Cross-links between stereocilia in the human organ of Corti

Human cochleae were fixed in glutaraldehyde, without the use of osmium. Cross-links were seen between the stereocilia, similar to those we have previously reported for the guinea pig: first, stereocilia of the same row on each hair cell were joined by horizontally-running links; secondly, the shorter stereocilia had pointed tips, each giving rise to a single, vertically-pointing link, which ran upwards to join the adjacent taller stereocilium of the next row. We suggest that distortion of this link is involved in sensory transduction. The links were sparser than had been seen in the guinea pig which may be a reflection of the vulnerability of the links to non-optimal fixation, and the greater difficulty in producing good fixation in human specimens.