Ionic conductances in sustentacular cells of the mouse olfactory epithelium

J Physiol. 2005 Feb 1;562(Pt 3):785-99. doi: 10.1113/jphysiol.2004.079228. Epub 2004 Dec 20.


The electrical properties of sustentacular cells (SCs) in the olfactory epithelium (OE) were investigated in tissue slices taken from neonatal mice (P0-P4). Conventional whole-cell recordings were obtained from SCs and also from olfactory receptor neurones (ORNs) in situ. SCs had a larger apparent cell capacitance (C(cell)) (18.6 +/- 0.5 pF) than ORNs (4.4 +/- 0.4 pF) and a lower apparent membrane resistance (R(m)) (160 +/- 11 MOmega versus 664 +/- 195 MOmega, respectively). When corrected for a seal resistance of 1 GOmega, these mean R(m) values were increased to 190 MOmega and 2 GOmega in SCs and ORNs, respectively. SCs generated a TTX (1 microm)-resistant voltage-activated Na(+) current (I(Na)) that had a peak density at -38 mV of -44 pA pF(-1) and supported action potential firing. Peak current density of I(Na) in neurones was 510 +/- 96 pA pF(-1). The outward K(+) current in SCs was composed (> 70%) of a TEA (2 mm)-sensitive component that was mediated by the opening of large-conductance (237 +/- 10 pS; BK) channels. The resting leak conductance (g(L)) of SCs was permeable to monovalent cations and anions and was largely inhibited by substitution of external Na(+) with NMDG and by internal F(-) with gluconate. g(L) deactivated up to 50% at potentials negative of -70 mV and was inhibited by 18beta-glycyrrhetinic acid (20 mum). SCs were identified using fluorescent dyes (Lucifer Yellow and Alexa Fluor 488) in the whole-cell patch pipette-filling solution. Our findings indicate that SCs in the OE of neonates are electrically excitable and are distinguishable from neurones by a having a resting g(L).

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Animals, Newborn
  • Cell Membrane / physiology*
  • Cell Membrane / ultrastructure*
  • Cells, Cultured
  • Electric Conductivity
  • Ion Channel Gating / physiology
  • Membrane Potentials / physiology*
  • Mice
  • Olfactory Mucosa / cytology*
  • Olfactory Mucosa / physiology*
  • Potassium / metabolism*
  • Sodium / metabolism*


  • Sodium
  • Potassium