Potassium, neuroglia, and oxidative metabolism in central gray matter.

Published

Journal Article

Reviewed is the author's investigation of potassium in extracellular fluid of cerebral neocortex and spinal cord determined with ion-selective microelectrodes, and of oxidative metabolism monitored by fluorometric determination of intramitochondrial NADH in intact cortex. When gray matter is excited by afferent input, or by direct electrical stimulation, the logarithm of the rise of extracellular potassium concentration ([K+]0), the sustained shift of electrical potential, and the response of oxidative metabolism are linearly correlated. However, during seizures and during spreading depression, the correlation is broken, suggesting that the demand for oxidative energy exceeds that corresponding to the elevation of [K+]0. There exists a critical concentration of [K+]0 at which spreading depression inevitably erupts (12 mM for cat cerveau isole), but no such critical level could be detected for seizures. The rate of clearance of excess potassium from extracellular fluid is slower for high concentrations than for low; this rate is further slowed by the administration of phenobarbital, and possibly also of diphenylhydantoin. Changes of membrane potential of glia cells in the mammalian spinal cord can adequately be described by the Nernst equation.

Full Text

Duke Authors

Cited Authors

  • Somjen, GG; Rosenthal, M; Cordingley, G; LaManna, J; Lothman, E

Published Date

  • May 1, 1976

Published In

Volume / Issue

  • 35 / 6

Start / End Page

  • 1266 - 1271

PubMed ID

  • 177318

Pubmed Central ID

  • 177318

International Standard Serial Number (ISSN)

  • 0014-9446

Language

  • eng

Conference Location

  • United States