Reduction of Cocaine Seeking by a Food-Based Inhibitor in Rats

Environmental stimuli can exert a powerful influence over drug seeking and taking. For example, previous experiments found that combining multiple drug-related stimuli tripled drug seeking and doubled drug intake ( L. V. Panlilio, S. J. Weiss, & C. W. Schindler, 1996 , 2000 ), whereas a signal for the absence of cocaine (i.e., a drug-related inhibitor) dramatically reduced cocaine seeking in rats by over 90% ( D. N. Kearns, S. J. Weiss, C. W. Schindler, & L. V. Panlilio, 2005 ). In the present experiment, a signal for the absence of food created through the A+/AB− conditioned inhibition paradigm also suppressed responding for cocaine by approximately 90%. Symmetrically, a signal for the absence of cocaine (i.e., a cocaine-based inhibitor) suppressed food seeking to a similar degree. These findings, consistent with the appetitive-aversive interaction theory of motivation, suggest that using inhibitors based on nondrug appetitive reinforcers might be a practical method of reducing drug seeking in human drug abusers and should be seriously considered for clinical test and application.