Morphologically specific vestibular hair cell degeneration in the jerker mouse mutant.
The vestibular organs in homozygote (je/je) and heterozygote (je/+) 1- to 12-month-old jerker mouse mutants were analyzed morphologically using light microscopy and transmission and scanning electron microscopy. The pathological changes were initially confined to the surface structure of predominantly type I hair cells. The latter cells showed disintegration of the cuticular plate, disarray of stereocilia and finally fusion of sensory hairs. The hair cells were then expelled into the endolymphatic space. A notable finding was that most expelled hair cells still showed a rather normal ultrastructure of their cytoplasm and nuclei. The morphological type of pathology was the same in je/je and je/+ mutants. However, in je/je animals the degeneration occurred within 1-3 months after birth, whereas in je/+ mutants a slowly progressive degeneration lasted for up to 1 year of age or even more. The degeneration was more extensive in the two maculae than in the three cristae ampullares.
Sjöström
B
B
Department of Oto-Rhino-Laryngology and Head and Neck Surgery, University Hospital, Umeå, Sweden.
Anniko
M
M
D000375:Aging; D000818:Animals; D005838:Genotype; D006198:Hair Cells, Auditory / Q000473:pathology* / Q000648:ultrastructure; D051379:Mice; D008818:Mice, Neurologic Mutants; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D015837:Vestibular Diseases / Q000235:genetics / Q000473:pathology*; D014722:Vestibule, Labyrinth / Q000473:pathology* / Q000648:ultrastructure