title: Brain noradrenergic systems as a prerequisite for developing tolerance to barbiturates.
abstract: Mice treated with 6-hydroxydopamine before they were chronically fed phenobarbital did not develop functional barbiturate tolerance, measured by duration of the loss of righting reflex and hypothermia. Injection of 6-hydroxydopamine caused significant depletion of brain norepinephrine, while brain dopamine levels were not significantly depleted. Intact brain noradrenergic systems seem to be necessary for developing tolerance to the hypnotic and hypothermic effects of the barbiturates.
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001833:Body Temperature Regulation / Q000187:drug effects; D001921:Brain / Q000187:drug effects*; D004361:Drug Tolerance; D006801:Humans; D006892:Hydroxydopamines / Q000494:pharmacology; D008297:Male; D051379:Mice; D009638:Norepinephrine / Q000378:metabolism*; D010634:Phenobarbital / Q000494:pharmacology*; D012018:Reflex / Q000187:drug effects; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology; D019966:Substance-Related Disorders / Q000503:physiopathology; D013564:Sympathetic Nervous System / Q000187:drug effects
chemical_list: D006892:Hydroxydopamines; D009638:Norepinephrine; D010634:Phenobarbital