Semester of Graduation

Spring 2026

Degree

Master of Arts (MA)

Department

Psychology

Document Type

Thesis

Abstract

Previous work with dietary protein restriction in rodents has demonstrated that rodents fed a low protein diet exhibit physiological effects such as lower rates of weight gain and increased levels of circulating fibroblast growth factor 21 (FGF21). Dietary protein restriction also produces behavioral effects. Compared to rodents that are not protein-restricted, rodents that are protein-restricted exhibit increased food intake and higher preference for a protein vs. carbohydrate solution. Additionally, protein-restricted rodents will respond at higher levels for a protein reinforcer than non-restricted rodents. The current study assessed the effect of dietary protein restriction on operant protein demand during and after a period of dietary protein restriction. Demand for a casein solution was assessed by varying the number of responses required to obtain access to the solution and measuring the number of deliveries obtained at each response requirement. Protein-restricted mice exhibited lower rates of weight gain, increased food intake, increased preference for protein, and increased operant responding and demand for a protein solution relative to non-restricted mice. Additionally, it was found that the inclusion of saccharin in the casein solution obscured group differences in operant demand. Further, when mice that were previously protein-restricted were fed a normal protein diet, demand for casein solution remained higher than in mice that had not been protein-restricted. These findings indicate that saccharin may obscure differences in demand and that having a history of protein restriction may lead to a non-selective increased demand for nutrients.

Date

4-14-2026

Committee Chair

Soto, Paul L.

LSU Acknowledgement

1

LSU Accessibility Acknowledgment

1

Download

Share

COinS