Elsevier

Neuroscience Letters

Volume 125, Issue 2, 29 April 1991, Pages 215-218
Neuroscience Letters

Effects of intra-axonal injection of Ca2+ buffers on evoked release and on facilitation in the crayfish neuromuscular junction

https://doi.org/10.1016/0304-3940(91)90032-OGet rights and content

Abstract

Ca2+ buffers were injected into the excitatory axon of the crayfish opener muscle. The magnitude and time course of evoked release and of facilitation were measured. EGTA (on-rate about 106 M−1s−1 had no effect on evoked release but reduced facilitation. BAPTA and nitr-5, buffers with similar Kd's but faster on-rates, reduced both evoked release and facilitation. However, these buffers had no effect on the time course of evoked release. These results show that fast Ca2+ buffers reduce the Ca2+ transient associated with evoked release and also the level of residual Ca2+ involved in facilitation. However, Ca2+ buffering is not the mechanism which controls the time course of release.

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