title: Adolescent and adult male spontaneous hyperactive rats (SHR) respond differently to acute and chronic methylphenidate (Ritalin).
abstract: Eight groups of male adolescent and adult spontaneous hyperactive rats (SHR) were used in a dose response (saline, 0.6, 2.5, and 10 mg/kg) experiment of methylphenidate (MPD). Four different locomotor indices were recorded for 2 hours postinjection using a computerized monitoring system. Acutely, the 0.6 mg/kg dose of MPD did not elicit an increase in locomotor activity in either the adolescent or in the adult male SHR. The 2.5 and the 10.0 mg/kg doses increased activity in the adolescent and the adult rats. Chronically, MPD treatment when comparing adolescent and adult gave the following results: the 0.6 mg/kg dose of MPD failed to cause sensitization in the adolescent group but caused sensitization in the adult group, while the 2.5 and 10 mg/kg both caused sensitization in the adolescent and adult groups.
authors.affiliation: Department of Neurobiology and Anatomy, The University of Texas Medical School at Houston, Houston, TX 77225, USA.
authors.forename: Elyssa
authors.initials: E
authors.lastname: Barron
authors.forename: Pamela B
authors.initials: PB
authors.lastname: Yang
authors.forename: Alan C
authors.initials: AC
authors.lastname: Swann
authors.forename: Nachum
authors.initials: N
authors.lastname: Dafny
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy* / Q000503:physiopathology; D001522:Behavior, Animal / Q000502:physiology; D001921:Brain / Q000187:drug effects / Q000503:physiopathology; D001923:Brain Chemistry / Q000187:drug effects / Q000502:physiology; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004351:Drug Resistance / Q000502:physiology*; D008297:Male; D008774:Methylphenidate / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D051381:Rats; D011918:Rats, Inbred SHR; D013997:Time Factors
chemical_list: D000697:Central Nervous System Stimulants; D008774:Methylphenidate