The role of NMDA-Rs in glutamate-activated cell signaling in SCs. A) rSCs were pretreated with MK801 (1 µM) or vehicle for 30 min, then with 80 µM glutamate or 10 nM neurotrophin-3 (NT3) for 10 min. Phospho-ERK1/2 and total ERK1/2 were determined by immunoblot analysis. B) rSCs were treated with MK801 or vehicle, then with glutamate, as shown in panel A. Phospho-Akt, phospho-p70 S6K, and total Akt were determined by immunoblot analysis. C) rSCs that were transfected with NR1-specific or NTC siRNA were treated with glutamate (80 µM) or NT3 (10 nM) for 10 min. Phospho-ERK1/2 and total ERK1/2 were determined by immunoblot analysis. D) rSCs that were transfected with NR1-specific or NTC siRNA were treated with glutamate (80 µM) or NT3 (10 nM) for 10 min. Phospho-Akt, phospho-p70 S6K, and total Akt were determined by immunoblot analysis. The presented images are representative of studies performed at least in triplicate.