All α subunits are expressed in neuronal cells except for the α1 subunit which is specifically expressed in skeletal muscle. Indeed, two different nAChR structural entities with the following stoichiometry are observed in this tissue: (α1)₂β1δγ in fetal muscle cells and (α1)₂β1δε at mature neuromuscular synapses.

The α1 extracellular domain contains the main immunogenic region, a region against which a large fraction of autoantibodies against nAChR is directed in the autoimmune disease myasthenia gravis (MG). This autoimmune disease is characterized by the malfunction of neuromuscular transmission as a result of nonfunctional nAChRs, leading to defective signaling at the neuromuscular junction.