Table 1

Subunit compositions of well established, naturally expressed and heterologously expressed nACh receptors

Naturally Expressed nACh ReceptorsHeterologously Expressed nACh Receptors
(α1)2β1γδFetal skeletal muscleα1β1γδ
(α1)2β1ɛδAdult skeletal muscleα1β1ɛδ
α1γδ plus β2 or β4
α2 plus β2 or β4
α3β4* Autonomic gangliaα3 plus β2 or β4
α3α5β4Autonomic gangliaα3α5β4
α3α5β2β4Autonomic ganglia
(α4)2(β2)3 CNSα4 plus β2 or β4
α6 plus β2 or β4
α7* Autonomic ganglia, CNSα7
α7α8* Chick retina, chick CNSα7α8 (chick)
α8* Chick retinaα8 (chick)
α9* Cochlea, pituitaryα9
  • Subunit compositions, stoichiometries if known, and principal locations (not exhaustively, but focusing on selected central, sensory, autonomic, and/or somatomotor nervous system locations) are indicated for well-characterized, naturally expressed nACh receptors. Also shown are subunit compositions known to form distinctive, functional receptor-channel complexes in heterologous expression systems based on studies using subunits derived from several species including man, rat, mouse, chick, and/or electric ray. Note that α8 subunits and receptors containing them have only been identified in chick.