Re: Norman AB, Tabet MR, Norman MK, and Tsibulsky VL (2014) Maintained Cocaine Self-Administration Is Determined by Quantal Responses: Implications for the Measurement of Antagonist Potency. J Pharmacol Exp Ther 348:311–315; doi:10.1124/jpet.113.210690

At the request of the authors, this paper has been retracted. The authors identified errors within the methods section and have not been able to locate some of the primary data used to generate Fig. 1. Because these data are foundational to the article, the authors cannot ensure that the conclusions are accurate and have asked that the paper be withdrawn.

The authors apologize for the error and any problems arising from it.