Fig. 4.

Naloxone-precipitated withdrawal after 72 h of morphine pellet implantation. 9–10-week-old TLR2 KO male mice and age-matched wild type male mice were implanted with a 25 mg morphine pellet subcutaneously or received a placebo pellet under isoflurane anesthesia as described under materials and methods. At 72 h after pellet implantation, mice received naloxone (1.0 mg/kg, i.p.) and morphine withdrawal symptoms for wet dog shakes (A), jumps (B), and weight loss (C) were monitored for 30 min. The weight of each mouse was determined before and 30 min after the naloxone injection. Means and SEs were calculated from 6 to 8 mice per group. * p < 0.01 compared with WT mice.