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A bushy cell network in the rat ventral cochlear nucleus
Author(s) -
GómezNieto Ricardo,
Rubio María E.
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.22139
Subject(s) - neuroscience , cochlear nucleus , inhibitory postsynaptic potential , excitatory postsynaptic potential , biology , neuron , dorsal cochlear nucleus , nucleus , retrograde tracing
Abstract Geometry of the dendritic tree and synaptic organization of afferent inputs are essential factors in determining how synaptic input is integrated by neurons. This information remains elusive for one of the first brainstem neurons involved in processing of the primary auditory signal from the ear, the bushy cells (BCs) of the ventral cochlear nucleus (VCN). Here, we labeled the BC dendritic trees with retrograde tracing techniques to analyze their geometry and synaptic organization after immunofluorescence for excitatory and inhibitory synaptic markers, electron microscopy, morphometry, double tract‐tracing methods, and 3D reconstructions. Our study revealed that BC dendrites provide space for a large number of compartmentalized excitatory and inhibitory synaptic interactions. The dendritic inputs on BCs are of cochlear and noncochlear origin, and their proportion and distribution are dependent on the branching pattern and orientation of the dendritic tree in the VCN. Three‐dimensional reconstructions showed that BC dendrites branch and cluster with those of other BCs in the core of the VCN. Within the cluster, incoming synaptic inputs establish divergent multiple‐contact synapses (dyads and triads) between BCs. Furthermore, neuron–neuron connections including puncta adherentia, sarcoplasmic junctions, and gap junctions are common between BCs, which suggests that these neurons are electrically coupled. Overall, our study demonstrates the existence of a BC network in the rat VCN. This network may establish the neuroanatomical basis for acoustic information processing by individual BCs as well as for enhanced synchronization of the output signal of the VCN. J. Comp. Neurol. 516:241–263, 2009. © 2009 Wiley‐Liss, Inc.