What effect does the cholinergic system have on the heart rate during sleep?

The cholinergic system is primarily associated with the parasympathetic nervous system, which is responsible for promoting rest and relaxation in the body. During sleep, especially in the deeper stages, the influence of the parasympathetic system increases significantly. As a result, the release of acetylcholine acts on the cardiac muscarinic receptors, leading to a decrease in heart rate.

This decrease in heart rate during sleep occurs because the body is in a state of decreased metabolic activity and requires less oxygen, as well as lower demand for blood flow to skeletal muscles. Therefore, the cholinergic system facilitates a reduction in heart rate, allowing for a restful state and recovery of bodily functions, which is crucial during sleep for overall health and bodily maintenance.