Figure 5.

DAMGO inhibits ligand-induced CXCR4 internalization. Plasma membrane proteins from neurons treated with DAMGO (1 μm, 24 h) or vehicle, followed by CXCL12 stimulation, were used for the CXCR4 and pCXCR4 immunoblots reported in A, whereas experiments with total extracts are reported in other panels. Data shown in B and C are from neuronal cultures treated with DAMGO for 15 min or 1, 3, 6, 18, or 24 h as indicated, followed by acute CXCL12 stimulation (20 nm; 15 min). Additional experiments (D) were performed with neurons incubated with DAMGO (1 μm; 24 h) in the presence or absence of CHX (1 μg/ml), followed by acute CXCL12 treatment (20 nm; 15 min).