Proposed classification of nAChRs in the mouse brain
| Receptor class | Putative composition | Predominant localization in CNS | High-affinity binding at equilibrium | Pharmacology in slices |
|---|---|---|---|---|
| Type 1 | α7 | Cortex and limbic areas | αBTX | αBTX and MLA-sensitive, very fast desensitization |
| Type 2 | β2-α4-(α5?) | All CNS | EPI > NIC = CYT = MCC = ACH | MLA-insensitive, NIC ≫ |
| β2-(α2?) | IPn | CYT, DHβE = MCA | ||
| β2-(α3?) | Hippocampus | |||
| β2-(α6-β3?) | Catecholaminergic nuclei | |||
| Type 3 | β4-α3-(α5?) | MHb, IPn, dorsal medulla | EPI | MLA-insensitive, CYT = NIC, DHβE < MCA slow decay at 100 μm NICO |
| Type 4 | (β4-α4?) | Lateral MHb | EPI > CYT > MCC = ACH | MLA-insensitive, CYT = |
| (β4-α2?) | Dorsal IPn | NIC, DHβE < MCA fast | ||
| decay at 100 μm NICO |
ACH, Acetylcholine; αBTX, α-bungarotoxin; MCC, methylcarbamylcholine; CYT, cytisine; DHβE, dihydro-β-erythroidine; EPI, epibatidine; IPn, interpeduncular nucleus; MCA, mecamylamine; MHb, medial habenula; MLA, methyllycaconitine; NIC, nicotine.