The effect of tetanic and post‐tetanic potentiation on facilitation of transmitter release at the frog neuromuscular junction
- 1 October 1973
- journal article
- Published by Wiley in The Journal of Physiology
- Vol. 234 (2), 353-371
- https://doi.org/10.1113/jphysiol.1973.sp010349
Abstract
1. End-plate potentials (e.p.p.s) were recorded from frog neuromuscular junctions blocked with high Mg and/or low Ca.2. Estimates of f(t), the facilitation contributed by each impulse, were obtained during and following repetitive stimulation from the incremental change in e.p.p. amplitudes following step changes in the stimulation rate during the conditioning and testing trains.3. Estimates of f(t) increased during the conditioning stimulation and returned to control in the post-tetanic period. This increase in f(t) was proportional to the magnitude of tetanic or post-tetanic potentiation (PTP) present.4. These results are described by: [Formula: see text] where h(t)/h(c) is the e.p.p. amplitude at time t expressed in terms of the control, P(t) is potentiation, F(t) is facilitation and 1 is the base level of transmitter release. Thus, potentiation has a multiplicative (gain) effect on facilitation and the base level of transmitter release.5. PTP was present immediately following the conditioning train. However, if depression occurred during the conditioning train, PTP developed after a delay.6. It is suggested that facilitation and potentiation represent increases in two independent factors which act jointly to increase the probability of transmitter release.Keywords
This publication has 22 references indexed in Scilit:
- The effects of changing the osmolarity of the ringer on acetylcholine release at the frog neuromuscular junctionLife Sciences, 1971
- Ionic mechanism of post-tetanic potentiation at the neuromuscular junction of the frogThe Journal of Physiology, 1971
- Tetanic and post‐tetanic rise in frequency of miniature end‐plate potentials in low‐calcium solutionsThe Journal of Physiology, 1971
- Neuromuscular facilitation with low-frequency stimulation and effects of some drugs.Journal of Neurophysiology, 1969
- Post‐tetanic potentiation at the neuromuscular junction of the frogThe Journal of Physiology, 1969
- A study of the mechanism of quantal transmitter release at a chemical synapseThe Journal of Physiology, 1968
- A dual effect of calcium ions on neuromuscular facilitationThe Journal of Physiology, 1968
- Potential changes recorded from the frog motor nerve terminal during its activationPflügers Archiv - European Journal of Physiology, 1966
- A quantitative study of end‐plate potentials in isolated human muscle.The Journal of Physiology, 1965
- NEUROMUSCULAR DEPRESSION AND THE APPARENT DEPLETION OF TRANSMITTER IN MAMMALIAN MUSCLEJournal of Neurophysiology, 1965