Sensitization and Tolerance Following Repeated Exposure to XXXX and @entity285 in @entity19 .

@entity167 @entity19 @entity5834 @entity8021 @entity285 @entity1068 @entity2055
BACKGROUND: Energy drinks are popular mixers with @entity285 . While energy drinks contain many ingredients, @entity5834 is an important pharmacologically active component and is generally present in larger amounts than in other caffeinated beverages. In these studies, we investigated the hypothesis that @entity5834 would influence the effects of @entity285 ( @entity1068 [ @entity167 ]) on conditioned taste aversion (CTA), @entity2055 , and locomotor activity (LA) after repeated exposure. METHODS: Four groups of @entity19 were exposed by oral gavage twice daily to vehicle, @entity167 (4  g/kg), @entity5834 (15  mg/kg), or the @entity167 / @entity5834 combination. CTA to @entity8021 and @entity2055 in the parallel rod task was evaluated after 8 or 16 gavages, respectively, using @entity167 (1 to 3  g/kg) or @entity167 / @entity5834 (3  mg/kg  +  2  g/kg) challenges. In addition, LA was evaluated initially and after repeated exposure to oral gavage of these drugs and doses. RESULTS: Repeated oral gavage of @entity167 produced significant locomotor sensitization, with those @entity19 increasing total distance traveled by 2-fold. The locomotor response to @entity5834 , while significantly greater than vehicle gavage, did not change with repeated exposure. On the other hand, repeated gavage of @entity5834 / @entity167 combination produced a substantial increase in total distance traveled after repeated exposure (~4-fold increase). After repeated @entity167 exposure, there was significant tolerance to @entity167 in the CTA and parallel rod tests. However, neither a history of @entity5834 exposure nor including @entity5834 influenced @entity167 -induced CTA. Interestingly, a history of @entity5834 exposure increased the ataxic response to the @entity5834 / @entity167 combination and appeared to reduce the ataxic response to high doses of @entity167 . CONCLUSIONS: The data support the general hypothesis that repeated exposure to @entity5834 influences the response to @entity167 . Together with previously published work, these data indicate that @entity5834 influences some @entity167 -related behaviors, notably locomotion and @entity2055 , but appears not to influence the expression of conditioned behaviors.
