Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2004-1-15
pubmed:abstractText
It is well established that manipulation of the sensory environment can significantly alter central auditory system development. For example, congenitally deaf white cats exhibit synaptic alterations in the cochlear nucleus distinct from age-matched, normal hearing controls. The large, axosomatic endings of auditory nerve fibers, called endbulbs of Held, display reduced size and branching, loss of synaptic vesicles, and a hypertrophy of the associated postsynaptic densities on the target spherical bushy cells. Such alterations, however, could arise from the cat's genetic syndrome rather than from deafness. In order to examine further the role of hearing on synapse development, we have studied endbulbs of Held in the shaker-2 ( sh2 ) mouse. These mice carry a point mutation on chromosome 11, affecting myosin 15 and producing abnormally short stereocilia in hair cells of the inner ear. The homozygous mutant mice are born deaf and develop perpetual circling behavior, although receptor cells and primary neurons remain intact at least for the initial 100 days of postnatal life. Endbulbs of Held in 7-month old, deaf sh2 mice exhibited fewer synaptic vesicles in the presynaptic ending, the loss of intercellular cisternae, and a hypertrophy of associated postsynaptic densities. On average, postsynaptic density area for sh2 endbulbs was 0.23 +/- 0.19 microm(2) compared to 0.07 +/- 0.04 microm(2) ( p < 0.001) for age-matched, hearing littermates. These changes at the endbulb synapse in sh2 mice resemble those of the congenitally deaf white cat and are consistent with the idea that they represent a generalized response to deafness.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0300-4864
pubmed:author
pubmed:issnType
Print
pubmed:volume
32
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
229-43
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Effects of congenital deafness in the cochlear nuclei of Shaker-2 mice: an ultrastructural analysis of synapse morphology in the endbulbs of Held.
pubmed:affiliation
Center for Hearing Sciences, Departments of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't