RT Journal Article
SR Electronic
T1 GluA2-Containing AMPA Receptors Distinguish Ribbon-Associated from Ribbonless Afferent Contacts on Rat Cochlear Hair Cells
JF eneuro
JO eneuro
FD Society for Neuroscience
SP ENEURO.0078-16.2016
DO 10.1523/ENEURO.0078-16.2016
VO 3
IS 2
A1 Rodrigo Martinez-Monedero
A1 Chang Liu
A1 Catherine Weisz
A1 Pankhuri Vyas
A1 Paul Albert Fuchs
A1 Elisabeth Glowatzki
YR 2016
UL http://www.eneuro.org/content/3/2/ENEURO.0078-16.2016.abstract
AB Mechanosensory hair cells release glutamate at ribbon synapses to excite postsynaptic afferent neurons, via AMPA-type ionotropic glutamate receptors (AMPARs). However, type II afferent neurons contacting outer hair cells in the mammalian cochlea were thought to differ in this respect, failing to show GluA immunolabeling and with many “ribbonless” afferent contacts. Here it is shown that antibodies to the AMPAR subunit GluA2 labeled afferent contacts below inner and outer hair cells in the rat cochlea, and that synaptic currents in type II afferents had AMPAR-specific pharmacology. Only half the postsynaptic densities of type II afferents that labeled for PSD-95, Shank, or Homer were associated with GluA2 immunopuncta or presynaptic ribbons, the “empty slots” corresponding to ribbonless contacts described previously. These results extend the universality of AMPAergic transmission by hair cells, and support the existence of silent afferent contacts.