Skip to main content
. Author manuscript; available in PMC: 2016 Sep 1.
Published in final edited form as: Neuropharmacology. 2014 Oct 15;96(0 0):150–156. doi: 10.1016/j.neuropharm.2014.10.004

Figure 1. Currents and states.

Figure 1

A. Single-channel currents from muscle AChRs. Clusters of openings arise from binding and gating events (Scheme 1), and silent periods between clusters are sojourns in desensitized states. Arrow, 2 AChRs open at the same time. B. Cyclic model for activation of a receptor having 1 agonist site. Scheme 1 is bold. ΔG, free energy difference between states; subscripts are LA (low affinity), HA (high affinity), n (number of bound agonists). The free energy difference between C and AO is the same regardless of the connecting route: ΔGLA+ΔG1=ΔG0+ΔGHA. The free energy from the affinity change is ΔGB1=ΔGHA−ΔGLA, so ΔG1=ΔG0+ΔGB1. Agonists increase the probability that a receptor is active because the O state has the higher affinity.