gms | German Medical Science

56. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e. V. (DGNC)
3èmes journées françaises de Neurochirurgie (SFNC)

Deutsche Gesellschaft für Neurochirurgie e. V.
Société Française de Neurochirurgie

07. bis 11.05.2005, Strasbourg

C-Fos functional mapping after electrical stimulation of the cochlear nerve in the rat: animal model for experimental auditory neuroprosthesis

Funktionelles Mapping mit c-Fos nach elektrischer Stimulation des Nervus cochlearis der Ratte: ein Tiermodell für experimentelle auditorische Neuroprothesen

Meeting Abstract

  • corresponding author M. Nakamura - Department of Neurosurgery, Klinikum Hannover Nordstadt, Hannover
  • S. Rosahl - Department of Neurosurgery, Albert Ludwigs University, Freiburg
  • E. Alkahlout - Department of Neurosurgery, Klinikum Duisburg
  • G. F. Walter - Medizinische Universität Graz, Austria
  • M. R. Gaab - Department of Neurosurgery, Klinikum Hannover Nordstadt, Hannover
  • M. Samii - Department of Neurosurgery, International Neuroscience Institute, Hannover

Deutsche Gesellschaft für Neurochirurgie. Société Française de Neurochirurgie. 56. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), 3èmes journées françaises de Neurochirurgie (SFNC). Strasbourg, 07.-11.05.2005. Düsseldorf, Köln: German Medical Science; 2005. Doc11.05.-15.01

The electronic version of this article is the complete one and can be found online at: http://www.egms.de/en/meetings/dgnc2005/05dgnc0253.shtml

Published: May 4, 2005

© 2005 Nakamura et al.
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Outline

Text

Objective

The functional response of auditory brainstem nuclei using C-Fos immunoreactivity mapping after direct electrical stimulation of the cochlear nerve was investigated in the rat. Aim of this study is to simulate and analyze effects of central electrical stimulation by auditory prosthesis in an animal model.

Methods

The cochlear nerve was electrically stimulated with biphasic pulses (120-250 mA, 5 Hz) for 30 minutes in the cerebellopontine angle of Lewis rats. In a control group, bilateral cochlectomy was performed in order to investigate basal expression of c-Fos in the auditory brainstem nuclei. The completeness of cochlear ablations and the response of auditory brainstem nuclei to electrical stimulation were electrophysiologically verified. C-Fos immunohistochemistry was performed using the free floating method. The results were morphologically analyzed and statistically compared among groups.

Results

In anaesthetized animals with unilateral electrical stimulation of the cochlear nerve, increased expression of c-Fos was detected in the ipsilateral ventral cochlear nucleus (VCN), bilateral dorsal cochlear nucleus (DCN), ipsilateral lateral superior olive (LSO) and contralateral inferior colliculus (IC). A bilateral slight increase of c-Fos expression in all subdivisions of the lateral lemniscus was statistically not significant. Contralateral inhibition of the nuclei of the trapezoid body was observed.

Conclusions

Our data show that electrical stimulation of the cochlear nerve leads to increased expression of c-Fos in most auditory brainstem nuclei, similar to the results after monaural auditory stimulation. C-Fos immunoreactivity mapping is an efficient tool to detect functional changes after direct electrical stimulation of the cochlear nerve on cellular level. This could be particularly helpful in studies of the differential activation of the central auditory system by experimental auditory brainstem implants.