Inhibition of microglia migration and invasion by blocking CRAC or SK3 channels. Cultured rat microglial cells were exposed for 24 hr to culture medium (MEM with 2% serum) (control), with or without a channel blocker. CRAC blockers were 5 μM Gd3+, 50 μM 2-APB, 10 μM BTP2. SK3 channels were inhibited using 7 μM NS8593. (A) Cell transmigration across 8 μm-diameter holes in the filter of Transwell™ inserts. (B) Migration into a scratch wound made in an essentially confluent layer of microglia. Scale bar, 100 μm. (C) Invasion of microglia through filters with Matrigel™-coated 8 μm-diameter holes (BioCoat Matrigel™ Invasion chambers). For each treatment, cell counts were tallied from five random fields of view at 40× magnification (transmigration, invasion) or 10× (scratch wound), and normalized to control (untreated) microglia (100%, dashed line). The number of individual cultures used is indicated on each bar. ***P < 0.001.