Astrocytes from dual reporter mice (a–c) or wild-type rat (d–e) were cultured alone or directly on top of an intact monolayer of bEND.3 cells for 10–14 days, and then were harvested for Western blot analysis of eGFP (a), GLT-1 (b) & (d), and GLAST (c) & (e) protein levels. Top: Representative blots and Bottom: summary of quantification, normalized to β-actin. The β-actin blots are identical in panels (b) and (c) and in panels (d) and (e), as GLT-1 and GLAST are quantified from the same immunoblot. Data are the mean ± SEM of six (dual reporter mice) or three (wild-type rat) independent experiments. mRNA was isolated from co-cultures of astrocytes from dual reporter mice with bEND.3 cells or from astrocytes alone and reverse transcribed. qPCR was performed for eGFP (f) and GLT-1 (g). Data were plotted on a standard curve and normalized to GAPDH. Data are the mean ± SEM of four independent experiments. * p ≤ 0.05, ** p ≤ 0.01, **** p ≤ 0.0001 for indicated comparisons.