[Distribution of L-type calcium channels on outer hair cells among various turns of guinea pig cochlea].
OBJECTIVE
To probe the relationship between the density of L-type calcium channels on outer hair cells(OHCs) among various turns and the tonotopic map in the guinea pig cochlea.


METHODS
The L-type calcium channels in outer hair cells of guinea pigs were labeled with DM-BODIPY DHP and RH414 and monitored using a laser scanning confocal microscope. The fluorescence ratio of DM-BODIPY DHP/RH414 revealed the distribution of L-type calcium channels on the cellular membrane.


RESULTS
The results showed that the cellular membrane had lesser DM-BODIPY DHP staining when pretreated with nifedipine, indicating that calcium channels on OHCs had the specificity of a L-type calcium channel. The density of L-type calcium channels had a tendency of increasing gradually from low frequency areas to high frequency areas. Variance analysis showed that the difference of the density of L-type calcium channels on OHCs between the fourth turn and the second turn was significant. There were no apparent differences in the distribution of L-type calcium channels among various regions on the cellular membrane of OHCs.


CONCLUSIONS
The descripency of the distribution of L-type calcium channels on OHCs among various turns of the guinea pig cochlea may be one of the molecular mechanisms of the tonotopic map of the cochlea.
Guo
Ying
Y
Department of Otorhinolaryngology, Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Otorhinolaryngology Institute, Beijing 100853, China. 856639@163.com
Su
Zhenlun
Z
Yang
Weiyan
W
Jiang
Sichang
S
D000818:Animals; D020746:Calcium Channels, L-Type / Q000378:metabolism*; D003051:Cochlea / Q000166:cytology*; D003593:Cytoplasm / Q000648:ultrastructure; D005260:Female; D005456:Fluorescent Dyes; D006168:Guinea Pigs; D018072:Hair Cells, Auditory, Outer / Q000378:metabolism*; D008297:Male; D018613:Microscopy, Confocal
D020746:Calcium Channels, L-Type; D005456:Fluorescent Dyes