Enduring behavioral effects of early exposure to methylphenidate in rats.

Journal Article (Journal Article)

BACKGROUND: Methylphenidate (MPH) is a stimulant prescribed for the treatment of attention-deficit/hyperactivity disorder (ADHD). Stimulant drugs can cause enduring behavioral adaptations, including altered drug sensitivity, in laboratory animals. We examined how early developmental exposure to stimulants affects behavior in several rodent models. METHODS: Rats received MPH or cocaine during preadolescence (P20-35). Behavioral studies began during adulthood (P60). We compared how early exposure to MPH and cocaine affects sensitivity to the rewarding and aversive properties of cocaine using place conditioning. We also examined the effects of early exposure to MPH on depressive-like signs using the forced swim test, and habituation of spontaneous locomotion, within activity chambers. RESULTS: In place-conditioning tests, early exposure to MPH or cocaine each made moderate doses of cocaine aversive and high doses less rewarding. Early MPH exposure also caused depressive-like effects in the forced swim test, and it attenuated habituation to the activity chambers. CONCLUSIONS: Early exposure to MPH causes behavioral changes in rats that endure into adulthood. Some changes (reduced sensitivity to cocaine reward) may be beneficial, whereas others (increases in depressive-like signs, reduced habituation) may be detrimental. The effects of MPH on cocaine-related behaviors may be a general consequence of early stimulant exposure.

Full Text

Duke Authors

Cited Authors

  • Carlezon, WA; Mague, SD; Andersen, SL

Published Date

  • December 15, 2003

Published In

Volume / Issue

  • 54 / 12

Start / End Page

  • 1330 - 1337

PubMed ID

  • 14675796

International Standard Serial Number (ISSN)

  • 0006-3223

Digital Object Identifier (DOI)

  • 10.1016/j.biopsych.2003.08.020


  • eng

Conference Location

  • United States