Which neurotransmitter is released by pre-ganglionic parasympathetic fibers?

Pre-ganglionic parasympathetic fibers release acetylcholine as their primary neurotransmitter. The parasympathetic nervous system is part of the autonomic nervous system, which facilitates bodily functions that occur unconsciously and regulate the body's rest-and-digest responses.

Acetylcholine plays a vital role in transmitting signals from pre-ganglionic neurons to post-ganglionic neurons in the parasympathetic pathway. This cholinergic transmission occurs at the ganglia where acetylcholine binds to nicotinic receptors on post-ganglionic neurons, leading to the continuation of the signal towards the targeted organs.

Understanding this function is integral to comprehending how autonomic responses are mediated in the body, particularly in processes such as slowing the heart rate, enhancing digestion, and facilitating glandular secretions.