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. 1972 Dec;227(3):691–708. doi: 10.1113/jphysiol.1972.sp010054

The kinetics of transmitter release at the frog neuromuscular junction

Ellen F Barrett, C F Stevens
PMCID: PMC1331282  PMID: 4405553

Abstract

1. Fluctuations in the latency of focally recorded end-plate currents were analysed to determine the time course of the probabilistic presynaptic process underlying quantal release evoked after single nerve stimuli at the frog neuromuscular junction.

2. The early falling phase of the presynaptic probability function can be fitted by a single exponential over two orders of magnitude of quantal release rate. The time constant of the early falling phase is about 0·5 msec at 11° C, and increases with decreasing temperature with a Q10 of at least 4 over the range 1-12° C.

3. After this early exponential fall, quantal release probability returns to control levels with a much slower time course.

4. Conditioning nerve stimuli increase the magnitude and slightly prolong the early time course of release evoked by a test stimulus. When facilitation is calculated for matched time intervals following the conditioning and testing stimuli, it is found that the magnitude of the small, late residual tail of release is facilitated by a greater percentage than the magnitude of larger, early portions of release.

5. These results are discussed in terms of the hypothesis (Katz & Miledi, 1968) that evoked release and facilitation are mediated by a common presynaptic factor which activates release in a non-linear manner.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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