title: Auditory Rehabilitation in Rhesus Macaque Monkeys (Macaca mulatta) with Auditory Brainstem Implants.
abstract: BACKGROUND
  The auditory brainstem implants (ABIs) have been used to treat deafness for patients with neurofibromatosis Type 2 and nontumor patients. The lack of an appropriate animal model has limited the study of improving hearing rehabilitation by the device. This study aimed to establish an animal model of ABI in adult rhesus macaque monkey (Macaca mulatta).
  
  
  METHODS
  Six adult rhesus macaque monkeys (M. mulatta) were included. Under general anesthesia, a multichannel ABI was implanted into the lateral recess of the fourth ventricle through the modified suboccipital-retrosigmoid (RS) approach. The electrical auditory brainstem response (EABR) waves were tested to ensure the optimal implant site. After the operation, the EABR and computed tomography (CT) were used to test and verify the effectiveness via electrophysiology and anatomy, respectively. The subjects underwent behavioral observation for 6 months, and the postoperative EABR was tested every two weeks from the 1 st month after implant surgery.
  
  
  RESULTS
  The implant surgery lasted an average of 5.2 h, and no monkey died or sacrificed. The averaged latencies of peaks I, II and IV were 1.27, 2.34 and 3.98 ms, respectively in the ABR. One-peak EABR wave was elicited in the operation, and one- or two-peak waves were elicited during the postoperative period. The EABR wave latencies appeared to be constant under different stimulus intensities; however, the amplitudes increased as the stimulus increased within a certain scope.
  
  
  CONCLUSIONS
  It is feasible and safe to implant ABIs in rhesus macaque monkeys (M. mulatta) through a modified suboccipital RS approach, and EABR and CT are valid tools for animal model establishment. In addition, this model should be an appropriate animal model for the electrophysiological and behavioral study of rhesus macaque monkey with ABI.
authors.forename: Zhen-Min
authors.initials: ZM
authors.lastname: Wang
authors.forename: Zhi-Jun
authors.initials: ZJ
authors.lastname: Yang
authors.forename: Fu
authors.initials: F
authors.lastname: Zhao
authors.forename: Bo
authors.initials: B
authors.lastname: Wang
authors.forename: Xing-Chao
authors.initials: XC
authors.lastname: Wang
authors.forename: Pei-Ran
authors.initials: PR
authors.lastname: Qu
authors.affiliation: Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University; Department of Neural Reconstruction, Beijing Neurosurgical Institute, Beijing 100050, China.
authors.forename: Pi-Nan
authors.initials: PN
authors.lastname: Liu
mesh_terms: D000818:Animals; D038262:Auditory Brain Stem Implants; D003638:Deafness / Q000601:surgery*; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D005260:Female; D008253:Macaca mulatta; D008297:Male