Figure 3.

Scattergram showing time in seconds (mean ± SEM) spent in drug-paired chamber for each animal and the drug dosing as assessed before dosing (day 2), on the day after the 4 consecutive days of dosing (day 9) and 5 days later (day 14). Dosing for the 3 groups was saline vs saline, saline vs morphine (3 mg/kg), or saline vs acetaminophen (APAP: 200 mg/kg). Two-way repeated-measures ANOVA was performed with post hoc assessment with Sidak multiple comparison. ****P < 0.001. APAP, acetaminophen.