1. Domain 3, comprising the basolateral calyx and the stretch of axon leading to the heminode, selectively expressed NaV channels, KCNQ3, and certain scaffolding proteins.
Domain 3, comprising the basolateral calyx and the stretch of axon leading to the heminode, selectively expressed NaV channels, KCNQ3, and certain scaffolding proteins. A, Pan-NaV antibody produced a complex pattern of label, including domains 1 and 3 (arrows) and the heminode (domain 4), as well as type I hair cells (arrowheads) and adjacent type II hair cells (asterisk). B, C, Pan-dystrophin (Pan-Dystr, red) labeled domain 3 of dimorphic (calretinin-negative), but not calyx-only (calretinin-positive, green) afferents (compare B with C1 and C2). D, Domain 3 in peripheral-zone dimorphic afferents was intensely immunoreactive for KCNQ3, as shown by this flattened projection of a stack of confocal images. KCNQ3 staining (arrows) extended throughout domain 3 from the basolateral outer surface of the calyx to the heminode. Note the lack of stain in domain 2, marked by dashed white lines. The inset shows a higher magnification single image of a dimorphic afferent with a “complex” calyx ending that envelops two adjacent type I hair cells. Antibody to ezrin (green) labeled the apical microvilli of the sensory epithelium and the heminode, where it combined with the red KCNQ3 immunolabel to form a yellow band. E, AnkyrinB antibody labeled domain 3 in dimorphic afferents (E1, E2, red, long arrows) but not calyx-only afferents (E1, E2, green, arrowheads). Scale bars: A, D, E, 10 μm; D, inset, 5 μm; B, C, 2 μm.
Anna Lysakowski et al. J. Neurosci. 2011;31:
©2011 by Society for Neuroscience