TABLE 2.

Parameters for ligand action at nAChR containing α6 nAChR subunits

Agonist potencies (micromolar EC₅₀ values with 95% confidence intervals), Hill coefficients (n_H ± SE), mean ± S.E. peak responses (I_max in nanoamps) and concentrations, where I_max is achieved (μm) are provided for nicotine acting at nAChR composed of the indicated subunits derived from the specified species and from the indicated number of independent experiments (n) based on studies as shown in Figs. 2–5. For the indicated potency of the agonist or peak current responses when acting at the specified nAChR subtype composed of the indicated subunits, significant (p < 0.05) increases or decreases, respectively, are indicated relative to the α6β2- or α6β4-nAChR subtype alone ( or ) or in the presence of wild-type α5 subunits (▴ or ▾), α5^V9′S subunits (▵ or ▿), or (α5/β3) subunits ( or ). Note that no or very rare and then small responses to nicotine were seen for the following subunit combinations (n = 4–9 each): hα6 + hβ2 alone or with hα5, hα5^V9′S, hα5/hβ3, or hα5/hβ3^V9′S; or hα6+ hβ4 alone or with hα5, hα5^V9′S, or hα5/hβ3; mα6 + hβ2 alone or with hα5, hα5^V9′S, hα5/hβ3, or hα5/hβ3^V9′S; mα6 + hβ4 a lone or with hα5, hα5^V9′S, or hα5/hβ3; and hα6(N143D+M145V) + hβ2 alone or with hα5, hα5^V9′S, or hα5/hβ3. No or very rare and then small responses were seen for the subunit combinations (n = 6–9 each) where data are entered as dashes.