title: Pulse stimulation with odors or IBMX/forskolin potentiates responses in isolated olfactory neurons.
abstract: Many odor responses are mediated by the adenosine 3',5'-cyclic monophosphate (cAMP) pathway in which the cAMP-gated current is amplified by Ca2+-dependent Cl- current. In olfactory neurons, prolonged exposure to odors decreases the odor response and is an adaptive effect. Several studies suggest that odor adaptation is linked to elevated intracellular Ca2+. In the present study, using the perforated configuration of the patch clamp technique, we found that repetitive odor stimulation elicits a potentiation of the subsequent responses in olfactory neurons. This potentiation is mimicked by stimulating the cAMP pathway and does not appear to be related to phosphorylation of ion channels since protein kinase inhibitors could not block it. Our data suggest that local increases in [Ca2+]i via activation of the cAMP pathway mediate the pulse-elicited potentiation. In the first odor application, entry of Ca2+ through cyclic nucleotide-gated channels appears to be buffered. Repetitive stimulation allows local increases in [Ca2+]i, recruiting more Ca2+-dependent Cl- channels with each subsequent odor pulse.
authors.affiliation: 104 Marsh Life Science Building, Department of Biology, University of Vermont, Burlington, VT 05405, USA.
authors.forename: Wenling
authors.initials: W
authors.lastname: Zhang
authors.forename: Rona J
authors.initials: RJ
authors.lastname: Delay
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D015220:Calcium Channels / Q000502:physiology; D002469:Cell Separation; D002478:Cells, Cultured; D018118:Chloride Channels / Q000502:physiology; D002712:Chlorides / Q000494:pharmacology*; D005576:Colforsin / Q000494:pharmacology*; D004357:Drug Synergism; D004594:Electrophysiology; D005260:Female; D008297:Male; D008954:Models, Biological; D009337:Necturus; D018034:Olfactory Receptor Neurons / Q000187:drug effects / Q000502:physiology*; D018408:Patch-Clamp Techniques; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D012903:Smell / Q000187:drug effects / Q000502:physiology*; D013268:Stimulation, Chemical
chemical_list: D015220:Calcium Channels; D018118:Chloride Channels; D002712:Chlorides; D047428:Protein Kinase Inhibitors; D005576:Colforsin; D002118:Calcium; D015056:1-Methyl-3-isobutylxanthine