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Experience‐dependent refinement of the inhibitory axons projecting to the medial superior olive
Author(s) -
Werthat Florian,
Alexandrova Olga,
Grothe Benedikt,
Koch Ursula
Publication year - 2008
Publication title -
developmental neurobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.716
H-Index - 129
eISSN - 1932-846X
pISSN - 1932-8451
DOI - 10.1002/dneu.20660
Subject(s) - trapezoid body , inhibitory postsynaptic potential , biology , neuroscience , excitatory postsynaptic potential , superior olivary complex , nucleus , anatomy , cochlear nucleus
Neurons in the medial superior olive (MSO) analyze interaural time differences (ITDs) by comparing the arrival times of the two excitatory inputs from each ear using a coincidence detection mechanism. They also receive a prominent inhibitory, glycinergic projection from the ipsilateral medial nucleus of the trapezoid body (MNTB), which contributes to the fine‐tuning of ITD analysis. Here, we investigated developmental changes of the axonal arborisation pattern of single Microruby‐labeled MNTB neurons projecting to the MSO region. During the first 2 weeks after hearing onset, the axonal arborisation of MNTB neurons was significantly refined resulting in a narrowed projection area across the tonotopic axis of the MSO and a redistribution of the axonal endsegments to a mostly somatic location. Rearing the animals in omnidirectional noise prevented the structural changes of single MNTB projections. These results indicate that the functional elimination of inhibitory inputs on MSO neurons after hearing onset, as described previously, is paralleled by a structural, site‐specific refinement of the inputs and is dependent on the normal acoustic experience of the animal. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008