Jump to main content
Jump to site search

Volume 193, 2016
Previous Article Next Article

Membrane patches as ion channel probes for scanning ion conductance microscopy

Author affiliations

Abstract

We describe dual-barrel ion channel probes (ICPs), which consist of an open barrel and a barrel with a membrane patch directly excised from a donor cell. When incorporated with scanning ion conductance microscopy (SICM), the open barrel (SICM barrel) serves to measure the distance-dependent ion current for non-invasive imaging and positioning of the probe in the same fashion of traditional SICM. The second barrel with the membrane patch supports ion channels of interest and was used to investigate ion channel activities. To demonstrate robust probe control with the dual-barrel ICP-SICM probe and verify that the two barrels are independently addressable, current–distance characteristics (approach curves) were obtained with the SICM barrel and simultaneous, current–time (IT) traces were recorded with the ICP barrel. To study the influence that the distance between ligand-gated ion channels (i.e., large conductance Ca2+-activated K+ channels/BK channels) and the ligand source (i.e., Ca2+ source) has on channel activations, ion channel activities were recorded at two fixed probe–substrate distances (Dps) with the ICP barrel. The two fixed positions were determined from approach curves acquired with the SICM barrel. One position was defined as the “In-control” position, where the probe was in close proximity to the ligand source; the second position was defined as the “Far” position, where the probe was retracted far away from the ligand source. Our results confirm that channel activities increased dramatically with respect to both open channel probability and single channel current when the probe was near the ligand source, as opposed to when the probe was far away from the ligand source.

Back to tab navigation
Please wait while Download options loads

Publication details

The article was received on 12 May 2016, accepted on 20 May 2016, published on 16 Sep 2016 and first published online on 16 Sep 2016


Article type: Paper
DOI: 10.1039/C6FD00133E
Citation: Faraday Discuss., 2016,193, 81-97
  •   Request permissions

    Membrane patches as ion channel probes for scanning ion conductance microscopy

    W. Shi, Y. Zeng, L. Zhou, Y. Xiao, T. R. Cummins and L. A. Baker, Faraday Discuss., 2016, 193, 81
    DOI: 10.1039/C6FD00133E

Search articles by author