Phenotypes Associated with This Genotype

Genotype
MGI:3832681

• Allelic Composition: Chrna9^tm1Elgo/Chrna9⁺
• Genetic Background: involves: 129S4/SvJae * FVB/N

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

hearing/vestibular/ear

abnormal cochlear inner hair cell physiology ( J:144698 )

• inner hair cells from mice 6 to 10 days old are more sensitive to acetylcholine (ACH) in voltage clamp studies with EC-50 values being about a third less than controls

• ACh-evoked membrane current was more sustained than that seen in wild-type mice

increased or absent threshold for auditory brainstem response ( J:144698 )

• mean ABR thresholds are elevated by 5-15 dB compared to controls

• threshold shifts are larger at frequencies above 16 kHz

abnormal distortion product otoacoustic emission ( J:144698 )

• mean DPOAEs thresholds are elevated by 5-15 dB compared to controls

• wild-type mice have a brief suppression of DPOAE in response to electrical shocking of the medial olivocochlear efferents (MOC) but recover to baseline levels even with subsequent shocking

• mutant mice have a much slower onset of DPOAE suppression but suppression continues to grow with subsequent shocks until no longer detected

• DPOE does not return until about 8 minutes after MOC shocking

decreased susceptibility to noise-induced hearing loss ( J:144698 )

• mice are resistant to permanent hearing loss induced by a 8-16-kHz noise band at 100 dB for 2 hours

nervous system

abnormal cochlear inner hair cell physiology ( J:144698 )

• inner hair cells from mice 6 to 10 days old are more sensitive to acetylcholine (ACH) in voltage clamp studies with EC-50 values being about a third less than controls

• ACh-evoked membrane current was more sustained than that seen in wild-type mice