Format

Send to

Choose Destination
Neuroscience. 2009 Aug 4;162(1):55-66. doi: 10.1016/j.neuroscience.2009.04.029. Epub 2009 Apr 17.

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

Author information

1
Department of Basic Medical Science, University of Missouri-Kansas City School of Medicine, 2411 Holmes Street, Kansas City, MO 64108, USA.

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.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center