Acetylcholine and the Cholinergic System

Professor Trevor Robbins discusses two functions of the cholinergic (acetylcholine) system. One is involved in arousal and memory, the other in the sleep/waking cycle.

The cholinergic system comes as two main branches. It is a fascinating system because there is a forebrain system in the so-called basal forebrain that is right out front of the bottom. That projects to the neocortex and another branch of it projects to the hippocampus. These areas of the basal forebrain, these cholinergic cells are involved in particular in a form of arousal we call vigilance. They are greatly involved in enhancing signal-to-noise ratios so that they enable you to detect targets with great fidelity. We also suspect that they contribute to memory-encoding processes and working-memory processes mainly by enhancing the power of the signals going into these processes. There is also a brain stem cholinergic system, which actually also stimulates the basal forebrain system. The brain stem is called the tegmental cholinergic system and it is very importantly involved in the sleep/waking cycle.