Figure 3.

(A) Sample dose-response relationships for strychnine block of muscle α₁β₁γδ (circles), neuronal α₂β₄ (triangles), and neuronal α₂β₂ (diamonds) AcChoRs. The currents were elicited by 2 μM AcCho for α₁β₁γδ and 50 μM AcCho for α₂β₄ and α₂β₂ receptors. The continuous lines represent least squares fit to the relation I_[strychnine] = I₀·IC₅₀/([strychnine]^nH + IC₅₀^nH), where I_[strychnine] is the AcCho-current amplitude inhibited by strychnine, I₀ is the control peak current, IC₅₀ is the half-inhibitory concentration of strychnine, and nH is the Hill coefficient. (B) Amplitude of progressive control AcCho-current (open diamonds) and AcCho-current in the presence of the strychnine concentrations shown in A for the α₂β₂ receptors (filled diamonds).