Correlation between nerve terminal size and transmitter release at the neuromuscular junction of the frog

J Physiol. 1971 Mar;213(3):545-56. doi: 10.1113/jphysiol.1971.sp009399.


1. End-plate potentials were recorded intracellularly at the frog neuromuscular junction bathed in a solution containing a low concentration of calcium and a high concentration of magnesium.2. The muscle was subsequently subjected to ;cholinesterase staining', and the area of the individual end-plates, studied with intracellular electrodes, was measured.3. A positive correlation was found between the end-plate area and the diameter of muscle fibres.4. The mean quantum content (m) showed a positive correlation with the size of end-plates.5. The frequency of spontaneous miniature end-plate potentials was positively correlated with m as well as with end-plate area.6. It is concluded that the amount of transmitter released following nerve stimulation is related to the size of nerve endings.

MeSH terms

  • Animals
  • Anura
  • Calcium / pharmacology
  • Cholinesterases
  • Electric Stimulation
  • Electrophysiology
  • In Vitro Techniques
  • Magnesium / pharmacology
  • Membrane Potentials
  • Myofibrils / physiology
  • Nerve Endings / anatomy & histology*
  • Neuromuscular Junction / physiology*
  • Synaptic Transmission*


  • Cholinesterases
  • Magnesium
  • Calcium