+**Ac4** commonly denotes the alpha-4 subunit, a key component of the nicotinic acetylcholine receptor. This [Protein](/wiki/Protein) is vital for proper [Neurotransmission](/wiki/Neurotransmission) in the central nervous system, influencing brain activity and cognitive functions. Its presence is essential for normal synaptic signaling.
+## See also
+- [Receptor](/wiki/Receptor)
+- [Acetylcholine](/wiki/Acetylcholine)
+- [Nervous System](/wiki/Nervous_System)