Analysis Tools
behavior/neurological
| N |
• adult mice display a normal righting response and show no overt vestibular abnormalities such as head bobbing or circling behaviors, unlike Whrnwi homozygotes
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hearing/vestibular/ear
| N |
• at P21, both IHC stereocilia bundle morphology and IHC stereocilia length are normal, suggesting that IHCs are least partially functional, unlike in Whrnwi homozygotes
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• at P28, some OHC stereocilia bundles exhibit lateral links between adjacent stereocilia
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• at P21, OHC stereocilia bundles appear rounded (U- rather than W-shaped) and show irregular spacing between stereocilia rows, similar to the phenotype observed in Whrnwi homozygotes
• however, OHC stereocilia length is normal at P21
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• at P21, mice show regional differences in vestibular hair cell stereociliary bundle morphology relative to heterozygous controls
• stereocilia bundles in the extrastriolar region of the utricular and saccular maculae are short, similar to Whrnwi homozygotes; however, bundles in the striolar region are more variable with longer stereocilia and nearly normal staircase organization
• regional differences are more prominent in the crista ampularis, where central zone bundles are much shorter than in heterozygous controls, while peripheral zone bundles are morphologically similar to control bundles
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• at P21, stereocilia bundles in the extrastriolar region of the utricular and saccular maculae are short, similar to Whrnwi homozygotes
• the length of tallest stereocilia in the extrastriolar and striolar bundles is reduced by ~80% and ~50%, respectively, relative to heterozygous controls
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• abnormal OHC morphology, poor frequency tuning, and increased DPOAE thresholds suggest impaired OHC function
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• at P98, ABR analysis revealed a profound impairment (absent ABR) only at higher frequencies (24-30 kHz) and only modest impairment at lower frequencies (6, 12, and 18 kHz) relative to control mice
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• at P98, mice produce a mean tuning curve that is flat across frequencies, whereas heterozygous controls produce a mean tuning curve with a sensitive tip close to the 12 kHz probe tone
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• at P98, mice exhibit a moderate increase in DPOAE thresholds for F2 frequencies of 6-18 kHz relative to heterozygous controls
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• at P98, DPOAEs from higher F2 frequencies (24-30 kHz) are often not evoked even at the highest stimulus levels tested
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• at P98, mice show only moderate to severe hearing loss
• hearing loss does not progress between 4 and 14 weeks of age
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nervous system
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• at P28, some OHC stereocilia bundles exhibit lateral links between adjacent stereocilia
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• at P21, OHC stereocilia bundles appear rounded (U- rather than W-shaped) and show irregular spacing between stereocilia rows, similar to the phenotype observed in Whrnwi homozygotes
• however, OHC stereocilia length is normal at P21
|
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• at P21, mice show regional differences in vestibular hair cell stereociliary bundle morphology relative to heterozygous controls
• stereocilia bundles in the extrastriolar region of the utricular and saccular maculae are short, similar to Whrnwi homozygotes; however, bundles in the striolar region are more variable with longer stereocilia and nearly normal staircase organization
• regional differences are more prominent in the crista ampularis, where central zone bundles are much shorter than in heterozygous controls, while peripheral zone bundles are morphologically similar to control bundles
|
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• at P21, stereocilia bundles in the extrastriolar region of the utricular and saccular maculae are short, similar to Whrnwi homozygotes
• the length of tallest stereocilia in the extrastriolar and striolar bundles is reduced by ~80% and ~50%, respectively, relative to heterozygous controls
|
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• abnormal OHC morphology, poor frequency tuning, and increased DPOAE thresholds suggest impaired OHC function
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