Mouse Genome Informatics
ht
    Cm/+
C3Sn.Cg-Cm/J
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
       

Inner ear defects in Cm/+ mice

behavior/neurological
N
• assessments from 2 to 20 days of age found normal results in the following behavioral tests: crossed extensor reflex, forelimb/hindlimb placing, rooting reflex, negative geotaxis, grasp reflex, vibrissa placing, and eye opening (J:30380)
• the hyperactivity can be diminished by treatment with d-amphetamine, but methylphenidate increases the hyperactivity
• amphetamine-treated mice exhibit a reduction in locomotor activity unlike similarly treated wild-type mice
• heterozygous have a developmental delay in learning to right themselves, righting themselves more slowly at 5 through 9 days of age but righting themselves comparably with wild-type controls from 11 through 13 days of age
• from 13 to 20 days of age pups supported their weight for a significantly shorter time in the bar holding task
• the hyperactivity can be diminished by treatment with d-amphetamine, but methylphenidate increases the hyperactivity (J:32588)
• all heterozygotes are much more active than wild-type controls and this hyperactivity can be reduced by subcutateous or intracerebroventricular injection of the neurotoxin DSP-4, which depletes norepinephrine (J:150776)
• mice exhibit hyperactivity compared with wild-type mice (J:156905)
• however, treatment with amphetamine reduces locomotor activity (J:156905)
• by 11 days of age in increased reactivity to touch is found, with this exaggerated responsiveness increasing at 14 days of age and decreasing at 20 days of age
• first observed in a minority of heterozygotes at 11 days of age, in half of the pups by 14 days of age, and in all adults

nervous system
• in the basal and middle regions of the cochleas, occasional short regions of only two rows of outer hair cells are present instead of the normal 3
• extra hair cells in the inner hair cell row are seen in the base and apex
• the very apical 10-35% of the cochlea, show an increase in outer hair cell rows, having 4-5 rows instead of the normal 3
• extracellular dopamine levels are increased more than 80% compared to in wild-type mice
• however, dopamine extraction fraction is normal
• brain slices treated with potassium chloride in the presence of calcium give a 35% increase in norepinephrine release from the striatum and nucleus accumbens compared with wild type controls

hearing/vestibular/ear
• in the basal and middle regions of the cochleas, occasional short regions of only two rows of outer hair cells are present instead of the normal 3
• extra hair cells in the inner hair cell row are seen in the base and apex
• the very apical 10-35% of the cochlea, show an increase in outer hair cell rows, having 4-5 rows instead of the normal 3
• anterior and posterior canal truncations near the ampullae, however the lateral canal is normal, and the respective ampullae are small or absent
• when the ampulla is present, the canal is still truncated

vision/eye
• iris colobomas
• in 27% of heterozygotes one eye fails to open

growth/size
• although the body weight of heterozygotes is comparable to wild-type siblings until 7 days of age, from 7 days of age on they weigh less

homeostasis/metabolism
• extracellular dopamine levels are increased more than 80% compared to in wild-type mice
• however, dopamine extraction fraction is normal

Mouse Models of Human Disease
OMIM IDRef(s)
Attention Deficit-Hyperactivity Disorder; ADHD 143465 J:1371