Effects of potassium channel-blocking agents on spontaneous discharges from neuromas in rats

Kim Burchiel, L. C. Russell

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Thirty-five Sprague-Dawley rats with saphenous neuromas underwent acute microfilament recording in the proximal nerve. The effect of the potassium channel-blocking agents, tetraethylammonium bromide (TEA) and 4-aminopyridine, on spontaneous activity in A fibers terminating in the neuroma was observed. The effects of gallamine were also tested. Of the two channel-blocking agents, TEA reliably increased spontaneous firing in active fibers and initiated spontaneous activity in some fibers with no spontaneous baseline discharge. 4-Aminopyridine had no effect on baseline activity of either spontaneously active or quiescent fibers; however, it inhibited spontaneous activity induced by prior TEA treatment. Gallamine application produced effects similar to TEA in that spontaneous activity was dramatically increased. These results imply that a tonic potassium conductance is present in regenerating fibers in the neuroma and that this conductance moderates the tendency toward hyperexcitability and spontaneous firing. Spontaneous activity in nociceptive afferent fibers may represent the mechanism of chronic pain and paresthesias that often accompany peripheral nerve injury. These results suggest that agents which either increase potassium conductance or selectively inhibit the sodium current in regenerating axons might be effective in the treatment of these chronic pain syndromes.

Original languageEnglish (US)
Pages (from-to)246-249
Number of pages4
JournalJournal of Neurosurgery
Volume63
Issue number2
StatePublished - 1985
Externally publishedYes

Fingerprint

Neuroma
Tetraethylammonium
Potassium Channels
Gallamine Triethiodide
4-Aminopyridine
Chronic Pain
Potassium
Myelinated Nerve Fibers
Peripheral Nerve Injuries
Paresthesia
Actin Cytoskeleton
Sprague Dawley Rats
Axons
Sodium
Therapeutics

ASJC Scopus subject areas

  • Clinical Neurology
  • Neuroscience(all)

Cite this

Effects of potassium channel-blocking agents on spontaneous discharges from neuromas in rats. / Burchiel, Kim; Russell, L. C.

In: Journal of Neurosurgery, Vol. 63, No. 2, 1985, p. 246-249.

Research output: Contribution to journalArticle

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