Figure 5. Inhibition of ACh release from myocyte by intracellular alkalinization.

Single channel recordings were made by cell-attached patch clamp in 1-day-old Xenopus cultured myocytes. The patch was hyperpolarized +60 mV from rest. The patch pipette was filled with Ringer solution containing 1 μM neostigmine to induce ACh-activated single channel current (A). Intracellular alkalinization by bath application of NH₄Cl in a dose-dependent manner inhibited channel opening (B-D). Data are presented as means ± s.e.m (n). *P < 0.05 compared with control.