Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2004-1-12
pubmed:abstractText
Ethacrynic acid (EA) is known to interact with aminoglycoside antibiotics such as gentamicin (GM). In the chinchilla, co-administration of GM and EA can produce hair cell lesions ranging from a small loss of outer hair cells (OHCs) in the base of the cochlea to complete destruction of all hair cells, depending on dosing parameters. Although hair cell loss has been characterized, little is known about the fate of efferent fibers or spiral ganglion neurons (SGNs) in this model. To study the time course of efferent fiber and SGN loss, chinchillas were injected with GM (125 mg/kg IM) followed immediately by EA (40 mg/kg IV). Estimates of efferent fiber loss and density changes were made after 3 days or 1, 2, 3, or 4 weeks of survival. Estimates of SGN loss and density changes were made after 15 days or 1, 2, 4, or 6 months of survival. Cochlear function was rapidly abolished and all cochlear hair cells were missing within 24 h after treatment. Inner hair cells (IHCs) in the middle turn of the cochlea died earlier than cells in the apex or base, and OHCs in Rows 1 and 2 died earlier than OHCs in Row 3. Degeneration of efferent nerve fibers began 3-7 days post-injection, versus 15-30 days for SGNs, and the loss of efferent fibers was essentially complete within 1 month, versus 2-4 months for SGNs. The rapid time course of efferent fiber and SGN loss in the chinchilla may make it a practical model for studying mechanisms of neural loss and survival in the mammalian inner ear.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-8993
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
997
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
40-51
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:14715148-Acetylcholinesterase, pubmed-meshheading:14715148-Action Potentials, pubmed-meshheading:14715148-Animals, pubmed-meshheading:14715148-Cell Count, pubmed-meshheading:14715148-Cell Death, pubmed-meshheading:14715148-Chinchilla, pubmed-meshheading:14715148-Cochlear Microphonic Potentials, pubmed-meshheading:14715148-Efferent Pathways, pubmed-meshheading:14715148-Ethacrynic Acid, pubmed-meshheading:14715148-Gentamicins, pubmed-meshheading:14715148-Hair Cells, Auditory, pubmed-meshheading:14715148-Hearing Loss, Sensorineural, pubmed-meshheading:14715148-Immunohistochemistry, pubmed-meshheading:14715148-Nerve Degeneration, pubmed-meshheading:14715148-Organ of Corti, pubmed-meshheading:14715148-Silver Nitrate, pubmed-meshheading:14715148-Spiral Ganglion, pubmed-meshheading:14715148-Time Factors
pubmed:year
2004
pubmed:articleTitle
Time course of efferent fiber and spiral ganglion cell degeneration following complete hair cell loss in the chinchilla.
pubmed:affiliation
Center for Hearing and Deafness, University at Buffalo, 215 Parker Hall, Buffalo, NY 14214, USA. mcfadden@buffalo.edu
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.