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Updated: Jun 17, 2026
A General Method for Evaluating Deep Brain Stimulation Effects on Intravenous Methamphetamine Self-Administration
Published on: January 22, 2016
The effects of adolescent methylphenidate self-administration on responding for a conditioned reward,
Christie L Burton1, José N Nobrega, Paul J Fletcher
1Department of Psychology, University of Toronto, 100 St. George Street, Toronto, ON M5S3G3, Canada. c.burton@utoronto.ca
Background:
Abuse of methylphenidate (Ritalin) is rising, particularly during adolescence and early adulthood, but the long-term effects of its abuse during adolescence are unclear.
Methods:
In experiment 1, we examined the effect of adolescent methylphenidate self-administration (0.0625 mg/infusion), as compared with cocaine self-administration (0.125 mg/infusion), under a fixed ratio 1 schedule of reinforcement in male Sprague-Dawley rats during adolescence (postnatal day (PND) 32-47) on adult dopamine-mediated behaviors (PND >70). These included responding for a conditioned reward (CR), a measure of incentive motivation, and amphetamine-induced locomotor activity. In experiment 2, we aimed to replicate and enhance the effects observed in experiment 1, and we also examined the effects of methylphenidate self-administration during adolescence on adult amphetamine-induced zif268 messenger ribonucleic acid (mRNA) expression.
Results:
Adolescent rats self-administered both cocaine and methylphenidate. There was no effect of adolescent drug self-administration on adult baseline or amphetamine-induced responding for a CR. However, both adolescent methylphenidate and cocaine self-administration increased amphetamine-induced locomotion. Adolescent methylphenidate self-administration also enhanced amphetamine-induced zif268 mRNA expression in the nucleus accumbens.
Conclusions:
Our findings suggest that repeated, behaviorally contingent exposure to methylphenidate during adolescence enhances responsivity to the locomotor-stimulating and neuronal activating effects of amphetamine but not incentive motivation.
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