Fig. 1.

PNB in rats with incisional pain produced VTA- and NAc-dependent CPP. PNB in injured rats 24 h, but not 96 h, following incision of the hind paw induced CPP as demonstrated by (A) increased time spent in chambers paired with popliteal fossa (PF) lidocaine and (B) difference scores. (C) Pretreatment with lidocaine or baclofen, but not naloxone, in the VTA 10 min before PNB abolished CPP. (D) Pretreatment with NAc lidocaine or flupenthixol blocked CPP. Mean ± SEM, n = 9–13, *P < 0.05, Student’s paired t test.