Figure 3.

Mean (± SEM) of total positive hedonic and negative affective responses in sham depleted and furosemide-sodium depleted rats pretreated with morphine or vehicle treated rats given I–O infusions of 0.3 M saline. (A) Positive hedonic responses (lateral tongue protrusions, rhythmic tongue protrusions, and paw licks) were quantified during I–O infusions of 0.3 M saline. Furosemide treated rats given vehicle (0 mg/kg) showed significantly more positive hedonic behaviors than sodium depleted rats given the two highest doses of morphine (2, 4 mg/kg), * p<0.05 compared to 0 mg/kg morphine in the furosemide treated group. (B) Negative affective responses (gapes, flails, head shakes, and face wipes) were quantified during I–O infusions of 0.3 M saline. Sham depleted rats given morphine (2 or 4 mg/kg) showed significantly fewer negative affective responses to I–O infusions of 0.3 M saline. Sodium depleted rats given the highest dose of morphine (4 mg/kg) displayed significantly fewer negative affective responses than sodium depleted rats given vehicle treatment. * p<0.05 as compared to 0 mg/kg group for both sham depleted and sodium depleted groups