Auditory and Vestibular SystemsMetabotropic glutamate receptors group I are involved in cochlear neurotransmissionKleinlogel, Sonja1; Oestreicher, Elmar1,2; Arnold, Thomas1; Ehrenberger, Klaus3; Felix, Dominik1,4Author Information 1Division of Neurobiology, University of Berne, Erlachstr. 9a, CH-3012 Berne, Switzerland 2ENT Department, Technical University of Munich, Germany 3ENT Department, University of Vienna, Austria. 4Corresponding Author: Dominik Felix ACKNOWLEDGEMENTS: This work was supported by the Stiftung zur Förderung wissenschaftlicher Forschung an der Universität Bern. We would especially like to thank Mrs R. Schweizer, Mrs S. Gygax and Mr R. Mosimann for technical assistance. Received 30 March 1999; accepted 23 April 1999 NeuroReport: June 23rd, 1999 - Volume 10 - Issue 9 - p 1879-1882 Buy Abstract ALL three types of ionotropic glutamate receptors, AMPA, NMDA and kainate, contribute to the neurotransmission between inner hair cells (IHC) and afferent neurons in the mammalian cochlea. We used microiontophoretic techniques to investigate whether metabotropic glutamate receptors group I (mGluR I) are also involved in the transmission of IHC afferents of the guinea pig. The mGluR I agonist DHPG produced an increase in afferent firing, which lasted significantly longer than that of the ionotropic agonists AMPA and NMDA. The activation was reversibly blocked by the mGluR I antagonist AIDA in a dose-dependent manner. AIDA also diminished spontaneous activity, but only slightly affected the AMPA- or NMDA-induced firing rate. Our results suggest that mGluR I are involved in peripheral auditory processing. © 1999 Lippincott Williams & Wilkins, Inc.