Early development of voltage-dependent sodium currents in cultured mouse spinal cord neurons

A. B. MacDermott, Gary Westbrook

Research output: Contribution to journalArticle

51 Scopus citations

Abstract

Spinal cord neurons were dissociated from 13-day embryonic mice and grown in culture for 1-28 days. Sodium currents of neurons in culture for 1-2 days were compared with those in culture for 2-4 weeks, using the whole-cell voltage clamp method. Rapid neurite outgrowth created space clamp limitations so that unclamped neuritic sodium action potentials prevented accurate analysis of sodium current properties. Therefore neurons were bathed in sodium-free solution and brief puffs of sodium were delivered to the cell soma so that only somatic sodium currents were recorded. Sodium currents of neurons at 1-2 days in culture had voltage-dependent activation and inactivation characteristic of these channels, both in mature cultured spinal neurons and in other preparations. However, the estimated channel density on the soma of neurons 1-2 days in culture was less than two channels per μm2. Since the available sodium conductance (as measured by action potential rise rates) increases during development of spinal cord neurons in culture (Westbrook and Brenneman, 1984), we suggest that changes in channel density and/or distribution, rather than in channel kinetics, may underlie the increase in sodium conductance.

Original languageEnglish (US)
Pages (from-to)317-326
Number of pages10
JournalDevelopmental Biology
Volume113
Issue number2
DOIs
Publication statusPublished - 1986
Externally publishedYes

    Fingerprint

ASJC Scopus subject areas

  • Developmental Biology

Cite this