Tectorial membrane repair in the quail following multiple exposures to intense sound.

Abstract

Adult quail were exposed one, two or three times to an intense octave band noise. Birds were sacrificed 0 or 14 days after the last exposure and their ears processed for scanning electron microscopy (SEM). SEM observations demonstrated a patch lesion in every ear at 0 and 14 days after exposure. In the single-exposed ear immediately after noise, the lesion lacked any tectorial membrane (TM). At 14 days of recovery, the site of injury was covered by a partially regenerated TM (referred to as the honeycomb). However, the patterns of TM damage and repair varied among the twice- and thrice-exposed papillae. At 0 days after exposure, the multiple-exposed ear displayed a lesion with two segments. In one portion the TM was missing, and in the other portion the TM was present as one or two honeycomb layers. Fourteen days later, a new honeycomb was observed underneath the remaining honeycomb. These results suggest that the quail is able to repeatedly repair its TM following multiple noise exposures.