Ion Conductances in Supporting Cells Isolated From the Mouse Vomeronasal Organ

• Published in: Journal of neurophysiology Vol. 89; no. 1; pp. 118 - 127
• Main Authors: Ghiaroni, Valeria, Fieni, Francesca, Tirindelli, Roberto, Pietra, Pierangelo, Bigiani, Albertino
• Format: Journal Article
• Language: English
• Published: United States Am Phys Soc 01.01.2003
• Subjects: Animals; Male; Membrane Potentials - physiology; Mice; Mice, Inbred C57BL; Neuroglia - physiology; Neurons, Afferent - physiology; Patch-Clamp Techniques; Potassium - metabolism; Potassium Channels, Voltage-Gated - physiology; Signal Transduction - physiology; Sodium - metabolism; Sodium Channels - physiology; Vomeronasal Organ - cytology; Vomeronasal Organ - innervation; Vomeronasal Organ - physiology
• ISSN: 0022-3077; 1522-1598
• DOI: 10.1152/jn.00545.2002

  1 Dipartimento di Scienze Biomediche, Università di Modena e Reggio Emilia, 41100 Modena; and   2 Istituto di Fisiologia Umana, Università di Parma, 43100 Parma, Italy Ghiaroni, Valeria, Francesca Fieni, Roberto Tirindelli, Pierangelo Pietra, and Albertino Bigiani. Ion Conductances in Supporting Cells Isolated From the Mouse Vomeronasal Organ. J. Neurophysiol. 89: 118-127, 2003. The vomeronasal organ (VNO) is a chemosensory structure involved in the detection of pheromones in most mammals. The VNO sensory epithelium contains both neurons and supporting cells. Data suggest that vomeronasal neurons represent the pheromonal transduction sites, whereas scarce information is available on the functional properties of supporting cells. To begin to understand their role in VNO physiology, we have characterized with patch-clamp recording techniques the electrophysiological properties of supporting cells isolated from the neuroepithelium of the mouse VNO. Supporting cells were distinguished from neurons by their typical morphology and by the lack of immunoreactivity for G 8 and OMP, two specific markers for vomeronasal neurons. Unlike glial cells in other tissues, VNO supporting cells exhibited a depolarized resting potential (about 29 mV). A Goldman-Hodgkin-Katz analysis for resting ion permeabilities revealed indeed an unique ratio of P K : P Na : P Cl  =   1:0.23:1.4. Supporting cells also possessed voltage-dependent K + and Na + conductances that differed significantly in their biophysical and pharmacological properties from those expressed by VNO neurons. Thus glial membranes in the VNO can sustain significant fluxes of K + and Na + , as well as Cl . This functional property might allow supporting cells to mop-up and redistribute the excess of KCl and NaCl that often occurs in certain pheromone-delivering fluids, like urine, and that could blunt the sensitivity of VNO neurons to pheromones. Therefore vomeronasal supporting cells could affect chemosensory transduction in the VNO by regulating the ionic strength of the pheromone-containing medium. * V. Ghiaroni and F. Fieni contributed equally to the work.