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Effect of lithium on veratridine-induced quantal and non-quantal release from inhibitory nerve terminals in crayfish muscle

Abstract

Muscle fibres of small crayfish were voltage clamped and superfused for about 10 min with Li+ saline (Na+ replaced by Li+) which contained 5 mmol/l glutamate to desensitize excitatory postsynaptic receptors. Then 100 μmol/l veratridine were added to the superfusate which caused strong asynchronous quantal release of inhibitory transmitter. However, in the presence of Li+ strong inhibitory quantal release was only transient. It could be activated a second time by removal of Li+ and readministration of Na+. From the total of 0.7 to 1.1 million quanta released by veratridine only about 30–35% could be released in Li+ saline. The voltage clamp DC-currents recorded during veratridine-induced quantal release suggested that a nonquantal release component is additionally involved. This non-quantal release component was most prominent during the period of quantal release in Li+ superfusate while it was less obvious during the second enhancement of quantal release in normal saline. Together with previous results (Martin and Finger 1988) it may be concluded that quantal release, but not non-quantal release, is decreased by Li+ in the nerve terminals.

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References

  1. Finger W (1983) Effects of glycine on the crayfish neuromuscular junction. II. Release of inhibitory transmitter activated by glycine. Pflügers Arch 397:128–134

  2. Finger W (1985) Excitatory transmitter release induced by high concentrations of γ-aminobutyric acid (GABA) in crayfish neuromuscular junctions. Pflügers Arch 405:265–273

  3. Finger W, Martin C (1987a) Veratridine-induced high frequency release of excitatory transmitter quanta in crayfish nerve-muscle synapses. Pflügers Arch 408 (Suppl): R67/260

  4. Finger W, Martin C (1987b) Differential effect of intraterminal sodium on spontaneous quantal release of transmitter in two neuromuscular junctions of crayfish. Neurosci Lett 75:293–298

  5. Finger W, Martin C (1987c) Inhibitory effect of intraterminal lithium on asynchronous release of excitatory quanta induced by veratridine in nerve-muscle synapses of crayfish. Neuro Sci Lett 83:113–117

  6. Finger W, Martin C (1988) Veratridine-induced quantal and nonquantal release from inhibitory terminals in crayfish and the effect of lithium. Pflügers Arch (Suppl) (in press)

  7. Finger W, Stettmeier H (1981) Analysis of miniature spontaneous inhibitory postsynaptic currents (sIPSCs) from current noise in crayfish opener muscle. Pflügers Arch 392:157–162

  8. Martin C, Finger W (1988) Veratridine-induced high-frequency asynchronous release of inhibitory transmitter quanta in crayfish nerve-muscle synapses superfused with normal and lowcalcium saline. Pflügers Arch 411:353–361

  9. Mayer ML, Higashi H, Gallagher IP, Shinnick-Gallagher P (1983) On the mechanism of action of GABA in pelvic vesical ganglia: biphasic responses evoked by two opposing actions on membrane conductance. Brain Res 260:233–248

  10. Ortiz CL, Junge D (1978) Depressant action of lithium at the crayfish neuromuscular junction: pre- and postsynaptic effects. J Exp Biol 75:171–187

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Author information

Correspondence to W. Finger.

Additional information

This investigation was supported by the Deutsche Forschungsgemeinschaft, SFB 220

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Finger, W., Martin, C. Effect of lithium on veratridine-induced quantal and non-quantal release from inhibitory nerve terminals in crayfish muscle. Pflugers Arch. 411, 478–480 (1988). https://doi.org/10.1007/BF00582367

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Key words

  • Inhibitory synapse
  • Veratridine
  • Lithium
  • Quantal release
  • Non-quantal release
  • Noise analysis