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Selective deletion of cochlear hair cells causes rapid age-dependent changes in spiral ganglion and cochlear nucleus neurons.
- Source :
-
The Journal of neuroscience : the official journal of the Society for Neuroscience [J Neurosci] 2015 May 20; Vol. 35 (20), pp. 7878-91. - Publication Year :
- 2015
-
Abstract
- During nervous system development, critical periods are usually defined as early periods during which manipulations dramatically change neuronal structure or function, whereas the same manipulations in mature animals have little or no effect on the same property. Neurons in the ventral cochlear nucleus (CN) are dependent on excitatory afferent input for survival during a critical period of development. Cochlear removal in young mammals and birds results in rapid death of target neurons in the CN. Cochlear removal in older animals results in little or no neuron death. However, the extent to which hair-cell-specific afferent activity prevents neuronal death in the neonatal brain is unknown. We further explore this phenomenon using a new mouse model that allows temporal control of cochlear hair cell deletion. Hair cells express the human diphtheria toxin (DT) receptor behind the Pou4f3 promoter. Injections of DT resulted in nearly complete loss of organ of Corti hair cells within 1 week of injection regardless of the age of injection. Injection of DT did not influence surrounding supporting cells directly in the sensory epithelium or spiral ganglion neurons (SGNs). Loss of hair cells in neonates resulted in rapid and profound neuronal loss in the ventral CN, but not when hair cells were eliminated at a more mature age. In addition, normal survival of SGNs was dependent on hair cell integrity early in development and less so in mature animals. This defines a previously undocumented critical period for SGN survival.<br /> (Copyright © 2015 the authors 0270-6474/15/357878-14$15.00/0.)
- Subjects :
- Animals
Cell Death
Cochlear Nucleus cytology
Cochlear Nucleus physiology
Diphtheria Toxin pharmacology
Hair Cells, Auditory drug effects
Hair Cells, Auditory metabolism
Hearing
Heparin-binding EGF-like Growth Factor genetics
Heparin-binding EGF-like Growth Factor metabolism
Mice
Mice, Inbred C57BL
Mice, Inbred CBA
Spiral Ganglion cytology
Spiral Ganglion physiology
Cochlear Nucleus growth & development
Hair Cells, Auditory cytology
Spiral Ganglion growth & development
Subjects
Details
- Language :
- English
- ISSN :
- 1529-2401
- Volume :
- 35
- Issue :
- 20
- Database :
- MEDLINE
- Journal :
- The Journal of neuroscience : the official journal of the Society for Neuroscience
- Publication Type :
- Academic Journal
- Accession number :
- 25995473
- Full Text :
- https://doi.org/10.1523/JNEUROSCI.2179-14.2015