(A) Effects of D1 dopamine receptor antagonist SCH23390 (10 µM, 30 min) on SKF83959 (30 µM, 10 min)-induced ERK1/2 phosphorylation. (B) Quantification of ERK1/2 phosphorylation level in astrocytes pre-incubated with SCH23390 and treated with SKF83959 (Mean ± S.E., n = 3, *P < 0.05, 10 min vs. 0 min). N.S.: no significance. (C) Effects of D2 receptor antagonist spiperone (10 µM, 30 min) on SKF83959 (30 µM, 10 min)-induced ERK1/2 phosphorylation. (D) Quantification of ERK1/2 phosphorylation level in astrocytes pre-incubated with spiperone and treated with SKF83959 (Mean ± S.E., n = 3, **P < 0.01 or *P < 0.05, 10 min vs. 0 min). (E) Effects of α-adrenoceptor antagonist prazosin (1 µM, 30 min) on SKF83959 (30 µM, 10 min)-induced ERK1/2 phosphorylation. (F) Quantification of ERK1/2 phosphorylation level in astrocytes pre-incubated with prazosin and treated with SKF83959 (Mean ± S.E., n = 3, **P < 0.01 or *P < 0.05, 10 min vs. 0 min).