Deletion of Shank1 has minimal effects on the molecular composition and function of glutamatergic afferent postsynapses in the mouse inner ear.

Deletion of Shank1 has minimal effects on the molecular composition and function of glutamatergic afferent postsynapses in the mouse inner ear.
Hear Res. 2015 Jan 28;
Authors: Braude JP, Vijayakumar S, Baumgarner K, Laurine R, Jones TA, Jones SM, Pyott SJ
Abstract
Shank proteins (1-3) are considered the master organizers of glutamatergic postsynaptic densities in the central nervous system, and the genetic deletion of either Shank1, 2, or 3 results in altered composition, form, and strength of glutamatergic postsynapses. To investigate the contribution of Shank proteins to glutamatergic afferent synapses of the inner ear and especially cochlea, we used immunofluorescence and quantitative real time PCR to determine the expression of Shank1, 2, and 3 in the cochlea. Because we found evidence for expression of Shank1 but not 2 and 3, we investigated the morphology, composition, and function of afferent postsynaptic densities from defined tonotopic regions in the cochlea of Shank1(-/-) mice. Using immunofluorescence, we identified subtle changes in the morphology and composition (but not number and localization) of cochlear afferent postsynaptic densities at the lower frequency region (8 kHz) in Shank1(-/-) mice compared to Shank1(+/+) littermates. However, we detected no differences in auditory brainstem responses at matching or higher frequencies. We also identified Shank1 in the vestibular afferent postsynaptic densities, but detected...

Source: Hearing Research - January 28, 2015 Category: Audiology Authors: Braude JP, Vijayakumar S, Baumgarner K, Laurine R, Jones TA, Jones SM, Pyott SJ Tags: Hear Res Source Type: research