Fig. 5.

Percentage of maximum possible effects of 2-BFI and μ-opioid receptor ligands on CFA-induced mechanical nociception in female rats (n = 6–7/group) (left). Enhancement of 2-BFI–induced antinociception by fentanyl (middle left), buprenorphine (middle right), or NAQ (right). Ordinates: percentage of maximum possible effects (top and middle) or percentage of control responding rate (bottom); abscissa: drug doses (mg/kg, i.p.) (left) or dose of 2-BFI (mg/kg, i.p.) (three right panels). PWT, paw withdrawal threshold.