Strial dysfunction in a melanocyte deficient mutant rat (Ws/Ws rat).
A homozygous mutant rat at the white spotting (Ws) locus showing a deficiency of melanocytes has recently been found (4, 5). The function and morphology of the inner ear of the Ws/Ws rat were examined by auditory brainstem response (ABR), endocochlear DC potential (EP), and electron microscopy. The mean ABR threshold of the Ws/Ws rat was significantly higher than that of the control +/+ rat. Most Ws/Ws rats showed no or very little EP. In electron microscopy, the stria vascularis of the Ws/Ws rat proved to be very thin and flat with poor interdigitation of marginal cells, and absence of intermediate cells. The organ of Corti appeared to be intact in both the +/+ rat and the Ws/Ws rat. These electrophysiological and morphological findings suggest that the Ws/Ws rat suffered from severe hearing loss caused by strial dysfunction.
Kitamura
K
K
Department of Otolaryngology, Osaka University Medical School, Japan.
Sakagami
M
M
Umemoto
M
M
Takeda
N
N
Doi
K
K
Kasugai
T
T
Kitamura
Y
Y
D000161:Acoustic Stimulation; D000818:Animals; D001309:Auditory Threshold / Q000502:physiology; D003053:Cochlear Duct / Q000503:physiopathology; D003055:Cochlear Microphonic Potentials / Q000502:physiology; D004195:Disease Models, Animal; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology*; D006311:Hearing Disorders / Q000503:physiopathology; D008544:Melanocytes; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D009925:Organ of Corti / Q000473:pathology; D051381:Rats; D011922:Rats, Mutant Strains; D011930:Reaction Time / Q000502:physiology; D012533:Scala Tympani / Q000503:physiopathology; D013316:Stria Vascularis / Q000473:pathology / Q000502:physiology*