TY - JOUR
T1 - Inner ear abnormalities in a Kcnq1 (Kvlqt1) knockout mouse
T2 - A model of Jervell and Lange-Nielsen syndrome
AU - Rivas, Alejandro
AU - Francis, Howard W.
PY - 2005/5
Y1 - 2005/5
N2 - Hypothesis: Mice lacking functional KCNQ1 (previously known as KvLQT1) channels exhibit functional and structural abnormalities that indicate disturbed production of endolymph. Background: Congenital deafness associated with cardiac conduction abnormalities (Jervell and Lange-Nielsen syndrome) is associated with dysfunctional KCNQ1/KCNE1 channel complex. This potassium channel plays a critical role in the production and homeostasis of endolymph by the stria vascularis. A preliminary report documented severe abnormalities of the scala media and vestibular compartments of a single mouse lacking functional KCNQ1 alleles. Methods: Hearing thresholds were measured in three Kcnq1 knockout mice, two heterozygous mice, and one wild-type mouse by auditory brainstem response recordings using clicks, after which the temporal bones were removed. After fixation and dehydration, the ears were embedded in araldite, sectioned at 20-μm thickness, stained with toluidine blue on glass slides, and examined with the light microscope. Results: Kcnq1 knockout mice were deaf and demonstrated circling behavior. They exhibited a marked atrophy of the stria vascularis, contraction of the endolymphatic compartments, and collapse and adhesion of surrounding membranes. There was a complete degeneration of the organ of Corti and an associated degeneration of the spiral ganglion. Conclusion: Kcnq1 knockout mice exhibit histopathologic findings that are comparable to those reported in human temporal bone cases of Jervell and Lange-Nielsen syndrome, and provide further evidence that KCNQ1 channel dysfunction can lead to congenital deafness in this syndrome.
AB - Hypothesis: Mice lacking functional KCNQ1 (previously known as KvLQT1) channels exhibit functional and structural abnormalities that indicate disturbed production of endolymph. Background: Congenital deafness associated with cardiac conduction abnormalities (Jervell and Lange-Nielsen syndrome) is associated with dysfunctional KCNQ1/KCNE1 channel complex. This potassium channel plays a critical role in the production and homeostasis of endolymph by the stria vascularis. A preliminary report documented severe abnormalities of the scala media and vestibular compartments of a single mouse lacking functional KCNQ1 alleles. Methods: Hearing thresholds were measured in three Kcnq1 knockout mice, two heterozygous mice, and one wild-type mouse by auditory brainstem response recordings using clicks, after which the temporal bones were removed. After fixation and dehydration, the ears were embedded in araldite, sectioned at 20-μm thickness, stained with toluidine blue on glass slides, and examined with the light microscope. Results: Kcnq1 knockout mice were deaf and demonstrated circling behavior. They exhibited a marked atrophy of the stria vascularis, contraction of the endolymphatic compartments, and collapse and adhesion of surrounding membranes. There was a complete degeneration of the organ of Corti and an associated degeneration of the spiral ganglion. Conclusion: Kcnq1 knockout mice exhibit histopathologic findings that are comparable to those reported in human temporal bone cases of Jervell and Lange-Nielsen syndrome, and provide further evidence that KCNQ1 channel dysfunction can lead to congenital deafness in this syndrome.
KW - Congenital deafness
KW - Inner ear abnormalities
KW - Jervell and Lange-Nielsen syndrome
KW - Kcnq1 knockout mice
KW - Stereology
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U2 - 10.1097/01.mao.0000169764.00798.84
DO - 10.1097/01.mao.0000169764.00798.84
M3 - Article
C2 - 15891643
AN - SCOPUS:18644364847
SN - 1531-7129
VL - 26
SP - 415
EP - 424
JO - Otology and Neurotology
JF - Otology and Neurotology
IS - 3
ER -