Our laboratory developed an animal model of hunger where male rats were trained to discriminate between 22-hours and 2-hours food deprivation in a two lever, operant choice task. Our present study assesses the female and male rats’ ability to acquire the same discrimination. Female and male rats learned to discriminate between the two conditions. We then tested the effects of food consumption and the antidepressant, duloxetine (an antidepressant in humans that increases serotonin and norepinephrine function) in this paradigm. Pre-session food intake reduced “hunger” in 91% of females and 82% of males. At least one duloxetine dose (1-32 mg/kg) administered 20 minutes before the test session reduced “hunger” stimuli in 50% of females and 57% of males. Larger duloxetine doses were needed to reduce lever pressing in females. Duloxetine reduced one hour, post-test session food intake in all rats. In sum, both female and male rats learned the task. Food consumption and duloxetine appear to produce similar, but not identical, decreases on the effects of 22-hours food deprivation in female and male rats.
