Uncertain access to shortening alters home cage intake but not operant performance in rats
Open Access
- Author:
- Vlassis, Stephen A
- Area of Honors:
- Nutritional Sciences
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Rebecca L Corwin, Thesis Supervisor
Rebecca L Corwin, Thesis Honors Advisor
Jill Patterson, Faculty Reader - Keywords:
- Uncertainty
binge
nutrition
rats
operant - Abstract:
- Current practices in the treatment of binge-related eating disorders in humans include the introduction of structured meal plans as well as re-introduction of “forbidden foods” [Murphy et al., 2010]. This approach eliminates the uncertainty associated with consuming highly palatable foods rich in fat and sugar. In rats, certainty has previously been shown to reduce appetitive behavior associated with bingeing. Whether or not uncertainty promotes bingeing has not been systematically evaluated. The current study aimed to study the effects of uncertainty on binge-type behavior. Rats in the present study were separated into a daily group (D) which received 30 minutes of access to Crisco® every day at the same time, an intermittent group (INT) which received 30 minutes of access to Crisco® every other day and a daily uncertainty group (DU) which received 30-minute access to Crisco® on an uncertain schedule. Uncertainty was introduced to the schedule of the DU group by the presentation of three jars in the home cage for 30-minute periods, with only one of the three presentations containing Crisco® and no cues as to which presentation it would be. After five weeks under these schedules of access in the home cage, operant performance under various schedules was assessed. In the home cage, the intermittent group consumed more than the daily group, but the daily uncertain group did not significantly differ from either the daily or intermittent group. The INT group earned significantly more reinforcers than the D and DU groups under various operant schedules, i.e uncertainty provoked a slight stimulation of intake. These results suggest that uncertainty may modestly stimulate consummatory behavior (home cage intake) without stimulating appetitive (operant) behavior.