FIGURE 2.

Functional properties of mα6*-nAChR. A, representative traces are shown for inward currents in oocytes held at −70 mV, responding to application at the indicated concentrations of nicotine (shown with the duration of drug exposure as black bars above the traces), and expressing nAChR mα6^V13′S, mβ4, and mβ3 subunits. B, results for these and other studies averaged across experiments were used to produce concentration-response curves (ordinate, mean normalized current ± S.E.; abscissa, ligand concentration in log μm) for inward current responses to nicotine as indicated for oocytes expressing nAChR mα6 and mβ4 subunits (■) or mα6^V13′S and mβ4 and mβ3 subunits (□), where current amplitudes are represented as a fraction of the peak inward current amplitude in response to the most efficacious concentration of nicotine. Much higher levels of evoked currents are evident for functional nAChR containing mα6^V13′S, mβ4, and mβ3 subunits when compared with receptors lacking mα6^V13′S subunits. See Table 1 for parameters.