Effect of Eserine on Neuromuscular Transmission

Eccles, John C.; Katz, Bernhard; Kuffler, Stephen W.

doi:10.1152/jn.1942.5.3.211

Cited by 194 publications

(110 citation statements)

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“…In accord with this suggestion was the increase in duration of the slow potential whenever ACh was applied to infected ganglia. Similar effects of physostigmine and tubocurarine on motor end-plate potentials had been observed earlier by Eccles, Katz & Kuffler (1941, 1942, and on miniature end-plate potentials more recently by Fatt & Katz (1952). The decrease in size of the presynaptic slow potential, with consequent decrease in the number of spikes, whenever possible inhibitors, gamma aminobutyric acid, adrenaline, and noradrenaline were applied, suggests that these agents depress excitability by decreasing the size of the slow potential.…”

Section: Discussionsupporting

confidence: 82%

A study of presynaptic slow potentials in virus‐infected sympathetic ganglia of the rat

Dempsher¹,

Zabara²

1960

The Journal of Physiology

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In order to explain the occurrence of spontaneous impulses, originating in presynaptic nerve endings and discharged simultaneously and synchronously in pre-and post-ganglionic nerves of rat sympathetic ganglia infected with pseudo-rabies virus, the following working hypothesis was adopted. Spontaneous impulses originated in presynaptic nerve endings because the virus infection interfered with the normal action of an inhibiting system having its origin in the central nervous system (c.N.s.) and exerting its action upon the presynaptic nerve endings through the release of substances such as gamma aminobutyric acid, adrenaline, and noradrenaline. Interference with the normal action of the inhibitory system resulted in a spontaneous release of acetylcholine (ACh), which stimulated the presynaptic nerve endings to initiate the discharge of impulses in both nerves, antidromic in the preganglionic nerve, orthodromic in the postganglionic nerve (Dempsher, Larrabee, Bang & Bodian, 1955;Dempsher & Riker, 1957;Dempsher, Tokumaru & Zabara, 1959).An inherent weakness of the working concept presented above has been that, although based on experiments in which we used electrophysiological techniques, no electrical event had been described which could actually be located in the presynaptic nerve endings, the suggested site of interaction of excitatory and inhibitory systems. The purpose of this paper is to report experiments supporting the suggestion that the electrical event in the presynaptic nerve endings accompanying interaction of excitatory and inhibitory systems in virus-infected rat sympathetic ganglia is a slowly changing, decreasing potential change, the presynaptic slow potential. METHODS Preparation of the virus inoculum to infect the rat superior cervical ganglion was described in detail in previous publications (Tokumaru, 1957;Dempsher et al. 1959). Briefly, rat superior cervical ganglia were infected following intraocular inoculations of 005 ml. of undiluted suspension of L strain pseudo-rabies virus harvested from infected 14 PHYSIO. CLI

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Section: Discussionsupporting

confidence: 82%

A study of presynaptic slow potentials in virus‐infected sympathetic ganglia of the rat

Dempsher¹,

Zabara²

1960

The Journal of Physiology

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“…Eccles et al (1942) attributed some ADA to a retrograde conduction of the muscle action potential. This mechanism is unlikely since we have seen even normal ADA after cutting, when there was no twitch or muscle action potential present in the rat diaphragm.…”

Section: Discussionmentioning

confidence: 99%

Antidromic activity in the rat phrenic nerve—diaphragm preparation

Randić¹,

Straughan²

1964

The Journal of Physiology

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“…2) and interstimulus interval (Fig. 3) in both toad and earthworm as predicted [4][5][6][11][12][13] . When the graphs are examined horizontally along the abscissa, the first impression is that chlorpyrifos increased the depolarizing rate (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…A second purpose of this paper is to determine whether facilitation occurs in an isolated neuromuscular preparation in order to exclude mechanisms outside the neuromuscular junction. Assuming that chlorpyrifos facilitates neuromuscular excitability by increasing the available acetylcholine in the neuromuscular junction after inhibiting its hydrolyzation by cholinesterase, it is expected to antagonize the inhibitory effect of curarizing agents such as flaxedil which decreases neuromuscular excitability by blocking acetylcholine binding to the postjunctional receptor and/or by blocking its prejunctional release [12,13] .…”

Section: Introductionmentioning

confidence: 99%

Antagonism Between Chlorpyrifos and Flaxedil in Toad and Earthworm Neuromuscular Transmission

Chang¹,

Bartoszeck²,

Madeira³

et al. 2006

American J. of Environmental Sciences

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Abstract:The cholinesterase inhibition effect of chlorpyrifos, a commercial insecticide, was tested by its antagonism to the acetylcholine inhibition effect of flaxedil in 30 isolated nerve-sartorius muscle preparations of the toad, compared with its antagonism in 30 isolated nerve cord-body wall muscle preparations of the earthworm. Inhibition and facilitation in this antagonism were measured by changes in depolarizing rate of toad endplate potential and in earthworm slow potential and by changes in interstimulus interval for evoking an action potential in toad preparations and a graded spike potential in earthworm preparations. Earthworm depolarizing rate (0.32 V s 1 ) in its normal Ringer was five times lower than that (1. [Flaxedil] o between 3 x 10 -4 g cc 1 and 5 x 10 -4 g cc 1 attenuated 25% of toad depolarizing rate and 23% of earthworm depolarizing rate, 60% of toad interstimulus interval and eliminated the earthworm interstimulus interval almost entirely. Enhancement of toad depolarizing rate and interstimulus interval by chlorpyrifos between 5 x 10 -4 g cc 1 and 10 -2 g cc 1 after being attenuated by flaxedil was not significant but was significant in the earthworm preparation. Inhibition of earthworm cholinesterase by chlorpyrifos may be related to its lower neuromuscular excitability than that of the toad.

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Effect of Eserine on Neuromuscular Transmission

Cited by 194 publications

References 0 publications

A study of presynaptic slow potentials in virus‐infected sympathetic ganglia of the rat

A study of presynaptic slow potentials in virus‐infected sympathetic ganglia of the rat

Antidromic activity in the rat phrenic nerve—diaphragm preparation

Antagonism Between Chlorpyrifos and Flaxedil in Toad and Earthworm Neuromuscular Transmission

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