NMR resolved multiple anesthetic binding sites in the TM domains of the α4β2 nAChR

► Anesthetics halothane and ketamine bound to multiple sites of the α4β2 nAChR. ► A common intra-subunit anesthetic site was near the extracellular end of the β2 TM. ► Halothane occupied inter-subunit sites near the extracellular end of the TM domain. ► Both drugs bound to intra- and inter-subunit sites near the selectivity filter. ► Anesthetics induced, directly or allosterically, dynamics changes of α4β2.