Timeline of oxytocin treatment in ovariectomized female rats with and without estrogen (E) and progesterone (P) replacement. All females received bilateral ovariectomies, and after one-week recovery, females received either sham or estrogen implants. After an additional three-week recovery period, females underwent 4 days of progesterone or oil treatment, and effect of ICV oxytocin on food intake was measured. After an additional 1-week washout, progesterone or oil treatment groups were switched and effect of ICV oxytocin on chow intake was examined.