TY - JOUR
T1 - Uptake of gentamicin by vestibular efferent neurons and superior olivary complex after transtympanic administration in guinea pigs
AU - Zhang, Yi Bo
AU - Zhang, Ru
AU - Zhang, Wei Feng
AU - Steyger, Peter S.
AU - Dai, Chun Fu
N1 - Funding Information:
This study was supported by Educational Ministry of China (No: NCET-06-0369 ); National Natural Science Foundation (No. 30772398 , No. 81070785 ); Project on Advanced and Frontier Techniques for Shanghai Municipal Hospital ( SHDC12010119 ); 973 Project ( 2011CB504504 ), and National Institute of Deafness and Other Communication Disorders ( DC 04555 , PSS).
PY - 2012/1
Y1 - 2012/1
N2 - Transtympanic administration of gentamicin is a widely accepted and effective approach for treating patients with intractable vertigo. Previous studies have demonstrated the uptake, distribution and effects of gentamicin in peripheral vestibular and cochlear structures after transtympanic injection. However, little is known about whether transtympanically administered gentamicin is trafficked into more central auditory and vestibular structures and its effect on these structures. In this study, we used immunofluorescence to determine the distribution of gentamicin within the auditory and vestibular brainstem. We observed gentamicin immunolabeling bilaterally in the vestibular efferent neurons, and in the superior olivary complex, and ipsilaterally in the cochlear nucleus 24. h after transtympanic administration of gentamicin, and that the drug could still be detected in these locations 30 days after injection. In contrast, no gentamicin labeling was detected in the vestibular nuclear complex. In the vestibular efferent neurons and superior olivary complex, gentamicin labeling was detected in the cytoplasm and cell processes, while in the cochlear nucleus gentamicin is mainly localized outside and adjacent to the cell bodies of neurons. Nerve fibers in cochlear nucleus, root of eighth nerve, as well as descending pathways from the superior olivary complex, are also immunolabeled with gentamicin continuously. Based on these data, we hypothesize that retrograde axonal transport of gentamicin is responsible for the distribution of gentamicin in these efferent nuclei including vestibular efferent neurons and superior olivary complex and anterograde axonal transport into the ipsilateral cochlear nucleus.
AB - Transtympanic administration of gentamicin is a widely accepted and effective approach for treating patients with intractable vertigo. Previous studies have demonstrated the uptake, distribution and effects of gentamicin in peripheral vestibular and cochlear structures after transtympanic injection. However, little is known about whether transtympanically administered gentamicin is trafficked into more central auditory and vestibular structures and its effect on these structures. In this study, we used immunofluorescence to determine the distribution of gentamicin within the auditory and vestibular brainstem. We observed gentamicin immunolabeling bilaterally in the vestibular efferent neurons, and in the superior olivary complex, and ipsilaterally in the cochlear nucleus 24. h after transtympanic administration of gentamicin, and that the drug could still be detected in these locations 30 days after injection. In contrast, no gentamicin labeling was detected in the vestibular nuclear complex. In the vestibular efferent neurons and superior olivary complex, gentamicin labeling was detected in the cytoplasm and cell processes, while in the cochlear nucleus gentamicin is mainly localized outside and adjacent to the cell bodies of neurons. Nerve fibers in cochlear nucleus, root of eighth nerve, as well as descending pathways from the superior olivary complex, are also immunolabeled with gentamicin continuously. Based on these data, we hypothesize that retrograde axonal transport of gentamicin is responsible for the distribution of gentamicin in these efferent nuclei including vestibular efferent neurons and superior olivary complex and anterograde axonal transport into the ipsilateral cochlear nucleus.
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U2 - 10.1016/j.heares.2011.10.003
DO - 10.1016/j.heares.2011.10.003
M3 - Article
C2 - 22063470
AN - SCOPUS:84856602018
SN - 0378-5955
VL - 283
SP - 169
EP - 179
JO - Hearing Research
JF - Hearing Research
IS - 1-2
ER -