Tonic And Stimulus-Dependent Conduction of Excitation Blocking in The Nerve by Means of Antiarythmisant Pentilaymalin

I have in a previous paper described investigation on the conduction of excitation in Mimosa pudica . It was there shown that the various characteristics of the propagation of excitation in the conducting tissue of the plant are in every way similar to those in the animal nerve. Hence it appeared probable that any newly found phenomenon in the one case was likely to lead to the discovery of a similar phenomenon in the other. A problem of great interest which has attracted my attention my attention for several years is the question whether, in a conducting tissue, excitation travels better with or against the direction of an electric current. The experimental difficulties presented in the prosecution of this enquiry are very numerous, the results being complicated by the joint effects of the direction of current on conductivity and of the poles on excitability. As regards the latter, the changes of excitability in the animal nerve under electrotonus have been demonstrated by the well-known experiments of pflüger. In a nerve-and-muscle preparation, the presence of a pole P is shown to induce a variation of excitability of a neighbouring point S. When P is kathode, the excitability of the point S, near it, is enhanced; stimulation of S, previously ineffective, now becomes effective, and the resulting excitation is transmitted to M, causing response of the muscle. Conversely, the application of anode at P causes a depression of excitability of S. Stimulus previously effective now becomes ineffective. In this manner the transmission of excitation may be indirectly modified by the polar variation of excitability of the stimulated point (fig. 1 a ).

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Effects of Na and Ca on the generation and conduction of excitation in the ureter

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1965.208.4.715 ◽

1965 ◽

Vol 208 (4) ◽

pp. 715-719 ◽

Cited By ~ 21

Author(s):

Makoto Kobayashi

Keyword(s):

Conduction Velocity ◽

Renal Pelvis ◽

Action Potentials ◽

Conduction Block ◽

Krebs Solution ◽

Taenia Coli ◽

Free Solution ◽

The Difference ◽

Conduction Of Excitation ◽

Normal Ringer

Effects of Na+ and Ca++ on the generation and the conduction of excitation were studied by using a pelvis ureter specimen of cat. Action potentials were recorded simultaneously from the renal pelvis and the various regions of the ureter, and they were used to indicate the arrival of excitation. In Na+-deficient solutions, both the frequency of excitation and the conduction velocity decreased gradually, and finally a conduction block occurred at the border between the renal pelvis and ureter. In Na+-free solution spontaneous excitation was not observed in most cases. When excess Ca++ was added to Na+-free solution, spontaneous excitation was restored, but the concentration of Ca++ necessary for the restoration had to be at least twice that in normal Ringer-Krebs solution. The difference between the ureter and taenia coli was considered with regard to the role that Na+ and Ca++ play in the generation of spontaneous excitation.

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Steinach. Ueber die centripetale Erregungsleitung im Bereiche des Spinalganglions. (On the centripetal conduction of excitation along the dorsal nodes). - Arch of Pfluger. Bd. 78, p. 291

Neurology Bulletin ◽

10.17816/nb52851 ◽

2020 ◽

Vol VIII (2) ◽

pp. 181-185

Author(s):

D. Polumordvinov

Keyword(s):

Spinal Cord ◽

Spinal Nerve ◽

Nerve Cells ◽

Point Of View ◽

Nerve System ◽

Conduction Of Excitation

According to the generally accepted view, sensory excitation in the spinal nerve system reaches the spinal cord through the nerve cells of the dorsal nodes, which from this point of view with full right can be attributed to the category of sensitive nerve cells. Working in the early 90s on the issue of negative fluctuations, Steinach came across a fact that remained completely inexplicable for him until the last day.

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