Slow depolarizing afterpotentials in neocortical neurons are sodium and calcium dependent

A. Friedman, J. Arens, U. Heinemann, M. J. Gutnick

Research output: Contribution to journalArticlepeer-review

30 Scopus citations

Abstract

Depolarizing afterpotentials (DAPs) were studied in intracellular recordings from neocortical slices bathed in tetrodotoxin (TTX) (1 μM) and tetraethylammonium chloride (TEA) (24 mM), to block voltage-dependent Na+ currents and most K+ currents. The DAP was Ca2+-dependent, in that its magnitude varied as a function of the duration of the preceding Ca2+ plateau. It had an apparent reversal potential of between -40 and -5 mV. The DAP was blocked when choline replaced all extracellular Na+; there was a hyperpolarizing shift in apparent reversal potential when extracellular Na+ was lowered. The DAP was blocked by amiloride (1 mM), which also decreased the preceding Ca2+ plateau. The data are consistent with the hypothesis that the DAP is due to electrogenic Na+ Ca2+ exchange.

Original languageEnglish
Pages (from-to)13-17
Number of pages5
JournalNeuroscience Letters
Volume135
Issue number1
DOIs
StatePublished - 20 Jan 1992

Keywords

  • Brain slice
  • Calcium spike
  • Depolarizing afterpotential
  • Guinea pig
  • Intracellular recording
  • Na Ca exchanger
  • Neocortex

Fingerprint

Dive into the research topics of 'Slow depolarizing afterpotentials in neocortical neurons are sodium and calcium dependent'. Together they form a unique fingerprint.

Cite this