Variations in nAChR hα6 subunit influence the current responses of hα6hβ4hβ3-nAChRs. Mean (±SE) peak inward current responses upon exposure to 100 μM nicotine (5 sec exposure; ordinate) are estimated from oocytes (n = 6-11) voltage clamped at −70 mV and heterologously expressing the indicated nAChR subunits. Oocytes coexpressing hα6(D57N, R87C, S156R or N171K) subunits plus hβ4 and hβ3 subunits do not yield current responses to nicotine though those coexpressing hα6, hβ4 and hβ3 subunit yield fairly robust current responses. hα6 subunit variation Asp92Glu (in loop D) partially abolishes the peak current responses of hα6hβ4hβ3-nAChRs. hα6 subunit variations Asn46Lys, Arg96His, Glu101Lys, Ala112Val, Ala184Asp, Asn203Thr, Ile226Thr or Ser233Cys do not affect nicotine elicited peak current responses of hα6hβ4hβ3-nAChRs. Comparisons between control (hα6hβ4hβ3) and variant groups were analyzed using one-way ANOVA with Dunnett’s multiple comparisons test (*, p < 0.05; and **, p < 0.01).