Related Experiment Video
Updated: May 31, 2026
Assessment of Cocaine-induced Behavioral Sensitization and Conditioned Place Preference in Mice
Published on: February 18, 2016
Meal schedule influences food restriction-induced locomotor sensitization to methamphetamine
Amanda L Sharpe1, Joshua D Klaus, Michael J Beckstead
1Department of Physiology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, MSC7756, San Antonio, TX 78229, USA.
Rationale:
Traditional protocols for inducing sensitization to psychostimulants use an intermittent or "binge"-like drug administration, and binge eating behavior is comorbid with drug abuse in humans. Food restriction increases the reinforcing properties and self-administration of many drugs of abuse.
Objective:
The present study tested the hypotheses that (1) food restriction induces sensitization to the locomotor stimulation observed in response to methamphetamine and (2) a binge-like feeding schedule during food restriction produces increased sensitization compared to equally restricted mice fed in three daily meals.
Methods:
Male DBA/2J mice were fed ad libitum or were food restricted to either an 8% or 16% loss of body weight. Additionally, the food-restricted mice were divided into two groups that were fed in either one meal (binge) or three equal-sized meals (meal). After the reduced body weight was stable, mice were tested for locomotor activity following saline and methamphetamine (1 mg/kg) injections.
Results:
Both 16% body weight loss groups exhibited sensitization to methamphetamine. Opposite to our hypothesis, the 8% meal but not the 8% binge food-restricted group demonstrated locomotor sensitization. Serum corticosterone levels were significantly higher in the meal-fed groups when compared to the binge- and ad libitum-fed groups.
Conclusions:
These results support a role for feeding schedule and plasma corticosterone levels in food restriction-induced enhancement of the effects of methamphetamine.
