Electrical Coupling in Sustentacular Cells of the Mouse Olfactory Epithelium

• Published in: Journal of neurophysiology 2005-08, Vol.94 (2), p.1001-1012
• Main Authors: Vogalis, Fivos, Hegg, Colleen C, Lucero, Mary T
• Format: Article
• Language: English
• Subjects: Adenosine Triphosphate - pharmacology; Animals; Animals, Newborn; Carbenoxolone - pharmacology; Chelating Agents - pharmacology; Coloring Agents - metabolism; Computer Simulation; Egtazic Acid - pharmacology; Electric Capacitance; Electric Stimulation - methods; Gap Junctions - drug effects; Gap Junctions - physiology; Glucuronides - pharmacology; Glycyrrhetinic Acid - analogs & derivatives; Glycyrrhetinic Acid - pharmacology; In Vitro Techniques; Labyrinth Supporting Cells - drug effects; Labyrinth Supporting Cells - physiology; Membrane Potentials - drug effects; Membrane Potentials - physiology; Mice; Olfactory Mucosa - cytology; Patch-Clamp Techniques - methods; Time Factors
• ISSN: 0022-3077; 1522-1598
• DOI: 10.1152/jn.01299.2004

Department of Physiology, University of Utah, Salt Lake City, Utah Submitted 17 December 2004; accepted in final form 17 March 2005 Sustentacular cells (SCs) line the apical surface of the olfactory epithelium (OE) and provide trophic, metabolic, and mechanical support for olfactory receptor neurons. Morphological studies have suggested that SCs possess gap junctions, although physiological evidence for gap junctional communication in mammalian SCs is lacking. In the present study we investigated whether coupling exists between SCs situated in tissue slices of OE from neonatal (P0–P4) mice. Using whole cell and cell-attached patch recordings from SCs, we demonstrate that SCs are electrically coupled by junctional resistances on the order of 300 M . Under whole cell recording conditions, Alexa 488 added to the pipette solution failed to reveal dye coupling between SCs. Electrical coupling was deduced from the biexponential decay of capacitive currents recorded from SCs and from the bell-shaped voltage dependency of a P2Y-receptor–activated current, both of which were abolished by 18 -glycyrrhetinic acid (20–50 µM), a blocker of gap junctions. These data provide strong evidence for functional coupling between SCs, the physiological importance of which is discussed. Address for reprint requests and other correspondence: M. T. Lucero, Department of Physiology, 410 Chipeta Way, Rm 155, Salt Lake City, UT 84108-1297 (E-mail: Mary.Lucero{at}m.cc.utah.edu )