Subunit compositions of well established, naturally expressed and heterologously expressed nACh receptors
| Naturally Expressed nACh Receptors | Heterologously Expressed nACh Receptors | |
|---|---|---|
| (α1)2β1γδ | Fetal skeletal muscle | α1β1γδ |
| (α1)2β1ɛδ | Adult skeletal muscle | α1β1ɛδ |
| α1γδ plus β2 or β4 | ||
| α2 plus β2 or β4 | ||
| α3β4* | Autonomic ganglia | α3 plus β2 or β4 |
| α3α5β4 | Autonomic ganglia | α3α5β4 |
| α3β3β4 | ||
| α3α5β2 | ||
| α3α5β2β4 | Autonomic ganglia | |
| (α4)2(β2)3 | CNS | α4 plus β2 or β4 |
| α4β2β4 | ||
| α4β2β3β4 | ||
| α4α5β2 | CNS | α4α5β2 |
| α6 plus β2 or β4 | ||
| α7* | Autonomic ganglia, CNS | α7 |
| α7α8* | Chick retina, chick CNS | α7α8 (chick) |
| α8* | Chick retina | α8 (chick) |
| α9* | Cochlea, pituitary | α9 |
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.