For OVX sham-treated (n = 5) or hormone-treated (n = 7) female rats (Experiment 2), in vivo DA assessments before and during restricted and unrestricted access to pup and food stimuli. A, Basal DA level data (mean ± SEM) represent the average DA concentration of 3 samples collected before any stimuli exposure. Hormone-treated females had decreased basal DA concentrations compared with their sham controls: ap < 0.05, treatment difference. B, After basal collection, the time course for in vivo DA responses relative to basal DA concentrations (mean ± SEM percentage of basal concentration) during restricted access to pups and food (counterbalanced); and unrestricted access to pups, then food.