Spontaneous activity of murine neuromuscular junctions in the presence of dantrolene

O. P. Balezina, Anna Bukiya

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

By recording miniature end-plate potentials (mEPP), the effects of dantrolene (10-100 μM), a blocker of ryanodine receptors, were studied on the isolated diaphragm of mice. The effects to be studied were as follows: on spontaneous secretion of acetylcholine quanta and on the pattern of interaction with ryanodine effects. Two-hour-long application of dantrolene to the muscle caused no significant changes in the amplitude and dispersion (σ2) of mEPP, nor on its time course. In the presence of 100 μM dantrolene, the mean frequency of mEPP increased, on average, by 58.3 ± 5.9% (P < 0.05). Dantrolene suppressed in a dose-dependent manner a number of ryanodine effects (this agent was used in a concentration of 0.5 μM as an intensifier of intracellular Ca2- mobilization): it completely prevented the appearance of the population of high-amplitude (the so-called giant) mEPP, reduced by 50-80% the increment of the mEPP amplitude dispersion, and increased by 25-45% the mEPP mean amplitude; the above effects were induced by ryanodine application for 120 min. After preliminary application of dantrolene (10-100 μM), ryanodine caused an effect not observable in the absence of dantrolene: mEPP became more frequent (140-210%). Thus, when acting on motor synapses, dantrolene behaves as a nontoxic agent, inducing only a pre-synaptic effect - a moderate increase in the mEPP frequency. The dual character of interaction between dantrolene and ryanodine in motor synapses was observed: on the one hand, dantrolene acts as a physiological antagonist of ryanodine by reducing the ryanodine-induced increase of dispersion and mEPP amplitude; on the other hand, dantrolene unmasks the ability of ryanodine to increase the mEPP frequency.

Original languageEnglish (US)
Pages (from-to)79-85
Number of pages7
JournalNeurophysiology
Volume33
Issue number2
DOIs
StatePublished - Dec 31 2001
Externally publishedYes

Fingerprint

Miniature Postsynaptic Potentials
Dantrolene
Neuromuscular Junction
Ryanodine
Synapses
Ryanodine Receptor Calcium Release Channel
Diaphragm
Acetylcholine

All Science Journal Classification (ASJC) codes

  • Neuroscience(all)
  • Physiology

Cite this

Spontaneous activity of murine neuromuscular junctions in the presence of dantrolene. / Balezina, O. P.; Bukiya, Anna.

In: Neurophysiology, Vol. 33, No. 2, 31.12.2001, p. 79-85.

Research output: Contribution to journalArticle

@article{638855055fa34e5c802e3ca9e3570d5f,
title = "Spontaneous activity of murine neuromuscular junctions in the presence of dantrolene",
abstract = "By recording miniature end-plate potentials (mEPP), the effects of dantrolene (10-100 μM), a blocker of ryanodine receptors, were studied on the isolated diaphragm of mice. The effects to be studied were as follows: on spontaneous secretion of acetylcholine quanta and on the pattern of interaction with ryanodine effects. Two-hour-long application of dantrolene to the muscle caused no significant changes in the amplitude and dispersion (σ2) of mEPP, nor on its time course. In the presence of 100 μM dantrolene, the mean frequency of mEPP increased, on average, by 58.3 ± 5.9{\%} (P < 0.05). Dantrolene suppressed in a dose-dependent manner a number of ryanodine effects (this agent was used in a concentration of 0.5 μM as an intensifier of intracellular Ca2- mobilization): it completely prevented the appearance of the population of high-amplitude (the so-called giant) mEPP, reduced by 50-80{\%} the increment of the mEPP amplitude dispersion, and increased by 25-45{\%} the mEPP mean amplitude; the above effects were induced by ryanodine application for 120 min. After preliminary application of dantrolene (10-100 μM), ryanodine caused an effect not observable in the absence of dantrolene: mEPP became more frequent (140-210{\%}). Thus, when acting on motor synapses, dantrolene behaves as a nontoxic agent, inducing only a pre-synaptic effect - a moderate increase in the mEPP frequency. The dual character of interaction between dantrolene and ryanodine in motor synapses was observed: on the one hand, dantrolene acts as a physiological antagonist of ryanodine by reducing the ryanodine-induced increase of dispersion and mEPP amplitude; on the other hand, dantrolene unmasks the ability of ryanodine to increase the mEPP frequency.",
author = "Balezina, {O. P.} and Anna Bukiya",
year = "2001",
month = "12",
day = "31",
doi = "10.1023/A:1012324008410",
language = "English (US)",
volume = "33",
pages = "79--85",
journal = "Neurophysiology",
issn = "0090-2977",
publisher = "Springer New York",
number = "2",

}

TY - JOUR

T1 - Spontaneous activity of murine neuromuscular junctions in the presence of dantrolene

AU - Balezina, O. P.

