Fig. 6.

Inhibition of PKC does not inhibit the dopamine-mediated internalization or the sensitization of the SR2-GFP receptor by 5-HT. (A) Control cells showed receptors localized to the cell surface after the initial cycloheximide treatment. (B) The receptor internalized upon application of 10 μM dopamine (Dop). (C) Internalization of SR2-GFP receptors by 10 μM dopamine was not inhibited by 50 μM sphingosine. (D) SR2-GFP receptors sensitized by prior application of 50 nM of 5-HT internalized upon application of 500 nM dopamine in the sphingosine-treated SB1 cells. (Scale bar, 50 μm.)