Mutant huntingtin enhances activation of dendritic Kv4 K + channels in striatal spiny projection neurons

Elife. 2019 Apr 24;8:e40818. doi: 10.7554/eLife.40818.

Abstract

Huntington's disease (HD) is initially characterized by an inability to suppress unwanted movements, a deficit attributable to impaired synaptic activation of striatal indirect pathway spiny projection neurons (iSPNs). To better understand the mechanisms underlying this deficit, striatal neurons in ex vivo brain slices from mouse genetic models of HD were studied using electrophysiological, optical and biochemical approaches. Distal dendrites of iSPNs from symptomatic HD mice were hypoexcitable, a change that was attributable to increased association of dendritic Kv4 potassium channels with auxiliary KChIP subunits. This association was negatively modulated by TrkB receptor signaling. Dendritic excitability of HD iSPNs was rescued by knocking-down expression of Kv4 channels, by disrupting KChIP binding, by restoring TrkB receptor signaling or by lowering mutant-Htt (mHtt) levels with a zinc finger protein. Collectively, these studies demonstrate that mHtt induces reversible alterations in the dendritic excitability of iSPNs that could contribute to the motor symptoms of HD.

Keywords: Huntington's disease; KChIP; Kv4; calcium imaging; dendrite; mouse; neuroscience; zinc finger protein.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Corpus Striatum / pathology*
  • Disease Models, Animal
  • Huntingtin Protein / genetics
  • Huntingtin Protein / metabolism*
  • Huntington Disease / pathology*
  • Huntington Disease / physiopathology*
  • Mice
  • Mutant Proteins / genetics
  • Mutant Proteins / metabolism*
  • Neurons / metabolism*
  • Shal Potassium Channels / metabolism*

Substances

  • Huntingtin Protein
  • Mutant Proteins
  • Shal Potassium Channels