Oxygen-glucose deprivation (OGD) and cell viability detection

To obtain the OGD conditions, primary mouse cortical neurons were cultured with DMEM without glucose under at 37°C in a 95%N₂ with 5% CO₂ incubator. Following 6 h incubation, OGD was terminated and primary mouse cortical neurons were cultured with fresh DMEM supplemented with 12% FBS at 37°C under 95% N₂ with 5% CO₂. Following another 6 h of OGD incubation, cortical neurons were treated with different doses of exogenous CART and DA (0, 0.2, 2 and 20 mg respectively), and cell viability was evaluated by MTT assay. Briefly, neurons in each group were treated with MTT (0.5 mg/ml, Sigma-Aldrich; Merck KGaA) for 4 h at 37°C and incubated with 100 µl dimethyl sulfoxide for 10 min. The absorbance was measured at 570 nm.