[Distribution of projection neurons of the superior olivary complex in the auditory brainstem in cats].
OBJECTIVE
To investigate the distribution and morphology of olivocochlear neurons of superior olivary complex in cats.


METHODS
Eight adult cats were divided into 2 groups randomly. Cholera toxin B subunit was injected to the left cochlea and fluoro-gold was injected to the right cochlea in the experimental group (n=5). Saline was injected to bilateral cochlea in the control group (n=3). Brainstem tissue was sectioned serially. All of the sections were immunohistochemically treated with ABC and stained with DAB, and then the labelled olivocochlear neurons were observed.


RESULTS
The labelled olivocochlear neurons in the experimental group were 2 518 in total. Of them, the number of lateral olivocochlear (LOC) neurons was 1 738 (69.0%), mainly located in the middle of the pons, predominantly projected ipsilaterally. The total of medial olivocochlear (MOC) neurons was 780 (31%), mainly located in dorsomedial periolivary nucleus, medial nucleus of the trapezoid body and ventral nucleus of the trapezoid body, mainly distributed in the rostral extent of the pons, predominantly projected contralaterally.


CONCLUSIONS
In the distribution of olivocochlear neurons in cats, LOC neurons mainly project to the ipsilateral. While the projection of MOC neurons is predominantly contralateral, the distribution of MOC neurons is more adjacent to the rostral extent of the pons than LOC neurons.
Tang
Qing-lai
QL
Department of Otolaryngology-Head Neck Surgery, Second Xiangya Hospital, Central South University, Changsha 410011, China.
Li
Jing-jia
JJ
Yang
Yi-da
YD
Yang
Xin-ming
XM
D000818:Animals; D001306:Auditory Pathways / Q000166:cytology*; D001933:Brain Stem / Q000166:cytology*; D002415:Cats; D002772:Cholera Toxin / Q000008:administration & dosage; D003051:Cochlea / Q000294:innervation; D017626:Cochlear Nucleus / Q000166:cytology*; D005260:Female; D007267:Injections; D008297:Male; D009474:Neurons / Q000166:cytology*; D009476:Neurons, Efferent / Q000166:cytology; D009847:Olivary Nucleus / Q000166:cytology*
D002772:Cholera Toxin