Impaired auditory processing and altered structure of the endbulb of Held synapse in mice lacking the GluA3 subunit of AMPA receptors.

Impaired auditory processing and altered structure of the endbulb of Held synapse in mice lacking the GluA3 subunit of AMPA receptors.
Hear Res. 2016 Dec 20;:
Authors: García-Hernández S, Abe M, Sakimura K, Rubio ME
Abstract
AMPA glutamate receptor complexes with fast kinetics conferred by subunits like GluA3 and GluA4 are essential for temporal precision of synaptic transmission. The specific role of GluA3 in auditory processing and experience related changes in the auditory brainstem remain unknown. We investigated the role of the GluA3 in auditory processing by using wild type (WT) and GluA3 knockout (GluA3-KO) mice. We recorded auditory brainstem responses (ABR) to assess auditory function and used electron microscopy to evaluate the ultrastructure of the auditory nerve synapse on bushy cells (AN-BC synapse). Since labeling for GluA3 subunit increases on auditory nerve synapses within the cochlear nucleus in response to transient sound reduction, we investigated the role of GluA3 in experience-dependent changes in auditory processing. We induced transient sound reduction by plugging one ear and evaluated ABR threshold and peak amplitude recovery for up to 60 days after ear plug removal in WT and GluA3-KO mice. We found that the deletion of GluA3 leads to impaired auditory signaling that is reflected in decreased ABR peak amplitudes, an increased latency of peak 2, early onset hearing loss and reduced numbers and sizes of postsy...

Source: Hearing Research - December 19, 2016 Category: Audiology Authors: García-Hernández S, Abe M, Sakimura K, Rubio ME Tags: Hear Res Source Type: research