Related Experiment Video
Updated: Jul 4, 2025
A Protocol for Measuring Cue Reactivity in a Rat Model of Cocaine Use Disorder
Published on: June 18, 2018
Chronic oral methylphenidate plus fluoxetine treatment in adolescent rats increases cocaine self-administration
Daniela Senior1, Madison McCarthy1, Rania Ahmed1,2
1Behavioral Neuropharmacology and Neuroimaging Laboratory (BNNL), Clinical Research Institute on Addictions, Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14051, USA.
Background:
Depression and attention deficit hyperactivity disorder are known to be comorbid. Treatment of these commonly coexisting diseases typically involves the combined prescription of methylphenidate (MP), a psychostimulant, and fluoxetine (FLX), a selective serotonin reuptake inhibitor (SSRI). MP and cocaine have similar mechanisms of action and this study examined the effects of chronic treatment of MP combined with FLX on cocaine consumption in rats.
Methods:
Four groups of rats received access to drinking solutions of water (control), MP (30/60 mg/kg/day), FLX (20 mg/kg/day), or the combination of MP (30/60 mg/kg/day) plus FLX (20 mg/kg/day), during 8 h per day for one month. Following these drug treatments, rats were allowed to self-administer cocaine for 14 days.
Results:
Our results showed that, during the first week of cocaine self-administration, the MP-treated rats had significantly greater numbers of active lever presses (plus 127%) and increased consumption of cocaine compared to the control rats. In contrast, during week two of cocaine self-administration, the rats treated with the MP + FLX combination showed significantly more lever presses (plus 198%) and significantly greater cocaine consumption (plus 84%) compared to the water controls.
Conclusion:
Chronic oral treatment during adolescence with the combination of MP plus FLX resulted in increased cocaine use after 2 weeks of cocaine self-administration in rats. These novel findings suggest that the combined exposure to these two drugs chronically, during adolescence, may produce increased vulnerability towards cocaine abuse during young adulthood.
