Successive E. P. P. Pattern and Presynaptic Factors in Neuro-muscular Transmission

Wakabayashi, Tsutomu; Iwasaki, Shizuko

doi:10.1620/tjem.83.225

Cited by 3 publications

(4 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This general pattern ofgrowth of e.p.p. amplitudes during repetitive stimulation at the Mg blocked neuromuscular junction was observed consistently in the more than 30 muscles used in this study, and has been described by previous investigators (Wakabayashi & Iwasaki, 1964;Maeno, 1969 Fig. 3.…”

supporting

confidence: 89%

“…The relative contribution of these two expressions of the long-term facilitation to the third term is a function of the stimulation rate and is given by the ratio of facilitation to the base level of transmitter release. INTRODUCTION Under conditions of high [Mg] and/or low [Ca] in the solution bathing a neuromuscular junction, repetitive stimulation of the motor nerve usually leads to a progressive increase in the amplitude of successive e.p.p.s which may continue for many seconds (Liley, 1956;Wakabayashi & Iwasaki, 1964;Braun, Schmidt & Zimmerman, 1966;Maeno, 1969). This facilitation of e.p.p.…”

mentioning

confidence: 99%

See 1 more Smart Citation

The effect of repetitive stimulation on facilitation of transmitter release at the frog neuromuscular junction

Magleby¹

1973

The Journal of Physiology

138

125

View full text Add to dashboard Cite

1. End-plate potentials (e.p.p.s) were recorded from frog neuromuscular junctions blocked with high Mg and/or low Ca to characterize the processes underlying increased transmitter release during repetitive stimulation.2. There was a progressive increase in the amplitude of successive e.p.p.s during repetitive stimulation. Increasing the frequency or duration of stimulation increased this facilitation of e.p.p. amplitudes. Facilitation is defined as the fractional increase in amplitude of a test e.p.p. over a control.3. By assuming that each impulse in a train contributes an identical increment of facilitation that sums linearly with the facilitation contributed by the previous impulses, estimates of the facilitation contributed by a single impulse, f(t), were made from the incremental increase in e.p.p. amplitudes during repetitive stimulation. The average value of f(t) contributed by the first impulse in the train during stimulation at 20/sec is given by f(t) = 0.8 e(-t/50) + 0.12 e (-t/300) + 0.025 e(-t/3000),where t is in msec. The first two terms in this equation were independent of the stimulation rate used to determine f(t) while the coefficient of the third term was a function of the stimulation rate, decreasing 2 to 3 times when the stimulation rate was decreased from 20/sec to 1/sec.4. This linear facilitation model predicted growth of e.p.p. amplitudes during the first several hundred msec of repetitive stimulation. Thereafter, e.p.p. amplitudes were typically facilitated more than predicted by the linear model.5. Several new methods are presented which can be used to obtain estimates of the magnitude and time course of facilitation contributed by specific impulses during repetitive stimulation.6. It is found that the value of short-term f(t) in the tested range of 25-300 msec progressively increases during repetitive stimulation while its time course of decay remains unchanged. After 9 sec of stimulation at 20/sec, the short-term f(t) increased to 1.4 times control.7. The increase in short-term f(t) was independent of whether it was determined from a step increase or decrease in total facilitation, excluding the possibility that the observed increase in short-term f(t) resulted from a change in the rate of decay of facilitation.8. It is suggested with supporting data from the following paper (Magleby, 1973) that each impulse contributes two types of facilitation that are responsible for the growth of e.p.p.s during repetitive stimulation: a short-term facilitation with linear summation properties described by the first two terms in the expression in paragraph 3 and a long-term cumulative facilitation approximated by the third term. The long-term facilitation is expressed as an increase in both the short-term facilitation and in the base level of transmitter release. The relative contribution of these two expressions of the long-term facilitation to the third term is a function of the stimulation rate and is given by the ratio of facilitation to the base level of transmitter release.

show abstract

supporting

confidence: 89%

mentioning

confidence: 99%

The effect of repetitive stimulation on facilitation of transmitter release at the frog neuromuscular junction

Magleby¹

1973

The Journal of Physiology

138

125

View full text Add to dashboard Cite

show abstract

“…The procedure was essentially the same as the previous report (Wakabayashi and Iwasaki 1964). Intra or extracellular electrodes were applied to m. sartorius frog (Rana nigromaculata).…”

Section: Methodsmentioning

confidence: 99%

“…"Bell pattern" seems to be characteristic in DNP , because other metabolic inhibitors, arsenite, azide, cyanate or temporal anoxia (Wakabayashi and Iwasaki, 1964) never produced any other change in e.p.p. than reduction of height, which was supposed to result from the depolarization of muscle and nerve membrane.…”

Section: ) Ineffectiveness Of Dnp On Mg-added or Ca Deficient Preparmentioning

confidence: 99%

Effect of DNP on Neuro-muscular Junction of Frog

Iwasaki

1964

Tohoku J. Exp. Med.

Self Cite

View full text Add to dashboard Cite

The modulation of neurotransmitter release at synaptic junctions

Erulkar

1983

Reviews of Physiology, Biochemistry and Pharmacology

View full text Add to dashboard Cite

Successive E. P. P. Pattern and Presynaptic Factors in Neuro-muscular Transmission

Cited by 3 publications

References 3 publications

The effect of repetitive stimulation on facilitation of transmitter release at the frog neuromuscular junction

The effect of repetitive stimulation on facilitation of transmitter release at the frog neuromuscular junction

Effect of DNP on Neuro-muscular Junction of Frog

The modulation of neurotransmitter release at synaptic junctions

Contact Info

Product

Resources

About