Apoptotic Pattern of Cochlear Outer Hair Cells and Frequency-specific Hearing Threshold Shift in Noise-exposed BALB/c Mice
Clinical and Experimental Otorhinolaryngology
;
: 80-85, 2008.
Artigo
em Inglês
| WPRIM
| ID: wpr-62425
ABSTRACT
OBJECTIVES:
Apoptosis of outer hair cell (OHC) can be identified through nuclear staining by specific nuclear changes. The change of filamentous actin (F-actin) is also involved in early cell death process. The study was designed to investigate OHC death along the whole length of the organ of Corti.METHODS:
BALB/c hybrid mice were used in this study. The noise group was exposed to white noise of 120 dB SPL for 3 hr per day for 3 consecutive days. The tone burst auditory brainstem response (ABR) test was conducted and cochleas from each group were obtained for the immunostaining of FITC phalloidin for F-actin and propidium iodide (PI) for nuclei.RESULTS:
ABR threshold of the noise group significantly increased after noise exposure (P<0.001). No threshold shift was found in the control group. Threshold shift of the noise group constantly increased from 4 to 16 kHz, but threshold shifts at 16 kHz and 32 kHz were similar. Patterns of OHC staining were subclassified as FITC+PI- cells, FITC+ PI+ cells, FITC-PI+ cells and missing cells. Proportion of normal live OHCs (FITC+PI-) rapidly decreased from the apex to the base. In the basal turn, FITC-PI+ cells and vacancy OHC (missing cells) were observed easily. Apoptotic and missing cells were most abundant at 60% of the whole length of the Corti organ.CONCLUSION:
We could subclassify morphologic changes in OHC death after noise exposure. Quantitative changes in OHCs along the whole Corti organ showed a plateau pattern similar to that of a frequency-specific threshold shift.
Texto completo:
DisponíveL
Índice:
WPRIM (Pacífico Ocidental)
Assunto principal:
Órgão Espiral
/
Faloidina
/
Propídio
/
Quimera
/
Potenciais Evocados Auditivos do Tronco Encefálico
/
Actinas
/
Fluoresceína-5-Isotiocianato
/
Morte Celular
/
Cóclea
/
Apoptose
Limite:
Animais
/
Humanos
Idioma:
Inglês
Revista:
Clinical and Experimental Otorhinolaryngology
Ano de publicação:
2008
Tipo de documento:
Artigo
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