Motivation, Emotion, Feeding, DrinkingRepeated injections of lipopolysaccharide attenuate the satiety effects of cholecystokininCross-Mellor, Shelley K.1,2; Kavaliers, Martin1; Ossenkopp, Klaus-Peter1Author Information 1Neuroscience Program and the Department of Psychology, University of Western Ontario, London, Ontario N6A 5C2, Canada 2Corresponding Author: Shelley K. Cross-Mellor ACKNOWLEDGEMENTS: This research was supported by Natural Sciences and Engineering Research Council of Canada operating grants to M.K. and K.-P.O. Received 8 September 1999; accepted 7 October 1999 NeuroReport: December 16th, 1999 - Volume 10 - Issue 18 - p 3847-3851 Buy Abstract THE present study examined the effects of repeated injections of lipopolysaccharide (LPS) and cholecystokinin (CCK) on both sucrose palatability and body weight. Rats received repeated injections of LPS (200 μg/kg), CCK (8 μg/kg) and/or NaCl on days 1, 4, 7 and 10. Body weight was monitored on each test day and sucrose palatability was assessed using the taste reactivity test (TRT) on days 7 and 10. Rats treated with LPS developed a rapid tolerance to the reductions in body weight; however, this tolerance did not affect sucrose palatability. Furthermore it was found that repeated exposures to LPS and CCK attenuated the typical satiety related behaviors produced in the TRT by administration of CCK. This desensitization to CCK with repeated exposures to LPS may be one of the mechanisms that could account for the rapid development of tolerance to LPS-induced hypophagia. © 1999 Lippincott Williams & Wilkins, Inc.