Changes in glial [Na+] in response to EAAT activation and GAT-2/3 blockade. (A) Confocal imaging reconstruction of protoplasmic astrocytes marked by sulforhodamine 101 (SR101) in the hippocampal CA1 region. R: str. radiatum, P: str. pyramidale, O: str. oriens. Scale bar = 50 μm. (B) Intracellular [Na+] in the soma of SR101 identified astrocytes measured by SBFI fluorescence during 100 μM SNAP-5114 applications with (black line) or without (red line) preceding activation of the Glu transporters by 200 μM t-PDC in normal ACSF (left) and [Mg2+] = 10 μM ACSF (right). Average of N = 16 cells/2 animals (normal ACSF) and N = 29 cells/3 animals ([Mg2+] = 10 μM).