Treatment of attention deficit hyperactivity disorder with the psychostimulant drug methylphenidate (MP) has increased dramatically among schoolchildren. We tested whether repeated exposure to moderate doses of MP (5 and 10 mg/kg IP for 5 or 7 days) in adolescent rats increased reactivity to cocaine measured by motor responses (ambulations and rearing) to a cocaine challenge in adulthood. We later tested whether repeated exposure to a low dose of MP (2 mg/kg IP for 7 days) enhanced the psychomotor effects of cocaine, measured by different challenge doses (0-30 mg/kg) as well as to the reinforcing effects of cocaine, measured by self-administration of low-dose infusion (75 mug/kg, IV). We found that exposure to moderate doses of MP enhanced psychomotor responses to cocaine but exposure to a low dose only increased cocaine self-administration. These results suggest that adolescent exposure to low doses of MP in rats may increase the incentive value of low reinforcers, thereby rendering adult rats more susceptible to cocaine self-administration. (C) 2001 American College of Neuropsychopharmacology. Published by Elsevier Science Inc.
机构:
Calif State Univ San Bernardino, Dept Psychol, San Bernardino, CA 92407 USACalif State Univ San Bernardino, Dept Psychol, San Bernardino, CA 92407 USA
Crawford, CA
;
McDougall, SA
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机构:Calif State Univ San Bernardino, Dept Psychol, San Bernardino, CA 92407 USA
McDougall, SA
;
Meier, TL
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h-index: 0
机构:Calif State Univ San Bernardino, Dept Psychol, San Bernardino, CA 92407 USA
Meier, TL
;
Collins, RL
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机构:Calif State Univ San Bernardino, Dept Psychol, San Bernardino, CA 92407 USA
Collins, RL
;
Watson, JB
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机构:Calif State Univ San Bernardino, Dept Psychol, San Bernardino, CA 92407 USA
机构:
Calif State Univ San Bernardino, Dept Psychol, San Bernardino, CA 92407 USACalif State Univ San Bernardino, Dept Psychol, San Bernardino, CA 92407 USA
Crawford, CA
;
McDougall, SA
论文数: 0引用数: 0
h-index: 0
机构:Calif State Univ San Bernardino, Dept Psychol, San Bernardino, CA 92407 USA
McDougall, SA
;
Meier, TL
论文数: 0引用数: 0
h-index: 0
机构:Calif State Univ San Bernardino, Dept Psychol, San Bernardino, CA 92407 USA
Meier, TL
;
Collins, RL
论文数: 0引用数: 0
h-index: 0
机构:Calif State Univ San Bernardino, Dept Psychol, San Bernardino, CA 92407 USA
Collins, RL
;
Watson, JB
论文数: 0引用数: 0
h-index: 0
机构:Calif State Univ San Bernardino, Dept Psychol, San Bernardino, CA 92407 USA