Molecular characterization of T-type Ca2+ channels responsible for low threshold spikes in hypothalamic paraventricular nucleus neurons

S. Lee, T. H. Han, P. M. Sonner, Javier Eduardo Stern, P. D. Ryu, S. Y. Lee

Research output: Contribution to journalArticle

18 Scopus citations

Abstract

The hypothalamic paraventricular nucleus (PVN) is composed of functionally heterogeneous cell groups, possessing distinct electrophysiological properties depending on their functional roles. Previously, T-type Ca2+ dependent low-threshold spikes (LTS) have been demonstrated in various PVN neuronal types, including preautonomic cells. However, the molecular composition and functional properties of the underlying T-type Ca2+ channels have not been characterized. In the present study, we combined single cell reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry and patch-clamp recordings to identify subtypes of T-type Ca2+ channels expressed in PVN cells displaying LTS (PVN-LTS), including identified preautonomic neurons. LTS appeared at the end of hyperpolarizing pulses either as long-lasting plateaus or as short-lasting depolarizing humps. LTS were mediated by rapidly activating and inactivating T-type Ca2+ currents and were blocked by Ni2+. Single cell RT-PCR and immunohistochemical studies revealed Cav3.1 (voltage-gated Ca2+ channel) as the main channel subunit detected in PVN-LTS neurons. In conclusion, these data indicate that Cav3.1 is the major subtype of T-type Ca2+ channel subunit that mediates T-type Ca2+ dependent LTS in PVN neurons.

Original languageEnglish (US)
Pages (from-to)1195-1203
Number of pages9
JournalNeuroscience
Volume155
Issue number4
DOIs
StatePublished - Sep 9 2008

Keywords

  • Cav3.1
  • nickel
  • preautonomic neurons
  • retrograde labeling
  • single cell RT-PCR
  • slice patch clamp

ASJC Scopus subject areas

  • Neuroscience(all)

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