Sensitization and cross-sensitization after chronic treatment with methylphenidate in adolescent Wistar rats.
An increasing debate exists about the potential of early exposure to methylphenidate to increase the risk for drug abuse. In addition, little is known about the neurobiological effects of early exposure to methylphenidate. This study was designed to investigate whether chronic treatment with methylphenidate induces behavioral sensitization to subsequent methylphenidate and D-amphetamine challenge in adolescent Wistar rats. Young Wistar rats (P25) were treated with either methylphenidate (1, 2, or 10 mg/kg, intraperitoneally) or saline for 28 days. After 14 days of washout, animals were challenged with methylphenidate 2.5 mg/kg intraperitoneally or D-amphetamine 2 mg/kg intraperitoneally (P67). Locomotor behavior was assessed using the open field test. Rats chronically treated with methylphenidate in the adolescent period showed augmented locomotor sensitization to D-amphetamine but not to methylphenidate in the adult phase. These findings suggest that early exposure do methylphenidate might increase the risk for subsequent D-amphetamine abuse. Further studies focusing on the neurobiological effects of early exposure to methylphenidate are warranted.
Valvassori
Samira S
SS
Laboratory of Neuroscience, Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense Criciúma, SC, Brazil.
Frey
Benício N
BN
Martins
Márcio R
MR
Réus
Gislaine Z
GZ
Schimidtz
Filipe
F
Inácio
Cecília G
CG
Kapczinski
Flávio
F
Quevedo
João
J
D000661:Amphetamine / Q000494:pharmacology; D019969:Amphetamine-Related Disorders / Q000523:psychology; D000818:Animals; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D008297:Male; D008774:Methylphenidate / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D012306:Risk; D019966:Substance-Related Disorders / Q000523:psychology
D000697:Central Nervous System Stimulants; D008774:Methylphenidate; D000661:Amphetamine