Recovery of the basilar papilla following intense sound exposure in the chick.
Newly hatched chicks were exposed to a 900-Hz tone at 120 dB SPL for 48 hours, then sacrificed, along with unexposed controls, at intervals of 0-15 days following exposure. Examination of the basilar papilla by scanning electron microscopy demonstrated a 32% loss of hair cells within the lesion area with substantial shrinkage of the apical surfaces of the survivors. Within days, the papilla returned to a nearly normal appearance, and new hair cells were seen, but the number of new cells was only a fraction--approximately 22%--of the number lost. Expansion of the apical surfaces of the surviving cells to larger than normal size was a major factor in the recovery of the papilla.
Marsh
R R
RR
Department of Otorhinolaryngology and Human Communication, Children's Hospital of Philadelphia, PA 19104.
Xu
L R
LR
Moy
J P
JP
Saunders
J C
JC
D000818:Animals; D001489:Basilar Membrane / Q000473:pathology* / Q000502:physiology; D002645:Chickens; D003051:Cochlea / Q000473:pathology*; D006198:Hair Cells, Auditory / Q000473:pathology / Q000502:physiology; D006317:Hearing Loss, Noise-Induced / Q000473:pathology* / Q000503:physiopathology; D008855:Microscopy, Electron, Scanning; D012038:Regeneration; D013997:Time Factors