Long-term methylphenidate treatment down-regulates c-fos in the striatum of male CD-1 mice.
Methylphenidate (Ritalin) is routinely prescribed to children with attention deficit hyperactivity disorder, but little is known about its long-term consequences on brain development. We treated pre- and peri-pubertal male CD-1 mice with repeated injections of methylphenidate hydrochloride (MPH) and quantified the expression of the immediate early gene c-fos in the striatum. A single injection of MPH (5 or 40 mg/kg) significantly elevated FOS immunoreactivity in the striatum in a dose-dependent manner, compared with saline. Repeated MPH treatment attenuated the effect of a single challenge dose of MPH on striatal c-fos expression. These results replicate those observed with rats and indicate that long-term use of MPH may alter neural activity by down-regulation of gene expression in the striatum.
Hawken
Christianne M
CM
Department of Psychology, Dalhousie University, Halifax, Nova Scotia B3H 4J1, Canada.
Brown
Richard E
RE
Carrey
Normand
N
Wilkinson
Michael
M
D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects* / Q000502:physiology; D016762:Genes, fos / Q000187:drug effects* / Q000502:physiology; D008297:Male; D008774:Methylphenidate / Q000008:administration & dosage*; D051379:Mice; D013995:Time
D008774:Methylphenidate