In the CNS, Acetylcholine (ACh) acts mainly via muscarinic (metabotropic) and nicotinic (ionotropic) receptors.1
References:
1. Neurotransmitters. In: Augustine GJ, Groh J, Huettel S, et al. (eds). Neuroscience. 7th edition. Oxford University Press, 2023.
2. Decker AL, Duncan K. Acetylcholine and the complex interdependence of memory and attention. Curr Opin Behav Sci 2020; 32: 1–8.