Glutamate increases motility in astrocytoma cells. A: Representative field showing U-87MG cells plated on Matrigel-coated dishes after 24 hours of migration in a wound healing model of migration (the white line indicates the border of the lesion). B: The speed of migration of U-87MG cells plated on matrigel-coated dishes was measured 24 h after lesion. The presence of 10% fetal calf serum (FCS) in the culture medium increases the rate of migration by 51%. Serum-dependent migration is reduced by 55% when the cells were first loaded for 30 minutes with 20 μM BAPTA-AM to chelate intracellular Ca2+. Glutamate increased serum-independent migration while serum-dependent migration was left unchanged. Data are mean ± SEM; n = 4 independent experiments with 120 to 240 cells analyzed per condition; ***p < 0.001. C: Cells loaded or not with 20 μM BAPTA, were allowed to migrate on Matrigel-coated glass coverslips and then immunostained with the anti-β1 integrin antibody. White arrows indicate the cellular tail and yellow arrows, patches of β1 integrin. Scale bar, 20 μm. The number of patches of β1 integrin-containing structures found at the rear of the cell was quantified in control and BAPTA-loaded cells. Data are mean ± SEM of 3 independent experiments with 4 fields analyzed per experiment.