Nucleus basalis magnocellularis and attention: effects of muscimol infusions

Behav Neurosci. 1993 Dec;107(6):1031-8. doi: 10.1037//0735-7044.107.6.1031.


The basal forebrain is important in cognitive processing. Most studies have focused on the importance of this area in mnemonic processing. However, the nucleus basalis magnocellularis (NBM), which is a major component of the basal forebrain, may also be involved in attentional processes. Attention can influence the sensitivity of perceptual processes, as assessed by discriminability, or the selection of response strategies, as assessed by bias. This experiment examined whether temporary inactivation of the NBM, using the GABA agonist muscimol, would interfere with attention. Each rat was tested in a 2-choice reaction time (RT) task in which stimulus frequency was varied. RT and error rate increased, and discriminability decreased following muscimol infusions into the NBM. Bias was unchanged. The pattern of results provides evidence that the NBM is important in attention, and this influence of the NBM acts primarily on perceptual aspects of attention.

Publication types

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

MeSH terms

  • Animals
  • Appetitive Behavior / drug effects
  • Appetitive Behavior / physiology
  • Attention / drug effects*
  • Attention / physiology
  • Conditioning, Operant / drug effects
  • Conditioning, Operant / physiology
  • Discrimination Learning / drug effects
  • Discrimination Learning / physiology
  • Dose-Response Relationship, Drug
  • Muscimol / pharmacology*
  • Olivary Nucleus / drug effects*
  • Olivary Nucleus / physiology
  • Pitch Perception / drug effects
  • Pitch Perception / physiology
  • Prosencephalon / drug effects*
  • Prosencephalon / physiology
  • Psychomotor Performance / drug effects
  • Psychomotor Performance / physiology
  • Rats
  • Reaction Time / drug effects
  • Reaction Time / physiology
  • Substantia Innominata / drug effects*
  • Substantia Innominata / physiology
  • Visual Perception / drug effects
  • Visual Perception / physiology
  • gamma-Aminobutyric Acid / physiology*


  • Muscimol
  • gamma-Aminobutyric Acid