Alterations of single potassium channel activity in CA1 pyramidal neurons after transient forebrain ischemia.

X. X. Chi, Z. C. Xu

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Selective neuronal injury in the CA1 zone of hippocampus following transient cerebral ischemia has been well documented. Extracellular potassium concentration markedly increases during ischemia/hypoxia. Accumulating evidence has indicated that the outward potassium currents, including delayed rectifier potassium current, not only influence membrane excitability but also mediate apoptosis. It has been shown that the amplitude of delayed rectifier potassium current in CA1 neurons significantly increased after cerebral ischemia. To elucidate the mechanisms underlying the changes of potassium currents following ischemia, single potassium channel activities of rat CA1 neurons were compared before and after transient forebrain ischemia. Using cell-attached configuration, depolarizing voltage steps activated outward single channel events. The channel properties, the kinetics and pharmacology of these events resemble the delayed rectifier potassium current. After ischemia, the unitary amplitude of single channels significantly increased, the open probability, mean open time and open time constant also significantly increased while the conductance remained unchanged. These data indicate that the increase of single channel activity is responsible, at least in part, for the increase of delayed rectifier potassium current in CA1 neurons after cerebral ischemia.

Original languageEnglish
Pages (from-to)535-540
Number of pages6
JournalNeuroscience
Volume108
Issue number4
DOIs
StatePublished - 2001

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Pyramidal Cells
Potassium Channels
Prosencephalon
Potassium
Ischemia
Brain Ischemia
Neurons
Transient Ischemic Attack
Hippocampus
Pharmacology
Apoptosis
Membranes
Wounds and Injuries

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

Alterations of single potassium channel activity in CA1 pyramidal neurons after transient forebrain ischemia. / Chi, X. X.; Xu, Z. C.

In: Neuroscience, Vol. 108, No. 4, 2001, p. 535-540.

Research output: Contribution to journalArticle

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