NUCLEUS BASALIS MAGNOCELLULARIS AND ATTENTION - EFFECTS OF MUSCIMOL INFUSIONS

The basal forebrain is important in cognitive processing. Most studies have focused on the importance of this area in mnemonic processing. H owever, the nucleus basalis magnocellularis (NBM), which is a major co mponent of the basal forebrain, may also be involved in attentional pr ocesses. Attention can influence the sensitivity of perceptual process es, as assessed by discriminability, or the selection of response stra tegies, as assessed by bias. This experiment examined whether temporar y inactivation of the NBM, using the GABA agonist muscimol, would inte rfere with attention. Each rat was tested in a 2-choice reaction time (RT) task in which stimulus frequency was varied. RT and error rate in creased, and discriminability decreased following muscimol infusions i nto the NBM. Bias was unchanged. The pattern of results provides evide nce that the NBM is important in attention, and this influence of the NBM acts primarily on perceptual aspects of attention.