Dopamine-induced changes in the expression of D1DR, D2DR, downstream effector genes, and DA synthetic enzyme DDC. Compared with Uninfected Control (Mock), SARS-CoV-2 significantly increases the expression of D1DR, D2DR, and respective downstream effectors PKA, ERK1, and GSK3β at 48 h post-infection. Compared with the SARS-CoV-2-Infected Control, 50 μM DA administration to SARS-CoV-2-Infected cells markedly reduces the expression of D2DR and the downstream kinase GSK3-β while increasing DDC expression. On the other hand, DA does not significantly affect the expression of D1DR or downstream effectors. mRNA quantification was performed through real-time qPCR and calculated by the 2−ΔΔCt equation. Results are presented as mean ± SEM from at least n = 3 independent experiments, each performed in triplicate. # p < 0.05 vs. Uninfected Control (Mock), * p < 0.05 vs. SARS-CoV-2 Infected Control.