Recovery of noise-induced changes in the dark cells of the quail tegmentum vasculosum.
Morphologic changes in the tegmentum vasculosum (TV) of adult quail after high intensity sound exposure were studied. Quail were continuously exposed to 115 dB SPL, 1500 Hz pure tone in a sound field for 12 h and either sacrificed immediately (0 day), 1, 2, 3, 4, 6 or 10 days later. Serial sections through the basilar papilla at 100 micron intervals from base to apex were obtained for study with light microscopy and TEM. Significant morphologic changes were found within the TV of quail sacrificed on days 0-4. On a quantitative scale, the majority of recovery occurred within the first 24 h. After four days survival the tegmentum appeared nearly normal. This recovery correlates well with the temporal pattern of threshold shift recovery. These results demonstrate a temporal correlation between ultrastructural changes in the TV and functional recovery of hearing after intense sound exposure. A potential etiologic role of the TV in avian temporary threshold shift is suggested.
Ryals
B M
BM
Department of Communication Sciences and Disorders, James Madison University Harrisonburg, Virginia USA.
Stalford
M D
MD
Lambert
P R
PR
Westbrook
E W
EW
D000161:Acoustic Stimulation / Q000009:adverse effects*; D000818:Animals; D001309:Auditory Threshold / Q000502:physiology; D001489:Basilar Membrane / Q000166:cytology / Q000473:pathology* / Q000648:ultrastructure; D003370:Coturnix; D006198:Hair Cells, Auditory / Q000166:cytology / Q000473:pathology* / Q000648:ultrastructure; D008854:Microscopy, Electron; D008871:Microvilli / Q000473:pathology / Q000648:ultrastructure