Actin cytoskeleton regulates ion channel activity in retinal neurons

Neuroreport. 1998 Mar 9;9(4):665-70. doi: 10.1097/00001756-199803090-00019.

Abstract

The actin cytoskeleton is an important contributor to the integrity of cellular shape and responses in neurons. However, the molecular mechanisms associated with functional interactions between the actin cytoskeleton and neuronal ion channels are largely unknown. Whole-cell and single channel recording techniques were thus applied to identified retinal bipolar neurons of the tiger salamander (Ambystoma tigrinum) to assess the role of acute changes in actin-based cytoskeleton dynamics in the regulation of voltage-gated ion channels. Disruption of endogenous actin filaments after brief treatment (20-30 min) with cytochalasin D (CD) activated voltage-gated K+ currents in bipolar cells, which were largely prevented by intracellular perfusion with the actin filament-stabilizer agent, phalloidin. Either CD treatment under cell-attached conditions or direct addition of actin to excised, inside-out patches of bipolar cells activated and/or increased single K+ channels. Thus, acute changes in actin-based cytoskeleton dynamics regulate voltage-gated ion channel activity in bipolar cells.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Actins / physiology*
  • Ambystoma
  • Animals
  • Cytochalasin D / pharmacology
  • Cytoskeleton / drug effects
  • Cytoskeleton / physiology*
  • Cytoskeleton / ultrastructure
  • Homeostasis
  • In Vitro Techniques
  • Ion Channels / physiology*
  • Membrane Potentials
  • Patch-Clamp Techniques
  • Phalloidine / pharmacology
  • Photoreceptor Cells / cytology
  • Photoreceptor Cells / drug effects
  • Photoreceptor Cells / physiology*
  • Potassium Channels / drug effects
  • Potassium Channels / physiology
  • Retinal Ganglion Cells / physiology*
  • Retinal Ganglion Cells / ultrastructure
  • Time Factors

Substances

  • Actins
  • Ion Channels
  • Potassium Channels
  • Phalloidine
  • Cytochalasin D