Lasting neuron depression induced by high potassium and its prevention by low calcium and NMDA receptor blockade.

Published

Journal Article

Spreading depression-like neuron depolarization was induced in CA1 of hippocampal tissue slices by irrigation with artificial cerebrospinal fluid containing 133.5 mM K+ for 8-40 min. Evoked responses disappeared during irrigation with high-K+ solution. Following 8-20 min irrigation orthodromic responses showed a triphasic recovery cycle: early partial return with evidence of neuron hyperexcitability, then secondary depression and finally slow partial recovery. After 30 min or more of high-K+ exposure, ortho- and antidromic responses remained severely depressed for at least 5.5 to 6.5 h. When, however, the tissue was deprived of calcium, or N-methyl-D-aspartate (NMDA) receptors were blocked by 10 microM 3-((+-)-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP), then evoked responses recovered partially after a 30- or 40-min high-K+ exposure. Post-exposure hyperexcitability was not prevented by CPP. We conclude that prolonged depolarization by elevated K+ causes irreversible neuron damage, which is triggered or accelerated by influx of calcium ions into neurons, mediated in part by NMDA receptor activation.

Full Text

Duke Authors

Cited Authors

  • Jing, J; Aitken, PG; Somjen, GG

Published Date

  • August 1991

Published In

Volume / Issue

  • 557 / 1-2

Start / End Page

  • 177 - 183

PubMed ID

  • 1660751

Pubmed Central ID

  • 1660751

Electronic International Standard Serial Number (EISSN)

  • 1872-6240

International Standard Serial Number (ISSN)

  • 0006-8993

Digital Object Identifier (DOI)

  • 10.1016/0006-8993(91)90132-f

Language

  • eng