Premium
Cilium‐attached and excised patch‐clamp recordings of odourant‐activated Ca‐dependent K channels from chemosensory cilia of olfactory receptor neurons
Author(s) -
Delgado Ricardo,
Bacigalupo Juan
Publication year - 2004
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.1460-9568.2004.03778.x
Subject(s) - cilium , patch clamp , biophysics , sensory receptor , olfactory receptor , electrophysiology , chemistry , stimulation , neuroscience , biology , sensory system , membrane potential , inhibitory postsynaptic potential , cyclic nucleotide gated ion channel , microbiology and biotechnology , olfactory system , biochemistry , gene , nucleotide , cyclic nucleotide
It has previously been proposed that a Ca 2+ ‐dependent K + conductance is implicated in the inhibitory odourant response in rat and toad olfactory receptor neurons. Previous whole‐cell and single‐channel measurements on inside‐out excised patches, in addition to immunochemical evidence, indicated the presence of Ca 2+ ‐dependent K + channels in olfactory cilia, the transducing structures of these sensory cells. Ca 2+ ‐dependent K + channels opened in ‘on‐cilium’ membrane patches from C. caudiverbera upon odourant stimulation. Furthermore, after excision in the inside‐out configuration, the channel could be opened by micromolar Ca 2+ , in a Ca 2+ ‐dependent fashion, but it was unresponsive to cyclic AMP. We estimated that the Ca 2+ concentration in the proximity of a Ca 2+ ‐dependent K + channel within the cilia reaches at least 100 µ m during the odour response. The K + channel displayed a higher selectivity for K + than for Na + . Our results support a role for this Ca 2+ ‐dependent K + channel in chemotransduction.