Fig 1: Dopamine receptors D1 and D2 are primarily expressed in excitatory neurons of the ACC. D1-Cre:Ai14 and D2-Cre:Ai14 mouse lines were generated to label D1 and D2, respectively, with red fluorescent protein tdTomato. The offspring mice were used for immunofluorescence staining with different cell markers. (a) Immunofluorescence staining with NeuN, GFAP andIba1 using ACC sections of D1-Cre:Ai14 mice showed that tdTomato-labeled D1 in the ACC was exclusively expressed in NeuN-positive neurons, but not GFAP-positive or Iba1-positive glial cells. (b) Immunofluorescence staining with NeuN, GFAP and Iba1 using ACC sections of D2-Cre:Ai14 mice showed that tdTomato-labeled D2 in the ACC was also exclusively expressed in NeuN-positive neurons, but not GFAP-positive or Iba1-positive glial cells. (c) Immunofluorescence staining with TLX3 and PAX2 using ACC sections of D1-Cre:Ai14 mice showed that tdTomato-labeled D1 in the ACC was mostly expressed in TLX3-positive excitatory neurons, but not in PAX2-positive inhibitory neurons. (d) Immunofluorescence staining with TLX3 and PAX2 using ACC sections of D2-Cre:Ai14 mice showed that tdTomato-labeled D2 in the ACC was expressed in both TLX3-positive excitatory neurons and PAX2-positive inhibitory neurons, but the majority of D2 was co-labeled with TLX3. The immunofluorescence staining experiments were repeated three times to confirm the data shown in this figure. Scale bar, 50 μm.