Rats and Cocaine Reward (image) Cell Press Share Print E-Mail Caption This cartoon depicts how a single-point (mGluR2) gene mutation alters a rat's sensitivity to cocaine reward and the subsequent drug-taking and drug-seeking behavior. Credit Zheng-Xiong Xi and Lauren Brick Usage Restrictions Credit Required. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.