FIG. 4.

Paradoxical signaling by hCB₁Rs in Drosophila. (A) WIN 55,212-2 and 2-LG induced rapid hCB₁R internalization in Drosophila adipocytes. The percentage of cells with internalized hCB₁Rs is shown in (A₁). (B) Canonical signal transduction pathways activated by the CB₁R in mammals. In Drosophila, 2-LG induced the inhibition of both extracellular signal-regulated protein kinase 1/2 (Erk1/2) and protein kinase B (Akt) pathways in an AM 251-dependent fashion. (B₁) Representative experiment. (B₂, B₃) Data from triplicate experiments expressed as mean±s.e.m.; *p<0.05 (Student's t-test). Scale bar = 15 μm (A).