Premium
Spatial compartmentalization of AMPA glutamate receptor subunits at the calyx of Held synapse
Author(s) -
Hermida Diana,
María Mateos José,
Elezgarai Izaskun,
Puente Nagore,
Bilbao Aurora,
Luis BuenoLópez José,
Streit Peter,
Grandes Pedro
Publication year - 2009
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.22189
Subject(s) - ampa receptor , calyx , trapezoid body , postsynaptic potential , biology , synapse , neuroscience , compartmentalization (fire protection) , glutamate receptor , superior olivary complex , nucleus , anatomy , cochlear nucleus , receptor , biochemistry , enzyme
The mature calyx of Held ending on principal neurons of the medial nucleus of the trapezoid body (MNTB) has very specialized morphological and molecular features that make it possible to transmit auditory signals with high fidelity. In a previous work we described an increased localization of the ionotropic α‐amino‐3‐hydroxy‐5‐methyl‐4 isoxazolepropionic acid (AMPA) glutamate receptor (GluA) subunits at postsynaptic sites of the calyx of Held‐principal cell body synapses from postnatal development to adult. The aim of the present study was to investigate whether the pattern of the synaptic distribution of GluA2/3/4c and ‐4 in adult MNTB principal cell bodies correlated with preferential subcellular domains (stalks and swellings) of the calyx. We used a postembedding immunocytochemical method combined with specific antibodies to GluA2/3/4c and GluA4 subunits. We found that the density of GluA2/3/4c in calyceal swellings (19 ± 1.54 particles/μm) was higher than in stalks (10.93 ± 1.37 particles/μm); however, the differences for GluA4 were not statistically significant (swellings: 13.84 ± 1.39 particles/μm; stalks: 10.42 ± 1.24 particles/μm). Furthermore, GluA2/3/4c and GluA4 labeling co‐localized to some extent in calyceal stalks and swellings. Taking these data together, the distribution pattern of GluA subunits in postsynaptic specializations are indicative of a spatial compartmentalization of AMPA subunits in mature calyx‐principal neuron synapses that may support the temporally precise transmission required for sound localization in the auditory brainstem. J. Comp. Neurol. 518:163–174, 2010. © 2009 Wiley‐Liss, Inc.