title: Cocaine decreases saccharin preference without altering sweet taste sensitivity.
abstract: In rodents, saccharin consumption is suppressed when the sweet taste stimulus is paired with moderate doses of cocaine. Several hypotheses have been used to explain the seemingly contradictory effect of decreased consumption of a normally preferred substance following a highly rewarding drug. A common theme across these hypotheses is that saccharin is interpreted as less rewarding after cocaine pairing. We considered the alternative possibility that suppression is caused not by a change in reward circuitry, but rather by a change in taste detection, for instance by altering the afferent taste response and decreasing sensitivity to sweet taste stimuli. To evaluate this possibility, we measured saccharin taste sensitivity of mice before and after a standard cocaine-pairing paradigm. We measured taste sensitivity using a brief-access lickometer equipped with multiple concentrations of saccharin solution and established concentration-response curves before and after saccharin-cocaine pairing. Our results indicate that the EC50 for saccharin was unaltered following pairing. Instead, the avidity of licking saccharin, an indicator of motivation, was depressed. Latency to first-lick, a negative indicator of motivation, was also dramatically increased. Thus, our findings are consistent with the interpretation that saccharin-cocaine pairing results in devaluing of the sweet taste reward.
authors: Graduate Program in Neurosciences, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
authors: Jennifer K
authors: JK
authors: Roebber
authors: Graduate Program in Neurosciences, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Department of Psychiatry and Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
authors: Sari
authors: S
authors: Izenwasser
authors: Graduate Program in Neurosciences, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, FL 33136, USA. Electronic address: NChaudhari@miami.edu.
authors: Nirupa
authors: N
authors: Chaudhari
mesh_terms: D000818:Animals; D003042:Cocaine / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D007274:Injections, Intraperitoneal; D008297:Male; D051379:Mice; D012439:Saccharin / Q000008:administration & dosage / Q000494:pharmacology*; D012646:Self Administration; D055697:Taste Perception / Q000187:drug effects*; D013997:Time Factors
chemical_list: D012439:Saccharin; D003042:Cocaine
keywords: Anticipatory contrast; Brief access taste test; Cocaine; Lickometer; Saccharin; Taste sensitivity