title: Locomotor hyperactivity induced by blockade of prefrontal cortical alpha2-adrenoceptors in monkeys.
abstract: BACKGROUND
  Stimulation of alpha(2)-adrenergic receptors (alpha(2)-ARs) in the prefrontal cortex (PFC) has a beneficial effect on working memory and attentional regulation in monkeys. alpha(2)-adrenergic agonists like clonidine and guanfacine have been used experimentally and clinically for the treatment of attention deficit and hyperactivity disorder (ADHD). However, it is unknown if alpha(2)-ARs in the PFC are involved in the neural mechanisms underlying regulation of locomotor activity.
  
  
  METHODS
  The alpha(2)-adrenergic antagonist yohimbine was infused bilaterally and chronically into the dorsolateral PFC (dlPFC) in two monkeys, using mini-osmotic pumps. Spontaneous locomotor activity was measured continuously before, during and after drug administration, using an activity monitor.
  
  
  RESULTS
  The monkeys exhibited a dramatic increase in motoric activity during infusion of yohimbine into the dlPFC. Similar treatment with saline was without effect. Thus, the locomotor hyperactivity was due to blockade of alpha(2)-ARs, not because of nonspecific factors such as cortical damage by drug administration.
  
  
  CONCLUSIONS
  The present study suggests that alpha(2)-ARs in the dlPFC are involved in inhibitory control of locomotor activity.
authors.affiliation: Institute of Neurobiology, Fudan University, Shanghai, The People's Republic of China.
authors.forename: Chao-Lin
authors.initials: CL
authors.lastname: Ma
authors.forename: Amy F T
authors.initials: AF
authors.lastname: Arnsten
authors.forename: Bao-Ming
authors.initials: BM
authors.lastname: Li
mesh_terms: D058669:Adrenergic alpha-2 Receptor Antagonists; D000317:Adrenergic alpha-Antagonists / Q000008:administration & dosage; D000818:Animals; D004334:Drug Administration Schedule; D005260:Female; D006948:Hyperkinesis / Q000139:chemically induced / Q000503:physiopathology*; D008253:Macaca mulatta; D008845:Microinjections; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology*; D017397:Prefrontal Cortex / Q000187:drug effects*; D018341:Receptors, Adrenergic, alpha-2 / Q000502:physiology*; D015016:Yohimbine / Q000008:administration & dosage
chemical_list: D058669:Adrenergic alpha-2 Receptor Antagonists; D000317:Adrenergic alpha-Antagonists; D018341:Receptors, Adrenergic, alpha-2; D015016:Yohimbine