title: Cholinergic neurotransmission influences covert orientation of visuospatial attention in the rat.
abstract: BACKGROUND
  Both monkey and human studies have suggested that attentional orienting may be mediated by the cholinergic neurotransmitter system.
  
  
  OBJECTIVE
  The purpose of the present study was to examine whether the cholinergic agonist (nicotine) and/or antagonist (scopolamine) influence covert orientation in the rat.
  
  
  METHODS
  Rats carried out a visual reaction time task to measure covert orienting of attention following systemic administration of nicotine or scopolamine.
  
  
  RESULTS
  Nicotine reduced reaction times, abolishing the validity effect by differentially speeding the reaction times for invalidly cued targets. Conversely, scopolamine increased the validity effect by disproportionately lengthening reaction times to invalidly cued targets.
  
  
  CONCLUSIONS
  Taken together, these data indicate that cholinergic transmission represents an important neurochemical substrate of visuospatial attention, specifically influencing disengagement or movement of attention.
authors.affiliation: School of Psychology, University of St. Andrews, UK.
authors.forename: J M
authors.initials: JM
authors.lastname: Phillips
authors.forename: K
authors.initials: K
authors.lastname: McAlonan
authors.forename: W G
authors.initials: WG
authors.lastname: Robb
authors.forename: V J
authors.initials: VJ
authors.lastname: Brown
mesh_terms: D000818:Animals; D001288:Attention / Q000187:drug effects / Q000502:physiology*; D008297:Male; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009538:Nicotine / Q000494:pharmacology; D018722:Nicotinic Agonists / Q000494:pharmacology; D009949:Orientation / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology*; D011950:Receptors, Cholinergic / Q000187:drug effects / Q000502:physiology; D011976:Receptors, Muscarinic / Q000187:drug effects / Q000502:physiology; D012601:Scopolamine / Q000494:pharmacology
chemical_list: D018727:Muscarinic Antagonists; D018722:Nicotinic Agonists; D011950:Receptors, Cholinergic; D011976:Receptors, Muscarinic; D009538:Nicotine; D012601:Scopolamine