CHRNA4 (Cholinergic Receptor Nicotinic Alpha 4 Subunit) is a gene that encodes a subunit of the nicotinic acetylcholine receptor, which plays a key role in neurotransmission within the nervous system. This receptor is important for modulating neuronal excitability and synaptic communication. Mutations in CHRNA4 have been associated with certain forms of epilepsy and other neurological disorders, highlighting its critical function in brain activity.