Specific expression of low-voltage-activated calcium channel isoforms and splice variants in thalamic local circuit interneurons.
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.
Broicher
Tilman
T
Institut für Physiologie I, Westfälische Wilhelms-Universität Münster, Robert-Koch-Str. 27a, D-48149 Münster, Germany.
Kanyshkova
Tatyana
T
Landgraf
Peter
P
Rankovic
Vladan
V
Meuth
Patrick
P
Meuth
Sven G
SG
Pape
Hans-Christian
HC
Budde
Thomas
T
D000818:Animals; D000831:Animals, Newborn; D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology; D002478:Cells, Cultured; D004558:Electric Stimulation / Q000379:methods; D004622:Embryo, Mammalian; D015870:Gene Expression / Q000502:physiology*; D017403:In Situ Hybridization; D066298:In Vitro Techniques; D007395:Interneurons / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D051379:Mice; D008818:Mice, Neurologic Mutants; D008959:Models, Neurological; D009415:Nerve Net / Q000166:cytology* / Q000502:physiology; D018408:Patch-Clamp Techniques / Q000379:methods; D020033:Protein Isoforms / Q000235:genetics* / Q000378:metabolism; D051381:Rats; D013788:Thalamus / Q000166:cytology*
D015220:Calcium Channels; D020033:Protein Isoforms