Adult astrocytes take up glutamate (A) and glucose (B).

<p>To determine the glutamate uptake, the culture medium was removed followed by the addition of DMEM/F12 supplemented with 5% FBS in the presence or absence 50 µM H₂O₂ for 3 h. To determine the glucose uptake, the medium was then replaced by DMEM/F12 supplemented with 1% FBS containing 1 µCi/ml [³H]2DG, in the presence or absence of 500 µM glutamate for 20 min. In all procedures, the cells were maintained at 5% CO₂/37°C. The assays were performed as described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0060282#s2" target="_blank">Materials and Methods</a> section. Absolute values obtained under control conditions were 0.8±0.08 nmol/mg protein/min for glutamate uptake and 172±20 fmol/mg protein for glucose uptake. The data represent the mean ± S.E. from 4 to 6 experimental determinations performed in triplicate. * P<0.05 indicates significant differences from the control values.