Characterization of acid-sensing ion channels in medium spiny neurons of mouse striatum

Q. Jiang, M. H. Li, C. J. Papasian, D. Branigan, Z. G. Xiong, J. Q. Wang, X. P. Chu

Research output: Contribution to journalArticlepeer-review

34 Scopus citations

Abstract

Acid-sensing ion channels (ASICs) regulate synaptic activities and play important roles in neurodegenerative diseases. They are highly expressed in the striatum, where medium spiny neurons (MSNs) are a major population. Given that the properties of ASICs in MSNs are unknown, in this study, we characterized ASICs in MSNs of the mouse striatum. A rapid drop in extracellular pH induced transient inward currents in all MSNs. The pH value for half-maximal activation was 6.25, close to that obtained in homomeric ASIC1a channels. Based on psalmotoxin 1 and zinc sensitivity, ASIC1a (70.5% of neurons) and heteromeric ASIC1a-2 channels (29.5% of neurons) appeared responsible for the acid-induced currents in MSNs. ASIC currents were diminished in MSNs from ASIC1, but not ASIC2, null mice. Furthermore, a drop in pH induced calcium influx by activating homomeric ASIC1a channels. Activation of ASICs increased the membrane excitability of MSNs and lowering extracellular Ca2+ potentiated ASIC currents. Our data suggest that the homomeric ASIC1a channel represents a majority of the ASIC isoform in MSNs. The potential function of ASICs in the striatum requires further investigation.

Original languageEnglish (US)
Pages (from-to)55-66
Number of pages12
JournalNeuroscience
Volume162
Issue number1
DOIs
StatePublished - Aug 4 2009

Keywords

  • acid-sensing ion channels
  • calcium imaging
  • medium spiny neurons
  • membrane excitability
  • patch-clamp
  • striatum

ASJC Scopus subject areas

  • Neuroscience(all)

Fingerprint Dive into the research topics of 'Characterization of acid-sensing ion channels in medium spiny neurons of mouse striatum'. Together they form a unique fingerprint.

Cite this