Specific expression of low-voltage-activated calcium channel isoforms and splice variants in thalamic local circuit interneurons

Mol Cell Neurosci. 2007 Oct;36(2):132-45. doi: 10.1016/j.mcn.2007.05.013. Epub 2007 Jul 24.


It has been suggested that the specific burst firing patterns of thalamic neurons reflect differential expression of low-voltage-activated (LVA) Ca(2+) channel subtypes and their splice variants. By combining electrophysiological, molecular biological, immunological, and computational modeling techniques we here show that diverging LVA Ca(2+) currents of thalamocortical relay (TC) and GABAergic interneurons of the dLGN correlate with a differential expression of LVA Ca(2+) channel splice variations and isoforms (alpha1G-a in TC; alpha1G-bc and alpha1I in interneurons). Implementation of the observed LVA Ca(2+) current differences into a TC neuron model changed the burst firing from TC-like to interneuron-like. We conclude that alternative splicing of the alpha1G isoform in dLGN TC and interneurons, and the exclusive expression of the alpha1I isoform in interneurons play a prominent role in setting the different LVA Ca(2+) current properties of TC and interneurons, which critically contribute to the diverging burst firing behavior of these neurons.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Newborn
  • Calcium Channels / genetics
  • Calcium Channels / metabolism*
  • Calcium Signaling / physiology
  • Cells, Cultured
  • Electric Stimulation / methods
  • Embryo, Mammalian
  • Gene Expression / physiology*
  • In Situ Hybridization
  • In Vitro Techniques
  • Interneurons / physiology*
  • Membrane Potentials / drug effects
  • Membrane Potentials / physiology
  • Membrane Potentials / radiation effects
  • Mice
  • Mice, Neurologic Mutants
  • Models, Neurological
  • Nerve Net / cytology*
  • Nerve Net / physiology
  • Patch-Clamp Techniques / methods
  • Protein Isoforms / genetics*
  • Protein Isoforms / metabolism
  • Rats
  • Thalamus / cytology*


  • Calcium Channels
  • Protein Isoforms