Coupling between sensory neurons in the olfactory epithelium.
Coupling of olfactory sensory neurons (OSNs) in the olfactory epithelium of Necturus maculosus was demonstrated by dye-transfer with Lucifer yellow CH; however, the incidence of dye-transfer was low. Immunocytochemistry and Western blot analysis indicated that connexin 43, a gap junction channel subunit, was widely expressed by cells in the olfactory epithelium. Electrical coupling by presumptive gap junctions was assessed using electrophysiological recordings, heptanol block, tracer-uptake through hemi-junctions, and tracer-injection into tissue whole-mounts. Coupling, which involved pairs of OSNs only, was detected in approximately 3-10% of the OSN population; there was no evidence that OSNs were coupled into extended neural syncitia. These results suggest that coupling of OSNs by gap junctions is unlikely to have a general role in olfactory responses by mature (odor responsive) OSNs. Instead, the incidence of inter-neuronal coupling was small, similar to the fraction of immature OSNs, suggesting a possible role of gap junctions in the continual turnover and development of OSNs or possibly their senescence.
Delay
Rona J
RJ
Department of Biology, University of Vermont, Burlington, VT 05405, USA.
Dionne
Vincent E
VE
D000375:Aging; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D025802:Electric Capacitance; D004594:Electrophysiology; D005456:Fluorescent Dyes / Q000378:metabolism; D019850:Heptanol / Q000494:pharmacology; D007150:Immunohistochemistry; D009338:Necturus maculosus; D009475:Neurons, Afferent / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D009831:Olfactory Mucosa / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D018408:Patch-Clamp Techniques
D005456:Fluorescent Dyes; D019850:Heptanol; D002118:Calcium