Cochlear Damage Induces Gap-43 Expression in Cholinergic Synapses of the Cochlear Nucleus in the Adult Rat: a Light and Electron Microscopic Study.
From: Neurobiological Research Laboratory, Department of Otorhinolaryngology, University of Freiburg, D-79106 Freiburg, Germany.
The European journal of neuroscience
- Publish Date: Jun 2006
- ISSN: 0953-816X
- Volume: 23
- Issue: 12
- Pages: 3187-99
- Medium: Print
- Language: English
- Citation (JAMA): Meidinger Markus A, Hildebrandt-Schoenfeld Heika, Illing Robert-Benjamin, et al. Cochlear Damage Induces Gap-43 Expression in Cholinergic Synapses of the Cochlear Nucleus in the Adult Rat: a Light and Electron Microscopic Study.. Eur. J. Neurosci. Jun 2006;23:3187-99
Abstract
Recent studies suggest a potential for activity-dependent reconstruction in the adult mammalian brainstem that exceeds previous expectations. We found that a unilateral cochlear lesion led within 1 week to a rise of choline acetyltransferase (ChAT) immunoreactivity in the ventral cochlear nucleus of the affected side, matching the lesion-induced expression of growth-associated protein 43 (GAP-43) previously described. The rise of both ChAT and GAP-43 immunoreactivity was reflected in the average density of the staining. Moreover, the number of light-microscopically identifiable boutons increased in both stains. GAP-43-positive boutons could, by distinct ultrastructural features, regularly be identified as presynaptic endings. However, GAP-43 immunoreactivity was not only found in presynaptic endings with a classical morphology, but also in profiles that suggest morphological dynamic structures by showing filopodia, assemblages of pleomorphic vesicles, large vesicles (diameter up to 200 nm) fusing with the presynaptic plasma membrane close to synaptic contacts, small dense-core vesicles (diameter about 80 nm) and presynaptic ribosomes. Moreover, we observed perforated synapses as well as GAP-43 immunoreactivity condensed in rafts, both indicative of growing or changing neuronal connections. Classical and untypical ultrastructural profiles that contained GAP-43 also contained ChAT. We conclude that there is extensive deafness-induced GAP-43-mediated synaptic plasticity in the cochlear nucleus, and that this plasticity is predominantly, if not exclusively, based on cholinergic afferents.
Mesh Headings (Keywords): Acetylcholine, Animals, Choline O-Acetyltransferase, Cochlea, Cochlear Nucleus, GAP-43 Protein, Immunohistochemistry, Neuronal Plasticity, Neurons, Rats, Rats, Wistar, Synapses
Check for Full Text / PubMed Unique Identifier (PMID): 16820009
This abstract is part of PubMed, a service of the U.S. National Library of Medicine. PubMed includes more than 17 million citations from MEDLINE and other life science journals for biomedical articles. See Copyright and Disclaimers.
Linked medical terms appearing on this page are added by Healia to help readers find more information and are not part of the original PubMed document.
The data herein was last updated on July 8th, 2008 and may not reflect the most current and accurate data available from NLM.