title: The alpha(2C)-adrenergic receptor mediates hyperactivity of coloboma mice, a model of attention deficit hyperactivity disorder.
abstract: Drugs that modify noradrenergic transmission such as atomoxetine and clonidine are increasingly prescribed for the treatment of attention deficit hyperactivity disorder (ADHD). However, the therapeutic targets of these compounds are unknown. Norepinephrine is also implicated in the hyperactivity exhibited by coloboma mice. To identify the receptor subtypes that regulate the hyperactivity, coloboma mice were systematically challenged with adrenergic drugs. The beta-adrenergic receptor antagonist propranolol and the alpha(1)-adrenergic receptor antagonist prazosin each had little effect on the hyperactivity. Conversely, the alpha(2)-adrenergic receptor antagonist yohimbine reduced the activity of coloboma mice but not control mice. Subtype-selective blockade of alpha(2C)-, but not alpha(2A)- or alpha(2B)-adrenergic receptors, ameliorated hyperactivity of coloboma mice without affecting activity of control mice, suggesting that alpha(2C)-adrenergic receptors mediate the hyperactivity. Localized in the basal ganglia, alpha(2C)-adrenergic receptors are in a prime position to impact locomotor activity and are, therefore, potential targets of pharmacotherapy for ADHD.
authors.affiliation: Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
authors.forename: Kristy J
authors.initials: KJ
authors.lastname: Bruno
authors.forename: Ellen J
authors.initials: EJ
authors.lastname: Hess
mesh_terms: D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001289:Attention Deficit Disorder with Hyperactivity / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology; D001479:Basal Ganglia / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D001921:Brain / Q000378:metabolism* / Q000503:physiopathology; D001923:Brain Chemistry / Q000235:genetics*; D002395:Catecholamines / Q000378:metabolism*; D004195:Disease Models, Animal; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006948:Hyperkinesis / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D008818:Mice, Neurologic Mutants; D009043:Motor Activity / Q000187:drug effects / Q000235:genetics; D018341:Receptors, Adrenergic, alpha-2 / Q000235:genetics / Q000378:metabolism*; D015016:Yohimbine / Q000494:pharmacology
chemical_list: C547775:Adra2c protein, mouse; D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D002395:Catecholamines; D018341:Receptors, Adrenergic, alpha-2; D015016:Yohimbine