What does acetylcholine from the basal forebrain do to the cortex? · Grey Matter

Cholinergic neurons of the nucleus basalis and nearby basal forebrain project across the cortex and are most active in attentive waking and in REM sleep.

What does acetylcholine from the basal forebrain do to the cortex?

Cholinergic neurons of the nucleus basalis and nearby basal forebrain project across the cortex and are most active in attentive waking and in REM sleep. Their acetylcholine makes cortical neurons more excitable and, in many studies, boosts responses carried by incoming sensory pathways relative to activity from recurrent connections within the cortex. One account is that this tilts the cortex toward taking in new information and encoding it, rather than recalling what it already holds. Loss of these neurons early in Alzheimer's disease is one reason cholinesterase inhibitors give a modest benefit there.