Analysis Tools
hearing/vestibular/ear
|
• multiple stereocilia of the third row of the OHC hair bundles are missing, predominantly at the wings of the hair bundles
|
|
• mice show progressive degeneration of hair cells
|
|
• the number of outer hair cells (OHCs), but not inner hair cells (IHCs), progressively decreases after P21
• OHCs start to degenerate along a basal to apical gradient along the cochlear duct, with very little OHC loss in the apical-middle turn of the cochlea but by P90, almost all OHCs in that region are lost
• however, P21 mice show a normal pattern of IHC ribbon synapses indicating that hearing loss is not of synaptogenic origin
|
|
• electrocochleographic responses evoked by condensation and rarefraction clicks recorded at maximum stimulation intensity of 120 dBSPL shows lower cochlear microphonic amplitude than in wild-type mice and the low-amplitude oscillatory activity following negative deflection, corresponding to the neural response, shows an opposite phase from condensation to rarefaction stimuli
|
|
• ABR waveforms show increased latencies and reduced peak amplitudes, indicating the presence of retrocochlear lesions
|
|
• 3- and 6-week-old mice exhibit increased auditory brainstem (ABR) thresholds at all frequencies
|
|
• the DPOAEs thresholds at high frequencies (12-32 kHz) fall within an abnormal range with DPOAE amplitudes ranging from 5 to 10 dBSPL, lower than in wild-type mice indicating OHC dysfunction
|
|
• mice exhibit severe progressive hearing loss at all frequencies
|
behavior/neurological
|
• P90-P120 mice exhibit impaired balance ability
• on the rotarod test with forced motor activity, mice fall off the rod quicker than wild-type mice
|
|
• mice exhibit significant swimming difficulty
|
|
• mice exhibit head-tilting behavior between 2 and 3 months of age, indicating vestibular defects
|
|
• mice exhibit circling behaviors between 2 and 3 months of age, circling 20-24 times per minute, indicating vestibular defects
|
nervous system
|
• multiple stereocilia of the third row of the OHC hair bundles are missing, predominantly at the wings of the hair bundles
|
|
• mice show progressive degeneration of hair cells
|
|
• the number of outer hair cells (OHCs), but not inner hair cells (IHCs), progressively decreases after P21
• OHCs start to degenerate along a basal to apical gradient along the cochlear duct, with very little OHC loss in the apical-middle turn of the cochlea but by P90, almost all OHCs in that region are lost
• however, P21 mice show a normal pattern of IHC ribbon synapses indicating that hearing loss is not of synaptogenic origin
|
|
• electrocochleographic responses evoked by condensation and rarefraction clicks recorded at maximum stimulation intensity of 120 dBSPL shows lower cochlear microphonic amplitude than in wild-type mice and the low-amplitude oscillatory activity following negative deflection, corresponding to the neural response, shows an opposite phase from condensation to rarefaction stimuli
|
|
• mice show a progressive decrease in the spiral ganglion neuron density after P30 with severe degeneration by P90
|
|
• degeneration of vestibular ganglion cells in the cochlea, with a decrease in neurons at P90
• however, vestibular hair cells remain intact at P90
|
Mouse Models of Human Disease |
DO ID | OMIM ID(s) | Ref(s) | |
| autosomal recessive nonsyndromic deafness 59 | DOID:0110511 |
OMIM:610220 |
J:332624 | |
