FIGURE 5.

Evaluation of motor coordination and balance in rotarod test during a 5-min trial in different groups, including; M/N-treated groups (a single dose of naloxone was administered after methadone overdose in apnea stage, in animals which experienced apnea and motor coordination was evaluated either on day 1, 5, or 10 day post-resuscitation; M/N-Day 1 (n = 9), M/N-Day 5 (n = 6) and M/N-Day 10 (n = 8) groups and their respective Saline control groups; n = 6; right panel), M/N-Sedate (n = 8; a single dose of naloxone was administered following methadone overdose, immediately in the initial stage of sedation, so behavioral evaluation was carried out only 1 day after drug administration), Saline; n = 10, methadone; n = 9 and naloxone; n = 6 (saline, methadone or naloxone was administered alone in separated groups in which coordination assessment was evaluated only 24 h following the drug administration in a 5-min trial in adolescent rats) groups. Animals received methadone (15 mg/kg; i.p.) or naloxone (2 mg/kg; i.p.) alone or both in a single dose. The time each rat stay on the rod before falling was recorded. Each bar shows the mean ± SEM for 6–10. ^∗∗P < 0.01 different from the Saline group.