Combined inhibition of dopamine D1/D2 receptors induces cognitive and emotional dysfunction through oxidative stress and dopaminergic neuron damage
Results: Low-dose co-DR1/2I significantly increased MAO-B and ROS levels (p < 0.01) and decreased SOD activity (p < 0.01) in the substantia nigra, striatum, and hippocampus. MAO-B activity positively correlated with ROS (r = 0.916, p < 0.001) and negatively correlated with SOD (r = −0.685, p < 0.001), whereas ROS negatively correlated with SOD (r = −0.661, p < 0.001) in co-DR1/2I-treated mice. The medium- and high-dose groups exhibited spatial memory impairment (longer escape latency, p < 0.05) in the water maze and more anxiety-like behavior (reduced central zone time, p < 0.01) in the open field test; however, no abnormalities in motor coordination were observed in the rotarod test (p > 0.05). Immunofluorescence and WB confirmed a reduction in the dopaminergic neuron count after co-DR1/2I.
