Extrasynaptic localization of inactivating calcium-activated potassium channels in mouse inner hair cells.
Auditory hair cells from nonmammalian vertebrates are electrically tuned to specific sound frequencies primarily by the interactions of voltage-gated calcium channels and calcium-activated potassium (BK) channels colocalized at synaptic active zones. Mammalian inner hair cells are not electrically tuned and, yet, BK channels are also thought to reside at active zones. Using patch-clamp recordings and immunofluorescence, we characterized BK channel expression in mouse inner hair cells. Unexpectedly, these channels have inactivating currents and are clustered near the apex of the cell away from synaptic sites near the base. These results indicate a novel function of BK channels in mammalian inner hair cells and provide a framework for future research.
Pyott
Sonja J
SJ
Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California 94305-5345, USA.
Glowatzki
Elisabeth
E
Trimmer
James S
JS
Aldrich
Richard W
RW
D000818:Animals; D005455:Fluorescent Antibody Technique; D006199:Hair Cells, Auditory, Inner / Q000737:chemistry / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D066298:In Vitro Techniques; D051036:Large-Conductance Calcium-Activated Potassium Channels; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D009925:Organ of Corti / Q000254:growth & development; D018408:Patch-Clamp Techniques; D010455:Peptides / Q000494:pharmacology; D024681:Potassium Channels, Calcium-Activated / Q000032:analysis* / Q000037:antagonists & inhibitors / Q000502:physiology; D013347:Subcellular Fractions / Q000737:chemistry
D051036:Large-Conductance Calcium-Activated Potassium Channels; D010455:Peptides; D024681:Potassium Channels, Calcium-Activated; C064719:iberiotoxin