Analysis Tools
behavior/neurological
|
• severe deficits in balance and coordination by P14
|
hyperactivity
(
J:33502
)
|
• marked hyperactivity by 5-6 weeks
|
hearing/vestibular/ear
|
• loss of neurons and nerve fibers in the apical cochlear turn
• ears have very few fibers in the area of Rosenthal's canal that leads to the osseous spiral lamina
• only a few peripheral nerve fibers are seen, which are thin and appear to preferentially grow toward the actin rich cells but not beyond them
• treatment with an adenovirus expressing BDNF results in robust nerve fiber generation at both the apex and base of the cochlea, showing sprouting of nerve fibers into the epithelium
|
|
• sensory epithelium shows no hair cells at 6 weeks of age, and cells with features of Deiters cells, pillar cells, and other supporting cells are not seen, although actin-rich cells are seen; instead, it resembles a flat epithelium, composed of a single layer of cuboidal epithelial cells
• actin-rich cells are clustered in patches along the auditory epithelium
|
|
• incomplete cavitation of the organ of Corti at P0
|
|
• at P0, IHCs and OHCs in the organ of Corti fail to show early signs of differentiation
|
|
• by P14, no hair cells are identified in the organ of Corti
(J:33502)
• auditory epithelium contains no sensory hair cells
(J:207266)
|
|
• lack of stereocilia in the auditory epithelium
(J:207266)
|
|
• at P0, IHCs in the organ of Corti fail to show early signs of differentiation, including growth of stereocilia and segregation of cell nuclei to a plane above the level of supporting cell nuclei
|
|
• at P0, OHCs in the organ of Corti fail to show early signs of differentiation, including growth of stereocilia and segregation of cell nuclei to a plane above the level of supporting cell nuclei
|
|
• lack of cuticular plate in the auditory epithelium
|
|
• by P14, many of the normal supporting cell populations are absent in the organ of Corti
|
|
• tunnel of Corti is sometimes absent
|
|
• at P0, no hair cells are identified in the sensory epithelia of the maculae and the cristae; the row of nuclei above the supporting cell nuclei is poorly organized
|
|
• at P0, stereocilia bundles are absent in the sensory epithelia of the maculae and the cristae
|
|
• at P42, mice exhibit a complete failure of click-evoked ABRs to stimuli up to 80 dB above normal threshold
|
nervous system
|
• at P0, IHCs and OHCs in the organ of Corti fail to show early signs of differentiation
|
|
• by P14, no hair cells are identified in the organ of Corti
(J:33502)
• auditory epithelium contains no sensory hair cells
(J:207266)
|
|
• lack of stereocilia in the auditory epithelium
(J:207266)
|
|
• at P0, IHCs in the organ of Corti fail to show early signs of differentiation, including growth of stereocilia and segregation of cell nuclei to a plane above the level of supporting cell nuclei
|
|
• at P0, OHCs in the organ of Corti fail to show early signs of differentiation, including growth of stereocilia and segregation of cell nuclei to a plane above the level of supporting cell nuclei
|
|
• at P0, no hair cells are identified in the sensory epithelia of the maculae and the cristae; the row of nuclei above the supporting cell nuclei is poorly organized
|
|
• at P0, stereocilia bundles are absent in the sensory epithelia of the maculae and the cristae
|
|
• the number of spiral ganglion neurons is greatly reduced in Rosenthal's canal
• the spiral ganglion neurons that remain are smaller and outer perimeters are irregular
• treatment with an adenovirus expressing BDNF results in preservation of spiral ganglion neurons
|
|
• at P0, the cochlea and spiral ganglion appear grossly normal
• however, most spiral ganglion cells degenerate by P14
|
|
• complete degeneration of vestibular ganglion by P14, with absence of calycial endings surrounding type I hair cells
|
