z-logo
Premium
Cellular & molecular Ca 2+ microdomains in olfactory cilia support low signaling amplification of odor transduction
Author(s) -
Castillo Karen,
Restrepo Diego,
Bacigalupo Juan
Publication year - 2010
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.1460-9568.2010.07393.x
Subject(s) - cyclic nucleotide gated ion channel , transduction (biophysics) , cilium , odor , biophysics , olfactory epithelium , signal transduction , microbiology and biotechnology , chemistry , olfaction , visual phototransduction , ion channel , olfactory system , biology , biochemistry , neuroscience , cyclic nucleotide , receptor , nucleotide , gene , retinal
Signal transduction depends critically on the spatial localization of protein constituents. A key question in odor transduction is whether chemotransduction proteins organize into discrete molecular complexes throughout olfactory cilia or distribute homogeneously along the ciliary membrane. Our recordings of Ca 2+ changes in individual cilia with unprecedented spatial and temporal resolution, by the use of two‐photon microscopy, provide solid evidence for Ca 2+ microdomains (transducisomes). Dissociated frog olfactory neurons were preloaded with caged‐cAMP and fluo‐4 acetoxymethyl ester probe Ca 2+ indicator. Ca 2+ influx through cyclic nucleotide‐gated (CNG) channels was evoked by uniformly photoreleasing cAMP, while ciliary Ca 2+ was measured. Discrete fluorescence events were clearly resolved. Events were missing in the absence of external Ca 2+ , consistent with the absence of internal Ca 2+ sources. Fluorescence events at individual microdomains resembled single‐CNG channel fluctuations in shape, mean duration and kinetics, indicating that transducisomes typically contain one to three CNG channels. Inhibiting the Na + /Ca 2+ exchanger or the Ca 2+ ‐ATPase prolonged the decay of evoked intraciliary Ca 2+ transients, supporting the participation of both transporters in ciliary Ca 2+ clearance, and suggesting that both molecules localize close to the CNG channel. Chemosensory transducisomes provide a physical basis for the low amplification and for the linearity of odor responses at low odor concentrations.

This content is not available in your region!

Continue researching here.

Having issues? You can contact us here