Effects of guanfacine on three forms of distraction in the aging macaque

Life Sci. 2000 Jul 14;67(8):877-85. doi: 10.1016/s0024-3205(00)00681-0.


alpha-2 adrenoceptor agonists, such as clonidine and guanfacine, enhance attention in aged animals. According to one theory, alpha-2 receptor agonists improve attention by decreasing distractibility to task-irrelevant stimuli. In two healthy aging bonnet macaques, we investigated the effects of low-(0.001 mg/kg) and high-dose (0.05 mg/kg) acute intramuscular guanfacine versus saline control on accuracy (number of trials correct) in three tasks requiring attention: delayed matching-to-sample, one-target visual tracking (test of focused attention) and two-target visual tracking (test of divided attention). Each task employed distracting stimuli in a different paradigmatic context. One monkey responded to guanfacine at both doses with significant rises in accuracy on all three tasks. The second monkey showed significant accuracy improvement for high-dose guanfacine only. No sedation was observed. These results suggest that guanfacine improves attention and reduces distractibility in multiple task contexts in healthy aging primates.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adrenergic alpha-Agonists / pharmacology*
  • Aging / psychology*
  • Animals
  • Attention / drug effects*
  • Dose-Response Relationship, Drug
  • Female
  • Guanfacine / pharmacology*
  • Macaca radiata


  • Adrenergic alpha-Agonists
  • Guanfacine