end-plate by high concentrations of acetylcholine. Journal of Physiology.
At concentrations higher than 200 microM-ACh, po (open probability - MJ)
declined as a result of open-channel block by free ACh itself. 3. At
positive membrane potentials (+100 mV) there was little channel block by
ACh; po reached a maximum value of 0.41 at 500 microM-ACh, with
half-maximum activation at 50 microM and Hill slope of 1.2 at this point.