# acetylcholine

/əˌsɛtəɫˈkoʊɫin/ (US) · CEFR C2 · Noun

Source: https://englishreference.com/word/acetylcholine
Updated: 2026-10-18

## Definition

a natural chemical in your body that carries signals between nerve cells and muscles. It helps you move, and it also plays a role in memory and attention.

For teachers: an ester of acetic acid and choline that transmits signals between nerve cells and to muscle cells, notably at neuromuscular junctions and in parasympathetic pathways.

## Examples

- Acetylcholine helps your muscles move when you walk.
- When you lift a cup, acetylcholine carries the signal from your nerves to your hand muscles.
- Researchers studying Alzheimer's disease often focus on acetylcholine because falling levels of this messenger disrupt memory and attention in the aging brain.

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