AU - Bukiya, Anna

PY - 2001/12/31

Y1 - 2001/12/31

N2 - By recording miniature end-plate potentials (mEPP), the effects of dantrolene (10-100 μM), a blocker of ryanodine receptors, were studied on the isolated diaphragm of mice. The effects to be studied were as follows: on spontaneous secretion of acetylcholine quanta and on the pattern of interaction with ryanodine effects. Two-hour-long application of dantrolene to the muscle caused no significant changes in the amplitude and dispersion (σ2) of mEPP, nor on its time course. In the presence of 100 μM dantrolene, the mean frequency of mEPP increased, on average, by 58.3 ± 5.9% (P < 0.05). Dantrolene suppressed in a dose-dependent manner a number of ryanodine effects (this agent was used in a concentration of 0.5 μM as an intensifier of intracellular Ca2- mobilization): it completely prevented the appearance of the population of high-amplitude (the so-called giant) mEPP, reduced by 50-80% the increment of the mEPP amplitude dispersion, and increased by 25-45% the mEPP mean amplitude; the above effects were induced by ryanodine application for 120 min. After preliminary application of dantrolene (10-100 μM), ryanodine caused an effect not observable in the absence of dantrolene: mEPP became more frequent (140-210%). Thus, when acting on motor synapses, dantrolene behaves as a nontoxic agent, inducing only a pre-synaptic effect - a moderate increase in the mEPP frequency. The dual character of interaction between dantrolene and ryanodine in motor synapses was observed: on the one hand, dantrolene acts as a physiological antagonist of ryanodine by reducing the ryanodine-induced increase of dispersion and mEPP amplitude; on the other hand, dantrolene unmasks the ability of ryanodine to increase the mEPP frequency.

AB - By recording miniature end-plate potentials (mEPP), the effects of dantrolene (10-100 μM), a blocker of ryanodine receptors, were studied on the isolated diaphragm of mice. The effects to be studied were as follows: on spontaneous secretion of acetylcholine quanta and on the pattern of interaction with ryanodine effects. Two-hour-long application of dantrolene to the muscle caused no significant changes in the amplitude and dispersion (σ2) of mEPP, nor on its time course. In the presence of 100 μM dantrolene, the mean frequency of mEPP increased, on average, by 58.3 ± 5.9% (P < 0.05). Dantrolene suppressed in a dose-dependent manner a number of ryanodine effects (this agent was used in a concentration of 0.5 μM as an intensifier of intracellular Ca2- mobilization): it completely prevented the appearance of the population of high-amplitude (the so-called giant) mEPP, reduced by 50-80% the increment of the mEPP amplitude dispersion, and increased by 25-45% the mEPP mean amplitude; the above effects were induced by ryanodine application for 120 min. After preliminary application of dantrolene (10-100 μM), ryanodine caused an effect not observable in the absence of dantrolene: mEPP became more frequent (140-210%). Thus, when acting on motor synapses, dantrolene behaves as a nontoxic agent, inducing only a pre-synaptic effect - a moderate increase in the mEPP frequency. The dual character of interaction between dantrolene and ryanodine in motor synapses was observed: on the one hand, dantrolene acts as a physiological antagonist of ryanodine by reducing the ryanodine-induced increase of dispersion and mEPP amplitude; on the other hand, dantrolene unmasks the ability of ryanodine to increase the mEPP frequency.

UR - http://www.scopus.com/inward/record.url?scp=0035215631&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0035215631&partnerID=8YFLogxK

U2 - 10.1023/A:1012324008410

DO - 10.1023/A:1012324008410

M3 - Article

VL - 33

SP - 79

EP - 85

JO - Neurophysiology

JF - Neurophysiology

SN - 0090-2977

IS - 2

ER -