title: Ca(2+)-BK channel clusters in olfactory receptor neurons and their role in odour coding.
abstract: Olfactory receptor neurons (ORNs) have high-voltage-gated Ca(2+) channels whose physiological impact has remained enigmatic since the voltage-gated conductances in this cell type were first described in the 1980s. Here we show that in ORN somata of Xenopus laevis tadpoles these channels are clustered and co-expressed with large-conductance potassium (BK) channels. We found approximately five clusters per ORN and twelve Ca(2+) channels per cluster. The action potential-triggered activation of BK channels accelerates the repolarization of action potentials and shortens interspike intervals during odour responses. This increases the sensitivity of individual ORNs to odorants. At the level of mitral cells of the olfactory bulb, odour qualities have been shown to be coded by first-spike-latency patterns. The system of Ca(2+) and BK channels in ORNs appears to be important for correct odour coding because the blockage of BK channels not only affects ORN spiking patterns but also changes the latency pattern representation of odours in the olfactory bulb.
authors.affiliation: Institute of Neurophysiology and Cellular Biophysics, University of Göttingen, Humboldtallee 23, 37073, Göttingen, Germany.|DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), University of Göttingen, Göttingen, Germany.
authors.forename: Guobin
authors.initials: G
authors.lastname: Bao
authors.affiliation: Institute of Neurophysiology and Cellular Biophysics, University of Göttingen, Humboldtallee 23, 37073, Göttingen, Germany.|DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), University of Göttingen, Göttingen, Germany.
authors.forename: Daniëlle
authors.initials: D
authors.lastname: de Jong
authors.affiliation: Institute of Neurophysiology and Cellular Biophysics, University of Göttingen, Humboldtallee 23, 37073, Göttingen, Germany.|DFG Excellence Cluster 171, University of Göttingen, Göttingen, Germany.
authors.forename: Mihai
authors.initials: M
authors.lastname: Alevra
authors.affiliation: Institute of Neurophysiology and Cellular Biophysics, University of Göttingen, Humboldtallee 23, 37073, Göttingen, Germany.|DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), University of Göttingen, Göttingen, Germany.|DFG Excellence Cluster 171, University of Göttingen, Göttingen, Germany.
authors.forename: Detlev
authors.initials: D
authors.lastname: Schild
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000378:metabolism; D018999:Charybdotoxin / Q000494:pharmacology; D051036:Large-Conductance Calcium-Activated Potassium Channels / Q000037:antagonists & inhibitors / Q000378:metabolism*; D007814:Larva; D018613:Microscopy, Confocal; D018377:Neurotransmitter Agents / Q000494:pharmacology; D009830:Olfactory Bulb / Q000187:drug effects / Q000502:physiology; D055696:Olfactory Perception / Q000187:drug effects / Q000502:physiology; D018034:Olfactory Receptor Neurons / Q000187:drug effects / Q000502:physiology*; D018408:Patch-Clamp Techniques; D010455:Peptides / Q000494:pharmacology; D012903:Smell / Q000187:drug effects / Q000502:physiology*; D046509:Tissue Culture Techniques; D056969:Voltage-Sensitive Dye Imaging; D014982:Xenopus laevis
chemical_list: D015220:Calcium Channels; D051036:Large-Conductance Calcium-Activated Potassium Channels; D018377:Neurotransmitter Agents; D010455:Peptides; D018999:Charybdotoxin; C064719:iberiotoxin; D002118:Calcium
keywords: Xenopus laevis; calcium; iberiotoxin; microdomains; voltage-gated calcium channels (VGCC)