Juvenile methylphenidate exposure and factors that influence incentive processing.
Methylphenidate (MPH) is one of the few psychotropic agents approved for use in pediatric populations, underscoring the importance of elucidating any long-term consequences following exposure to this agent. Here, we examined the influence of several variables (i.e. age of assessment, age of exposure, sex, route of administration) on the effect of chronic low-dose MPH (2 mg/kg, twice daily) exposure on place conditioning to cocaine. Juvenile exposure to MPH, but not later exposure, resulted in aversions to cocaine-paired environments when assessed in young adult male rats, but not those entering adolescence. Juvenile MPH enhanced place preferences for cocaine-paired environments in female adolescent rats. The route of administration (i.p. injection or oral ingestion) did not produce enduring differential effects on behavior, and D-MPH was confirmed as the active enantiomer. These observations add to the growing literature on the enduring effects of MPH exposure, and highlight the need for more research in females.
Laboratory for Developmental Neuropsychopharmacology, Department of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, MA 02478, USA.
Heather C
HC
Brenhouse
Lee
L
Napierata
Lucinda
L
Kussmaul
Melanie
M
Leussis
Susan L
SL
Andersen
D000284:Administration, Oral; D000375:Aging / Q000502:physiology; D000818:Animals; D000697:Central Nervous System Stimulants / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity*; D003216:Conditioning, Operant / Q000187:drug effects; D005260:Female; D007274:Injections, Intraperitoneal; D008297:Male; D008774:Methylphenidate / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity*; D009042:Motivation; D009043:Motor Activity / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D012727:Sex Characteristics; D013237:Stereoisomerism; D019966:Substance-Related Disorders / Q000523:psychology
D000697:Central Nervous System Stimulants; D008774:Methylphenidate