Figure 2.

Representative traces of individual experiments illustrating the change in fluorescence in (A) AtT20-CB1 and (C) AtT20-CB2 cells following addition of CUMYL-4CN-BINACA (4CN) and CP 55,940, and concentration response curves for activation of (B) CB₁ and (D) CB₂ receptors by CUMYL-4CN-BINACA (4CN) and CP 55,940 in AtT20 cells. For representative traces, a drop in fluorescence represents an efflux of membrane potential sensitive dye from cells as they hyperpolarize. The data are presented as fluorescence normalized to the average of the fluorescence 30 s immediately prior to drug addiction. The effects of vehicle (DMSO) addition are illustrated, and have not been subtracted from the drug traces. For concentration response curves, the drug response is expressed as a proportion of that to CP 55,940, 1 µM. Data points represent the mean ± SEM of at least six independent experiments, and were fit to a four parameter logistic equation.