Mechanism of spreading depression: a review of recent findings and a hypothesis.

Published

Journal Article (Review)

Spreading depression of Leão (SD) can be provoked by numerous nonspecific mechanical, electrical, and chemical stimuli. A similar, if not identical, phenomenon can be provoked by hypoxia. SD is characterized by drastic depolarization of neurons, severe reduction of membrane resistance, and redistribution of ions across cell membranes. Glial cells also depolarize but retain membrane resistance. Tetraethylammonium hastens the onset of hypoxic SD but reduces the sustained potential shift and K+ outflow from cells; 4-aminopyridine also accelerates SD but has no effect on the voltage shift. N-Methyl-D-aspartate receptor antagonists delay the onset of SD, while nickel and cobalt reduce the amplitude of SD-related redistribution of Ca2+. Yet, no specific blocker of SD has been found. Microdialysis of high-K+ solution in hippocampal CA1 region induces recurrent waves of SD propagating semi-independently in adjacent tissue layers, and a prolonged unstable depressed state that has not previously been described. Neither the release of K+ ions nor of glutamate is the unique agent of SD propagation. On the basis of recent findings we propose a hypothetical sequence of events that reconcile many of the previously seemingly paradoxical observations.

Full Text

Duke Authors

Cited Authors

  • Somjen, GG; Aitken, PG; Czéh, GL; Herreras, O; Jing, J; Young, JN

Published Date

  • 1992

Published In

Volume / Issue

  • 70 Suppl /

Start / End Page

  • S248 - S254

PubMed ID

  • 1295674

Pubmed Central ID

  • 1295674

International Standard Serial Number (ISSN)

  • 0008-4212

Digital Object Identifier (DOI)

  • 10.1139/y92-268

Language

  • eng

Conference Location

  • Canada