increased levels of K_v1.3 expression that were co-localized with microglia (Iba1 staining) in rat hippocampus slices. Rat hippocampus slices were stained with mouse anti-Iba1 Ab (1∶1000, red), whereas K_v1.3 was stained with goat polyclonal antibody (1∶200, green). Images were visualized by confocal microscopy. <b>B</b>: TUNEL staining showed that Tat produced neuronal apoptosis in rat hippocampus slices that was attenuated by MgTx, PAP, or 4-AP. Numerical numbers in each image panel represents the average apoptotic cells (M ± SD, n = 3 slices, 5 random visual fields were counted in each slice) in experimental conditions as indicated.