First Author | Jiang Q | Year | 2009 |
Journal | Neuroscience | Volume | 162 |
Issue | 1 | Pages | 55-66 |
PubMed ID | 19376200 | Mgi Jnum | J:152937 |
Mgi Id | MGI:4360442 | Doi | 10.1016/j.neuroscience.2009.04.029 |
Citation | Jiang Q, et al. (2009) Characterization of acid-sensing ion channels in medium spiny neurons of mouse striatum. Neuroscience 162(1):55-66 |
abstractText | 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. |