Figure. 7.

Mirtazapine protects dopaminergic neurons by modulating MT-1/2 secretion from Mir-NCM-treated astrocytes via 5-HT1A receptors. (a) Neuroprotective effects of mirtazapine on astrocytes. Astrocytes were treated with Mir-NCM containing fresh mirtazapine (5 µM) with or without WAY100635 (WAY; 10 nM) for 24 h. Mesencephalic neurons were treated with Mir-NCM-ACM for 24 h and then exposed to 6-OHDA (50 µM). (b) Concentration of MT-1 in the conditioned medium from control-NCM or Mir-NCM-treated astrocytes. Astrocytes were treated with another flesh mirtazapine-added Mir-NCM for 24 h. Data are means ± SEM (n = 6). (c) MT-1/2 secreted from Mir-NCM-treated astrocytes protects dopaminergic neurons against 6-OHDA-induced toxicity. To neutralize MT-1/2 in Mir-NCM-ACM, Mir-NCM-ACM was preincubated with an anti-MT-1/2 antibody for 1 h (Mir-NCM-ACM + MT-1/2 Ab), and then applied to neuronal cultures. After treatment with Mir-NCM-ACM or Mir-NCM-ACM + MT-1/2 Ab for 24 h, neuronal cultures were treated with 6-OHDA (50 µM). Data are presented as means ± SEM (n = 6) and expressed as a percentage of the control group. **p < 0.01 and ***p < 0.001 versus each control group. ^#p < 0.05, ^##p < 0.01 between the two indicated groups.