Spatial analysis of slowly oscillating electric activity in the gut of mice using low impedance arrayed microelectrodes

PLoS One. 2013 Oct 4;8(10):e75235. doi: 10.1371/journal.pone.0075235. eCollection 2013.

Abstract

Smooth and elaborate gut motility is based on cellular cooperation, including smooth muscle, enteric neurons and special interstitial cells acting as pacemaker cells. Therefore, spatial characterization of electric activity in tissues containing these electric excitable cells is required for a precise understanding of gut motility. Furthermore, tools to evaluate spatial electric activity in a small area would be useful for the investigation of model animals. We thus employed a microelectrode array (MEA) system to simultaneously measure a set of 8×8 field potentials in a square area of ∼1 mm(2). The size of each recording electrode was 50×50 µm(2), however the surface area was increased by fixing platinum black particles. The impedance of microelectrode was sufficiently low to apply a high-pass filter of 0.1 Hz. Mapping of spectral power, and auto-correlation and cross-correlation parameters characterized the spatial properties of spontaneous electric activity in the ileum of wild-type (WT) and W/W(v) mice, the latter serving as a model of impaired network of pacemaking interstitial cells. Namely, electric activities measured varied in both size and cooperativity in W/W(v) mice, despite the small area. In the ileum of WT mice, procedures suppressing the excitability of smooth muscle and neurons altered the propagation of spontaneous electric activity, but had little change in the period of oscillations. In conclusion, MEA with low impedance electrodes enables to measure slowly oscillating electric activity, and is useful to evaluate both histological and functional changes in the spatio-temporal property of gut electric activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Electric Impedance*
  • Electrophysiology
  • Mice
  • Microelectrodes*
  • Models, Theoretical
  • Muscle, Smooth / physiology
  • Neurons / cytology
  • Neurons / metabolism*

Grants and funding

This work was partly supported by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion Science, and the Japan Gut Club. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.