Figure 7.
Systemic morphine administration failed to alter TRR-induced spontaneous pain. (A) preconditioning times spent in the saline- or morphine-paired chambers were equivalent across all groups and all data were pooled across groups for preconditioning graphical representation (mean ±SE, n=28). (B) After conditioning, the rats in all groups showed no preference for the saline- or morphine-paired chamber.