Cochleae were fixed by perfusing the cochlea with 2.5% glutaraldehyde in 0.1 M sodium cacodylate buffer (pH 7.2), and immersed in the same fixative overnight. Cochleae were then washed 3 times in 0.1 M sodium cacodylate buffer pH 7.2 and decalcified in 0.5 M EDTA pH 8.0 for 2-3 days at 4°C. Pieces of organ of Corti were then dissected in 0.1 M sodium cacodylate following the method described previously for cochlear wholemounts (Legan et al. 2014 (link)). Samples were then post-fixed in 1% osmium tetroxide for 3 h at room temperature, washed in cacodylate buffer and dehydrated through a series of ascending concentrations of ethanol. Following critical-point drying, samples were mounted on SEM stubs and sputter coated with platinum before viewing in a Jeol JSM-6700F SEM operating at 5 kV.