Figure 1.

Timeline of the long-term nortriptyline treatment procedures. Nortriptyline treatment began at day 15 post-surgery, with mice receiving two daily injections, morning and afternoon. For the time-course experiment (Figure 3), animals were tested for mechanical allodynia at least twice a week. The mechanical threshold was tested before a morning injection. For the opioid antagonist experiments, after at least 2 weeks of treatment and while the daily saline and nortriptyline treatments were still maintained, the acute effect of the DOP receptor antagonist naltrindole (Figure 4) and of the KOP receptor antagonist nor-BNI (Figure 5) were tested.